In view of the distinguished photochemical and photobiological characteristics of 2-Benzooxazol-2-yl-5-diethylamino-phenol (BYDP) and its derivatives, herein, we mainly focus on probing into excited-state behaviours of the three chalcogen element substituted BYDP derivatives (i.e. BYDP-O, BYDP-S and BYDP-Se). For these three different fluorophores, we detangle the effects of atomic electronegativity and charge recombination related to oxygen elements in excited-state intramolecular proton-transfer (ESIPT) processes. Because of the low potential energy barriers, we confirm that the ESIPT is controlled by atomic electronegativity. We sincerely hope our work could provide a theoretical reference for proving this novel mechanism of ESIPT experimentally.
Read full abstract