Effects of oxygen family elements on electron-withdrawing nitryl-substituted 2-(2’-hydroxyphenyl)benzazole derivatives: a theoretical investigation

Abstract

The excited state intramolecular proton transfer (ESIPT) reaction is a well-studied photo reaction, based on this mechanism, many high-performance organic chromophores can be selected. It is widely acknowledged that the 2-(2’-hydroxyphenyl)benzazole (HBX) derivatives undergo the ESIPT process. This work mainly uses DFT and TDDFT methods to clarify the effects of oxygen family substituted elements on excited states for HBX derivatives. First, we probe into the molecular structures of HBX derivatives (HBX-O, HBX-S and HBX-Se) and explore their infrared (IR) vibrational behaviours. The results confirm that light excitation in S₁ state enhances the hydrogen bonds of HBX dyes. Additionally, analysis of the frontier molecular orbitals shows that charge redistribution promotes the ESIPT process. This article provides a detailed explanation of the excited state reaction behaviours of three HBX dyes and demonstrates that substitution effects regulate the ESIPT processes of these dyes. This finding will contribute to the development of new photo-reactive substances in the future.

GRAPHICAL ABSTRACT

KEYWORDS:

• Intramolecular hydrogen bond
• excited state intramolecular proton transfer
• frontier molecular orbital
• charge redistribution
• oxygen family elements

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data are available on request from the corresponding author.

Additional information

Funding

This work was supported by the Liaoning Revitalization Talents Program [Grant Number XLYC2203155], the Support Program for Young and Middle-aged Scientific and Technological Innovation Talents of Shenyang City [Grant Number RC230960], the Major Incubation Program of Shenyang Normal University [Grant Number ZD202304]. The main part of this work was carried out at Bianshui Riverside Supercomputing Center (BRSC) of China.