Solvent-Mediated Hydrogen Bond-driven Self-Assembly Materials for Dynamic Phosphorescence Emission

Solvent-Mediated Hydrogen Bond-driven Self-Assembly Materials for Dynamic Phosphorescence Emission | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 28 August 2025 V1 Latest version Share on Solvent-Mediated Hydrogen Bond-driven Self-Assembly Materials for Dynamic Phosphorescence Emission Authors : Ziyi Lu , Bin Li , Wensheng Xu , Jiang Liu , Run Wang , Ligong Chen 0000-0002-3442-5694 [email protected] , and Bowei Wang Authors Info & Affiliations https://doi.org/10.22541/au.175634649.93463949/v1 151 views 63 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Organic room-temperature phosphorescence (RTP) materials with tunable emission intensity, lifetime, and quantum yield are vital for optoelectronics, bioimaging, and anti-counterfeiting. Herein, a facile strategy enables continuous RTP adjustment through hydrogen bonding-driven self-assembly of melamine (MA), cyanuric acid (CA), and 3,5-dicarboxyphenylboronic acid (IB, organic phosphor), mediated by protic (H 2 O) and aprotic (DMSO) solvents. Interestingly, DMSO facilitates the formation of a disordered, low-crystallinity assembly (MC-IB 0 ) with weak RTP, while H 2 O promotes the formation of an ordered, high-crystallinity framework (MC-IB 100 ) with strong RTP. Notably, increasing water content (from 0% to 100%) of the mixed solvent of H 2 O and DMSO could continuously improves the crystallinity and RTP performance of the material, with phosphorescence lifetime extending from 0.81 s to 1.18 s and phosphorescence quantum yield rising from 1.73% to 11.93%. Solvent ultrasonic treatment enables the reversible switching between MC-IB 0 and MC-IB 100 . The materials exhibit excellent performance in water content detection, pH sensing, and information storage. This work provides a simple pathway for dynamically responsive RTP materials, expanding their application scope. Solvent-Mediated Hydrogen Bond-driven Self-Assembly Materials for Dynamic Phosphorescence Emission Ziyi Lu 1 , Bin Li 1 , Wensheng Xu 1 , Jiang Liu 1 , Run Wang 1 , Ligong Chen 12 *, Bowei Wang 12 * 1 School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China. 2 Zhejiang Institute of Tianjin University, Shaoxing 312300, PR China * Co-corresponding authors. E-mail: [email protected] (L.C.); [email protected] (B.W.). Keywords: room-temperature phosphorescence materials, hydrogen-bonded frameworks, solvent-mediated assemblies, boronic acid groups Abstract text. Organic room-temperature phosphorescence (RTP) materials with tunable emission intensity, lifetime, and quantum yield are vital for optoelectronics, bioimaging, and anti-counterfeiting. Herein, a facile strategy enables continuous RTP adjustment through hydrogen bonding-driven self-assembly of melamine (MA), cyanuric acid (CA), and 3,5-dicarboxyphenylboronic acid (IB, organic phosphor), mediated by protic (H₂O) and aprotic (DMSO) solvents. Interestingly, DMSO facilitates the formation of a disordered, low-crystallinity assembly (MC-IB 0 ) with weak RTP, while H₂O promotes the formation of an ordered, high-crystallinity framework (MC-IB 100 ) with strong RTP. Notably, increasing water content (from 0% to 100%) of the mixed solvent of H₂O and DMSO could continuously improves the crystallinity and RTP performance of the material, with phosphorescence lifetime extending from 0.81 s to 1.18 s and phosphorescence quantum yield rising from 1.73% to 11.93%. Solvent ultrasonic treatment enables the reversible switching between MC-IB 0 and MC-IB 100 . The materials exhibit excellent performance in water content detection, pH sensing, and information storage. This work provides a simple pathway for dynamically responsive RTP materials, expanding their application scope. 1. Introduction Organic room-temperature phosphorescent (RTP) materials have demonstrated great potential in flexible optoelectronic devices, [1-2] biological imaging, [3-6] information storage and anti-counterfeiting encryption due to their ease of synthesis, tunable structure, and long-life emission. [7-16] To achieve efficient RTP, it is essential to enhance the intersystem crossing (ISC) from the singlet state to the triplet state of the phosphorescent molecule, suppress the non-radiative decay and the quenching of water and oxygen. [17] Recently, the research has mainly focused on host-guest complexation, [18 -20] crystallization induction and H-aggregation, [21-24] aiming to promote ISC and inhibit rapid non-radiative decay. Among them, polymer-based organic RTP materials have attracted extensive attention due to their good processability and flexibility. [25-27] For instance, Cui et al. developed ε-polylysine (ε-PL)-based multicolor RTP materials, where the hydrogen-bond networks of ε-PL matrix contribute to stabilize triplet excitons. [28] Gao et al. constructed polyvinyl alcohol (PVA)-based RTP films with ultralong phosphorescence and multicolor afterglow, relying on the hydrogen bonds between PVA and guest molecules to suppress non-radiative decay. [29] Nevertheless, the hydrogen-bond networks in both ε-PL-based and PVA-based polymer materials are vulnerable to water, thereby leading to the weakening or quenching of phosphorescence in water. Meanwhile, since oxygen quenching plays a more crucial role in the phosphorescence emission process than non-radiative decay, and there are significant differences in the oxygen shielding performance of polymer matrices, it becomes extremely urgent to develop more stable and environmentally tolerant RTP materials. Hydrogen-bonded organic frameworks (HOFs) may address this challenge via their rigid hydrogen bonding networks that will resist the quenching of triplet excitons by oxygen and water, making them promising for stable RTP emission. [30-32] In fact, their rigid frameworks not only suppress the movement of guest molecules but also shield them from quenching by quenchers, thereby maintaining the stable phosphorescence emission of the material at high temperature. Meanwhile, their strong intermolecular hydrogen bonds make them exhibit exceptional water resistance, maintaining stable phosphorescent emission even when dispersed in water. Xia et al. reported some RTP materials with excellent performance in both air and aqueous solutions, which were obtained by using HOFs composed of melamine (MA) and cyanuric acid (CA) as the host matrix (MCA) to confine the phosphor guest. (30) Luo et al. illustrated stable RTP in water, strong acidic and basic medium for more than 10 days by in situ self-assembly of MCA and naphthoic acid. [31] Chen et al. fabricated a series of robust blue RTP materials via assemble phosphors of dimethyl alkoxy isophthalates with MCA in water (H₂O) and dimethyl sulfoxide (DMSO), respectively. [32] However, previous work mainly focused on the assembly process in a single solvent, lacking systematic research on how mixed solvents can dynamically regulate the self-assembly process and the RTP performance. Herein, we achieved dynamic RTP with tunable lifetime and quantum yield via solvent-mediated self-assembly processes. As shown in Figure 1 , 3,5-dicarboxyphenylboronic acid (IB, organic phosphor), MA and CA were self-assembled by hydrogen bonding to form assemblies (MC-IB N , N% = water volume percentage), whose structure and photophysical behavior were dynamically mediated by solvent. Increasing the water volume fraction in DMSO aqueous solution from 0% to 100% drove MC-IB N to be transformed from disordered amorphous state (MC-IB 0 ) to highly ordered crystalline state (MC-IB 100 ). This transformation resulted in the continuous tuning of its phosphorescence lifetime from 0.81 s to 1.18 s and the significant improvement of its phosphorescence quantum yield from 1.73% to 11.93%. Solvent ultrasonic treatment could realize the reversible switching between the morphologies and photophysical properties of MC-IB 0 and MC-IB 100 . We further demonstrated the outstanding performance of MC-IB N in water content detection, pH sensing, and information storage. Our study provided a simple and efficient pathway for fabricating dynamically responsive RTP materials, thereby expanding the application scope of RTP materials. Figure 1. Schematic illustration of solvent-mediated hydrogen bond-driven self-assembly to construct materials with dynamic phosphorescence emission. 2. Results and Discussion 2.1 Preparation and Characterizations of Self-Assembling Materials MC-IB 0 and MC-IB 100 were obtained respectively by self-assembly of IB, MA and CA in DMSO and H₂O. The optimal IB doping mole fraction was 1%, and the resulting MC-IB0.01 displayed the maximal crystallinity and phosphorescence lifetime (Figure S1, Support Information). To investigate the solvent effect on the optical performance, we recorded the afterglow time, the photoluminescence (PL) spectra, phosphorescence spectra, phosphorescence decay lifetime and CIE coordinates of MC-IB 0 and MC-IB 100 . Under 270 nm UV irradiation, MC-IB 100 exhibited a prolonged blue afterglow of 16 s with a phosphorescence lifetime of 1.18 s at 405 nm, while MC-IB 0 showed a weak afterglow of 6 s with a shorter lifetime of 0.81 s (Figure 2A-D, Figure S2). CIE coordinates confirmed dark blue emission for both materials (Figure 2E). To further reveal the phosphorescent source, the photophysical properties of IB, MA, CA were examined (Figure S3). Crucially, the phosphorescence spectra of both MC-IB 0 and MC-IB 100 were similar to each other and matched well with that of the ethanol solution of IB (1.0×10 −5 M) at 77 K, all exhibiting phosphorescence peaks around 400 nm (Figure S3A). Furthermore, their phosphorescence excitation spectra at 298 K (Figure S3B) were identical, showing the same two characteristic excitation wavelengths of 260 nm and 287 nm as IB. However, it is noted that the aggregation of IB caused a redshift in its phosphorescence excitation spectrum (Figure S3B) and emission spectrum (Figure S3C). The phosphorescence excitation wavelengths (Figure S3D) and phosphorescence emission wavelengths (Figure S3E) of MA and CA were not consistent with those of MC-IB 0 and MC-IB 100 , thus ruling out the possibility that MA and CA were the phosphorescent sources. Notably, IB itself did not emit any afterglow, whereas its frozen solution did (Figure S4). These results indicated that the blue afterglow of the assemblies originated from IB confined within the rigid matrix of MA and CA. Figure 2. Photophysical properties of MC-IB 100 and MC-IB 0 . (A) Photoluminescence (PL) spectra, (B) phosphorescence spectra and (C) phosphorescence decay lifetime curves and lifetime histogram under 260 nm UV excitation. (D) Afterglow photographs under 270 nm UV excitation. (E) CIE 1931 coordinates of phosphorescence. To elucidate the mechanism underlying the distinct photophysical behavior, a series of characterizations were carried out. Fourier-transform infrared spectroscopy (FT-IR) showed characteristic shifts in -NH₂ stretching vibrations (Figure 3A). Upon IB addition, the peaks originally at 3382 cm⁻¹ and 3389 cm⁻¹ for MCA 100 and MCA 0 shifted to 3368 cm⁻¹ and 3372 cm⁻¹ respectively, indicating the stronger hydrogen bonding between IB phosphor and MCA matrix of MC-IB 100 . Powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) verified the structure and morphologies of the materials. MC-IB 100 and matrix MCA 100 showed sharp PXRD peaks indicative of high crystallinity (Figure 3B-C) and ordered hexagonal prism structures in SEM images. In contrast, MC-IB 0 and MCA 0 exhibited broad peaks with disordered spherical morphologies (Figure 3G). This demonstrated that the incorporated IB did not disrupt the original hydrogen-bonded network but participated in the co-assembly with the MCA matrix. The single-crystal X-ray diffraction (SCXRD) pattern of MCA 100 and MC-IB 100 revealed a 2D hexagonal layered structure formed by N-H···O and N-H···N hydrogen bonding (Table S1, S2), stacking into a hexagonal columnar crystal (Figure S5A-B) without solvent molecule incorporated. Thermogravimetric (TGA) and differential scanning calorimetry (DSC) analyses showed the decomposition signature of the MCA matrix without residual solvent signals (Figure 3D-F), confirming solvent-free assemblies. Figure 3. Structure characterization of MC-IB and MCA assemblies. (A) FT-IR spectra. (B) PXRD patterns of MCA 100 and MCA 0 . (C) PXRD patterns of MC-IB 100 and MC-IB 0 . (D) TGA curves. (E) First-order derivative of TGA curves. (F) DSC curves. (G) SEM images. 2.2 Solvent-mediated Hydrogen Bond-driven Self-Assembly Materials for Dynamic Phosphorescence Emission Using H₂O/DMSO mixed solvents, a series of self-assembly materials (MC-IB N , N% = water volume percentage) were prepared to probe the relationship between solvent composition and their RTP performance. PL spectra and Phosphorescence spectra showed consistent emission bands of MC-IB N (Figure 4A-B), with phosphorescence emission intensity at 405 nm increasing 50-fold from MC-IB 0 to MC-IB 100 (Figure 4C). Phosphorescence lifetimes extended from 0.81 s to 1.18 s (Figure 4D-E), photoluminescence quantum yields (Φ PL ) increased from 2.06% to 12.53%, and phosphorescence quantum yields increased (Φ RTP ) from 1.73% to 11.93% (Figure 4F, Table S3), representing a good example of continuously regulating the RTP of assembly material via solvent-mediated self-assembly. Under 270 nm UV irradiation, MC-IB N displayed dark blue luminescence with afterglow duration from 6 s (MC-IB 0 ) to 16 s (MC-IB 100 ) (Figure S2), directly indicating a positive correlation between water content and RTP performance. In order to deeply reveal the mechanism of the solvent-mediated phosphorescence, further characterization was conducted. Upon the FT-IR spectra, the -NH₂ stretching vibration peak of MC-IB N shifted towards a lower wavenumber (Figure 4H), indicating the successful preparation of self-assembly materials. Compared to the simulated XRD pattern (Figure S5C), MC-IB N exhibited diffraction peaks at coincident positions, further proving the successful preparation of the materials (Figure 4G). Notably, the diffraction peaks sharpened and intensified from MC-IB 0 to MC-IB 100 , indicating a transition from low-crystalline state to high-crystalline state. This crystallinity improvement was attributed to the solvent-mediated regulation of the hydrogen bond-driven self-assembly process, which promoted orderly molecular stacking. SEM analysis (Figure 4I) further validated this enhanced improvement. With the increase of water content of the mixed solvent, the morphology of MC-IB N gradually transformed from amorphous spherical particles to ordered hexagonal prisms. Control experiments with assemblies (MCA N ) of MA and CA showed identical structural transitions but negligible phosphorescence (Figure S6-S8), confirming that IB phosphor was the essential luminescent source for efficient RTP, while solvent-mediated crystallinity provided a rigid matrix to suppress non-radiative decay. The above collective characterization results demonstrated that the competition of hydrogen bonding between the solvent, MA, CA and IB guest molecule regulated the self-assembly process, the morphology and crystallinity of the assembled material, thereby causing the dynamic changes in phosphorescence. In summary, DMSO helped to form disordered low-crystallinity materials with weak phosphorescence, while water promoted the formation of ordered framework materials with strong RTP emission. Remarkably, the gradually increasing water content could continuously regulate the crystallinity and RTP performance of the material, thereby making the water fraction a precise modulator for RTP emission. Figure 4. Photophysical properties and structures characterization of MC-IB N (N% = water volume percentage). (A) PL spectra and (B) phosphorescence spectra under 260 nm UV excitation. (C) Comparison of fluorescence emission intensity at 350nm (upper) and phosphorescence intensity at 405 nm (lower). (D) Phosphorescence decay lifetime curves and (E) lifetime histograms under 260 nm UV excitation. (F) PL quantum yields (Φ PL ) and phosphorescence quantum yields (Φ RTP ). (G) PXRD patterns. (H) FT-IR spectra. (I) SEM images. 2.3 Solvent-Mediated Reversible Morphology Transformation and Phosphorescence Switching Based on the continuous changes in morphology and crystallinity of MC-IB N , the solvent-mediated reversible conversion between MC-IB 0 and MC-IB 100 was observed. The ultrasonic treatment of MC-IB 0 in water induced the reorganization of its hydrogen bond network, eventually transforming it into the ordered MC-IB 100 (Figure 5A). SEM showed the spherical-to-prismatic morphological change (Figure S9a), while PXRD pattern revealed much sharper diffraction peaks (Figure 5B). Meanwhile, the RTP performance was enhanced: the afterglow duration increased from 6 s to 11 s (Figure S10), the phosphorescence intensity at 405 nm rose from 561 to 1655 (Figure 5C), the lifetime extended from 0.81 s to 1.16 s (Figure 5E). Conversely, the ultrasonic treatment of MC-IB 100 in DMSO induced morphological transformation to amorphous MC-IB 0 (Figure S9B) with reduced crystallinity (Figure 5B), decreased emission intensity (Figure 5C) and a shortened lifetime of 0.65 s (Figure 5E). Through cyclic ultrasonic treatment in water and DMSO, a reversible cyclic change in morphology from disordered state to ordered state could be achieved, thereby resulting in a reversible cyclic change in its phosphorescence performance from weak to strong (Figure 5A), and this reversible process could be repeated at least for 3 cycles (Figure 5D-E). Thermal stability tests showed that the phosphorescent afterglow of MC-IB 0 dispersed in water stayed stable between 298–373 K, with only a slight decrease in intensity at 373 K (Figure S11). This demonstrated a negligible temperature effect on the solvent-mediated reversible RTP phenomenon. In conclusion, this reversible morphological transformation and phosphorescence switching demonstrated the reversibility of hydrogen-bond-driven self-assembly. The amorphous MC-IB 0 was dissolved upon ultrasonic treatment in water and reassembled into highly crystalline MC-IB 100 , while the crystalline MC-IB 100 was dissolved and disassembled into disordered, low-crystallinity MC-IB 0 under ultrasonic treatment in DMSO. Figure 5. Solvent-mediated reversible conversion of MC-IB assemblies. (A) Schematic illustration of the reversible morphological and RTP emission switching by ultrasonic treatment in H₂O/DMSO. (B) PXRD patterns of MC-IB 0 and MC-IB 100 after the first ultrasonic cycle. (C) Phosphorescence spectra of MC-IB 0 and MC-IB 100 after the first ultrasonic cycle. (D) Phosphorescence intensity variations over three ultrasonic cycles. (E) Phosphorescence lifetime variations over three ultrasonic cycles. 2.4 Mechanism of Solvent-Mediated Self-Assembly and Its Regulation on RTP Performance Theoretical calculations were performed to investigate the solvent-mediated RTP mechanism. Surface electrostatic potential (ESP) analysis (Figure S12-13) and binding energy calculations (Table S4) revealed that MA, CA, and IB possessed effective hydrogen bond donors and acceptors, laying the foundation for hydrogen bond-driven self-assembly to yield MC-IB assemblies. Since protic solvent (water) and aprotic solvent (DMSO) differed significantly in hydrogen-bonding capacity, their effects on self-assembly process diverged. Water, with stronger hydrogen bonding capacity, bound to MA, CA and IB with larger binding energies (-561, -531 and -182 kJ mol -1 , respectively) than DMSO (-556, -489, and -129 kJ mol -1 ) (Figure 6A, Table S5). In water, the stronger water-MA, CA and IB binding energies (Figure 6B-i) created the greater competition with inter-MA, CA and IB hydrogen-bonding (Figure 6B-ii), thereby slowed down the self-assembly process and provided sufficient time for their reorientation during crystal growth (Figure 5B-iii). This promoted the formation of ordered, high-crystallinity materials. Conversely, weaker DMSO-MA, CA and IB binding energies (Figure 6B-iv) reduced such competition and rapidly resulted in unregulated disordered assemblies (Figure 6B-v) with low-crystallinity. Consistent with this characteristic of solvent-mediated self-assembly, MC-IB exhibited higher stability in water than in DMSO, as indicated by its stronger binding energy (-23.03 kJ mol -1 ) compared to that in DMSO (-19.81 kJ mol -1 ) (Figure 6C, Table S6-7). This enhanced stability was further supported by the elevated ESP values of MA, CA, and IB in water (Figure 6D, Figure S12-13) and the shorter hydrogen bond length between CA and IB (2.46 Å) relative to DMSO (Figure 6E). These findings confirmed that MC-IB assemblies achieved greater stability in water, aligning with the role of water in promoting ordered structural formation. The solvent-mediated structural change of MC-IB directly modulated RTP performance. MC-IB in water exhibited higher crystallinity and planarity with a molecular planarity parameter (MPP) of 0.027 Å, much lower than the 0.379 Å observed in DMSO (Figure 6F). This ordered structure provided a rigid environment to suppress non-radiative transitions. Meanwhile, MC-IB exhibited a significantly smaller singlet-triplet energy gap (ΔE ST = 0.001 eV) than IB itself (1.360 eV), accompanied by efficient intersystem crossing (ISC) channels and large spin-orbit coupling (SOC) coefficients (Figure 6G). These factors enhanced ISC efficiency and RTP emission. In contrast, with DMSO as solvent, the opposite result was obtained, leading to a decrease in phosphorescence performance. These results conclusively demonstrated that the solvent can mediate the self-assembly process via hydrogen bonding, thereby regulating the crystallinity of the materials and their RTP performance. To further validate this mechanism, methanol (MeOH) and N,N -dimethylformamide (DMF) were selected as model solvent. MeOH exhibited stronger hydrogen-bonding capacity, analogous to water, whereas DMF demonstrated weaker hydrogen-bonding capacity, similar to DMSO. ESP analysis (Figure S14) revealed that IB in MeOH exhibited more pronounced charge separation (-46.20 and 83.75 kcal mol -1 ) compared to DMF (-41.98 and 77.07 kcal mol -1 ), mirroring the trend observed between water and DMSO. MC-IB 0 was separately ultrasonically treated in MeOH and DMF to afford MC-IB 0 @M and MC-IB 0 @F. MC-IB 0 @M exhibited a significant improvement in both phosphorescence intensity and lifetime, whereas MC-IB 0 @F showed a decline in both phosphorescence lifetime and intensity (Figure S15). These findings further confirmed that the hydrogen-bonding capacity of solvent played a crucial role in regulating the RTP performance of the material. Figure 6. Mechanistic investigations of solvent-mediated self-assembly. (A) Binding energies of solvents (H 2 O/DMSO) with MA, CA, and IB molecules. (B) Schematic illustration of solvent-mediated self-assembly mechanism. (C) Binding energies of MC-IB assemblies. (D) Maximum ESP values of MC-IB. (E) Hydrogen bond lengths between CA and IB and (F) Molecular planarity parameter (MPP) of MC-IB in H₂O and DMSO. (G) DFT-calculated energy level distributions and SOC constants of IB and MC-IB. Universality of Solvent-mediated Phosphorescence Regulation To prove the universality of solvent-mediated phosphorescence, 2-borono-1,4-benzenedicarboxylic acid (TB) was assembled with MA and CA in the mixed solvent of DMSO and H 2 O to construct RTP materials (MC-TB N ). Analogous to IB, TB also featured carboxyl and boronic acid groups with high ESP value, which enabled strong hydrogen bonding with MA and CA (Figure S16). Compared with TB itself, MC-TB exhibited efficient ISC channels and a large SOC coefficient (Figure S17), jointly promoting stronger phosphorescence emission. Their PXRD and SEM results showed that the crystallinity exhibited a solvent-dependent characteristic from MC-TB 0 to MC-TB 100 (Figure 7A, Figure S18), similar to that of MC-IB N . Photophysical characterization revealed a phosphorescence peak at 420 nm, with the intensity increasing 48-fold from MC-TB 0 to MC-TB 100 (Figure 7B), phosphorescence lifetimes extending from 0.49 s to 1.21 s (Figure 7C-D) and phosphorescence quantum yield increasing from 1.13% to 18.42% (Table S2). Furthermore, we selected a series of guest molecules containing carboxyl groups, such as 2-methyl-1,4-benzenedicarboxylic acid (TM), 2-hydroxyterephthalic acid (TO), and 5-aminoisophthalic acid (IN), and self-assembled them with MA and CA respectively to enrich the RTP emission performance of assembly materials. Their phosphorescence spectra showed the phosphorescence emission peaks at 435 nm, 465 nm, and 512 nm, respectively (Figure 7E), with decay lifetime of 0.65 s, 1.02 s, and 0.41 s (Figure S19). Upon ceasing UV irradiation, MC-TM, MC-TO, and MC-IN emitted dark blue, blue-green, and pale green afterglow, respectively, consistent with their CIE coordinates (Figure 7F). Figure 7. Photophysical performance of MC-TB N and other RTP assemblies. (A) PXRD patterns of MC-TB N . (B) Phosphorescence spectra of MC-TB N under 280 nm UV excitation. (C) Phosphorescence decay lifetime curves and (D) Lifetime histograms of MC-TB N under 280 nm UV excitation. (E) Phosphorescence spectra of MC-TM, MC-TO and MC-IN. (F) Afterglow photographs and CIE 1931 coordinates of MC-TM, MC-TO and MC-IN. Applications of Solvent-Mediated RTP materials DMSO serves as a critical cryoprotectant in cell preservation protocols, typically used at 5%–10% concentrations to prevent intracellular ice crystal formation during cryopreservation. However, since the water content of DMSO aqueous solution can alter the osmotic pressure and freezing rate of the solution, the fluctuation in water content will significantly affect the survival rate of cells. To address this issue, MC-IB 0 was developed as a luminescent probe for real-time monitoring of water content based on its solvent-responsive phosphorescence characteristics. MC-IB 0 was ultrasonically dispersed in a DMSO aqueous solution with a preset water content (0–100 vol%) to form a stable colloidal suspension. As illustrated in Figure 8A-B, the phosphorescence intensity at 405 nm increased linearly with the increase in water content, and described by the regression equation y =16.09 x +526.56 (R² = 0.9914). Additionally, under 270 nm UV light irradiation, as the water content increased, the color of the MC-IB 0 suspension transformed from a faint blue to a deeper and more intense blue (Figure 8B). Generally, the pH value of aqueous solution may have an impact on the stability of the probe. Thus, we systematically investigated the optical performance of MC-IB 100 in aqueous solutions (pH 2–13). While the emission peak remained unchanged, the phosphorescence intensity exhibited a bell-shaped trend with respect to pH value (Figure 8C-D), increasing linearly from pH 4–7 (R 2 = 0.9987) and decreasing linearly from pH 8–11 (R 2 = 0.9640, Figure 8E), likely due to the disruption of hydrogen bond networks under extreme environmental conditions. Notably, MC-IB 100 maintained a stable RTP lifetime across all pH conditions (Figure 8F), demonstrating its potential for pH sensing applications. Figure 8. Applications of MC-IB assemblies in water content detection and pH sensing. (A) Phosphorescence spectra of MC-IB 0 suspensions in DMSO aqueous solution (0–100 vol% water fraction). (B) Linear fitting of phosphorescence intensity at 405 nm to water content for MC-IB 0 suspensions. (C) Phosphorescence spectra of MC-IB 100 in aqueous solutions with pH value of 2–13. (D) pH-dependent phosphorescence intensity at 405 nm. (E) Linear fitting of phosphorescence intensity at 405 nm to pH value in pH 4–7 and 8–11 ranges. (F) Phosphorescence decay lifetime curves of MC-IB 100 at different pH values. Moreover, based on the materials’ excellent water resistance, MC-IB 100 was blended with sodium alginate (SA) to fabricate a hydrogel film MC-IB@SA. The hydrogel still maintained the luminescent property and was pressure resistant and processable (Figure 9A). Further, colorful anti-counterfeiting patterns were similarly fabricated using the multicolor RTP hydrogels (Figure 9B), that was, the flower was composed of MC-IB@SA, MC-TB@SA and MC-TM@SA, the branch was filled with MC-TO@SA, the leaves were composed of MC-IN@SA. Under 270 nm UV excitation, the pattern exhibited time-resolved luminescence decay: green leaves faded within 2 s, blue-green branches disappeared at 3 s, and dark blue flowers persisted for more than 4 s (Figure 9B). As the luminescence sequence and duration served as unique identification codes, this dynamic emission feature provided a multi-level security guarantee. Compared to the static fluorescence-based anti-counterfeiting, this method resisted photocopying and chemical forgery, and also had the advantage of visual readout without the need for special equipment. Figure 9. Applications of RTP hydrogel film. (A) Ultralong afterglow photograph of flexible MC-IB@SA hydrogel film. (B) Anti-counterfeiting patterns fabricated with multicolor RTP hydrogel films and their time-resolved luminescence under 270 nm UV excitation. 3. Conclusion In conclusion, we have successfully fabricated dynamically responsive RTP materials through hydrogen bond-driven self-assembly of MA, CA, and organic phosphors in DMSO aqueous solutions with varying water contents. The incorporation of phosphors bearing carboxyl and boronic acid groups facilitated efficient ISC process. Crucially, the distinct hydrogen-bonding capacities of protic (H₂O) and aprotic (DMSO) solvents mediated the morphology and photophysical behavior of the assembly. Increasing the water content from 0% to 100% drove the assembly to be transformed from disordered, low-crystallinity state to highly ordered crystalline state. This morphological transformation enabled continuous tuning of the assemblies’ phosphorescence lifetime from 0.81 s to 1.18 s and the phosphorescence quantum yield from 1.73% to 11.93%. Remarkably, reversible switching between these distinct morphological states and their RTP emissions was achieved through solvent-mediated ultrasonic treatment, highlighting the dynamic nature of the hydrogen-bonded assemblies. Mechanistic insights from theoretical calculations revealed that water could form stronger hydrogen bonds with MA, CA and guest molecule than DMSO, compete more effectively and slow down the self-assembly process, thereby contribute to the formation of ordered crystalline assembly. The rigid framework effectively suppressed non-radiative transitions of triplet excitons and accounted for the enhanced RTP performance. The universality of this solvent-mediated regulation strategy was further validated using another phosphor (TB), yielding assemblies with similarly tunable crystallinity and enhanced RTP performance upon increasing water content. Leveraging their solvent-mediated RTP, the materials demonstrated promising applications in water content detection, pH sensing, and information storage. Overall, this work established a facile solvent-mediated hydrogen bond-driven self-assembly strategy for creating dynamically tunable RTP materials, significantly enhancing their potential in sensing, information security, and advanced optoelectronics. While this study offers broad utility, its applicability to diverse phosphor types and complex environments requires further validation. Future efforts should focus on enhancing material stability for real-world sensing and scalable device integration. 4. Experimental Section Reagents and materials All chemical reagents used in the study were purchased from commercial sources without further purification. Melamine (MA) and cyanuric acid (CA) were purchased from Shanghai Meryer Chemical Technology Company. Dimethyl sulfoxide (DMSO), methanol (MeOH) and N, N -dimethylformamide (DMF) were purchased from Anhui Zesheng Technology Company. 3,5-Dicarboxyphenylboronic acid (IB) and Sodium alginate (SA) were purchased from Tianjin Heowns Optide Technology Company. 2-Brono-1,4-benzenedicarboxylic acid (TB), 2-hydroxyterephthalic acid (TO), 2-methyl-1,4-benzenedicarboxylic acid (TM) and 5-aminoisophthalic acid (IN) were purchased from Shanghai Bide Pharmatech Company. Measurements Absolute quantum yields were measured on an Edinburg FLS1000 fluorescence spectrophotometer (Edinburgh Instruments, UK). Steady-state Photoluminescence (PL) spectra, phosphorescence spectra and phosphorescence decay time curves were measured on Hitachi F4700 Photoluminescence Spectrometer. Powder X-ray diffraction (PXRD) patterns were collected on Rigaku Smartlab using Cu Kα radiation at 60 kV, 220 mA. Field emission scanning electron microscopy (SEM) was operated on a Thermo Fisher Scientific Apero microscope. Fourier transform infrared (FT-IR) spectra were collected on a Nicolet 380 FT-IR spectrometer. Thermo-gravimetric analysis (TGA) was performed on NETZSCH TG 209F3 with a heating rate of 10 °C min -1 . Differential scanning calorimetry (DSC) analyses were performed on a HITACHI DSC200 with a heating rate of 10 °C min -1 . A smartphone was used to record luminescent photos of these prepared materials. Single-crystal X-ray diffraction data was collected at 100 K on a Bruker D8 Venture diffractometer employing monochromatized Cu Kα (λ = 1.54178 Å) and Mo Kα radiation (λ = 0.71073 Å). Using Olex2, [33] the crystal structure was resolved with the SHELXT structure solution program using Intrinsic Phasing and refined with the XL refinement package using Least Squares minimization. [34-35] Theory Calculation The energy of Sn and Tn states were obtained with time-dependent density functional theory (TD-DFT) at the B3LYP/6-31G(D) level. The calculations were performed by Gaussian 09, Revision D.01 package in the PowerLeader workstation. [36] Spin-orbit coupling (SOC) of RTP materials was also calculated under B3LYP/6-31G(D) by ORCA 5.0. [37] The optimized electronic structures were analyzed by Multiwfn software. [38] All surface electrostatic potential analysis were rendered by Visual Molecular Dynamics (VMD) software. [39] The binding energy (BE) was computed using the equation: BE(A-B) = E(A-B)–E(A)–E(B). Here, E(A-B), E(A), and E(B) denote the single-point energies of the complex A-B, constituent A, and constituent B, respectively. These energies were calculated via the Gaussian 09 program using the B3LYP/6-31G(D) with Grimme’s D3 empirical dispersion correction including Becke-Johnson damping (EM=GD3BJ keyword). The binding energies and ESP maps of materials in different solvents were calculated using the solute electron density-based implicit solvent model (SMD). Explicit solvent modeling was employed to characterize hydrogen bond length and the molecular planarity parameter (MPP). Preparation of MC-IB N and MCA N MC-IB N (MC-IB 0 , MC-IB 20 , MC-IB 40 , MC-IB 60 , MC-IB 80 , MC-IB 100 ) were prepared in DMSO aqueous solution (water fraction: 0%, 20%, 40%, 60%, 80%, 100%). Taking MC-IB 20 as an example. Solution A: 0.126 g (1 mmol) MA was dissolved in a mixture of 2 mL water and 3 mL DMSO via ultrasonic treatment. Solution B: 0.129 g (1 mmol) CA was dissolved in 5 mL DMSO, then 0.002 g (0.01 mmol) IB was added to the above solution to yield solution B. Solutions A and B were mixed (water fraction is 20%), stirred overnight, centrifuged, washed with ethanol, and vacuum-dried at 60℃ for 12 h. MC-IB 0 , MC-IB 40 , MC-IB 60 , MC-IB 80 , MC-IB 100 were prepared using the identical procedure with adjusted water/DMSO ratios. MCA N was prepared following the same procedure as MC-IB N but without IB doping. MC-IB samples with varying host-guest molar ratios (1:0.001 to 1:1, denoted as MC-IB0.001 to MC-IB1.0) was prepared by adjusting IB dosage as above. MC-TB, MC-TO, MC-TM, MC-IN were prepared following the same procedure as MC-IB, except that the IB guest molecule was changed. Preparation of CA-IB and MA-IB CA-IB: First, 0.129 g (1 mmol) of CA was dissolved in 5 mL water. Then, 0.002 g (0.01 mmol) of IB was added to the solution. After complete dissolution, CA-IB was obtained by gradual cooling. MA-IB was obtained in the same procedure by replacing CA with MA. Ultrasonic treatment Cycle Between MC-IB 0 and MC-IB 100 A complete solvent-mediated ultrasonic cycle was performed as follows: 0.250 g of MC-IB 0 was subjected to ultrasonic treatment in 10 mL water for 12 hours. The mixture was filtered, and the solid was washed with ethanol and dried to obtain MC-IB 100 . The as-obtained MC-IB 100 powder was then subjected to ultrasonic treatment in 10 mL DMSO. After filtration, the solid was washed with ethanol and dried to regenerate MC-IB 0 . Preparation of SA hydrogel film To prepare MC-IB@SA hydrogel films, 0.126 g MA (1 mmol) was first added to 15 mL water in a 100 mL three-necked flask, heated in a 70 ℃ oil bath until fully dissolved, then mixed with 2.000 g SA under continuous stirring to form a MA-SA hydrogel suspension. Separately, 0.129 g CA (1 mmol) and 0.002 g IB (0.01 mmol) were dissolved in 15 mL water, magnetically stirred in a 70 ℃ oil bath for 1 h to prepare the CA-IB solution. This solution was then added dropwise to the MA-SA suspension under vigorous stirring, with stirring continued for 3 h to yield the MC-IB@SA hydrogel. The hydrogel was poured into a plastic mold, which was immersed in a CaCl₂ solution (0.300 g in 10 mL water) overnight to form a film; the film was subsequently washed thoroughly with water. Other hydrogel films were prepared identically. Acknowledgements Funding: Thanks to the Instrumentation Platform of the Advanced Instrumental Analysis Center, School of Chemical Engineering and Technology, Tianjin University, for their support and assistance in the analysis of compound structures and characterization of material dielectric properties. Author contributions: Conceptualization: Z.L. Methodology: Z.L., R.W. Investigation: Z.L., J.L. Visualization: Z.L., W.X. Supervision: Z.L., B.L. Writing—original draft: Z.L., L.C. Writing—review & editing: Z.L., L.C., B.W. Competing interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper . Data Availability Statement All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. References 1. R. Kabe, N. Notsuka, K. Yoshida, C. Adachi, Adv. Mater. 2016 , 28 , 655–660. 2. T. Wang, X. Su, X. Zhang, X. Nie, L. Huang, X. Zhang, X. Sun, Y. Luo, G. Zhang, Adv. Mater. 2019 , 31 , 1904273. 3. X. Zhen, Y. Tao, Z. An, P. Chen, C. Xu, R. Chen, W. Huang, K. Pu, Adv. Mater. 2017 , 29 , 1606665. 4. H. Shi, L. Zou, K. Huang, H. Wang, C. Sun, S. Wang, H. Ma, Y. He, J. Wang, H. Yu, W. Yao, Z. An, Q. Zhao, W. Huang, ACS Appl. Mater. Interfaces 2019 , 11 , 18103–18110. 5. X. Zhen, Y. Tao, Z. An, P. Chen, C. Xu, R. Chen, W. Huang, K. Pu, Adv. Mater. 2017 , 29 , 1606665. 6. Y. Fan, S. Liu, M. Wu, L. Xiao, Y. Fan, M. Han, K. Chang, Y. Zhang, X. Zhen, Q. Li, Z. Li, Adv. Mater. 2022 , 34 , 2201280. 7. Q. Gao, M. Shi, Z. Lu, Q. Zhao, G. Chen, J. Bian, H. Qi, J. Ren, B. Lu, F. Peng, Adv. Mater. 2023 , 35 , 2305126. 8. Y. Gao, W. Ye, K. Qiu, X. Zheng, S. Yan, Z. Wang, Z. An, H. Shi, W. Huang, Adv. Mater. 2023 , 35 , 2306501. 9. J. Zhang, S. Qin, S. Zhang, C. Sun, Y. Ren, L. Zhang, J. Liu, J. Xiao, W. Hu, H. Yang, D. Yang, Adv. Mater. 2024 , 36 , 2305872. 10. S. Yan, F. S. Z. Phua, Y. Li, X. Zhou, D. Jana, G. Liu, W. Q. Lim, W. K. Ong, C. Yang, Y. Zhao, Sci. Adv. 2018 , 4 , eaas9732. 11. Y. Miao, F. Lin, D. Guo, J. Chen, K. Zhang, T. Wu, H. Huang, Z. Chi, Z. Yang, Sci. Adv. 2024 , 10 , eadk3354. 12. F. Nie, D. Yan, Nat. Commun. 2024 , 15 , 9491. 13. L. Gu, H. Shi, M. Gu, K. Ling, H. Ma, S. Cai, L. Song, C. Ma, H. Li, G. Xing, X. Hang, J. Li, Y. Gao, W. Yao, Z. Shuai, Z. An, X. Liu, W. Huang, Angew. Chem. Int. Ed. 2018 , 57 , 8425–8431. 14. X. Wang, H. Ma, M. Gu, C. Lin, N. Gan, Z. Xie, H. Wang, L. Bian, L. Fu, S. Cai, Z. Chi, W. Yao, Z. An, H. Shi, W. Huang, Chem. Mater. 2019 , 31 , 5584–5591. 15. J. Li, Y. Wu, X. Gong, Chem. Sci. 2023 , 14 , 3705–3729. 16. C. Wu, A. C. Wang, W. Ding, H. Guo, Z. L. Wang, Adv. Energy Mater. 2019 , 9 , 1802906. 17. W. Qin, J. Ma, Y. Zhou, Q. Hu, Y. Zhou, G. Liang, Chem. Eng. J. 2020 , 400 , 125934. 18. X. Yang, C. Zhu, F. Cao, Y. Shen, M. Ouyang, Y. Zhang, Angew. Chem. Int. Ed. 2023 , 62 , e202217547. 19. W. Zhu, C. Herok, A. Friedrich, B. Engels, T. B. Marder, Z. M. Hudson, J. Am. Chem. Soc. 2024 , 146 , 31507–31517. 20. J. Guo, Y. Zhao, L. Ma, Y. Wang, Chin. J. Struct. Chem. 2024 , 43 , 100335. 21. L. Bian, H. Ma, W. Ye, A. Lv, H. Wang, W. Jia, L. Gu, H. Shi, Z. An, W. Huang, Nat. Photonics 2019 , 13 , 406–411. 22. Z. Yin, M. Gu, H. Ma, X. Jiang, J. Zhi, Y. Wang, H. Yang, W. Zhu, Z. An, Angew. Chem. Int. Ed. 2021 , 60 , 2086–2091. 23. A. Goudappagouda, A. D. Nidhankar, R. A. Nayak, S. S. Babu, Org. Biomol. Chem. 2021 , 19 , 1004–1008. 24. Z. An, C. Zheng, Y. Tao, R. Chen, H. Shi, T. Chen, Z. Wang, H. Li, R. Deng, X. Liu, W. Huang, Nat. Mater. 2015 , 14 , 685–690. 25. Z. Shen, X. Yan, S. Cui, C. Bo, J. Liu, B. Wang, Y. Li, L. Chen, Dyes Pigment. 2023 , 212 , 111113. 26. X. Lin, Q. Xu, X. Ma, Adv. Opt. Mater. 2022 , 10 , 2101646. 27. Z. A. Yan, X. Lin, S. Sun, X. Ma, H. Tian, Angew. Chem. Int. Ed. 2021 , 60 , 19735–19739. 28. J. Cui, S. H. Ali, Z. Shen, W. Xu, J. Liu, P. Li, Y. Li, L. Chen, B. Wang, Chem. Sci. 2024 , 15 , 4171–4178. 29. G. Li, Z. Shen, W. Xu, J. Liu, Q. Jia, C. Jin, L. Chen, B. Wang, Nano Today 2024 , 59 , 102515. 30. Q. Xia, J. Yu, Z. Chen, Z. Xue, X. Wang, X. Liu, M. Wu, Cell Rep. Phys. Sci. 2023 , 4 , 101427. 31. W. Luo, J. Zhou, Y. Nie, F. Li, S. Cai, G. Yin, T. Chen, Z. Cai, Adv. Funct. Mater. 2024 , 34 , 2401728. 32. Z. Chen, Z. Chen, Y. Zhu, M. Zhuo, G. Yang, X. Wang, M. Wu, Adv. Funct. Mater. 2024 , 34, 2408023. 33. O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard, H. Puschmann, J. Appl. Cryst. 2009 , 42 , 339–341. 34. G. M. Sheldrick, Acta Crystallogr. C Struct. Chem. 2015 , 71 , 3–8. 35. G. M. Sheldrick, Acta Cryst. A 2008 , 64 , 112–122. 36. M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, G. Scalmani, V. Barone, G. A. Petersson, H. Nakatsuji, X. Li, M. Caricato, A. Marenich, J. Bloino, B. G. Janesko, R. Gomperts, B. Mennucci, H. P. Hratchian, J. V. Ortiz, A. F. Izmaylov, J. L. Sonnenberg, D. Williams-Young, F. Ding, F. Lipparini, F. Egidi, J. Goings, B. Peng, A. Petrone, T. Henderson, D. Ranasinghe, V. G. Zakrzewski, J. Gao, N. Rega, G. Zheng, W. Liang, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, K. Throssell, J. A. Montgomery, J. E. Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V. N. Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M. Cossi, J. M. Millam, M. Klene, C. Adamo, R. Cammi, J. W. Ochterski, R. L. Martin, K. Morokuma, O. Farkas, J. B. Foresman, D. J. Fox, Gaussian 09, Revision D.01, Gaussian, Inc., Wallingford, CT 2016 . 37. F. Neese, WIREs Comput. Mol. Sci. 2018 , 8 , e1327. 38. T. Lu, F. Chen, J. Comput. Chem. 2012 , 33 , 580–592. 39. W. Humphrey, A. Dalke, K. Schulten, J. Mol. Graphics 1996 , 14, 33–38. Information & Authors Information Version history V1 Version 1 28 August 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Keywords boronic acid groups hydrogen-bonded frameworks room-temperature phosphorescence materials solvent-mediated assemblies Authors Affiliations Ziyi Lu Tianjin University School of Chemical Engineering and Technology View all articles by this author Bin Li Tianjin University School of Chemical Engineering and Technology View all articles by this author Wensheng Xu Tianjin University School of Chemical Engineering and Technology View all articles by this author Jiang Liu Tianjin University School of Chemical Engineering and Technology View all articles by this author Run Wang Tianjin University School of Chemical Engineering and Technology View all articles by this author Ligong Chen 0000-0002-3442-5694 [email protected] Tianjin University School of Chemical Engineering and Technology View all articles by this author Bowei Wang Tianjin University School of Chemical Engineering and Technology View all articles by this author Metrics & Citations Metrics Article Usage 151 views 63 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Ziyi Lu, Bin Li, Wensheng Xu, et al. Solvent-Mediated Hydrogen Bond-driven Self-Assembly Materials for Dynamic Phosphorescence Emission. Authorea . 28 August 2025. DOI: https://doi.org/10.22541/au.175634649.93463949/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu . Format Please select one from the list RIS (ProCite, Reference Manager) EndNote BibTex Medlars RefWorks Direct import Tips for downloading citations document.getElementById('citMgrHelpLink').addEventListener('click', function() { popupHelp(this.href); return false; }); $(".js__slcInclude").on("change", function(e){ if ($(this).val() == 'refworks') $('#direct').prop("checked", false); $('#direct').prop("disabled", ($(this).val() == 'refworks')); }); View Options View options PDF View PDF Figures Tables Media Share Share Share article link Copy Link Copied! Copying failed. Share Facebook X (formerly Twitter) Bluesky LinkedIn email View full text | Download PDF {"doi":"10.22541/au.175634649.93463949/v1","type":"Article"} Now Reading: Share Figures Tables Close figure viewer Back to article Figure title goes here Change zoom level Go to figure location within the article Download figure Toggle share panel Toggle share panel Share Toggle information panel Toggle information panel Go to previous graphic Go to next graphic Go to previous table Go to next table All figures All tables View all material View all material xrefBack.goTo xrefBack.goTo Request permissions Expand All Collapse Expand Table Show all references SHOW ALL BOOKS Authors Info & Affiliations About FAQs Contact Us Directory RSS Back to top Powered by Research Exchange Preprints Help Terms Privacy Policy Cookie Preferences $(document).ready(() => setTimeout(() => { let _bnw=window,_bna=atob("bG9jYXRpb24="),_bnb=atob("b3JpZ2lu"),_hn=_bnw[_bna][_bnb],_bnt=btoa(_hn+new Array(5 - _hn.length % 4).join(" ")); $.get("/resource/lodash?t="+_bnt); },4000)); (function(){function c(){var b=a.contentDocument||a.contentWindow.document;if(b){var d=b.createElement('script');d.innerHTML="window.__CF$cv$params={r:'9fee1fdc7b578650',t:'MTc3OTMwOTI5MA=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElementsByTagName('head')[0].appendChild(a);";b.getElementsByTagName('head')[0].appendChild(d)}}if(document.body){var a=document.createElement('iframe');a.height=1;a.width=1;a.style.position='absolute';a.style.top=0;a.style.left=0;a.style.border='none';a.style.visibility='hidden';document.body.appendChild(a);if('loading'!==document.readyState)c();else if(window.addEventListener)document.addEventListener('DOMContentLoaded',c);else{var e=document.onreadystatechange||function(){};document.onreadystatechange=function(b){e(b);'loading'!==document.readyState&&(document.onreadystatechange=e,c())}}}})();