Effects of solvents and substituents controlling the adiabatic or diabatic modes of the cis → trans isomerization of styrylpyrenes in the excited singlet state
作者:Yoshihiko Kikuchi、Hiroaki Okamoto、Tatsuo Aral、Katsumi Tokumaru
DOI:10.1016/0009-2614(94)01071-4
日期:1994.11
The effects of polar solvents and polar substituents on the potential energy surfaces of the cis → trans isomerization of 1-styrylpyrenes in the excited singlet state are investigated by fluorescence spectroscopy. In less polar solvents, cis-1-styrylpyrene undergoes an adiabatic isomerization from the cis excited singlet state (1c∗) to the trans one (1t∗), overcoming an energy barrier around the perpendicular
通过荧光光谱研究了极性溶剂和极性取代基对激发单线态1-苯乙烯基苯乙烯的顺式→反式异构化的势能表面的影响。在极性较小的溶剂中,顺式-1-苯乙烯基苯乙烯经历了从顺式激发单重态(1 c ∗)到反式一(1 t ∗)的绝热异构化过程,克服了垂直构象周围的能垒(1 p ∗)。溶剂极性的增加和/或在苯环上引入极性p-取代基可改变反应进程,并从1 p ∗失活 导致非绝热异构化。