Cu(Ii)(Salophen-Phome)Complex: Greener Pasture Biological Study, Xrd/Hsa-Interactions, and Mep

PhOMe-salophen (1b) (salophen= N,N-bis-(salycilidene)-1,2-phenylenediamine with two tert-butyl on each ring) and  Cu(II)) complex with PhOMe-salophen (1c) were synthesized and characterized using various tools, including XRD for the Cu(II)) complex. The copper complex was obtained by Cu2+ templated approach using 1b.PhOMe-salophen (1b) was obtained in reasonably high yield using a mixture of the Schiff-base, 1a, Pd(OAc)2, PPh3, Na2CO3, 4-methoxy phenylboronic acid in benzene. We focus in this work on the structural and electronic properties of the Cu–Schiff base complex. The tetra-coordinate τ4 index was calculated, indicating almost a perfect square planner in agreement with XRD results. MEP reveals the maximum positive regions in 1cassociated with the azomethine and methoxyphenyl C─H bonds with an average value of 0.03 a.u.Hirshfeld surface analysis (HSA) was also studied to highlight the significant inter-atomic contacts and their percentage contribution through 2D Fingerprint plot. In a fair comparative molecular docking study, 1b and 1c were docked together with (N-{[(5-methylisoxazol-3-yl)- carbonyl]alanyl}-l-valyl-N1-((1R,2Z)-4-(benzyloxy)-4-oxo-1-{[(3R)-2-oxopyrrolidin-3-yl]methyl}but-2-enyl)-l-leucinamide) N3 against main protease Mpro, (PDB code7BQY) using the same parameters and conditions. Worth pointing out here that using free energy in silco molecular docking approach aims to rank the title molecules compared to the well-known inhibitor, N3. The binding scores of 1b, 1c, N3 are -7.8, -9.0 and -8.4 kcal/mol, respectively. These preliminary results propose that ligands merit further study in the context of possible therapeutic agents for COVID-19.