Theoretical study on the ESIPT processes and fluorescence properties of 2-(1H-Benzimidazol-2-yl)phenol-based derivatives

摘要: Abstract The molecules based on the excited state intramolecular proton transfer (ESIPT) process are widely used in fluorescent probes, organic light-emitting diodes and other fields due to their unique optical properties. However, relationship between structures properties of ESIPT-based still needs be further explored. Herein, effects different functional groups embedded with benzene ring ESIPT electronic spectra 2-(1H-Benzimidazol-2-yl)phenol (HBYP)-based derivatives (DPYP, HAYP HIYP) were explored by using density theory time-dependent methods. Utilizing theoretical calculations, geometric parameters, including bond lengths angles, infrared vibration spectra, frontier molecular orbitals, potential energy curves as well topological analysis critical point ground states acquired. results manifest that is facile occur for HBYP its three upon photo-excitation, which can confirmed comparing crucial IR stretching peaks barriers S0 S1 states. It worth noting molecule exhibits largest barrier at among studied molecules, fluorescence corresponding enol keto forms show most obvious Stokes shifts 260 nm 284 nm, respectively. Therefore, we deduce affected regulating characteristics via group substitution.