Solvent Polarity Dependence of Photochromic Reactions of a Diarylethene Derivative As Revealed by Steady-State and Transient Spectroscopies
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- 作者：Yukihide Ishibashi ; Toshiyuki Umesato ; Mika Fujiwara ; Kanako Une ; Yusuke Yoneda ; Hikaru Sotome ; Tetsuro Katayama ; Seiya Kobatake ; Tsuyoshi Asahi ; Masahiro Irie ; Hiroshi Miyasaka
- 刊名：Journal of Physical Chemistry C
- 出版年：2016
- 出版时间：January 21, 2016
- 年：2016
- 卷：120
- 期：2
- 页码：1170-1177
- 全文大小：482K
- ISSN：1932-7455
文摘
Solvent polarity dependence of photochromic reactions such as cyclization and cycloreversion of a photochromic diarylethene derivative, 1,2-bis(2-methyl-3-benzothienyl)perfluorocyclopentene, was investigated by steady-state spectroscopic and femtosecond laser photolysis methods. For the cyclization reaction, it was revealed that the quantum yield decreased with an increase in solvent polarities, mainly due to the decrease in the fraction of the conformer with C2 symmetry favorable for the cyclization. This result indicated that the branching ratio for the cyclization and the deactivation to the open-ring isomer at the conical intersection was almost independent of the solvent polarity. On the other hand, it was found for the cycloreversion process that the closed-ring isomer in the S1 state rapidly deactivated into the ground state in competition with the activated process leading to the conical intersection providing a pathway toward both open- and closed-ring minima in the ground state. The cycloreversion reaction quantum yield also decreasing with an increase in the solvent polarity was attributed to larger increase of the direct deactivation into the ground state from the excited state minimum of the closed-ring isomer.