Work

Tuning of Thermal Back Reactivity of Aza‐Diarylethene Photoswitches by Introducing Benzazole Groups

Year: 2025

Type: article

Abstract: Molecular photoswitches have attracted significant attention due to their potential applications in materials science and life science. In this study, we synthesize a series of aza‐diarylethenes incorporating benzazole groups as the nitrogen atom source for 6π azaelectrocyclization and investigate their photochromic behaviors. Compounds 1–3, bearing benzothiazole, benzoxazole, and benzimidazole groups, exhibit thermally reversible type photochromism with thermal back reaction half‐lives (t1/2) ranging from milliseconds to seconds at 293 K. Additional derivatives 4–6 with benzothiophene‐S,S‐dioxide at the ethene bridge moiety further expand the range of thermal back reactivity, with t1/2 values extending up to tens of minutes. Quantum chemical calculations confirm that the variation in thermal back reactivity is governed by the energy difference between open‐ and closed‐ring isomers, in accordance with the Bell−Evans−Polanyi principle. These findings provide a molecular design strategy for controlling the thermal back reactivity of aza‐diarylethenes, enabling further development of functional photochromic materials.

Source: Chemistry - A European Journal

DOI: 10.1002/chem.202501077

Authors: Daichi Kitagawa, Takahito Mori, Hikaru Sawa, Shota Hamatani, Seiya Kobatake

Institution: Osaka Metropolitan University

Language: English

Topic: Photochromic and Fluorescence Chemistry

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: bronze

Funders: Iketani Science and Technology Foundation, Japan Society for the Promotion of Science