Aza-Diarylethenes Undergoing Both Photochemically and Thermally Reversible Electrocyclic Reactions.
Angew Chem Int Ed Engl
; : e202414121, 2024 Aug 28.
Article
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| MEDLINE
| ID: mdl-39198686
ABSTRACT
Exploring novel molecular photoswitches plays a crucial role in the field of photo-functional materials chemistry. In this study, we synthesized aza-diarylethenes with benzothiophene-S,S-dioxide as a part of hexatriene structure and investigated their photochromic properties. Unlike previously reported aza-diarylethenes, which exhibit fast thermally reversible photochromism, the compounds synthesized here exhibited pseudo-photochemically reversible photochromism. Due to their thermal stability, we successfully isolated the colored isomer. X-ray crystallographic analysis revealed for the first time that the colored isomer adopts a closed-ring structure with a bond between carbon and nitrogen atoms. Remarkably, these aza-diarylethenes exhibited not only photochemical ring-closing and ring-opening reactions but also thermal ring-closing and ring-opening reactions, driven by a thermal equilibrium between the open- and closed-ring isomers. This behavior, unprecedented for common diarylethenes, was elucidated through kinetic analysis, revealing an energy-level diagram for the thermal equilibrium between these isomers. Furthermore, 1H NMR spectroscopy revealed that both photochemically and thermally generated closed-ring isomers adopt the same structure, which was well explained based on the reaction mechanism of photochemical and thermal ring-closing reactions. These findings not only advance the field of aza-diarylethenes but also inspire future research in the development of new photoswitches.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2024
Tipo del documento:
Article
País de afiliación:
Japón