Organic Luminescent Cocrystals Based on Benzotriazole Derivatives: Synthesis, Characterization, Crystal Structure and Fluorescence Behavior

Organic cocrystals have garnered significant research attention owing to their distinctive properties and promising applications. However, challenges in molecular structure design and control of intermolecular interactions continue to impede further advancements. In this study, two novel cocrystals were successfully formed from a series of synthesized benzotriazole derivatives. The resulting cocrystals exhibit bright green and yellow fluorescence under 365 nm light. To elucidate the microstructure of the obtained cocrystals, systematic characterization techniques such as solid-state fluorescence emission spectroscopy, Single-crystal X-ray diffraction (SCXRD), Power X-ray diffraction (PXRD) and density functional theory (DFT) were performed. These benzotriazole-based cocrystals demonstrate distinct fluorescent responses to alkaline and acidic environments, respectively. Additionally, preliminary tests for fingerprint recognition yielded satisfactory results. These findings suggest that the two cocrystals hold potential applications in acid-alkali sensing, anti-counterfeiting labels, and smart material development, while also providing valuable insights for the design and optimization of solid-state luminescent materials.