Photorelease Reaction Mechanism Study of a Diarylethene Caged Dual Functions Compound

• Published in: The journal of physical chemistry letters Vol. 14; no. 8; pp. 2119 - 2124
• Main Authors: Tan, Qian-qian, Guo, Yan, Phillips, David Lee, Xu, Tongyu, Ma, Jiani
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.03.2023
• Subjects: Physical Insights into Chemistry, Catalysis, and Interfaces
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.3c00131

Femtosecond transient absorption, nanosecond transient absorption, and nanosecond resonance Raman spectroscopy techniques coupled with density functional theory calculations were performed to unravel the photocyclization and photorelease mechanisms of a diarylethene based compound (1o) containing two caged groups (OMe and OAc). Since the ground state parallel (P) conformer of 1o with a large dipole moment is stable in DMSO, the fs-TA transformations observed for 1o in DMSO mainly have contributions from the P conformer, which undergoes an intersystem crossing to generate a corresponding triplet state species. In a less polar solvent like 1,4-dioxane, in addition to the P path behavior of 1o, an antiparallel (AP) conformer can also take place to give a photocyclization reaction from the Franck–Condon state and finally give a deprotection via this pathway. This work provides a deeper understanding for these reactions, which not only facilitate the applications of diarylethene compounds but also help for the future design of functionalized diarylethene derivatives for particular applications.