Simulated insights into regulated <scp>ESDPT</scp> behavior for the oxygen elements substituted 3,7‐dihydroxy‐4‐oxo‐2‐phenyl‐chroman‐6‐carbaldehyde derivatives

Abstract Given the importance of oxygen group element doping in designing novel multifunctional organic molecules, herein, the classical 3,7‐dihydroxy‐4‐oxo‐2‐phenyl‐chroman‐6‐carbaldehyde (DOPCC) has been selected to probe into the related excited‐state double‐proton‐transfer (ESDPT) mechanism. Three DOPCC chalcogen‐doped derivatives (DOPCC, DOPCC‐S, and DPOCC‐Se) are considered in this work based on DFT and TDDFT methods. Analyses of principal geometrical variations, infrared (IR) spectral shifts, core‐valence bifurcation (CVB), and electronic density ρ(r) within the framework of bond critical point (BCP) confirm that dual hydrogen bonds of DOPCC, DOPCC‐S, and DPOCC‐Se are enhanced by photo‐induced excitation facilitating the ESDPT process. From the perspective of theoretical vertical excitation, the charge reorganization further confirms the tendency of the ESDPT reaction. The constructed potential energy surfaces (PESs) on the S1 state present three kinds of reaction paths, which all could support the ESDPT reactional behaviors. Comparing the reactional barriers among DOPCC, DOPCC‐S, and DPOCC‐Se derivatives, it could be found that DPOCC‐Se should be the most favorable ESDPT reaction since it owns the lowest atomic electronegativity of chalcogen elements among DOPCC, DOPCC‐S, and DPOCC‐Se compounds. In brief, we present the atomic electronegativity of chalcogen elements regulating the ESDPT mechanism for DPOCC derivatives.