Theoretical simulations about chalcogen-substituted hydrogen bonding interactions and ESIPT behaviors for 3-benzooxazol-2-yl-3′-dimethylamino-biphenyl-2-ol derivatives

2-(2′-hydroxyphenyl)benzazoles (HBX) derivatives possess significant biological and photochemical applications. 3-benzooxazol-2-yl-3′-dimethylamino-biphenyl-2-ol (BYDBO) as one of novel HBX derivatives exhibits an asymmetrical configuration with intramolecular hydrogen bonding wire that present superior luminescent properties. Inspired by the regulated excited state dynamics by doping chalcogen elements, in this work, we mainly focus on clarifying the related excited state behaviors for three BYDBO derivatives (i.e., BYDBO-O, BYDBO-S and BYDBO-Se) theoretically. Elucidating the intramolecular hydrogen bonding interactions, photo-induced charge recombination, effects of atomic electronegativity related to oxygen elements, and relative excited state intramolecular proton transfer (ESIPT) behaviors, we mainly elaborate the chalcogen-element-related ESIPT mechanism for BYDBO derivatives. Based on our results, we sincerely wish our work could facilitate comprehending molecular excited state dynamics and designing novel luminescent organic materials for HBX derivatives.