Photoluminescence property of ESIPT-based HBIA-2OH combined with solvent effect: A theoretical study

Abstract

The excited state intramolecular proton transfer (ESIPT) and photoluminescence properties of HBIA-2OH in various solvents are explored employing quantum computational methods. Potential energy curves reveal that the ESIPT process can occur, exhibiting a tiny solvent dependence. Simulated fluorescence spectra demonstrate increasing solvent polarity diminishes enol-form fluorescence, while blue-shifting the keto-form emission. Furthermore, hole-electron analysis combined with dihedral angle changes unveils that concurrent ESIPT process and twist intramolecular charge transfer (TICT) process of HBIA-2OH, explaining weakened keto-form fluorescence. These findings resolve the solvent-regulated ESIPT-TICT synergy of HBIA-2OH, addressing theoretical gaps in its photophysics and guiding rational design of advanced luminescent materials.