Mononuclear Cu(II), Zn(II) Complexes with 2-Aminoethylpyridine and carboxylate ligands: Structure, DFT, DNA binding, Docking and Catecholase Like Activities

Mononuclear Cu(II), Zn(II) Complexes with 2-Aminoethylpyridine and carboxylate ligands: Structure, DFT, DNA binding, Docking and Catecholase Like Activities | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Mononuclear Cu(II), Zn(II) Complexes with 2-Aminoethylpyridine and carboxylate ligands: Structure, DFT, DNA binding, Docking and Catecholase Like Activities Popuri Sureshbabu, Koyal Pattanaik, Suman Bhattacharya, Shahulhameed Sabiah This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4173894/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Mononuclear copper(II) and zinc(II) complexes of composition [Cu(2-AEP)(BA) 2 ] 1, [Cu(2-AEP)(TPAA) 2 ] 2 , [Zn(2-AEP)(Cl) 2 ] 3 , [Zn(2-AEP) 2 ](ClO 4 ) 2 4 , and [Zn(2-AEP)(TPAA) 2 ] 5 , were synthesized by using, 2-aminoethylpyridine (2-AEP) as ligand, benzoic acid (BA) and triphenylaceticacid (TPAA) as ancillary ligands. Complexes 1-5 were characterized using elemental study, UV-Vis, FT-IR, ESI-MS, and ESR spectroscopy (incase of Cu). Single crystal XRD of complexes revealed 1 in octahedral, 2 & 5 in square pyramidal and 3 & 4 in tetrahedral geometry. The interactions towards DNA with complexes 1-5 were studied by spectral titration, electrochemical techniques, and CD measurements. These complexes were interacted strongly via groove binding with CT-DNA with binding efficacy in the range k b = 0.45-4.69 × 10 4 M -1 . Among the complexes, zinc(II) complex 4 showed higher binding affinity than remaining complexes ( 1 - 3 , 5 ). The binding affinity order is 4 > 5 > 3 > 1 > 2 . In addition, copper(II) complexes ( 1 and 2 ) showed catecholase like activity with reaction rate, k = 2.68 × 10 -3 M s -1 and 2.63 × 10 -3 M s -1 respectively. 2-Aminoethylpyridine mononuclear Copper(II) Zinc(II) DNA binding catecholase like activity Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 1. Introduction Recently, metal complexes with different ligand environment have gained paramount importance because of their numerous uses in both chemistry and biology [ 1 ]. Among them copper and zinc complexes play pivotal roles as artificial nucleases and also as pharmaceutical agents [ 2 ]. These complexes are found to bind with the biomelecules such as nucleic acids (DNA and RNA). Since these biomolecules consists phosphodiester bonds, for the activities it controls to be effectively carried out and maintained, it must be resistant to damage [ 3 ]. The phosphodiester bonds are responsible for its remarkably stable structure. The half-life of phosphodiester bonds around pH 7 and 25°C for natural hydrolysis is calculated to be about 10 11 years, indicating their high stability against hydrolysis [ 4 ]. Cisplatin and related platinum analogues was successfully used as anticancer agents on various types of cancer cell lines. Moreover, cisplatin could bind covalently to DNA, and arises serious adverse effects, which can lead to toxicity and acquired drug resistance [ 5 ]. Therefore, development of non-covalently DNA binding, more potent, less hazardous, target-specific anticancer agents is a challenging topic. Several mononuclear simple and mixed ligand complexes of copper and zinc have been widely prepared and used as anticancer and DNA binding/cleavage agents [ 6 ]. In addition, copper complexes play a crucial role as catalyst in the biological transformations for example catechol oxidase and tyrosinase enzyme [ 7 ]. An enzyme catechol oxidase classified as a type III protein that uses two electron oxidation to change o-phenols also known as catechols into corresponding o-quinones. Since active site of type III proteins containing two copper centers, each copper ion surrounded by three histidine nitrogens. In general, dinuclear copper complexes were frequently study for catecholase studies [ 8 ]. While very less number of mono nuclear copper complexes have been reported for catecholase like studies [ 9 ]. In our recent reports, we have explored the mono nuclear homoleptic and heteroleptic complexes of copper & zinc from N -donor ligands such as 1,2-diaminocyclohexane, 2-aminoethylpyridine and diethylenetriamine along with axial ligands and explored for biomolecule interaction such as DNA binding, cleavage and anticancer analysis [ 10 ]. In continuation to our previous research work, mononuclear copper(II) and zinc(II) complexes from 2-AEP and carboxylates have been synthesized. The purpose of these complexes' experiments was to determine how well they bound DNA. To this end, molecular docking, UV-Vis titration, and circular dichroism were employed. Moreover, copper(II) complexes 1 & 2 showed catecholase activity. 9. Experimental Section 9.1. Materials Metal salts of copper and zinc (copper perchlorate hexahydrate, zinc perchlorate hexahydrate, zinc chloride respectively) and other chemicals 2-animoethylpyridine, triethylamine, benzoicacid, triphenylaceticacid and calf-thymus DNA were commercially accessible, acquired from Aldrih company and utilized as it was obtained. Standard distillation methods were used to dry the solvents [11]. 9.2. Physical C, H, N analysis was performed on a Thermo Scientific FLASH 2000 Organic Elemental instrument. UV-Vis absorption spectral analysis were studied using an UV-2450 Model equipment. FT-IR analysis were done with KBr pellets using a Shimadzu IR-470 spectrophotometer. EPR spectral data were collected from a Varian E-112 X-band spectrophotometer. Cirular dichroism spectral measurements were carried out on the JASCO J-815 spectrophotometer. 9.3. DNA–Complexes interaction studies 9.3.1. UV-Vis spectrophotometric study The bindig mechanism study was investigated by using a Shimadzu (UV-2450) instrument with 1 cm channel distance rectangular quartz cuvette at room temperature. CT-DNA was dissolved in a pH = 7.4 of the 10 mM Tris–HCl buffer and the quantity of the CT-DNA was determined at 260 nm with extinction coefficient is (ɛ) 6600 M − 1 cm − 1 [ 12 ]. The ratio that the CT-DNA solution provided at 260 and 280 nm was approximately 1.8–1.9, which amply demonstrating that the CT-DNA was satisfactorily protein free. The concentration of all compounds was maintained uniform while the concentration of CT-DNA was progressively increased from 0–20 mM. 9.3.2. CD spectroscopic study CD spectroscopy is one helpful analytical method to determine whether any changes in DNA structure resulted from interactions with metal complexes. Initially, CD spectrum of free CT-DNA (100 µM) was recorded in the wavelength in the region 220–320 nm. 50 µM metal compounds 1 – 5 were then carefully mixed to the CT-DNA and the CD spectra was recorded. 9.4. X-Ray refinement X-Ray crystal analysis were done on a Ragiku X calibur Eos instrument Ltd. with Mo-Kα radiation where λ is 0.71073. The structural data was resolved and refined anisotropically using SHELXS and SHELXL respectively [ 13 ]. For hydrogen atoms bonded to carbon atoms, their positions were generated in accordance with stereochemistry and subsequently incorporated employing the riding mode integrated within SHELXL-2018. All hydrogens were placed in calculated positions. To address this issue, a riding model refinement strategy was employed after making their locations at geometrically plausible locations. With the exception of complexes 2 and 3 , all structures had certain positional abnormalities, which could be fixed using typical techniques. X-ray crystal data were collected, crystallographic parameters and refinement information were shown in Tables 1 and 2 . 9.5. Docking analysis Rigid virtual docking investigations were carried out on the AutoDock 4.2 tool to examine the interaction between heteroleptic copper(II) and zinc(II) compounds with DNA. [ 14 ]. Docking analysis were done utilizing the AutoDock Tools (ADT) application, which aimed to recognize the optimal binding location of the metal complexes to DNA. The complex structures were constructed using Chem Bio Draw Ultra 13, saved as mol format, and transformed to pdb format using OPENBABEL ( http://www.vcclab.org/lab/babel/ ). From the Protein Data Bank From the Protein Data Bank, the B-DNA dodecamer with sequence d(CGCGAATTCGCG)2 (PDB ID:1BNA) was obtained ( http://www.rcsb.org./pdb ) and employed as the DNA receptor for the docking study. 9.6. 3,5-DTBC oxidation study The catechol oxidase like mechanism of mononuclear copper(II) complex was investigated using the reaction of > 100 folds of 3,5-di-tert-butylcatechol (3,5- DTBC) with 1 equivalent of the compounds under aerobic circumstances at ambient temperature in DMF solvent. The reaction was recorded and examined on an UV-Vis spectrophotometer. The band intensity at 400 nm was kept on increasing as a function of time which is corresponding band of o-quinone formation. The kinetic investigation was done applying the initial rate process. The [complex] was varied from 0.03 mM to 0.15 mM by keeping the [3,5- DTBC] at 5 mM constant value. We plotted the [complex] vs rate and calculated the overall rate constant. The kinetic parameters Vmax, kM, and kcat of complex 1 and 2 were determined from both Michaelis–Menten equation and a Lineweaver–Burk plot. 9.7. Synthesis of metal complexes 1–5 9.7.1. Synthesis of [Cu(2-AEP)(BA) 2 ] (1) To an oven dried pear shaped flask (50 mL) with a magnetic stir bar, copper perchlorate hexahydrate (0.37 g, 1 mmol) was taken and ethanol (3 mL) was added. To this, ethanolic solution 2-AEP (0.122 g, 1 mmol) was added slowly, a pale blue color precipitate started to form and continued stirring for ten minutes. Subsequently, in a beaker benzoicacid (0.244 g, 2 mmol) and triethylamine (0.212 g, 2 mmol) were taken in ethanol and added dropwise via micropippet to the aforementioned pale blue color metal-ligand solution. The color intensity was observed and it was uniformly stirred for 2 h. After completion of reaction, ppt was collected and dried using vacuum to yield 1 (0.416 g, 88%). Good quality single crystals of complex 1 were collected at room temperature after two days from methanol. Anal.Calcd. for (C 21 H 20 CuN 2 O 4 ) (Mr = 427.947 g mol − 1 ) calcd: C 58.94; H 4.71; N 6.55%; found: C 59.01; H 4.77; N 6.61%. UV-Vis (DMF); λ max , 679 nm (ε = 122 M − 1 cm − 1 ). FT-IR (KBr, cm − 1 ): 3434 (ν N−H stretching), 3239 (ν C=C−H stretching); 2924 (ν C−H stretching), 1596 (ν C=O stretching), 1554 (ν C=C stretching); 1385 (ν N−H bending), 1117 − 1069 (ν C−O/C−N stretching). ESI-MS: [Cu(2-AEP)(BA) 2 ] + m/z = 427.3814, calcd = 427.0719. 9.7.2. Synthesis of [Cu(2-AEP)(TPAA) 2 (2) Utilizing the identical process outlined for complex 1 , complex 2 was synthesized by taking copper perchlorate hexahydrate (0.37 g, 1 mmol). A dark blue color precipitate started to form and continued stirring for ten minutes. Following that, in a beaker triphenylaceticacid (0.576 g, 2 mmol) and triethylamine (0.212 g, 2 mmol) were taken in ethanol and added dropwise via micropippet to the aforementioned dark blue color metal-ligand solution. The color of the reaction mixture became light blue and it was uniformly stirred for another 2 h. After completion of reaction, ppt was collected and dried under vacuum to produce 2 (0.66 g, 86%). Good diffracted single crystals of complex 2 were collected after one week from dichloromethane solvent by slow evaporation method. Anal.Calcd. for (C 47 H 40 CuN 2 O 4 ) (Mr = 760.39 g mol − 1 ) calcd: C 74.24; H 5.30; N 3.68%; found: C 74.31; H 5.36; N 3.75%. UV-Vis (DMF); λ max , 698 nm (ɛ = 206 M − 1 cm − 1 ). FT-IR (KBr, cm − 1 ): 3432 (ν N−H stretching), 3241 (ν C=C−H stretching); 2923, (ν C−H stretching). ESI-MS: [Cu(2-AEP)(TPAA) 2 ] + m/z = 759.2237, calcd = 759.2284. 9.7.3. Synthesis of [Zn(2AEP)(Cl) 2 ] (3) Utilizing the identical process outlined for complex 1 , complex 3 was synthesized by taking zinc chloride (0.136 g, 1 mmol) in ethanol. A yellow color precipitate started to form and continued stirring for 2 h. After finishing of reaction it was followed by filtration and vaccum dried to yield 3 (0.219 g, 85%). Single crystals of complex 3 were collected after three days from acetonitrile solution by gradual evaporation process. Anal.Calcd. for C 7 H 10 Cl 2 ZnN 4 (258.451): C, 32.53; H, 3.90; N, 10.84. found: C 32.62; H 3.98; N 10.93%.; UV-Vis (DMF); λ max , 207 nm (ε = 138 M − 1 cm − 1 ), 260 nm (ε = 138 M − 1 cm − 1 ). FT-IR (KBr, cm − 1 ): 3436 (stretching ν N−H ); 3152–3253 (ν C=C−H stretching); 2881–2956 (ν C−H stretching), 1601 (ν C=C/C=N stretching); 1363 (ν N−H bending), 1103–1143 (ν C−O/C−N stretching). ESI-MS: [Zn(2-AEP)Cl 2 ] + m/z = 255.9392., calcd = 255.9513. 9.7.4. Synthesis of [Zn(2-AEP) 2 ](ClO 4 ) 2 (4) Utilizing the identical process outlined for complex 1 , complex 4 was synthesized by taking zinc perchlorate hexahydrate (0.372 g, 1 mmol) and 2-AEP (0.244 g, 2 mmol) in ethanol. A light orange precipitate formed and continued stirring for 2 h. After completion of reaction it was followed by filtration and vaccum dried to produce 4 (0.53 g, 86%). X-ray suitable single crystals of complex 4 were collected after two days from acetonitrile solvent by slow evaporation method. Anal.Calcd. for C 14 H 20 Cl 2 ZnN 4 O 8 (508.614): C, 33.06; H, 3.96; N, 11.02. Found: C, 33.11; H, 4.01; N, 11.09%. UV-Vis (DMF); λ max , 207 nm (ε = 138 M − 1 cm − 1 ), 260 nm (ε = 138 M − 1 cm − 1 ) and 326 nm (ε = 138 M − 1 cm − 1 ), 339 nm (ε = 138 M − 1 cm − 1 ). FT-IR (KBr, cm − 1 ): 3483 (stretching ν N−H ); 3157 (ν C=C−H stretching); 2852 (ν C−H stretching), 1577 (ν C=C/C=N stretching); 1353 (ν N−H bending), 1074 (bs), ν(ClO 4 , asymmetric stretching); 947 (s), ν(ClO 4 symmetric stretching); 625 (s), ν(ClO 4 asymmetric bending); 508 (s), ν(ClO 4 asymmetric bending). ESI-MS: [Zn(2-AEP) 2 ](ClO 4 ) 2 + m/z = 506.024, calcd = 505.995. 9.7.5. Synthesis of [Zn(2-AEP)(TPAA) 2 ] (5) Utilizing the identical process outlined for complex 1 , complex 5 was synthesized by taking zinc perchlorate hexahydrate (0.372 g, 1 mmol) in EtOH, a light yellow color suspension that formed was stirred for ten minutes. Later on, in a beaker ethanolic solution of triphenylaceticacid (0.576 g, 2 mmol) and triethylamine (0.212 g, 2 mmol) were added dropwise to the aforementioned yellow color metal-ligand solution. There was no color change was noticed and continued stirring for another 2 h. Then the generated ppt was collected and dried under vacuum to yield 5 (0.69 g, 90%). X-ray quality crystals of complex 5 were grown after one week from dichloromethane solvent. Anal.Calcd. for (C 47 H 40 N 2 O 4 Zn) (Mr = 762.227 g mol − 1 ) calcd: C 74.06; H 5.29; N 3.68%; found: C 74.12; H 5.35; N 3.75%. UV-Vis (DMF); λ max , 238 nm (ε = 138 M − 1 cm − 1 ) and 259 nm (ε = 138 M − 1 cm − 1 ). FT-IR (KBr, cm − 1 ): 3316 (stretching ν N−H ); 3057–3149 (ν C=C−H stretching); 2831–2952 (ν C−H stretching), 1602 (ν C=O stretching), 1488 − 1441 (ν C=C/C=N stretching); 1361 (ν N−H bending), 1090 (ν C−O/C−N stretching). ESI-MS: [Zn(2-AEP)(TPAA) 2 ] + m/z = 761.2428, calcd = 760.228. 2. Results and discussion 2.1. Synthetic and structural determination of 1-5 2-Aminoethylpyridine (2-AEP) is a simple heterocyclic bidentate N , N ligand. The complexation of the ligand 2-AEP: Acid: Cu(ClO 4 ) 2 .6H 2 O/ Zn(ClO 4 ) 2 .6H 2 O in 1:1:1 ratio achieved the corresponding complexes 1, 2 and 5 in excellent yields; 2-AEP with ZnCl 2 and Zn(ClO 4 ) 2 .6H 2 O in a 1:1 and 2:1 proportion accomplished the corresponding compounds 3 and 4 in high yields as demonstrated in scheme 1. These compounds were synthesized using ethanol as a solvent at ambient temperature. The molecular structure of prepared mononuclear complexes 1-5 has been unambiguously determined by S-XRD and thoroughly characterized by elemental study, UV-Vis, FT-IR ESI-MS, ESR (incase of copper complexes 1 , 2 ) spectra. All complexes are turn out to be fairly stable and soluble in the majority of organic solvents. However, they are found to be soluble in DMSO ( 1 – 5), DMF ( 1 – 5), DCM ( 2 & 5) and CH 3 CN ( 1 , 3 & 4) . 2.2. Crystal Structures of 1-5 The structure of compounds 1-5 were comfirmed by X-ray technique (Figure 1 and 2). Dichloromethane and acetonitrile solvents were used to grow the adequate single crystals of compounds 1 & 5 and 2-4 respectively. The color of the crystals 1 is blue and 2 is fent blue; 3 - 5 are pale yellow. The crystallographic refinement details, significant bond parameters of 1-5 are tabulated in Table 1, 2 and 3 respectively. The molecular diagrams of 1-5 are shown in Figures 1 and 2. Crystal packing diagrams are depicted in Figures 3 and 4. 2.2.1. Complex [Cu(2-AEP)(BA) 2 ] 1 : From the single crystal data, it revealed that complex 1 results in the monoclinic, P2 1 space group. The molecular representation of the complex is depicted in Figure 1. In complex 1 , the asymmetric unit is made up of one molecule of 2-AEP ligand and two benzoate molecules. The shape of copper(II) ion in 1 possesses distorted octahedral. This coordination is afforded by one bidentate amine and pyridine nitrogens from 2-AEP, along with four oxygen atoms from two benzoate molecules to the copper(II) ion. The standard length of the Cu–N is 2.006 Å (Table 2), which is comprable with reported measurements for other mixed ligand copper(II) diamine and carboxylate complexes [15]. The structure is further stabilized by certain hydrogen bonds between the hydrogens on N(2) and the benzoate oxygens. Moreover, two compound molecules are interconnected via a relatively strong hydrogen bonding contact connecting the hydrogen on N(2) with O(2) and O(4), with bond lengths of d= 2.264 Å and d= 1.990 Å, respectively. The corresponding bond angles are O(2)∙∙∙H(2A)-N(2) = 147.93° and O(4)∙∙∙H(2B)-N(2) = 167.74°. 2.2.2. Complex [Cu(2-AEP)(TPAA) 2 ] 2 : From the single crystal data, it revealed that complex 2 develops in the triclinic, P-1 space group. The structural diagram of the complex is depicted in Figure 1. In complex 2 , the asymmetric unit is made up of one molecule of 2-AEP ligand and two triphenylacetate molecules. The shape of copper(II) ion in 2 possesses distorted square pyramidal. This coordination is furnished by one bidentate amine nitrogens from 2-AEP, along with four oxygen atoms from two triphenylacetate molecules to the copper(II) ion. The mean distance of the Cu–N is 2.032 Å (Table 2), which is comprable with reported measurements for other mixed ligand copper(II) diamine and carboxylate complexes [15]. The structure is further stabilized by some hydrogen bonds between the hydrogens on N(2) and the benzoate oxygens. Moreover, two compound molecules are interconnected via a modestly strong hydrogen bonding contact among the hydrogen on N(2) with O(1) with bond lengths of d= 2.148 Å. The corresponding bond angle is O(1)∙∙∙H(2A)-N(2) = 167.47°. 2.2.3. Complex [Zn(2-AEP)(Cl) 2 ] 3 : Analysis from the single crystal showed that complex 3 grows in the monoclinic, P21/a space group. The structural diagram of the complex was revealed in Figure 2. The asymmetric unit in 3 comprises of one molecule of 2-AEP ligand and two chloride ions. Zinc(II) ion is occupied by one bidentate amine that is pyridine nitrogens from 2-AEP and two chloride to form distorted tetrahedral coordination geometry. The mean distance of the Zn–N is 2.045 Å (Table 3) is matching with documented mononuclear zinc(II) amine complexes [16]. Two hydrogen bonds were formed between two hydrogens on N(1) with two chloride ions Cl(1) and Cl(2). The bond lengths are d= 2.497 Å [Cl(1)-H(A)], d= 2.548 Å [Cl(2)-H(B)] and bond angles are Cl(1)∙∙∙H(A)-N(1) = 148.14° and Cl(2)∙∙∙H(B)-N(1) = 164.32° Overall the structure was stabilized by hydrogen bonding interactions. 2.2.4. Complex [Zn(2-AEP) 2 ](ClO 4 ) 2 4 : It was evident from the single crystal data that complex 4 develops in the monoclinic, P21/n. space group. The compound diagram is illistrated in Figure 2. In complex 4 , the asymmetric unit contains two molecule of 2-AEP ligand and two perchlorate molecules. Zinc(II) ion is occupied by one primary amine and pyridine nitrogens from two 2-AEP ligands to form distorted tetrahedral coordination geometry. The average bond distance of the Zn–N is 2.009 Å (Table 2) is an consistent with published mononuclear homoleptic zinc(II) amine complexes [16]. The structure is further stabilized by several hydrogen bonds between the hydrogens on aliphatic amine nitrogens N(2), and the oxygens of perchlorate and water to stabilize the structure. Among them few hydrogen bonding were explained below, the hydrogen on N(8) with O(1) and N(5) with O(5) bond length of d= 2.590 Å and d= 2.503 Å and bond angles are O(1)∙∙∙H(A)-N(8) = 147.33° and O(5)∙∙∙H(B)-N(5) = 122.56°; hydrogen on N(5) with O(11) and N(5) with O(12) bond length of d= 2.588 Å and d= 2.380 Å and bond angles are O(11)∙∙∙H(A)-N(5) = 147.18° and O(12)∙∙∙H(B)-N(5) = 132.95°. In addition, oxygen atoms of water molecules also formed the hydrogen bonding with amine nitrogens. Hydrogen on N(8) with O(2) and N(5) with O(2) bond length of d= 2.359 Å and d= 2.474 Å and bond angles are O(2)∙∙∙H(A)-N(8) = 151.93° and O(2)∙∙∙H(B)-N(5) = 147.43°; hydrogen on N(5) with O(13) and N(11) with O(13) bond length of d= 2.513 Å and d= 2.545 Å and bond angles are O(13)∙∙∙H(A)-N(5) = 150.82° and O(12)∙∙∙H(B)-N(11) = 145.40°. The packing diagram shows 2-D sheet arrangement of the complex (Figure 4). 2.2.5. Complex [Zn(2-AEP)(TPAA) 2 ] 5 : From the single crystal data, it displayed that compound 5 forms in the triclinic, P-1 space group. The schematic diagram of 5 is depicted in Figure 2. In complex 5 , the asymmetric group is made up of one molecule of 2-AEP ligand and two triphenylacetate molecules. The shape of zinc(II) ion in 2 possesses twisted square pyramidal. This coordination is furnished by one bidentate amine nitrogens from 2-AEP, along with four oxygen atoms from two triphenylacetate molecules to the copper(II) ion. The average length of the Cu–N is 2.045 Å (Table 2), which is comprable with reported measurements for other mixed ligand zinc(II) diamine and carboxylate complexes [15]. The structure is further strengthened by various hydrogen bonds connecting between hydrogen on N(2) with O(4) and N(4) with O(8) bond length of d= 2.245 Å and d= 2.286 Å and bond angles are O(4)∙∙∙H(A)-N(2) = 129.13° and O(8)∙∙∙H(B)-N(4) = 145.57°. Overall two different H-bonds froms from the hydrogens on N(2) of 2-AEP and the oxygens of triphenyl acetate stabilize the complex. Table 1. An overview of crystal and refinement information of complexes 1–5 Parameters 1 2 3 4 5 CCDC 2256235 2256236 2256239 2256237 2256238 Moleculr formula C 21 H 20 CuN 2 O 4 C 47 H 38 N 2 CuO 4 C 7 H 10 N 2 ZnC l2 C 14 H 20 N 4 ZnO 8 Cl 2 C 47 H 38 N 2 ZnO 4 Molecular weight 427.95 760.39 258.44 508.61 762.22 Crystal system Monoclinic Triclinic Monoclinic Monoclinic Triclinic Space group, Z P 2 1 , 3 P-1, 1 P121/a1, 4 I12/a1, 8 P-1, 2 a (Å) 10.570(4) 8.994(10) 9.0461(10) 15.1218(10) 9.8521(3) b (Å) 8.848(12) 13.859(2) 12.9316(11) 14.6255(8) 18.7675(7) c (Å) 11.793(4) 16.303(2) 9.3261(9) 19.4598(12) 20.6444(7) α (⁰) 90 69.537(14) 90 90 84.980(3) β (⁰) 115.32(4) 80.256(11) 112.156(11) 112.358(7) 84.280(3) γ (⁰) 90 85.732(12) 90 90 89.422(3) V (Å 3 ) 997.0(6) 1876.2(5) 1010.42(1) 3980.3(4) 3783.5(2) Temperature (K) 293(2) 298(2) 298(2) 298(2) 293(2) λ (Å) 0.71073 0.71073 0.71073 0.71073 0.71073 D c (mg/m 3 ) 1.4255 1.342 1.699 1.698 1.344 µ (mm -1 ) 1.124 0.630 2.907 1.553 0.697 Refl. Collected 3353 8486 2346 6377 17422 Reflections used 2219 2844 1527 23155 11673 No.of refined parameters 254 470 109 323 970 a R 1 [1 > 2s(I)] 0.0846 0.1195 0.0574 0.0745 0.0444 b wR 2 0.2240 0.2858 0.1457 0.2138 0.0935 Goodness –of-fit 1.031 0.956 0.930 0.923 1.015 a R 1 =Σ||F o | -|F c ||/Σ|F o |, b wR 2 =|Σ w (|F o | 2 -|F c | 2 )|/Σ|w|(F o ) 2 | 1/2 Table 2. Significant bond parameters of complexes 1 - 2 Complex 1 Bond length (Å) Bond angle (°) Cu-N1 1.973(12) N1-Cu-N2 95.0(5) N2-Cu-O3 160.5(4) Cu-N2 2.046(9) N1-Cu-O1 106.3(3) N2-Cu-O4 104.4(7) Cu-O1 2.546(5) N1-Cu-O2 162.9(5) O1-Cu-O2 56.6(6) Cu-O2 1.972(10) N1-Cu-O3 89.53(4) O1-Cu-O3 98.8(6) Cu-O3 1.980(9) N1-Cu-O4 105.3(8) O1-Cu-O4 138.9(6) Cu-O4 2.591(6) N2-Cu-O1 98.0(5) O2-Cu-O3 91.5(4) N2-Cu-O2 89.7(5) O2-Cu-O4 89.2(9) Complex 2 Bond length (Å) Bond angle (°) Cu-N1 1.994(7) N1-Cu-N2 94.0(3) N2-Cu-O2 162.9(2) Cu-N2 2.020(7) N1-Cu-O1 95.9(3) N2-Cu-O3 90.2(2) Cu-O1 2.429(7) N1-Cu-O2 90.8(3) O1-Cu-O2 57.94(19) Cu-O2 2.014(5) N1-Cu-O3 164.1(3) O1-Cu-O3 97.7(2) Cu-O3 1.920(6) N2-Cu-O1 105.2(2) O2-Cu-O3 89.6(2) Table 3. Significant bond parameters of complexes 3-5 Complex 3 Bond length (Å) Bond angle (°) Zn-N1 2.042(4) N1-Zn-N2 97.63(16) N2-Zn-Cl2 115.8(13) Zn-N2 2.049(4) N1-Zn-Cl1 115.62(12) Cl1-Zn-Cl2 113.42(6) Zn-Cl1 2.234(14) N1-Zn-Cl2 106.24(12) Zn-Cl2 2.236(14) N2-Zn-Cl1 106.24(12) Complex 4 Bond length (Å) Bond angle (°) Zn1-N1A 1.85(4) N1A-Zn1-N1B 122.5(7) N3B-Zn2-N4 98.62(18) Zn1-N1B 2.10(3) N1A-Zn1-N2 117.7(14) N3B-Zn2-N4 117.03(19) Zn1-N2 2.023(4) N1A-Zn1-N2 94.2(9) N3B-Zn2-N3B 123.0(3) Zn2-N3B 1.983(4) N2-Zn1-N2 103.0(2) N4-Zn2-N4 101.3(2) Zn2-N4 2.046(4) N1B-Zn1-N2 115.6(10) Complex 5 Bond length (Å) Bond angle (°) Zn1-N1 2.109(19) N1-Zn1-N2 95.18(8) N3-Zn2-N4 95.44(8) Zn1-N2 2.010(18) N1-Zn1-O2 99.11(7) N3-Zn2-O5 99.86(8) Zn1-O2 1.9446(15) N1-Zn1-O3 153.6(7) N3-Zn2-O7 155.94(7) Zn1-O3 2.408(18) N1-Zn1-O4 96.5(7) N3-Zn2-O8 99.36(7) Zn1-O4 2.009(15) N2-Zn1-O2 123.03(8) N4-Zn2-O5 134.93(9) Zn2-N3 2.083(18) N2-Zn1-O3 94.97(7) N4-Zn2-O7 88.32(8) Zn2-N4 2.008(2) N2-Zn1-O4 123.52(8) N4-Zn2-O8 116.11(9) Zn2-O5 1.964(17) O2-Zn1-O3 95.61(7) O5-Zn2-O7 94.06(7) Zn2-O7 2.430(17) O2-Zn1-O4 109.17(7) O5-Zn2-O8 102.86(7) Zn2-O48 2.008(15) O3-Zn1-O4 57.76(6) O7-Zn2-O8 58.15(6) 3. DFT Studies Density functional theoretical (DFT) [ 17 ] studies has been performed using B3LYP method. For non metal 6-31G* and for copper atom LANL2DZ basis sets were used. The optimized energies and geometries of complexes 1 – 5 are depicted in the Fig. 5 . FMOs of complexes i.e., HOMO and LUMO (highest occupied and lowest unoccupied) molecular orbitals are shown in Fig. 6 , indicating that majority of the electron cloud in HOMO resides on the carboxylate aromaric rings in 1, 2 and 5 ; chlorides in 3 ; Pyridine ring in 4 ;. HOMO–LUMO energy differences in copper(II) compounds 4.55 eV ( 1 ) and 4.81 eV ( 2 ), and in zinc(II) complexes are 3.93 eV ( 3 ), 0.54 eV ( 4 ), 4.55 eV ( 5 ) respectively. Complex 4 shoud be more reactive compared with other complexes because of the least amount of energy between the HOMO and LUMO. Overall, copper(II) complexes have little higher energy gaps than zinc(II) complexes. 4. Compounds characterization 4.1. UV-Vis data The UV absorption diagram of complexes 1 – 5 have been acquired within the 200–900 nm range and delineated in Fig. 7 . This study suggested that the copper(II) cores in 1 and 2 showed bands in the lower energy region [λmax, nm; (ε, M -1 cm -1 )] at 679 (122) and 698 (206) corresponding to d-d transitions of distorted octahedral geometry and distorted square pyramidal geometry respectively [ 18 ]. Zinc(II) complexes displayed higher energy bands [λmax, nm; (ε, M -1 cm -1 )] at 207 (138), 260 (138) in 3 ; 207 (138), 260 (138) and 326 (138), 339 (138) in 4 due to π-π* transitions and charge transfer transitions respectively; 238 (138) and 259 (138) in 5 attributed to π-π* transitions [ 18 ]. 4.2. Infrared analysis The FT-IR graph of complexes 1 – 5 were carried out in the 400–4000 cm -1 region. The complexes 1 – 5 exhibit distinctive broad sachet at 3316–3483 cm -1 relating to ν (NH2) bound to the metal centers [ 19 ]. The sharp bands observed at 3057–3253 cm -1 , are attributed to ν (C=CH2) vibrations of the aromating rings. Additionally, sharp bands at 2831–2956 cm -1 , are assigned to ν (C-CH2) vibrations of the aliphatic methylene. The sharp bands at 1441–1601 cm -1 , are responsible for ν (C=C, C=N) vibrations of the aromatic (BA and TPAA) and pyridine rings. Apart from these bands, in complex 2 a wide intense band was displayed at 1074 cm -1 which corresponding to triply degenerate asymmetric vibrational mode of the tetrahedral ClO 4 anion; band at 947 cm -1 , due to triply degenerate symmetric stretching and sharp band at 625 cm -1 , which is because of triply degenerate asymmetric bending frequency of the ClO 4 anion. Furthermore, in compounds 1 – 3 , intense bands were appeared at around 1596–1602 cm -1 ascribed to carboxylate asymmetric vibrational frequency. These stetching frequencies are matching with the reported values [ 20 ]. 4.3. EPR analysis The ESR diagram of mixed ligand copper(II) complexes 1 and 2 were collected in acetonitrile solvent with a magnetic field potential in the range 0-6000 G (Fig. 8 ). The obtained EPR diagram of complex 1 exhibits an isotropic character with a wide signal demonstrating that the copper(II) ion in distorted octahedral coordination shape with g iso = 2.041. Conversely, complex 2 showed two signs at an ambient temperature with g || = 2.304 and g ⊥ = 2.431, representing that the copper(II) ion is in twisted square pyramidal coordination geometry. The observed g || and g ⊥ measurements closely match with various mixed ligand Cu(II) complexes in the literature reports [ 21 ]. 5. Binding Studies 5.1. DNA interaction activities by UV-Vis The binding capability of mononuclear copper(II) and zinc(II) compounds 1 – 5 towards CT-DNA were explored using an electronic spectrophotometer. This is one of the basic and straightforward approaches to identify the interactions of metal compounds towards nucleic acids (here is CT-DNA). The ternary complexes concentration was held constant while the CT-DNA concentration varied between 0-160 µM for the absorbance analysis. For copper complexes 1 and 2 , a hypsochromic shift (a progressive decrease in absorbance band intensity) were seen with every single addition of CT-DNA. Incase of zinc(II) complexes 3 – 5 , hyperchromic shift was observed (a gradually increase in absorption band intensity) with each single addition of the CT-DNA. The obtained outcomes for complexes 1 and 4 towards CT-DNA were displyed in Figs. 9 a and 10 a, respectively. The subsequent equation was applied to obtaine the binding constants of 1 – 5 [ 22 ]. [DNA]/|ɛ a -ɛ f | = [DNA]/|ɛ b -ɛ f |+1/K b |ɛ b -ɛ f | In this case, [DNA] corresponds to the CT-DNA concentration, ɛ a , ɛ b and ɛ f denote the extinction coefficients of complexes moderately interacted to CT-DNA, completely interacted to CT-DNA, and a free metal complex. The calculation of intrinsic binding efficacy (Kb) values was performed by plotting [DNA]/(ɛ a -ɛ f ) against [DNA]. This yields a straight line whose slope to intercept ratio is equal to the binding constant. The obtained K b results for complexes 1 – 5 (0.45–4.69 × 10 4 M − 1 ) follows the order, 4 > 5 > 3 > 1 > 2 and illustrated in Table 4 . The present prepared mixed-ligand mononuclear copper(II) and zinc(II) complexes are not planar structures. Hence, the bulky ethyl groups, phenyl/triphenyl carboxylate groups around copper(II) can interact with CT-DNA through electrostatic or groove method of interactions. Among these complexes, zinc(II) complexes exhibited the highest order of interaction affinities compared to the copper complexes. Moreover homoleptic mononuclear zinc complex 4 showed highest binding affinity than zinc ( 3 & 5 ) and copper ( 1 & 2 ) complexes. This may be because there are two 2-ethyl pyridine rings are coordinated to the metal center which are perpendicular to each other. Two ethyl groups are not in the same plane and interacted with phosphate groups via hydrophobic interaction. Hence it will prevent the interaction of pyridine rings with DNA base pairs. These structural motifs might be well fitted in the binding site, responsible for the groove/electrostatic way of interactions to CT-DNA. The binding affinities of the our heteroleptic copper(II) and zinc(II) complexes displayed similar activity to many other documented mixed ligand copper(II) and zinc(II) complexes in the documents [ 23 , 24 ]. In the current study, zinc(II) complex 4 exhibited the highest binding affinity (4.69 × 10 4 M − 1 ) among the all complexes ( 1 – 5 ). The current intrinsic binding affinity (K b ) aligns with those published for various copper(II) and zinc(II) complexes in the literature. Notably, Palaniandavar et al. investigated copper(II) complexes with 2-NO and 3-N-ligands, revealing DNA binding affinity ranging from 3.0 × 10 3 M − 1 to 10.0 × 10 3 M − 1 [25a]. In another study, same group explored mixed ligand copper(II) complexes, showcasing binding constants spanning from 3.0 × 10 3 M − 1 to 2.27 × 10 5 M − 1 [25b]. Deka and coworkers documented mixed-ligand copper(II) complexes with binding values of 6.3–7.4 × 10 4 M − 1 [25c], while Zhao and colleagues explained ternary copper(II) complexes with binding values of 2.4-3 × 10 4 M − 1 [25d]. Rajarajeswari and co-workers documented phen-based heteroleptic copper(II) complexes with DNA binding affinity (K b ) values ranging from 0.85 to 1.8 × 10 4 M − 1 [25e]. Tapan K. Mondal's research group synthesized novel NNO-based copper(II) complexes, revealing DNA binding values in the range of 5.70 × 104 M − 1 to 2.35 × 10 5 M − 1 [25f]. In our earlier work, we reported mononuclear homoleptic copper(II) complexes with 1,2-diaminocyclohexane, exhibiting DNA binding affinities ranging from 4.5 × 10 3 M − 1 to 4.2 × 10 4 M − 1 [10a]. Subsequently, we documented heteroleptic copper(II) complexes using cyclohexadiamine and axial N -donor ligands, demonstrating Kb values of 2.0 × 10 4 M − 1 to 16.0 × 10 4 M − 1 [10b]. Additionally, Arjmand and co-workers represented a copper(II) complex involving an L-phenylalanine–DACH conjugate with a binding value of 5.30× 10 4 M − 1 [25g]. Raman and his research group reported copper(II) and zinc(II) complexes using mixed compounds such as schiff base and 1,8-diaminonaphthalene ligand with K b values 3.9 × 10 4 M − 1 and 2.4 × 10 4 M − 1 respectively [21h]. Later, Rahiman et al. demonstrated mononuclear zinc(II) complexes prepared from 2-((2-(piperazin-1-yl)ethylimino) methyl)-4-substituted phenol ligands and their intrinsic binding constants from 1.8 × 10 4 M − 1 − 7.9 × 10 4 M − 1 [25i]. Iqbal et al. documented binding constant 1.34 × 10 5 M − 1 for zinc(II) complex containing carboxylate and phenathroline ligand [25j]. Zhu and coworkers reported zinc(II) complex from 2-(1,2,4)triazol-1-yl-isonicotinic acid, showed K b 3.36 × 10 3 M − 1 [25k]. Ali et al. synthesized homo and heteroleptic zinc(II) complexes, studied their binding interactions with K b values ranging from 1.09 × 10 4 M − 1 − 4.24 × 10 4 M − 1 [25l]. Later, same group reported binding constants 1.6 × 10 5 M − 1 – 7.05 × 10 5 M − 1 for zinc(II) complex containing carboxylates (4-(o-toluidino)-4-oxobutanoic acid and 4-(4-nitrophenyl amino)-4-oxobut-2-enoic acid) and N -donor ligands [25m]. Table 4 DNA Binding outcomes of the complexes 1–5 S. No Complex DNA (k b M − 1 ) 1 [Cu(2-AEP)(BA) 2 ] 1 0.55 × 10 4 2 [Cu(2-AEP)(TPAA) 2 ] 2 0.45 × 10 4 3 [Zn(2-AEP)(Cl) 2 ] 3 1.62 × 10 4 4 [Zn(2-AEP) 2 ](ClO 4 ) 2 4 4.69 × 10 4 5 [Zn(2-AEP)(TPAA) 2 ] 5 3.16 × 10 4 5.2. Circular Dichroism Study The circular dichroism (CD) spectroscopic tehnique is an another basic approach for understanding the binding mechanism of both metal compounds or small organic molecules with macromoleules like DNA [ 26 ]. This analysis will give the valuable information such as secondary structural alterations after compounds binding to CT-DNA. The CD spectrum of free CT-DNA demonstrates a positive band at 277 nm and a negative band at 245 nm which are because of base stacking and helicity, respectively, which are highly sensible to the metal complexes. When these complexes react with DNA by groove mechanism/electrostatic mode of interaction will display an insignificant or no disruption on the base stacking bands of CT-DNA and intercalation progressively raises the intensity of both bands. Complexes 1 – 5 are prepared with CT-DNA at 1/R= [Complex]/[DNA] = 0.5 and the CD analysis were carried out at ambient temperature in Tris/HCl buffer with pH 7.4. The spectra confirmed that there is diminutive modifications in both base stacking and helicity bands (Fig. 11 ). These negligible changes in the band intensities, unveiled that the compounds 1–5 interacted and disrupt the helicity of CT-DNA. Our previous investigations have yielded consistent findings in the context of mononuclear complexes involving 1,2-diaminocyclohexane [19a], as well as mixed ligand complexes incorporating DACH and diethyltriamine with N-donor ligands [19b, 19e]. Furthermore, we explored dinuclear complexes of 2-aminoethylpyridine, revealing their binding interactions with CT-DNA [19c]. Parallel results have been reported by other research groups, including Arjmand [25f], Palaniandavar [22a], Mao [26b], and Zeng [26c]. These groups similarly observed analogous behavior in mononuclear simple and mixed ligand complexes, reinforcing the consistency of the observed phenomena in DNA interaction studies. Therefore, these results are strongly supporting the groove binding as described in the literature [ 26 ]. 6. Docking studies The interaction between copper(II) and zinc(II) compounds towards DNA was investigated using in silico DNA docking studies. The dodecamer duplex DNA with the sequence d(CGCGAATTCGCG)2 (PDB ID: 1BNA) was used in the study. The results were presented in Fig. 12 , which showed the least energy docked conformation of all complexes. The copper(II) and zinc(II) complexes were found to aligned nicely into the groove binding of DNA [ 10 , 27 ]. The study found that copper(II) complexes 1 , 3 , and 4 primarily bind via minor groove interaction, while complexes 2 and 5 interacted via major groove mechanism. This mode of difference in binding could be attributed to the bulky carboxylate ligands around the metal, which enter specific sites of the DNA. The relative binding energy for the DNA interacted conformations of complexes 1 – 5 ranged between − 5.0 and − 8.2 kcal mol − 1 , as listed in Table 5 . In our earlier investigations, we determined the relative binding strengths for DNA interacted structures of mixed-ligand copper(II) complexes. Specifically, for complexes involving 1,2-cyclohexadiamine and diethylenetriamine with N-donor axial ligands, the binding energies. Furthermore, the binding efficacy of the current complexes aligns with that of previously reported mononuclear complexes [25g, 28], indicating comparable strength and stability in their interactions with DNA. Table 5 DNA docking results Complex Dock Score Mode of binding 1 -8.2 Minor groove 2 -7.6 Major groove 3 -5.0 Minor groove 4 -6.6 Minor groove 5 -6.7 Major groove 7. Catecholase like activity Catechol oxidase catalyzes catechols to corresponding quinones where two copper centers involve in the reaction mechanism. In general, dinuclear copper(II) complexes show the catecholase like activity since these structural features resemble the active center of the real enzyme. Many research groups have reported numerous dinuclear copper(II) complexes [ 8 ] and also few mononuclear copper(II) complexes [ 9 ]. The 3,5-ditertiary butyl catechol (3,5-DTBC) is a typical model compound for catechol oxidase-like property since it is rapidly transformed into the equivalent quinones (3,5-DTBQ) in the presence of aerial circumstances, which results in the characteristic DTBQ band at 400 nm (= 1900 M -1 cm -1 ). The catecholase analysis of mono nuclear copper(II) complexes 1 and 2 was performed employing UV-Vis spectroscopy at ambient temperature by adding 18–90 µL complex solutions in DMF (0.03–0.15 mM) and 100 µL of 3,5-DTBC in DMF solutions (5 mM). An UV-Vis spectrophotometer was employed to quantity the generation of quinones at a wavelength of about 400 nm. The total volume of complexes and 3,5-DTBC were rigidly maintained at equal volumes (3 mL) at all times. Complexes 1 and 2 underwent a kinetic analysis (Fig. 13 ) by raising the absorbance of 3,5-DTBQ at 400 nm every two minutes. A linear relationship between the initial rate and complex concentration was observed from the plot between rate vs complex concentration which means the system is dependent on the catalyst concentration. The saturation kinetics were noted at high catechol concentrations. The kinetic values V max , k m and k cat values for 1 and 2 complexes were obtained by applying both Michaelis–Menten equation (Fig. 14), a Lineweaver–Burk method and listed in Table 6 [ 29 ]. Table 6 K m , V max and k cat results for complexes 1 and 2 . S. No Complex V max (M s − 1 ) K m (M) k cat (s − 1 ) 1 [Cu(2-AEP)(BA) 2 ] 1 19 1.1 2.68 × 10 − 6 2 [Cu(2-AEP)(TPAA) 2 2 3.8 0.5 2.63 × 10 − 6 In a recent study conducted in 2023, Samanta et al. investigated copper(II) complexes featuring NNN and NNO tridentate schiff base ligands. Their research demonstrated into the catechol oxidase-like activity of these complexes, revealing Kcat values of 5.1 × 10 5 h − 1 , 4.52 × 10 5 h − 1 , and 4.66 × 10 5 h − 1 for mononuclear, dinuclear, and polymeric Cu(II) complexes, respectively [ 30 ]. Singha Mahapatra and coworkers reported a mononuclear copper(II) Schiff base compound with a catecholase activity Kcat of 19.87 h − 1 [ 31 ]. Tapan K. Mondal's research group synthesized novel NNO-based copper(II) complexes, observing catecholase activities in the range of 1.42× 10 5 h − 1 to 1.82× 10 5 h − 1 [ 32 ]. Ramasamy et al. reported a mononuclear copper(II) complex with a thiosemicarbazone ligand, exhibiting a Kcat of 163.30 h − 1 [ 33 ]. The present mononuclear copper(II) complexes demonstrates catecholase activity analogous to that of earlier copper(II) complexes documented in literature [19c, 30–34]. 8. Conclusions In the present study, five mononuclear copper(II) and zinc(II) complexes resulting from simple 2-aminoethyl pyridine ligand and carboxylates were prepared and analysed by several physicochemical methods like, elemental study, electrochemical, spectroscopic and single crystal X-ray analysis. Complexes showed distorted octahedral geometry for 1 , distorted square pyramidal shape for 2 & 5 and tetrahedral geometry in the case of 3 & 4 . UV-Vis spectral analysis, electrochemical techniques, CD technique and docking activities confirmed that all complexes were strongly interacted towards CT-DNA via groove binding. Homoleptic zinc(II) complex 4 showed superior binding efficacy than remaining complexes with the binding affinity follows the order is 4 > 5 > 3 > 1 > 2 . Mono nuclear heteroliptic copper(II) complexes showed the catecholase like activity and complex 1 showed better catecholase activity than 2 . Declarations Author Contribution Popuri Sureshbabu- data collection, analysis, and interpretation of results, and manuscript preparation.Koyal Pattanaik-Data collection and analysisSuman Bhattacharya-Single crystal XRD data and refinementShahulhameed Sabiah- study conception, design, and manuscript revision Acknowledgement S.S. acknowledges SERB-Inida (CRG/2022/004536) for the funding. We thank the Pondicherry University start-up grant to support this work and CIF-Pondicherry University, for the analytical and instrumental facilities. PS is grateful for the SRF from CSIR New Delhi. PS also thanks the University of Oklahoma for financial support. We are grateful to UGC-SAP for mass data and DST-FIST for single-crystal X-ray analysis. References (a) Evano G, Blanchard N, Toumi M (2008) Chem Rev 108:3054. (b) Iakovidis I, Delimaris I, Piperakis SM (2011) Mol Biol Int 2011:594529. (c) Drewry JA, Gunning PT (2011) Coord Chem Rev 255:459. 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(c) Mukherjee S, Pal CK, Kotakonda M, Joshi M, Shit M, Ghosh P, Choudhury AR, Biswas B (2021) J Mol Struct 1245:131057. (d) Rakshit T, Mandal B, Alenezi KM, Ganguly R, Mandal D (2021) J Mol Struct 1227:129544. (a) Hegg EL, Mortimore SH, Cheung CL, Huyett JE, Powell DR, Burstyn JN, (1999) Inorg Chem 38:2961. (b) Osório REHMB (2012) Inorg Chem 51:1569. Schemes Scheme 1 is available in the Supplementary Files section Additional Declarations No competing interests reported. Supplementary Files TOC.png Scheme1.png Scheme1. Synthetic route of mononuclear complexes 1-5. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 02 Apr, 2024 Editor assigned by journal 02 Apr, 2024 Submission checks completed at journal 02 Apr, 2024 First submitted to journal 27 Mar, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4173894","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":286743724,"identity":"5d30690b-691c-4b4d-b439-7519c3b65c5b","order_by":0,"name":"Popuri Sureshbabu","email":"","orcid":"","institution":"Pondicherry University","correspondingAuthor":false,"prefix":"","firstName":"Popuri","middleName":"","lastName":"Sureshbabu","suffix":""},{"id":286743725,"identity":"9a299516-5852-4375-bbdc-d0569d81b0b4","order_by":1,"name":"Koyal Pattanaik","email":"","orcid":"","institution":"Pondicherry University","correspondingAuthor":false,"prefix":"","firstName":"Koyal","middleName":"","lastName":"Pattanaik","suffix":""},{"id":286743726,"identity":"76219539-8f4c-4bfc-af0c-c4e83ffdb937","order_by":2,"name":"Suman Bhattacharya","email":"","orcid":"","institution":"University of Limerick","correspondingAuthor":false,"prefix":"","firstName":"Suman","middleName":"","lastName":"Bhattacharya","suffix":""},{"id":286743727,"identity":"8f3b49c4-43f6-404d-8781-ed9b53d93b7a","order_by":3,"name":"Shahulhameed Sabiah","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5klEQVRIie2OrQrCUBSAjwiuTFYX/HmFK4LafJV7EbRsRuMwHcvEV7Gp7Y5Tp3mCwRWTCjYNglvwB8HrbIb7wYFzwsf5ADSav8QEmRtCJV1tnp4pPINS/02BRBHDVMmUVR0tA3mZe72ZMQ6iGDclMGgL8fyzwsI+D8YhuQt/1WkJ3JlgdhmIUKGAw2QRpTuNnIYtkJJOB0CgImyyZ8EVvR57KNZerUDkMCpinj8V+8sXFh05lZFqCz+st/iKzIK9Y1Id5tLpgF61afi19XlAbcvqxPFFFfZ4d18KycgMwoui0Wg0mndu60xUt3eUHG4AAAAASUVORK5CYII=","orcid":"","institution":"Pondicherry University","correspondingAuthor":true,"prefix":"","firstName":"Shahulhameed","middleName":"","lastName":"Sabiah","suffix":""}],"badges":[],"createdAt":"2024-03-27 06:35:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4173894/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4173894/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":54174997,"identity":"c6fa1187-d7fb-4b10-b999-c511e0ac629f","added_by":"auto","created_at":"2024-04-05 15:32:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":192201,"visible":true,"origin":"","legend":"\u003cp\u003e(a)\u003cstrong\u003e \u003c/strong\u003eCrystal plot of \u003cstrong\u003e1\u003c/strong\u003e and \u003cstrong\u003e2\u003c/strong\u003e. H-atoms were excluded for clear visibility.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/a24c13b6ebb6cb109c31aa18.png"},{"id":54175640,"identity":"d7047b1e-7430-4fa1-aa7c-eaaa203e77a2","added_by":"auto","created_at":"2024-04-05 15:40:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":233274,"visible":true,"origin":"","legend":"\u003cp\u003e(a)\u003cstrong\u003e \u003c/strong\u003eCrystal structure of mononuclear zinc(II) complexes \u003cstrong\u003e3-5\u003c/strong\u003e. H-atoms and counter ions (ClO\u003csub\u003e4\u003c/sub\u003e) (in case of \u003cstrong\u003e4\u003c/strong\u003e) are omitted for clear visibility.\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/33ee03cef612782302036cbf.png"},{"id":54175006,"identity":"23140b93-af33-49ac-adc1-da09301ca866","added_by":"auto","created_at":"2024-04-05 15:32:02","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":336974,"visible":true,"origin":"","legend":"\u003cp\u003eIllustration of crystal packing diagram in 2-D sheet of complex (a) \u003cstrong\u003e1\u003c/strong\u003e presented through b-axis (b) \u003cstrong\u003e2\u003c/strong\u003e presented along side a-axis.\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/e98c1d66f0a94857d73094bd.png"},{"id":54175001,"identity":"cc297427-a9b3-447e-a7ec-985ee1ec18c2","added_by":"auto","created_at":"2024-04-05 15:32:01","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":448549,"visible":true,"origin":"","legend":"\u003cp\u003eIllustration of crystal packing diagrams in 2-D sheet of complex (a) \u003cstrong\u003e3\u003c/strong\u003epresented in a-axis (b) \u003cstrong\u003e4\u003c/strong\u003e presented via b-axis (c) \u003cstrong\u003e5\u003c/strong\u003e presented through a-axis.\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/948f81f39cd0211d8708e238.png"},{"id":54175641,"identity":"35da6e68-d518-44e9-9344-1d6277ecbbfc","added_by":"auto","created_at":"2024-04-05 15:40:01","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":272373,"visible":true,"origin":"","legend":"\u003cp\u003eOptimized geometries of \u003cstrong\u003e1\u003c/strong\u003e-\u003cstrong\u003e5.\u003c/strong\u003eColor information: C, N, O, Cu and Zn (grey, blue, red, orange red and dark grey, respectively).\u003c/p\u003e","description":"","filename":"image7.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/6a51bb15deb11b8a5c1a3555.png"},{"id":54175012,"identity":"2d793c4f-817a-4cbb-848f-271536c6900d","added_by":"auto","created_at":"2024-04-05 15:32:02","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":221875,"visible":true,"origin":"","legend":"\u003cp\u003eFrontier molecular orbital energies of \u003cstrong\u003e1\u003c/strong\u003e-\u003cstrong\u003e5.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"image8.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/3125894091042bd2476d0eb9.png"},{"id":54175010,"identity":"5762041a-87fb-4980-824d-094b46fea35d","added_by":"auto","created_at":"2024-04-05 15:32:02","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":164705,"visible":true,"origin":"","legend":"\u003cp\u003eUV-Vis diagram of (a) complexes \u003cstrong\u003e1\u003c/strong\u003e and \u003cstrong\u003e2 \u003c/strong\u003e(5 mM); (b) complexes \u003cstrong\u003e3\u003c/strong\u003e-\u003cstrong\u003e5\u003c/strong\u003e (0.5 mM) in DMF\u003c/p\u003e","description":"","filename":"image9.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/33baa811dfc68ddb932360f1.png"},{"id":54175000,"identity":"04558b8c-0e29-44cd-8912-b8d32853d095","added_by":"auto","created_at":"2024-04-05 15:32:01","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":69173,"visible":true,"origin":"","legend":"\u003cp\u003eEPR spectrum of (a) [Cu(AEP)(BA)\u003csub\u003e2\u003c/sub\u003e], \u003cstrong\u003e1\u003c/strong\u003e (b) [Cu(AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e], \u003cstrong\u003e2\u003c/strong\u003e at RT, scan range = 0–6000 G.\u003c/p\u003e","description":"","filename":"image10.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/78bdbc949c9135c47e9f1d2a.png"},{"id":54176217,"identity":"1007b9c4-91dc-4381-8a59-b3083c283cbc","added_by":"auto","created_at":"2024-04-05 15:48:01","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":191998,"visible":true,"origin":"","legend":"\u003cp\u003e(a) UV-Vis spectral analysis for complex \u003cstrong\u003e1\u003c/strong\u003e (5 mM) and CT-DNA (0–160 µM). (b) The [DNA]/(ɛ\u003csub\u003ea\u003c/sub\u003e-ɛ\u003csub\u003ef\u003c/sub\u003e) against [DNA] plot.\u003c/p\u003e","description":"","filename":"image11.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/2c7a352594aeca50ee562192.png"},{"id":54175005,"identity":"fda28219-2b7b-48a9-8359-a10058f53ab3","added_by":"auto","created_at":"2024-04-05 15:32:02","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":169400,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Absorption spectral titration for complex \u003cstrong\u003e4\u003c/strong\u003e (0.125 mM) and CT-DNA (0–160 µM). (b) [DNA]/(ɛ\u003csub\u003ea\u003c/sub\u003e-ɛ\u003csub\u003ef\u003c/sub\u003e) against [DNA] plot.\u003c/p\u003e","description":"","filename":"image12.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/776fb907b574ed60fbdd2fba.png"},{"id":54175008,"identity":"feab525c-7e0c-4624-830c-e667b391c2bb","added_by":"auto","created_at":"2024-04-05 15:32:02","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":192443,"visible":true,"origin":"","legend":"\u003cp\u003eCT-DNA CD spectra and its binding with \u003cstrong\u003e1-5\u003c/strong\u003ewhere [complex]/[CT DNA] = 0.5. Every spectrum were collected in Tris/HCl buffer solution at ambient temperature.\u003c/p\u003e","description":"","filename":"image13.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/baa9c629f220db74069bff21.png"},{"id":54175009,"identity":"66b8e5e5-1c1d-445e-9cd8-d55789c043d8","added_by":"auto","created_at":"2024-04-05 15:32:02","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":783016,"visible":true,"origin":"","legend":"\u003cp\u003eLeast docking conformation of \u003cstrong\u003e1\u003c/strong\u003e-\u003cstrong\u003e5\u003c/strong\u003e with DNA order d(CGCGAATTCGCG)\u003csub\u003e2\u003c/sub\u003e (PDB ID: 1BNA).\u003c/p\u003e","description":"","filename":"image14.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/18c403b0c53b19548249e894.png"},{"id":54175004,"identity":"5e834785-c939-4e1c-926b-bb3e23781049","added_by":"auto","created_at":"2024-04-05 15:32:01","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":235554,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Spectral profile denoting the raise of intensity at 400 nm, complex \u003cstrong\u003e1\u003c/strong\u003e (0.15 mM) recorded in DMF. (b) Conc against time for \u003cstrong\u003e1\u003c/strong\u003e(0.03–0.15 mM) plot.\u003c/p\u003e","description":"","filename":"image15.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/1545ce20f4fe8ed924b07c49.png"},{"id":54175011,"identity":"066452e0-bb31-4be0-ac58-4da0bbba0274","added_by":"auto","created_at":"2024-04-05 15:32:02","extension":"png","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":79752,"visible":true,"origin":"","legend":"\u003cp\u003eRate against concentration plot of \u003cstrong\u003e1\u003c/strong\u003e. Inset indicates reciprocal Lineweaver–Burk plot .\u003c/p\u003e","description":"","filename":"image16.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/72d441429a62f274cb700c6c.png"},{"id":54176560,"identity":"600ec16c-6f06-4ac3-82a3-96858f0ac52f","added_by":"auto","created_at":"2024-04-05 15:56:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3938932,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/2c9bd7f3-da25-45a8-ad13-6877786cffb9.pdf"},{"id":54174996,"identity":"85bce864-1be0-49a4-8bf1-2316e8caf4e4","added_by":"auto","created_at":"2024-04-05 15:32:01","extension":"png","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":435482,"visible":true,"origin":"","legend":"","description":"","filename":"TOC.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/29965b56a29087e3bd8fcbf1.png"},{"id":54174999,"identity":"59784f7f-c8c2-4280-b924-2c062550bd76","added_by":"auto","created_at":"2024-04-05 15:32:01","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":73714,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScheme1. \u003c/strong\u003eSynthetic route of mononuclear complexes \u003cstrong\u003e1-5\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"Scheme1.png","url":"https://assets-eu.researchsquare.com/files/rs-4173894/v1/8129878ca0120e6633bd00b5.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Mononuclear Cu(II), Zn(II) Complexes with 2-Aminoethylpyridine and carboxylate ligands: Structure, DFT, DNA binding, Docking and Catecholase Like Activities","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eRecently, metal complexes with different ligand environment have gained paramount importance because of their numerous uses in both chemistry and biology [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Among them copper and zinc complexes play pivotal roles as artificial nucleases and also as pharmaceutical agents [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. These complexes are found to bind with the biomelecules such as nucleic acids (DNA and RNA). Since these biomolecules consists phosphodiester bonds, for the activities it controls to be effectively carried out and maintained, it must be resistant to damage [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The phosphodiester bonds are responsible for its remarkably stable structure. The half-life of phosphodiester bonds around pH 7 and 25\u0026deg;C for natural hydrolysis is calculated to be about 10\u003csup\u003e11\u003c/sup\u003e years, indicating their high stability against hydrolysis [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Cisplatin and related platinum analogues was successfully used as anticancer agents on various types of cancer cell lines. Moreover, cisplatin could bind covalently to DNA, and arises serious adverse effects, which can lead to toxicity and acquired drug resistance [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Therefore, development of non-covalently DNA binding, more potent, less hazardous, target-specific anticancer agents is a challenging topic. Several mononuclear simple and mixed ligand complexes of copper and zinc have been widely prepared and used as anticancer and DNA binding/cleavage agents [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn addition, copper complexes play a crucial role as catalyst in the biological transformations for example catechol oxidase and tyrosinase enzyme [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. An enzyme catechol oxidase classified as a type III protein that uses two electron oxidation to change o-phenols also known as catechols into corresponding o-quinones. Since active site of type III proteins containing two copper centers, each copper ion surrounded by three histidine nitrogens. In general, dinuclear copper complexes were frequently study for catecholase studies [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. While very less number of mono nuclear copper complexes have been reported for catecholase like studies [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003eIn our recent reports, we have explored the mono nuclear homoleptic and heteroleptic complexes of copper \u0026amp; zinc from \u003cem\u003eN\u003c/em\u003e-donor ligands such as 1,2-diaminocyclohexane, 2-aminoethylpyridine and diethylenetriamine along with axial ligands and explored for biomolecule interaction such as DNA binding, cleavage and anticancer analysis [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In continuation to our previous research work, mononuclear copper(II) and zinc(II) complexes from 2-AEP and carboxylates have been synthesized. The purpose of these complexes' experiments was to determine how well they bound DNA. To this end, molecular docking, UV-Vis titration, and circular dichroism were employed. Moreover, copper(II) complexes \u003cb\u003e1\u003c/b\u003e \u0026amp; \u003cb\u003e2\u003c/b\u003e showed catecholase activity.\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"9. Experimental Section","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e9.1. Materials\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eMetal salts of copper and zinc (copper perchlorate hexahydrate, zinc perchlorate hexahydrate, zinc chloride respectively) and other chemicals 2-animoethylpyridine, triethylamine, benzoicacid, triphenylaceticacid and calf-thymus DNA were commercially accessible, acquired from Aldrih company and utilized as it was obtained. Standard distillation methods were used to dry the solvents [11].\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003e9.2. Physical\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eC, H, N analysis was performed on a Thermo Scientific FLASH 2000 Organic Elemental instrument. UV-Vis absorption spectral analysis were studied using an UV-2450 Model equipment. FT-IR analysis were done with KBr pellets using a Shimadzu IR-470 spectrophotometer. EPR spectral data were collected from a Varian E-112 X-band spectrophotometer. Cirular dichroism spectral measurements were carried out on the JASCO J-815 spectrophotometer.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003e9.3. DNA\u0026ndash;Complexes interaction studies\u003c/h2\u003e\n \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\n \u003ch2\u003e9.3.1. UV-Vis spectrophotometric study\u003c/h2\u003e\n \u003cp\u003eThe bindig mechanism study was investigated by using a Shimadzu (UV-2450) instrument with 1 cm channel distance rectangular quartz cuvette at room temperature. CT-DNA was dissolved in a pH\u0026thinsp;=\u0026thinsp;7.4 of the 10 mM Tris\u0026ndash;HCl buffer and the quantity of the CT-DNA was determined at 260 nm with extinction coefficient is (ɛ) 6600 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003ecm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e]. The ratio that the CT-DNA solution provided at 260 and 280 nm was approximately 1.8\u0026ndash;1.9, which amply demonstrating that the CT-DNA was satisfactorily protein free. The concentration of all compounds was maintained uniform while the concentration of CT-DNA was progressively increased from 0\u0026ndash;20 mM.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\n \u003ch2\u003e9.3.2. CD spectroscopic study\u003c/h2\u003e\n \u003cp\u003eCD spectroscopy is one helpful analytical method to determine whether any changes in DNA structure resulted from interactions with metal complexes. Initially, CD spectrum of free CT-DNA (100 \u0026micro;M) was recorded in the wavelength in the region 220\u0026ndash;320 nm. 50 \u0026micro;M metal compounds \u003cstrong\u003e1\u003c/strong\u003e\u0026ndash;\u003cstrong\u003e5\u003c/strong\u003e were then carefully mixed to the CT-DNA and the CD spectra was recorded.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003e9.4. X-Ray refinement\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eX-Ray crystal analysis were done on a Ragiku X calibur Eos instrument Ltd. with Mo-K\u0026alpha; radiation where \u0026lambda; is 0.71073. The structural data was resolved and refined anisotropically using SHELXS and SHELXL respectively [\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e]. For hydrogen atoms bonded to carbon atoms, their positions were generated in accordance with stereochemistry and subsequently incorporated employing the riding mode integrated within SHELXL-2018. All hydrogens were placed in calculated positions. To address this issue, a riding model refinement strategy was employed after making their locations at geometrically plausible locations. With the exception of complexes \u003cstrong\u003e2\u003c/strong\u003e and \u003cstrong\u003e3\u003c/strong\u003e, all structures had certain positional abnormalities, which could be fixed using typical techniques. X-ray crystal data were collected, crystallographic parameters and refinement information were shown in Tables \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003e9.5. Docking analysis\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eRigid virtual docking investigations were carried out on the AutoDock 4.2 tool to examine the interaction between heteroleptic copper(II) and zinc(II) compounds with DNA. [\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e]. Docking analysis were done utilizing the AutoDock Tools (ADT) application, which aimed to recognize the optimal binding location of the metal complexes to DNA. The complex structures were constructed using Chem Bio Draw Ultra 13, saved as mol format, and transformed to pdb format using OPENBABEL (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.vcclab.org/lab/babel/\u003c/span\u003e\u003c/span\u003e). From the Protein Data Bank From the Protein Data Bank, the B-DNA dodecamer with sequence d(CGCGAATTCGCG)2 (PDB ID:1BNA) was obtained (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.rcsb.org./pdb\u003c/span\u003e\u003c/span\u003e) and employed as the DNA receptor for the docking study.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n \u003ch2\u003e9.6. 3,5-DTBC oxidation study\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eThe catechol oxidase like mechanism of mononuclear copper(II) complex was investigated using the reaction of \u0026gt;\u0026thinsp;100 folds of 3,5-di-tert-butylcatechol (3,5- DTBC) with 1 equivalent of the compounds under aerobic circumstances at ambient temperature in DMF solvent. The reaction was recorded and examined on an UV-Vis spectrophotometer. The band intensity at 400 nm was kept on increasing as a function of time which is corresponding band of o-quinone formation. The kinetic investigation was done applying the initial rate process. The [complex] was varied from 0.03 mM to 0.15 mM by keeping the [3,5- DTBC] at 5 mM constant value. We plotted the [complex] vs rate and calculated the overall rate constant. The kinetic parameters Vmax, kM, and kcat of complex \u003cstrong\u003e1\u003c/strong\u003e and \u003cstrong\u003e2\u003c/strong\u003e were determined from both Michaelis\u0026ndash;Menten equation and a Lineweaver\u0026ndash;Burk plot.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003e9.7. Synthesis of metal complexes 1\u0026ndash;5\u003c/h2\u003e\n \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\n \u003ch2\u003e9.7.1. Synthesis of [Cu(2-AEP)(BA)\u003csub\u003e2\u003c/sub\u003e] (1)\u003c/h2\u003e\n \u003cp\u003eTo an oven dried pear shaped flask (50 mL) with a magnetic stir bar, copper perchlorate hexahydrate (0.37 g, 1 mmol) was taken and ethanol (3 mL) was added. To this, ethanolic solution 2-AEP (0.122 g, 1 mmol) was added slowly, a pale blue color precipitate started to form and continued stirring for ten minutes. Subsequently, in a beaker benzoicacid (0.244 g, 2 mmol) and triethylamine (0.212 g, 2 mmol) were taken in ethanol and added dropwise via micropippet to the aforementioned pale blue color metal-ligand solution. The color intensity was observed and it was uniformly stirred for 2 h. After completion of reaction, ppt was collected and dried using vacuum to yield \u003cstrong\u003e1\u003c/strong\u003e (0.416 g, 88%). Good quality single crystals of complex \u003cstrong\u003e1\u003c/strong\u003e were collected at room temperature after two days from methanol. Anal.Calcd. for (C\u003csub\u003e21\u003c/sub\u003eH\u003csub\u003e20\u003c/sub\u003eCuN\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e) (Mr\u0026thinsp;=\u0026thinsp;427.947 g mol\u003csup\u003e\u003cem\u003e\u0026minus;\u003c/em\u003e\u0026thinsp;1\u003c/sup\u003e) calcd: C 58.94; H 4.71; N 6.55%; found: C 59.01; H 4.77; N 6.61%. UV-Vis (DMF); \u0026lambda;\u003csub\u003emax\u003c/sub\u003e, 679 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;122 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). FT-IR (KBr, cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): 3434 (\u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e stretching), 3239 (\u0026nu;\u003csub\u003eC=C\u0026minus;H\u003c/sub\u003e stretching); 2924 (\u0026nu;\u003csub\u003eC\u0026minus;H\u003c/sub\u003e stretching), 1596 (\u0026nu;\u003csub\u003eC=O\u003c/sub\u003e stretching), 1554 (\u0026nu;\u003csub\u003eC=C\u003c/sub\u003e stretching); 1385 (\u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e bending), 1117\u0026thinsp;\u0026minus;\u0026thinsp;1069 (\u0026nu;\u003csub\u003eC\u0026minus;O/C\u0026minus;N\u003c/sub\u003e stretching). ESI-MS: [Cu(2-AEP)(BA)\u003csub\u003e2\u003c/sub\u003e]\u003csup\u003e+\u003c/sup\u003e \u003cem\u003em/z\u003c/em\u003e\u0026thinsp;=\u0026thinsp;427.3814, calcd\u0026thinsp;=\u0026thinsp;427.0719.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e\n \u003ch2\u003e9.7.2. Synthesis of [Cu(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e (2)\u003c/h2\u003e\n \u003cp\u003eUtilizing the identical process outlined for complex \u003cstrong\u003e1\u003c/strong\u003e, complex \u003cstrong\u003e2\u003c/strong\u003e was synthesized by taking copper perchlorate hexahydrate (0.37 g, 1 mmol). A dark blue color precipitate started to form and continued stirring for ten minutes. Following that, in a beaker triphenylaceticacid (0.576 g, 2 mmol) and triethylamine (0.212 g, 2 mmol) were taken in ethanol and added dropwise via micropippet to the aforementioned dark blue color metal-ligand solution. The color of the reaction mixture became light blue and it was uniformly stirred for another 2 h. After completion of reaction, ppt was collected and dried under vacuum to produce \u003cstrong\u003e2\u003c/strong\u003e (0.66 g, 86%). Good diffracted single crystals of complex \u003cstrong\u003e2\u003c/strong\u003e were collected after one week from dichloromethane solvent by slow evaporation method. Anal.Calcd. for (C\u003csub\u003e47\u003c/sub\u003eH\u003csub\u003e40\u003c/sub\u003eCuN\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e) (Mr\u0026thinsp;=\u0026thinsp;760.39 g mol\u003csup\u003e\u003cem\u003e\u0026minus;\u003c/em\u003e\u0026thinsp;1\u003c/sup\u003e) calcd: C 74.24; H 5.30; N 3.68%; found: C 74.31; H 5.36; N 3.75%. UV-Vis (DMF); \u0026lambda;\u003csub\u003emax\u003c/sub\u003e, 698 nm (ɛ = 206 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). FT-IR (KBr, cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): 3432 (\u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e stretching), 3241 (\u0026nu;\u003csub\u003eC=C\u0026minus;H\u003c/sub\u003e stretching); 2923, (\u0026nu;\u003csub\u003eC\u0026minus;H\u003c/sub\u003e stretching). ESI-MS: [Cu(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e]\u003csup\u003e+\u003c/sup\u003e \u003cem\u003em/z\u003c/em\u003e\u0026thinsp;=\u0026thinsp;759.2237, calcd\u0026thinsp;=\u0026thinsp;759.2284.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e\n \u003ch2\u003e9.7.3. Synthesis of [Zn(2AEP)(Cl)\u003csub\u003e2\u003c/sub\u003e] (3)\u003c/h2\u003e\n \u003cp\u003eUtilizing the identical process outlined for complex \u003cstrong\u003e1\u003c/strong\u003e, complex \u003cstrong\u003e3\u003c/strong\u003e was synthesized by taking zinc chloride (0.136 g, 1 mmol) in ethanol. A yellow color precipitate started to form and continued stirring for 2 h. After finishing of reaction it was followed by filtration and vaccum dried to yield \u003cstrong\u003e3\u003c/strong\u003e (0.219 g, 85%). Single crystals of complex \u003cstrong\u003e3\u003c/strong\u003e were collected after three days from acetonitrile solution by gradual evaporation process. Anal.Calcd. for C\u003csub\u003e7\u003c/sub\u003eH\u003csub\u003e10\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003eZnN\u003csub\u003e4\u003c/sub\u003e (258.451): C, 32.53; H, 3.90; N, 10.84. found: C 32.62; H 3.98; N 10.93%.; UV-Vis (DMF); \u0026lambda;\u003csub\u003emax\u003c/sub\u003e, 207 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), 260 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). FT-IR (KBr, cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): 3436 (stretching \u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e); 3152\u0026ndash;3253 (\u0026nu;\u003csub\u003eC=C\u0026minus;H\u003c/sub\u003e stretching); 2881\u0026ndash;2956 (\u0026nu;\u003csub\u003eC\u0026minus;H\u003c/sub\u003e stretching), 1601 (\u0026nu;\u003csub\u003eC=C/C=N\u003c/sub\u003e stretching); 1363 (\u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e bending), 1103\u0026ndash;1143 (\u0026nu;\u003csub\u003eC\u0026minus;O/C\u0026minus;N\u003c/sub\u003e stretching). ESI-MS: [Zn(2-AEP)Cl\u003csub\u003e2\u003c/sub\u003e]\u003csup\u003e+\u003c/sup\u003e \u003cem\u003em/z\u003c/em\u003e\u0026thinsp;=\u0026thinsp;255.9392., calcd\u0026thinsp;=\u0026thinsp;255.9513.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e\n \u003ch2\u003e9.7.4. Synthesis of [Zn(2-AEP)\u003csub\u003e2\u003c/sub\u003e](ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e (4)\u003c/h2\u003e\n \u003cp\u003eUtilizing the identical process outlined for complex \u003cstrong\u003e1\u003c/strong\u003e, complex \u003cstrong\u003e4\u003c/strong\u003e was synthesized by taking zinc perchlorate hexahydrate (0.372 g, 1 mmol) and 2-AEP (0.244 g, 2 mmol) in ethanol. A light orange precipitate formed and continued stirring for 2 h. After completion of reaction it was followed by filtration and vaccum dried to produce \u003cstrong\u003e4\u003c/strong\u003e (0.53 g, 86%). X-ray suitable single crystals of complex \u003cstrong\u003e4\u003c/strong\u003e were collected after two days from acetonitrile solvent by slow evaporation method. Anal.Calcd. for C\u003csub\u003e14\u003c/sub\u003eH\u003csub\u003e20\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003eZnN\u003csub\u003e4\u003c/sub\u003eO\u003csub\u003e8\u003c/sub\u003e (508.614): C, 33.06; H, 3.96; N, 11.02. Found: C, 33.11; H, 4.01; N, 11.09%. UV-Vis (DMF); \u0026lambda;\u003csub\u003emax\u003c/sub\u003e, 207 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), 260 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and 326 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), 339 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). FT-IR (KBr, cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): 3483 (stretching \u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e); 3157 (\u0026nu;\u003csub\u003eC=C\u0026minus;H\u003c/sub\u003e stretching); 2852 (\u0026nu;\u003csub\u003eC\u0026minus;H\u003c/sub\u003e stretching), 1577 (\u0026nu;\u003csub\u003eC=C/C=N\u003c/sub\u003e stretching); 1353 (\u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e bending), 1074 (bs), \u0026nu;(ClO\u003csub\u003e4\u003c/sub\u003e, asymmetric stretching); 947 (s), \u0026nu;(ClO\u003csub\u003e4\u003c/sub\u003e symmetric stretching); 625 (s), \u0026nu;(ClO\u003csub\u003e4\u003c/sub\u003e asymmetric bending); 508 (s), \u0026nu;(ClO\u003csub\u003e4\u003c/sub\u003e asymmetric bending). ESI-MS: [Zn(2-AEP)\u003csub\u003e2\u003c/sub\u003e](ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e \u003cem\u003em/z\u003c/em\u003e\u0026thinsp;=\u0026thinsp;506.024, calcd\u0026thinsp;=\u0026thinsp;505.995.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\n \u003ch2\u003e9.7.5. Synthesis of [Zn(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e] (5)\u003c/h2\u003e\n \u003cp\u003eUtilizing the identical process outlined for complex \u003cstrong\u003e1\u003c/strong\u003e, complex \u003cstrong\u003e5\u003c/strong\u003e was synthesized by taking zinc perchlorate hexahydrate (0.372 g, 1 mmol) in EtOH, a light yellow color suspension that formed was stirred for ten minutes. Later on, in a beaker ethanolic solution of triphenylaceticacid (0.576 g, 2 mmol) and triethylamine (0.212 g, 2 mmol) were added dropwise to the aforementioned yellow color metal-ligand solution. There was no color change was noticed and continued stirring for another 2 h. Then the generated ppt was collected and dried under vacuum to yield \u003cstrong\u003e5\u003c/strong\u003e (0.69 g, 90%). X-ray quality crystals of complex \u003cstrong\u003e5\u003c/strong\u003e were grown after one week from dichloromethane solvent. Anal.Calcd. for (C\u003csub\u003e47\u003c/sub\u003eH\u003csub\u003e40\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003eZn) (Mr\u0026thinsp;=\u0026thinsp;762.227 g mol\u003csup\u003e\u003cem\u003e\u0026minus;\u003c/em\u003e\u0026thinsp;1\u003c/sup\u003e) calcd: C 74.06; H 5.29; N 3.68%; found: C 74.12; H 5.35; N 3.75%. UV-Vis (DMF); \u0026lambda;\u003csub\u003emax\u003c/sub\u003e, 238 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and 259 nm (\u0026epsilon;\u0026thinsp;=\u0026thinsp;138 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). FT-IR (KBr, cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): 3316 (stretching \u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e); 3057\u0026ndash;3149 (\u0026nu;\u003csub\u003eC=C\u0026minus;H\u003c/sub\u003e stretching); 2831\u0026ndash;2952 (\u0026nu;\u003csub\u003eC\u0026minus;H\u003c/sub\u003e stretching), 1602 (\u0026nu;\u003csub\u003eC=O\u003c/sub\u003e stretching), 1488\u0026thinsp;\u0026minus;\u0026thinsp;1441 (\u0026nu;\u003csub\u003eC=C/C=N\u003c/sub\u003e stretching); 1361 (\u0026nu;\u003csub\u003eN\u0026minus;H\u003c/sub\u003e bending), 1090 (\u0026nu;\u003csub\u003eC\u0026minus;O/C\u0026minus;N\u003c/sub\u003e stretching). ESI-MS: [Zn(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e]\u003csup\u003e+\u003c/sup\u003e \u003cem\u003em/z\u003c/em\u003e\u0026thinsp;=\u0026thinsp;761.2428, calcd\u0026thinsp;=\u0026thinsp;760.228.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"2. Results and discussion","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.1. Synthetic and structural determination of 1-5\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e2-Aminoethylpyridine (2-AEP) is a simple heterocyclic bidentate \u003cem\u003eN\u003c/em\u003e,\u003cem\u003eN\u003c/em\u003e ligand. The complexation of the ligand 2-AEP: Acid: Cu(ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e.6H\u003csub\u003e2\u003c/sub\u003eO/ Zn(ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e.6H\u003csub\u003e2\u003c/sub\u003eO in 1:1:1 ratio achieved the corresponding complexes \u003cstrong\u003e1, 2\u003c/strong\u003e and \u003cstrong\u003e5\u003c/strong\u003e in excellent yields; 2-AEP with ZnCl\u003csub\u003e2\u003c/sub\u003e and Zn(ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e.6H\u003csub\u003e2\u003c/sub\u003eO in a 1:1 and 2:1 proportion accomplished the corresponding compounds \u003cstrong\u003e3\u003c/strong\u003e and\u003cstrong\u003e\u0026nbsp;4\u003c/strong\u003e in high yields as demonstrated in scheme 1. These compounds were synthesized using ethanol as a solvent at ambient temperature. The molecular structure of prepared mononuclear complexes \u003cstrong\u003e1-5\u003c/strong\u003e has been unambiguously determined by S-XRD and thoroughly characterized by elemental study, UV-Vis, FT-IR ESI-MS, ESR (incase of copper complexes \u003cstrong\u003e1\u003c/strong\u003e, \u003cstrong\u003e2\u003c/strong\u003e) spectra. All complexes are turn out to be fairly stable and soluble in the majority of organic solvents. However, they are found to be soluble in DMSO (\u003cstrong\u003e1\u003c/strong\u003e\u0026ndash;\u003cstrong\u003e5),\u0026nbsp;\u003c/strong\u003eDMF (\u003cstrong\u003e1\u003c/strong\u003e\u0026ndash;\u003cstrong\u003e5),\u0026nbsp;\u003c/strong\u003eDCM (\u003cstrong\u003e2\u0026nbsp;\u003c/strong\u003e\u0026amp;\u003cstrong\u003e\u0026nbsp;5)\u003c/strong\u003e and CH\u003csub\u003e3\u003c/sub\u003eCN (\u003cstrong\u003e1\u003c/strong\u003e, \u003cstrong\u003e3\u003c/strong\u003e \u0026amp; \u003cstrong\u003e4)\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.2. \u0026nbsp; Crystal Structures of 1-5\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe structure of compounds \u003cstrong\u003e1-5\u003c/strong\u003e were comfirmed by X-ray technique (Figure 1 and 2). Dichloromethane and acetonitrile solvents were used to grow the adequate single crystals of compounds \u003cstrong\u003e1\u003c/strong\u003e \u0026amp; \u003cstrong\u003e5\u003c/strong\u003e and\u003cstrong\u003e\u0026nbsp;2-4\u0026nbsp;\u003c/strong\u003erespectively. The color of the crystals \u003cstrong\u003e1\u003c/strong\u003e is blue and \u003cstrong\u003e2\u003c/strong\u003e is fent blue;\u003cstrong\u003e\u0026nbsp;3\u003c/strong\u003e-\u003cstrong\u003e5\u003c/strong\u003e are pale yellow. The crystallographic refinement details, significant bond parameters of \u003cstrong\u003e1-5\u003c/strong\u003e are tabulated in Table 1, 2 and 3 respectively. The molecular diagrams of \u003cstrong\u003e1-5\u003c/strong\u003e are shown in Figures 1 and 2. \u0026nbsp; Crystal packing diagrams are depicted in Figures 3 and 4.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.2.1. Complex\u0026nbsp;[Cu(2-AEP)(BA)\u003csub\u003e2\u003c/sub\u003e]\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e1\u003c/em\u003e\u003c/strong\u003e: From the single crystal data, it revealed that complex \u003cstrong\u003e1\u003c/strong\u003e results in the monoclinic,\u0026nbsp;P2\u003csub\u003e1\u003c/sub\u003e space group. The molecular representation of the complex is depicted in Figure 1. In complex \u003cstrong\u003e1\u003c/strong\u003e, the asymmetric unit is made up of one molecule of 2-AEP ligand and two benzoate molecules. The shape of copper(II) ion in \u003cstrong\u003e1\u003c/strong\u003e possesses distorted octahedral. This coordination is afforded by one bidentate amine and pyridine nitrogens from 2-AEP, along with four oxygen atoms from two benzoate molecules to the copper(II) ion. The standard length of the Cu\u0026ndash;N is 2.006 \u0026Aring; (Table 2), which is comprable with reported measurements for other mixed ligand copper(II) diamine and carboxylate complexes [15]. The structure is further stabilized by certain hydrogen bonds between the hydrogens on N(2) and the benzoate oxygens. Moreover, two compound molecules are interconnected via a relatively strong hydrogen bonding contact connecting the hydrogen on N(2) with O(2) and O(4), with bond lengths of d= 2.264 \u0026Aring; and d= 1.990 \u0026Aring;, respectively. The corresponding bond angles are O(2)∙∙∙H(2A)-N(2) = 147.93\u0026deg; and O(4)∙∙∙H(2B)-N(2) = 167.74\u0026deg;.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.2.2. Complex\u0026nbsp;[Cu(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e]\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e2\u003c/em\u003e\u003c/strong\u003e: From the single crystal data, it revealed that complex \u003cstrong\u003e2\u003c/strong\u003e develops in the triclinic, P-1 space group. The structural diagram of the complex is depicted in Figure 1. In complex \u003cstrong\u003e2\u003c/strong\u003e, the asymmetric unit is made up of one molecule of 2-AEP ligand and two triphenylacetate molecules. The shape of copper(II) ion in \u003cstrong\u003e2\u003c/strong\u003e possesses distorted square pyramidal. This coordination is furnished by one bidentate amine nitrogens from 2-AEP, along with four oxygen atoms from two triphenylacetate molecules to the copper(II) ion. The mean distance of the Cu\u0026ndash;N is 2.032 \u0026Aring; (Table 2), which is comprable with reported measurements for other mixed ligand copper(II) diamine and carboxylate complexes [15]. The structure is further stabilized by some hydrogen bonds between the hydrogens on N(2) and the benzoate oxygens. Moreover, two compound molecules are interconnected via a modestly strong hydrogen bonding contact among the hydrogen on N(2) with O(1) with bond lengths of d= 2.148 \u0026Aring;. The corresponding bond angle is O(1)∙∙∙H(2A)-N(2) = 167.47\u0026deg;.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.2.3. Complex\u003c/em\u003e\u003c/strong\u003e\u003cem\u003e\u0026nbsp;\u003cstrong\u003e[Zn(2-AEP)(Cl)\u003csub\u003e2\u003c/sub\u003e]\u0026nbsp;\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e\u003cem\u003e3\u003c/em\u003e\u003c/strong\u003e: Analysis from the single crystal showed that complex \u003cstrong\u003e3\u003c/strong\u003e grows in the monoclinic, P21/a space group. The structural diagram of the complex was revealed in Figure 2. The asymmetric unit in \u003cstrong\u003e3\u003c/strong\u003e comprises of one molecule of 2-AEP ligand and two chloride ions. Zinc(II) ion is occupied by one bidentate amine that is pyridine nitrogens from 2-AEP and two chloride to form distorted tetrahedral coordination geometry. The mean distance of the Zn\u0026ndash;N is 2.045 \u0026Aring; (Table 3) is matching with documented mononuclear zinc(II) amine complexes [16]. Two hydrogen bonds were formed between two hydrogens on N(1) with two chloride ions Cl(1) and Cl(2). The bond lengths are d= 2.497 \u0026Aring; [Cl(1)-H(A)], d= 2.548 \u0026Aring; [Cl(2)-H(B)] and bond angles are Cl(1)∙∙∙H(A)-N(1) = 148.14\u0026deg; and Cl(2)∙∙∙H(B)-N(1) = 164.32\u0026deg; Overall the structure was stabilized by hydrogen bonding interactions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.2.4. Complex\u0026nbsp;[Zn(2-AEP)\u003csub\u003e2\u003c/sub\u003e](ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e4\u003c/em\u003e\u003c/strong\u003e: It was evident from the single crystal data that complex \u003cstrong\u003e4\u003c/strong\u003e develops in the monoclinic,\u0026nbsp;P21/n. space group. The compound diagram is illistrated in Figure 2. In complex \u003cstrong\u003e4\u003c/strong\u003e, the asymmetric unit contains two molecule of 2-AEP ligand and two perchlorate molecules. Zinc(II) ion is occupied by one primary amine and pyridine nitrogens from two 2-AEP ligands to form distorted tetrahedral coordination geometry. The average bond distance of the Zn\u0026ndash;N is 2.009 \u0026Aring; (Table 2) is an consistent with published mononuclear homoleptic zinc(II) amine complexes [16]. The structure is further stabilized by several hydrogen bonds between the hydrogens on aliphatic amine nitrogens N(2), and the oxygens of perchlorate and water to stabilize the structure. Among them few hydrogen bonding were explained below, the hydrogen on N(8) with O(1) and N(5) with O(5) bond length of d= 2.590 \u0026Aring; and d= 2.503 \u0026Aring; and bond angles are O(1)∙∙∙H(A)-N(8) = 147.33\u0026deg; and O(5)∙∙∙H(B)-N(5) = 122.56\u0026deg;; hydrogen on N(5) with O(11) and N(5) with O(12) bond length of d= 2.588 \u0026Aring; and d= 2.380 \u0026Aring; and bond angles are O(11)∙∙∙H(A)-N(5) = 147.18\u0026deg; and O(12)∙∙∙H(B)-N(5) = 132.95\u0026deg;. In addition, oxygen atoms of water molecules also formed the hydrogen bonding with amine nitrogens. Hydrogen on N(8) with O(2) and N(5) with O(2) bond length of d= 2.359 \u0026Aring; and d= 2.474 \u0026Aring; and bond angles are O(2)∙∙∙H(A)-N(8) = 151.93\u0026deg; and O(2)∙∙∙H(B)-N(5) = 147.43\u0026deg;; hydrogen on N(5) with O(13) and N(11) with O(13) bond length of d= 2.513 \u0026Aring; and d= 2.545 \u0026Aring; and bond angles are O(13)∙∙∙H(A)-N(5) = 150.82\u0026deg; and O(12)∙∙∙H(B)-N(11) = 145.40\u0026deg;. The packing diagram shows 2-D sheet arrangement of the complex (Figure 4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.2.5. Complex\u0026nbsp;[Zn(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e]\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e5\u003c/em\u003e\u003c/strong\u003e: From the single crystal data, it displayed that compound \u003cstrong\u003e5\u003c/strong\u003e forms in the triclinic,\u0026nbsp;P-1\u0026nbsp;space group. The schematic diagram of \u003cstrong\u003e5\u003c/strong\u003e is depicted in Figure 2. In complex \u003cstrong\u003e5\u003c/strong\u003e, the asymmetric group is made up of one molecule of 2-AEP ligand and two triphenylacetate molecules. The shape of zinc(II) ion in \u003cstrong\u003e2\u003c/strong\u003e possesses twisted square pyramidal. This coordination is furnished by one bidentate amine nitrogens from 2-AEP, along with four oxygen atoms from two triphenylacetate molecules to the copper(II) ion. The average length of the Cu\u0026ndash;N is 2.045 \u0026Aring; (Table 2), which is comprable with reported measurements for other mixed ligand zinc(II) diamine and carboxylate complexes [15]. The structure is further strengthened by various hydrogen bonds connecting \u0026nbsp;between hydrogen on N(2) with O(4) and N(4) with O(8) bond length of d= 2.245 \u0026Aring; and d= 2.286 \u0026Aring; and bond angles are O(4)∙∙∙H(A)-N(2) = 129.13\u0026deg; and O(8)∙∙∙H(B)-N(4) = 145.57\u0026deg;. Overall two different H-bonds froms from the hydrogens on N(2) of 2-AEP and the oxygens of triphenyl acetate stabilize the complex.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1.\u0026nbsp;\u003c/strong\u003e An overview of crystal and refinement information of complexes \u003cstrong\u003e1\u0026ndash;5\u0026nbsp; \u0026nbsp; \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"714\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameters\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e\u003cstrong\u003e1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e\u003cstrong\u003e4\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eCCDC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e2256235\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e2256236\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e2256239\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e2256237\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e2256238\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eMoleculr formula\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003eC\u003csub\u003e21\u003c/sub\u003eH\u003csub\u003e20\u003c/sub\u003eCuN\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003eC\u003csub\u003e47\u003c/sub\u003eH\u003csub\u003e38\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003eCuO\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003eC\u003csub\u003e7\u003c/sub\u003eH\u003csub\u003e10\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003eZnC\u003csub\u003el2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003eC\u003csub\u003e14\u003c/sub\u003eH\u003csub\u003e20\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003eZnO\u003csub\u003e8\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003eC\u003csub\u003e47\u003c/sub\u003eH\u003csub\u003e38\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003eZnO\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eMolecular weight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e427.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e760.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e258.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e508.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e762.22\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eCrystal system\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003eMonoclinic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003eTriclinic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003eMonoclinic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003eMonoclinic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003eTriclinic\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eSpace group, Z\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003eP 2\u003csub\u003e1\u003c/sub\u003e, 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003eP-1, 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003eP121/a1, 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003eI12/a1, 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003eP-1, 2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003ea (\u0026Aring;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e10.570(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e8.994(10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e9.0461(10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e15.1218(10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e9.8521(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eb (\u0026Aring;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e8.848(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e13.859(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e12.9316(11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e14.6255(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e18.7675(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003ec (\u0026Aring;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e11.793(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e16.303(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e9.3261(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e19.4598(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e20.6444(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003e\u0026alpha; (⁰)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e69.537(14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e84.980(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003e\u0026beta; (⁰)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e115.32(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e80.256(11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e112.156(11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e112.358(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e84.280(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003e\u0026gamma; (⁰)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e85.732(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e89.422(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eV (\u0026Aring;\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e997.0(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e1876.2(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e1010.42(1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e3980.3(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e3783.5(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eTemperature (K)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e293(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e298(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e298(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e298(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e293(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003e\u0026lambda; (\u0026Aring;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e0.71073\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e0.71073\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e0.71073\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e0.71073\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e0.71073\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eD\u003csub\u003ec\u003c/sub\u003e (mg/m\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e1.4255\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e1.342\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e1.699\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e1.698\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e1.344\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003e\u0026micro; (mm\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e1.124\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e0.630\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e2.907\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e1.553\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e0.697\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eRefl. Collected\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e3353\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e8486\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e2346\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e6377\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e17422\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eReflections used\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e2219\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e2844\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e1527\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e23155\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e11673\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eNo.of refined parameters\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e254\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e470\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e109\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e323\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e970\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\" valign=\"top\"\u003e\n \u003cp\u003e\u003csup\u003ea\u003c/sup\u003eR\u003csub\u003e1\u003c/sub\u003e [1 \u0026gt; 2s(I)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e0.0846\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e0.1195\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e0.0574\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e0.0745\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e0.0444\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\" valign=\"top\"\u003e\n \u003cp\u003e\u003csup\u003eb\u003c/sup\u003ewR\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e0.2240\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e0.2858\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e0.1457\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e0.2138\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e0.0935\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"18.067226890756302%\"\u003e\n \u003cp\u003eGoodness \u0026ndash;of-fit\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.966386554621849%\"\u003e\n \u003cp\u003e1.031\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.406162464985995%\"\u003e\n \u003cp\u003e0.956\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.126050420168067%\"\u003e\n \u003cp\u003e0.930\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.207282913165265%\"\u003e\n \u003cp\u003e0.923\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.22689075630252%\"\u003e\n \u003cp\u003e1.015\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003eR\u003csub\u003e1\u003c/sub\u003e=\u0026Sigma;||F\u003csub\u003eo\u003c/sub\u003e| -|F\u003csub\u003ec\u003c/sub\u003e||/\u0026Sigma;|F\u003csub\u003eo\u003c/sub\u003e|, \u003csup\u003eb\u003c/sup\u003ewR\u003csub\u003e2\u003c/sub\u003e=|\u0026Sigma;\u003csub\u003ew\u003c/sub\u003e(|F\u003csub\u003eo\u003c/sub\u003e|\u003csup\u003e2\u003c/sup\u003e-|F\u003csub\u003ec\u003c/sub\u003e|\u003csup\u003e2\u003c/sup\u003e)|/\u0026Sigma;|w|(F\u003csub\u003eo\u003c/sub\u003e)\u003csup\u003e2\u003c/sup\u003e|\u003csup\u003e1/2\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u003c/strong\u003e Significant bond parameters of complexes \u003cstrong\u003e1\u003c/strong\u003e-\u003cstrong\u003e2\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"596\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003eComplex \u003cstrong\u003e1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.36241610738255%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond length (\u0026Aring;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"70.63758389261746%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond angle (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-N1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e1.973(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e95.0(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e160.5(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e2.046(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-O1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e106.3(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Cu-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e104.4(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-O1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e2.546(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e162.9(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO1-Cu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e56.6(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e1.972(10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e89.53(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO1-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e98.8(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e1.980(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e105.3(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO1-Cu-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e138.9(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e2.591(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Cu-O1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e98.0(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO2-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e91.5(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Cu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e89.7(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO2-Cu-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e89.2(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003eComplex \u003cstrong\u003e2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.36241610738255%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond length (\u0026Aring;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"70.63758389261746%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond angle (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-N1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e1.994(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e94.0(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Cu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e162.9(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e2.020(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-O1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e95.9(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e90.2(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-O1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e2.429(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e90.8(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO1-Cu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e57.94(19)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e2.014(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e164.1(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO1-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e97.7(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.100671140939598%\" valign=\"top\"\u003e\n \u003cp\u003eCu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.261744966442953%\" valign=\"top\"\u003e\n \u003cp\u003e1.920(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Cu-O1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.114093959731544%\" valign=\"top\"\u003e\n \u003cp\u003e105.2(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.107382550335572%\" valign=\"top\"\u003e\n \u003cp\u003eO2-Cu-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.28187919463087%\" valign=\"top\"\u003e\n \u003cp\u003e89.6(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3.\u003c/strong\u003e Significant bond parameters of complexes \u003cstrong\u003e3-5\u003c/strong\u003e \u0026nbsp;\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"596\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003eComplex \u003cstrong\u003e3\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.36241610738255%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond length (\u0026Aring;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"70.63758389261746%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond angle (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn-N1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.042(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Zn-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e97.63(16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Zn-Cl2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e115.8(13)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.049(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Zn-Cl1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e115.62(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eCl1-Zn-Cl2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e113.42(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn-Cl1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.234(14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Zn-Cl2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e106.24(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn-Cl2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.236(14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Zn-Cl1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e106.24(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003eComplex \u003cstrong\u003e4\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.36241610738255%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond length (\u0026Aring;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"70.63758389261746%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond angle (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn1-N1A\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e1.85(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1A-Zn1-N1B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e122.5(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN3B-Zn2-N4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e98.62(18)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn1-N1B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.10(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1A-Zn1-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e117.7(14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN3B-Zn2-N4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e117.03(19)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;Zn1-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.023(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1A-Zn1-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e94.2(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN3B-Zn2-N3B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e123.0(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn2-N3B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e1.983(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Zn1-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e103.0(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN4-Zn2-N4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e101.3(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn2-N4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.046(4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1B-Zn1-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e115.6(10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"100%\" colspan=\"6\" valign=\"top\"\u003e\n \u003cp\u003eComplex \u003cstrong\u003e5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.36241610738255%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond length (\u0026Aring;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"70.63758389261746%\" colspan=\"4\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eBond angle (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn1-N1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.109(19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Zn1-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e95.18(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN3-Zn2-N4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e95.44(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn1-N2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.010(18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Zn1-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e99.11(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN3-Zn2-O5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e99.86(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn1-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e1.9446(15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Zn1-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e153.6(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN3-Zn2-O7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e155.94(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn1-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.408(18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN1-Zn1-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e96.5(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN3-Zn2-O8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e99.36(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn1-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.009(15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Zn1-O2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e123.03(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN4-Zn2-O5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e134.93(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn2-N3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.083(18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Zn1-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e94.97(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN4-Zn2-O7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e88.32(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn2-N4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.008(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eN2-Zn1-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e123.52(8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eN4-Zn2-O8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e116.11(9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn2-O5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e1.964(17)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eO2-Zn1-O3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e95.61(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eO5-Zn2-O7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e94.06(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn2-O7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.430(17)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eO2-Zn1-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e109.17(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eO5-Zn2-O8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e102.86(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"13.758389261744966%\" valign=\"top\"\u003e\n \u003cp\u003eZn2-O48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e2.008(15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.13422818791946%\" valign=\"top\"\u003e\n \u003cp\u003eO3-Zn1-O4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.604026845637584%\" valign=\"top\"\u003e\n \u003cp\u003e57.76(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.12751677852349%\" valign=\"top\"\u003e\n \u003cp\u003eO7-Zn2-O8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.771812080536913%\" valign=\"top\"\u003e\n \u003cp\u003e58.15(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"3. DFT Studies","content":"\u003cp\u003eDensity functional theoretical (DFT) [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e17\u003c/span\u003e] studies has been performed using B3LYP method. For non metal 6-31G* and for copper atom LANL2DZ basis sets were used. The optimized energies and geometries of complexes \u003cb\u003e1\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e are depicted in the Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. FMOs of complexes i.e., HOMO and LUMO (highest occupied and lowest unoccupied) molecular orbitals are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e, indicating that majority of the electron cloud in HOMO resides on the carboxylate aromaric rings in \u003cb\u003e1, 2\u003c/b\u003e and \u003cb\u003e5\u003c/b\u003e; chlorides in \u003cb\u003e3\u003c/b\u003e; Pyridine ring in \u003cb\u003e4\u003c/b\u003e;. HOMO\u0026ndash;LUMO energy differences in copper(II) compounds 4.55 eV (\u003cb\u003e1\u003c/b\u003e) and 4.81 eV (\u003cb\u003e2\u003c/b\u003e), and in zinc(II) complexes are 3.93 eV (\u003cb\u003e3\u003c/b\u003e), 0.54 eV (\u003cb\u003e4\u003c/b\u003e), 4.55 eV (\u003cb\u003e5\u003c/b\u003e) respectively. Complex \u003cb\u003e4\u003c/b\u003e shoud be more reactive compared with other complexes because of the least amount of energy between the HOMO and LUMO. Overall, copper(II) complexes have little higher energy gaps than zinc(II) complexes.\u003c/p\u003e "},{"header":"4. Compounds characterization","content":"\u003cdiv id=\"Sec22\" class=\"Section2\"\u003e\n \u003ch2\u003e4.1. UV-Vis data\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eThe UV absorption diagram of complexes \u003cstrong\u003e1\u003c/strong\u003e\u0026ndash;\u003cstrong\u003e5\u003c/strong\u003e have been acquired within the 200\u0026ndash;900 nm range and delineated in Fig. \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e. This study suggested that the copper(II) cores in \u003cstrong\u003e1\u003c/strong\u003e and \u003cstrong\u003e2\u003c/strong\u003e showed bands in the lower energy region [\u0026lambda;max, nm; (\u0026epsilon;, M\u003csup\u003e-1\u003c/sup\u003e cm\u003csup\u003e-1\u003c/sup\u003e)] at 679 (122) and 698 (206) corresponding to d-d transitions of distorted octahedral geometry and distorted square pyramidal geometry respectively [\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e]. Zinc(II) complexes displayed higher energy bands [\u0026lambda;max, nm; (\u0026epsilon;, M\u003csup\u003e-1\u003c/sup\u003e cm\u003csup\u003e-1\u003c/sup\u003e)] at 207 (138), 260 (138) in \u003cstrong\u003e3\u003c/strong\u003e; 207 (138), 260 (138) and 326 (138), 339 (138) in \u003cstrong\u003e4\u003c/strong\u003e due to \u0026pi;-\u0026pi;* transitions and charge transfer transitions respectively; 238 (138) and 259 (138) in \u003cstrong\u003e5\u003c/strong\u003e attributed to \u0026pi;-\u0026pi;* transitions [\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec23\" class=\"Section2\"\u003e\n \u003ch2\u003e4.2. Infrared analysis\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eThe FT-IR graph of complexes \u003cstrong\u003e1\u003c/strong\u003e\u0026ndash;\u003cstrong\u003e5\u003c/strong\u003e were carried out in the 400\u0026ndash;4000 cm\u003csup\u003e-1\u003c/sup\u003e region. The complexes \u003cstrong\u003e1\u003c/strong\u003e\u0026ndash;\u003cstrong\u003e5\u003c/strong\u003e exhibit distinctive broad sachet at 3316\u0026ndash;3483 cm\u003csup\u003e-1\u003c/sup\u003e relating to \u0026nu;\u003csub\u003e(NH2)\u003c/sub\u003e bound to the metal centers [\u003cspan class=\"CitationRef\"\u003e19\u003c/span\u003e]. The sharp bands observed at 3057\u0026ndash;3253 cm\u003csup\u003e-1\u003c/sup\u003e, are attributed to \u0026nu;\u003csub\u003e(C=CH2)\u003c/sub\u003e vibrations of the aromating rings. Additionally, sharp bands at 2831\u0026ndash;2956 cm\u003csup\u003e-1\u003c/sup\u003e, are assigned to \u0026nu;\u003csub\u003e(C-CH2)\u003c/sub\u003e vibrations of the aliphatic methylene. The sharp bands at 1441\u0026ndash;1601 cm\u003csup\u003e-1\u003c/sup\u003e, are responsible for \u0026nu;\u003csub\u003e(C=C, C=N)\u003c/sub\u003e vibrations of the aromatic (BA and TPAA) and pyridine rings. Apart from these bands, in complex \u003cstrong\u003e2\u003c/strong\u003e a wide intense band was displayed at 1074 cm\u003csup\u003e-1\u003c/sup\u003e which corresponding to triply degenerate asymmetric vibrational mode of the tetrahedral ClO\u003csub\u003e4\u003c/sub\u003e anion; band at 947 cm\u003csup\u003e-1\u003c/sup\u003e, due to triply degenerate symmetric stretching and sharp band at 625 cm\u003csup\u003e-1\u003c/sup\u003e, which is because of triply degenerate asymmetric bending frequency of the ClO\u003csub\u003e4\u003c/sub\u003e anion. Furthermore, in compounds \u003cstrong\u003e1\u003c/strong\u003e\u0026ndash;\u003cstrong\u003e3\u003c/strong\u003e, intense bands were appeared at around 1596\u0026ndash;1602 cm\u003csup\u003e-1\u003c/sup\u003e ascribed to carboxylate asymmetric vibrational frequency. These stetching frequencies are matching with the reported values [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec24\" class=\"Section2\"\u003e\n \u003ch2\u003e4.3. EPR analysis\u003c/h2\u003e\n \u003cp\u003eThe ESR diagram of mixed ligand copper(II) complexes \u003cstrong\u003e1\u003c/strong\u003e and \u003cstrong\u003e2\u003c/strong\u003e were collected in acetonitrile solvent with a magnetic field potential in the range 0-6000 G (Fig. \u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e ). The obtained EPR diagram of complex \u003cstrong\u003e1\u003c/strong\u003e exhibits an isotropic character with a wide signal demonstrating that the copper(II) ion in distorted octahedral coordination shape with g\u003csub\u003eiso\u003c/sub\u003e = 2.041. Conversely, complex \u003cstrong\u003e2\u003c/strong\u003e showed two signs at an ambient temperature with g\u003csub\u003e||\u003c/sub\u003e = 2.304 and g\u003csub\u003e\u0026perp;\u003c/sub\u003e = 2.431, representing that the copper(II) ion is in twisted square pyramidal coordination geometry. The observed g\u003csub\u003e||\u003c/sub\u003e and g\u003csub\u003e\u0026perp;\u003c/sub\u003e measurements closely match with various mixed ligand Cu(II) complexes in the literature reports [\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e"},{"header":"5. Binding Studies","content":"\u003cdiv id=\"Sec26\" class=\"Section2\"\u003e \u003ch2\u003e5.1. DNA interaction activities by UV-Vis\u003c/h2\u003e \u003cp\u003eThe binding capability of mononuclear copper(II) and zinc(II) compounds \u003cb\u003e1\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e towards CT-DNA were explored using an electronic spectrophotometer. This is one of the basic and straightforward approaches to identify the interactions of metal compounds towards nucleic acids (here is CT-DNA). The ternary complexes concentration was held constant while the CT-DNA concentration varied between 0-160 \u0026micro;M for the absorbance analysis. For copper complexes \u003cb\u003e1\u003c/b\u003e and \u003cb\u003e2\u003c/b\u003e, a hypsochromic shift (a progressive decrease in absorbance band intensity) were seen with every single addition of CT-DNA. Incase of zinc(II) complexes \u003cb\u003e3\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e, hyperchromic shift was observed (a gradually increase in absorption band intensity) with each single addition of the CT-DNA. The obtained outcomes for complexes \u003cb\u003e1\u003c/b\u003e and \u003cb\u003e4\u003c/b\u003e towards CT-DNA were displyed in Figs.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003ea and \u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003ea, respectively. The subsequent equation was applied to obtaine the binding constants of \u003cb\u003e1\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e[DNA]/|ɛ\u003csub\u003ea\u003c/sub\u003e-ɛ\u003csub\u003ef\u003c/sub\u003e| = [DNA]/|ɛ\u003csub\u003eb\u003c/sub\u003e-ɛ\u003csub\u003ef\u003c/sub\u003e|+1/K\u003csub\u003eb\u003c/sub\u003e|ɛ\u003csub\u003eb\u003c/sub\u003e-ɛ\u003csub\u003ef\u003c/sub\u003e|\u003c/p\u003e \u003cp\u003eIn this case, [DNA] corresponds to the CT-DNA concentration, ɛ\u003csub\u003ea\u003c/sub\u003e, ɛ\u003csub\u003eb\u003c/sub\u003e and ɛ\u003csub\u003ef\u003c/sub\u003e denote the extinction coefficients of complexes moderately interacted to CT-DNA, completely interacted to CT-DNA, and a free metal complex.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe calculation of intrinsic binding efficacy (Kb) values was performed by plotting [DNA]/(ɛ\u003csub\u003ea\u003c/sub\u003e-ɛ\u003csub\u003ef\u003c/sub\u003e) against [DNA]. This yields a straight line whose slope to intercept ratio is equal to the binding constant. The obtained K\u003csub\u003eb\u003c/sub\u003e results for complexes \u003cb\u003e1\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e (0.45\u0026ndash;4.69 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) follows the order, \u003cb\u003e4\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e5\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e3\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e1\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e2\u003c/b\u003e and illustrated in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. The present prepared mixed-ligand mononuclear copper(II) and zinc(II) complexes are not planar structures. Hence, the bulky ethyl groups, phenyl/triphenyl carboxylate groups around copper(II) can interact with CT-DNA through electrostatic or groove method of interactions. Among these complexes, zinc(II) complexes exhibited the highest order of interaction affinities compared to the copper complexes. Moreover homoleptic mononuclear zinc complex \u003cb\u003e4\u003c/b\u003e showed highest binding affinity than zinc (\u003cb\u003e3\u003c/b\u003e \u0026amp; \u003cb\u003e5\u003c/b\u003e) and copper (\u003cb\u003e1\u003c/b\u003e \u0026amp; \u003cb\u003e2\u003c/b\u003e) complexes. This may be because there are two 2-ethyl pyridine rings are coordinated to the metal center which are perpendicular to each other. Two ethyl groups are not in the same plane and interacted with phosphate groups via hydrophobic interaction. Hence it will prevent the interaction of pyridine rings with DNA base pairs. These structural motifs might be well fitted in the binding site, responsible for the groove/electrostatic way of interactions to CT-DNA. The binding affinities of the our heteroleptic copper(II) and zinc(II) complexes displayed similar activity to many other documented mixed ligand copper(II) and zinc(II) complexes in the documents [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In the current study, zinc(II) complex \u003cb\u003e4\u003c/b\u003e exhibited the highest binding affinity (4.69 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) among the all complexes (\u003cb\u003e1\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe current intrinsic binding affinity (K\u003csub\u003eb\u003c/sub\u003e) aligns with those published for various copper(II) and zinc(II) complexes in the literature. Notably, Palaniandavar et al. investigated copper(II) complexes with 2-NO and 3-N-ligands, revealing DNA binding affinity ranging from 3.0 \u0026times; 10\u003csup\u003e3\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 10.0 \u0026times; 10\u003csup\u003e3\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25a]. In another study, same group explored mixed ligand copper(II) complexes, showcasing binding constants spanning from 3.0 \u0026times; 10\u003csup\u003e3\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 2.27 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25b]. Deka and coworkers documented mixed-ligand copper(II) complexes with binding values of 6.3\u0026ndash;7.4 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25c], while Zhao and colleagues explained ternary copper(II) complexes with binding values of 2.4-3 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25d]. Rajarajeswari and co-workers documented phen-based heteroleptic copper(II) complexes with DNA binding affinity (K\u003csub\u003eb\u003c/sub\u003e) values ranging from 0.85 to 1.8 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25e]. Tapan K. Mondal's research group synthesized novel NNO-based copper(II) complexes, revealing DNA binding values in the range of 5.70 \u0026times; 104 M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 2.35 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25f]. In our earlier work, we reported mononuclear homoleptic copper(II) complexes with 1,2-diaminocyclohexane, exhibiting DNA binding affinities ranging from 4.5 \u0026times; 10\u003csup\u003e3\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 4.2 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [10a]. Subsequently, we documented heteroleptic copper(II) complexes using cyclohexadiamine and axial \u003cem\u003eN\u003c/em\u003e-donor ligands, demonstrating Kb values of 2.0 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 16.0 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [10b]. Additionally, Arjmand and co-workers represented a copper(II) complex involving an L-phenylalanine\u0026ndash;DACH conjugate with a binding value of 5.30\u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25g]. Raman and his research group reported copper(II) and zinc(II) complexes using mixed compounds such as schiff base and 1,8-diaminonaphthalene ligand with K\u003csub\u003eb\u003c/sub\u003e values 3.9 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 2.4 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e respectively [21h]. Later, Rahiman et al. demonstrated mononuclear zinc(II) complexes prepared from 2-((2-(piperazin-1-yl)ethylimino) methyl)-4-substituted phenol ligands and their intrinsic binding constants from 1.8 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e \u0026minus;\u0026thinsp;7.9 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25i]. Iqbal et al. documented binding constant 1.34 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for zinc(II) complex containing carboxylate and phenathroline ligand [25j]. Zhu and coworkers reported zinc(II) complex from 2-(1,2,4)triazol-1-yl-isonicotinic acid, showed K\u003csub\u003eb\u003c/sub\u003e 3.36 \u0026times; 10\u003csup\u003e3\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [25k]. Ali et al. synthesized homo and heteroleptic zinc(II) complexes, studied their binding interactions with K\u003csub\u003eb\u003c/sub\u003e values ranging from 1.09 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e \u0026minus;\u0026thinsp;4.24 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e[25l]. Later, same group reported binding constants 1.6 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e \u0026ndash; 7.05 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for zinc(II) complex containing carboxylates (4-(o-toluidino)-4-oxobutanoic acid and 4-(4-nitrophenyl amino)-4-oxobut-2-enoic acid) and \u003cem\u003eN\u003c/em\u003e-donor ligands [25m].\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDNA Binding outcomes of the complexes \u003cb\u003e1\u0026ndash;5\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026times;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS. No\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eComplex\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDNA (k\u003csub\u003eb\u003c/sub\u003e M\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[Cu(2-AEP)(BA)\u003csub\u003e2\u003c/sub\u003e] \u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026times;\" colname=\"c3\"\u003e \u003cp\u003e0.55 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[Cu(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e] \u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026times;\" colname=\"c3\"\u003e \u003cp\u003e0.45 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[Zn(2-AEP)(Cl)\u003csub\u003e2\u003c/sub\u003e] \u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026times;\" colname=\"c3\"\u003e \u003cp\u003e1.62 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[Zn(2-AEP)\u003csub\u003e2\u003c/sub\u003e](ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e \u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026times;\" colname=\"c3\"\u003e \u003cp\u003e4.69 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[Zn(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e] \u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026times;\" colname=\"c3\"\u003e \u003cp\u003e3.16 \u0026times; 10\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec27\" class=\"Section2\"\u003e \u003ch2\u003e5.2. Circular Dichroism Study\u003c/h2\u003e \u003cp\u003eThe circular dichroism (CD) spectroscopic tehnique is an another basic approach for understanding the binding mechanism of both metal compounds or small organic molecules with macromoleules like DNA [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. This analysis will give the valuable information such as secondary structural alterations after compounds binding to CT-DNA. The CD spectrum of free CT-DNA demonstrates a positive band at 277 nm and a negative band at 245 nm which are because of base stacking and helicity, respectively, which are highly sensible to the metal complexes. When these complexes react with DNA by groove mechanism/electrostatic mode of interaction will display an insignificant or no disruption on the base stacking bands of CT-DNA and intercalation progressively raises the intensity of both bands. Complexes \u003cb\u003e1\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e are prepared with CT-DNA at 1/R= [Complex]/[DNA]\u0026thinsp;=\u0026thinsp;0.5 and the CD analysis were carried out at ambient temperature in Tris/HCl buffer with pH 7.4. The spectra confirmed that there is diminutive modifications in both base stacking and helicity bands (Fig.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e11\u003c/span\u003e). These negligible changes in the band intensities, unveiled that the compounds \u003cb\u003e1\u0026ndash;5\u003c/b\u003e interacted and disrupt the helicity of CT-DNA. Our previous investigations have yielded consistent findings in the context of mononuclear complexes involving 1,2-diaminocyclohexane [19a], as well as mixed ligand complexes incorporating DACH and diethyltriamine with N-donor ligands [19b, 19e]. Furthermore, we explored dinuclear complexes of 2-aminoethylpyridine, revealing their binding interactions with CT-DNA [19c]. Parallel results have been reported by other research groups, including Arjmand [25f], Palaniandavar [22a], Mao [26b], and Zeng [26c]. These groups similarly observed analogous behavior in mononuclear simple and mixed ligand complexes, reinforcing the consistency of the observed phenomena in DNA interaction studies. Therefore, these results are strongly supporting the groove binding as described in the literature [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"6. Docking studies","content":"\u003cp\u003eThe interaction between copper(II) and zinc(II) compounds towards DNA was investigated using in silico DNA docking studies. The dodecamer duplex DNA with the sequence d(CGCGAATTCGCG)2 (PDB ID: 1BNA) was used in the study. The results were presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003e, which showed the least energy docked conformation of all complexes. The copper(II) and zinc(II) complexes were found to aligned nicely into the groove binding of DNA [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The study found that copper(II) complexes \u003cb\u003e1\u003c/b\u003e, \u003cb\u003e3\u003c/b\u003e, and \u003cb\u003e4\u003c/b\u003e primarily bind via minor groove interaction, while complexes \u003cb\u003e2\u003c/b\u003e and \u003cb\u003e5\u003c/b\u003e interacted via major groove mechanism. This mode of difference in binding could be attributed to the bulky carboxylate ligands around the metal, which enter specific sites of the DNA. The relative binding energy for the DNA interacted conformations of complexes \u003cb\u003e1\u003c/b\u003e\u0026ndash;\u003cb\u003e5\u003c/b\u003e ranged between \u0026minus;\u0026thinsp;5.0 and \u0026minus;\u0026thinsp;8.2 kcal mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, as listed in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. In our earlier investigations, we determined the relative binding strengths for DNA interacted structures of mixed-ligand copper(II) complexes. Specifically, for complexes involving 1,2-cyclohexadiamine and diethylenetriamine with N-donor axial ligands, the binding energies. Furthermore, the binding efficacy of the current complexes aligns with that of previously reported mononuclear complexes [25g, 28], indicating comparable strength and stability in their interactions with DNA.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDNA docking results\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplex\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDock Score\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMode of binding\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-8.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMinor groove\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-7.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMajor groove\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-5.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMinor groove\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-6.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMinor groove\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-6.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMajor groove\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"7. Catecholase like activity","content":"\u003cp\u003eCatechol oxidase catalyzes catechols to corresponding quinones where two copper centers involve in the reaction mechanism. In general, dinuclear copper(II) complexes show the catecholase like activity since these structural features resemble the active center of the real enzyme. Many research groups have reported numerous dinuclear copper(II) complexes [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] and also few mononuclear copper(II) complexes [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. The 3,5-ditertiary butyl catechol (3,5-DTBC) is a typical model compound for catechol oxidase-like property since it is rapidly transformed into the equivalent quinones (3,5-DTBQ) in the presence of aerial circumstances, which results in the characteristic DTBQ band at 400 nm (=\u0026thinsp;1900 M\u003csup\u003e-1\u003c/sup\u003e cm\u003csup\u003e-1\u003c/sup\u003e). The catecholase analysis of mono nuclear copper(II) complexes \u003cb\u003e1\u003c/b\u003e and \u003cb\u003e2\u003c/b\u003e was performed employing UV-Vis spectroscopy at ambient temperature by adding 18\u0026ndash;90 \u0026micro;L complex solutions in DMF (0.03\u0026ndash;0.15 mM) and 100 \u0026micro;L of 3,5-DTBC in DMF solutions (5 mM). An UV-Vis spectrophotometer was employed to quantity the generation of quinones at a wavelength of about 400 nm. The total volume of complexes and 3,5-DTBC were rigidly maintained at equal volumes (3 mL) at all times.\u003c/p\u003e \u003cp\u003eComplexes \u003cb\u003e1\u003c/b\u003e and \u003cb\u003e2\u003c/b\u003e underwent a kinetic analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003e) by raising the absorbance of 3,5-DTBQ at 400 nm every two minutes. A linear relationship between the initial rate and complex concentration was observed from the plot between rate vs complex concentration which means the system is dependent on the catalyst concentration. The saturation kinetics were noted at high catechol concentrations. The kinetic values V\u003csub\u003emax\u003c/sub\u003e, k\u003csub\u003em\u003c/sub\u003e and k\u003csub\u003ecat\u003c/sub\u003e values for \u003cb\u003e1\u003c/b\u003e and \u003cb\u003e2\u003c/b\u003e complexes were obtained by applying both Michaelis\u0026ndash;Menten equation (Fig.\u0026nbsp;14), a Lineweaver\u0026ndash;Burk method and listed in Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eK\u003csub\u003em\u003c/sub\u003e, V\u003csub\u003emax\u003c/sub\u003e and k\u003csub\u003ecat\u003c/sub\u003e results for complexes \u003cb\u003e1\u003c/b\u003e and \u003cb\u003e2\u003c/b\u003e.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026times;\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eS. No\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eComplex\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eV\u003csub\u003emax\u003c/sub\u003e (M s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eK\u003csub\u003em\u003c/sub\u003e (M)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ek\u003csub\u003ecat\u003c/sub\u003e (s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[Cu(2-AEP)(BA)\u003csub\u003e2\u003c/sub\u003e] \u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026times;\" colname=\"c5\"\u003e \u003cp\u003e2.68 \u0026times; 10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e[Cu(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e \u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026times;\" colname=\"c5\"\u003e \u003cp\u003e2.63 \u0026times; 10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn a recent study conducted in 2023, Samanta et al. investigated copper(II) complexes featuring NNN and NNO tridentate schiff base ligands. Their research demonstrated into the catechol oxidase-like activity of these complexes, revealing Kcat values of 5.1 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 4.52 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and 4.66 \u0026times; 10\u003csup\u003e5\u003c/sup\u003e h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for mononuclear, dinuclear, and polymeric Cu(II) complexes, respectively [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Singha Mahapatra and coworkers reported a mononuclear copper(II) Schiff base compound with a catecholase activity Kcat of 19.87 h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Tapan K. Mondal's research group synthesized novel NNO-based copper(II) complexes, observing catecholase activities in the range of 1.42\u0026times; 10\u003csup\u003e5\u003c/sup\u003e h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 1.82\u0026times; 10\u003csup\u003e5\u003c/sup\u003e h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Ramasamy et al. reported a mononuclear copper(II) complex with a thiosemicarbazone ligand, exhibiting a Kcat of 163.30 h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. The present mononuclear copper(II) complexes demonstrates catecholase activity analogous to that of earlier copper(II) complexes documented in literature [19c, 30\u0026ndash;34].\u003c/p\u003e"},{"header":"8. Conclusions","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eIn the present study, five mononuclear copper(II) and zinc(II) complexes resulting from simple 2-aminoethyl pyridine ligand and carboxylates were prepared and analysed by several physicochemical methods like, elemental study, electrochemical, spectroscopic and single crystal X-ray analysis. Complexes showed distorted octahedral geometry for \u003cb\u003e1\u003c/b\u003e, distorted square pyramidal shape for \u003cb\u003e2\u003c/b\u003e \u0026amp; \u003cb\u003e5\u003c/b\u003e and tetrahedral geometry in the case of \u003cb\u003e3\u003c/b\u003e \u0026amp; \u003cb\u003e4\u003c/b\u003e. UV-Vis spectral analysis, electrochemical techniques, CD technique and docking activities confirmed that all complexes were strongly interacted towards CT-DNA \u003cem\u003evia\u003c/em\u003e groove binding. Homoleptic zinc(II) complex \u003cb\u003e4\u003c/b\u003e showed superior binding efficacy than remaining complexes with the binding affinity follows the order is \u003cb\u003e4\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e5\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e3\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e1\u003c/b\u003e\u0026thinsp;\u0026gt;\u0026thinsp;\u003cb\u003e2\u003c/b\u003e. Mono nuclear heteroliptic copper(II) complexes showed the catecholase like activity and complex \u003cb\u003e1\u003c/b\u003e showed better catecholase activity than \u003cb\u003e2\u003c/b\u003e.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003ePopuri Sureshbabu- data collection, analysis, and interpretation of results, and manuscript preparation.Koyal Pattanaik-Data collection and analysisSuman Bhattacharya-Single crystal XRD data and refinementShahulhameed Sabiah- study conception, design, and manuscript revision\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eS.S. acknowledges SERB-Inida (CRG/2022/004536) for the funding. We thank the Pondicherry University start-up grant to support this work and CIF-Pondicherry University, for the analytical and instrumental facilities. PS is grateful for the SRF from CSIR New Delhi. PS also thanks the University of Oklahoma for financial support. We are grateful to UGC-SAP for mass data and DST-FIST for single-crystal X-ray analysis.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003e(a) Evano G, Blanchard N, Toumi M (2008) Chem Rev 108:3054. (b) Iakovidis I, Delimaris I, Piperakis SM (2011) Mol Biol Int 2011:594529. (c) Drewry JA, Gunning PT (2011) Coord Chem Rev 255:459. (d) Desbouis D, Troitsky IP, Belousoff MJ, Spiccia L, Graham B (2012) Coord Chem Rev 256:897. (e) Allen SE, Walvoord RR, Padilla-Salinas R, Kozlowski MC (2013) Chem Rev 113:6234. (f) Mjos KD, Orvig C (2014) Chem. Rev. 114:4540. (g) Guo XX, Gu DW, Wu Z, Zhang W (2015) Chem Rev 115:1622. (h) Pellei M, Bello FD, Porchia M, Santini C Coord. (2021) Chem Rev 445:214088. (h) Lin Y, Betts H, Keller S, Cariou K, Gasser G (2021) Chem Soc Rev 50:10346. 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(b) Os\u0026oacute;rio REHMB (2012) Inorg Chem 51:1569.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Schemes","content":"\u003cp\u003eScheme 1 is available in the Supplementary Files section\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"transition-metal-chemistry","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tmch","sideBox":"Learn more about [Transition Metal Chemistry](http://link.springer.com/journal/11243)","snPcode":"11243","submissionUrl":"https://submission.nature.com/new-submission/11243/3","title":"Transition Metal Chemistry","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"2-Aminoethylpyridine, mononuclear Copper(II), Zinc(II), DNA binding, catecholase like activity","lastPublishedDoi":"10.21203/rs.3.rs-4173894/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4173894/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMononuclear copper(II) and zinc(II) complexes of composition [Cu(2-AEP)(BA)\u003csub\u003e2\u003c/sub\u003e] \u003cstrong\u003e1,\u003c/strong\u003e [Cu(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e] \u003cstrong\u003e2\u003c/strong\u003e,\u003cstrong\u003e \u003c/strong\u003e[Zn(2-AEP)(Cl)\u003csub\u003e2\u003c/sub\u003e] \u003cstrong\u003e3\u003c/strong\u003e, [Zn(2-AEP)\u003csub\u003e2\u003c/sub\u003e](ClO\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e \u003cstrong\u003e4\u003c/strong\u003e, and [Zn(2-AEP)(TPAA)\u003csub\u003e2\u003c/sub\u003e] \u003cstrong\u003e5\u003c/strong\u003e, were synthesized by using, 2-aminoethylpyridine (2-AEP) as ligand, benzoic acid (BA) and triphenylaceticacid (TPAA) as ancillary ligands. Complexes \u0026nbsp;\u003cstrong\u003e1-5\u003c/strong\u003e were characterized using elemental study, UV-Vis, FT-IR, ESI-MS, and ESR spectroscopy (incase of Cu). Single crystal XRD of complexes revealed \u003cstrong\u003e1\u003c/strong\u003e in octahedral, \u003cstrong\u003e2\u003c/strong\u003e \u0026amp; \u003cstrong\u003e5\u003c/strong\u003e in square pyramidal and \u003cstrong\u003e3\u003c/strong\u003e \u0026amp; \u003cstrong\u003e4\u003c/strong\u003e in tetrahedral geometry. The interactions towards DNA with complexes \u003cstrong\u003e1-5\u003c/strong\u003e were studied by spectral titration, electrochemical techniques, and CD measurements. These complexes were interacted strongly via groove binding with CT-DNA with binding efficacy in the range k\u003csub\u003eb\u003c/sub\u003e = 0.45-4.69 × 10\u003csup\u003e4\u003c/sup\u003e M\u003csup\u003e-1\u003c/sup\u003e. Among the complexes, zinc(II) complex \u003cstrong\u003e4\u003c/strong\u003e showed higher binding affinity than remaining complexes (\u003cstrong\u003e1\u003c/strong\u003e-\u003cstrong\u003e3\u003c/strong\u003e, \u003cstrong\u003e5\u003c/strong\u003e). The binding affinity order is \u003cstrong\u003e4\u003c/strong\u003e \u0026gt; \u003cstrong\u003e5\u003c/strong\u003e \u0026gt; \u003cstrong\u003e3\u003c/strong\u003e \u0026gt; \u003cstrong\u003e1\u003c/strong\u003e \u0026gt; \u003cstrong\u003e2\u003c/strong\u003e. In addition, copper(II) complexes (\u003cstrong\u003e1\u003c/strong\u003e and \u003cstrong\u003e2\u003c/strong\u003e) showed catecholase like activity with reaction rate, k = 2.68 × 10\u003csup\u003e-3\u003c/sup\u003e M s\u003csup\u003e-1\u003c/sup\u003e and 2.63 × 10\u003csup\u003e-3\u003c/sup\u003e M s\u003csup\u003e-1\u003c/sup\u003e respectively.\u003c/p\u003e","manuscriptTitle":"Mononuclear Cu(II), Zn(II) Complexes with 2-Aminoethylpyridine and carboxylate ligands: Structure, DFT, DNA binding, Docking and Catecholase Like Activities","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-05 15:31:56","doi":"10.21203/rs.3.rs-4173894/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-04-02T16:25:57+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-04-02T16:12:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-04-02T16:00:49+00:00","index":"","fulltext":""},{"type":"submitted","content":"Transition Metal Chemistry","date":"2024-03-27T06:34:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"transition-metal-chemistry","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tmch","sideBox":"Learn more about [Transition Metal Chemistry](http://link.springer.com/journal/11243)","snPcode":"11243","submissionUrl":"https://submission.nature.com/new-submission/11243/3","title":"Transition Metal Chemistry","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"0385a180-bddb-408b-8875-1a31392e0a3c","owner":[],"postedDate":"April 5th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-04-05T17:20:14+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-05 15:31:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4173894","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4173894","identity":"rs-4173894","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}