Combined effect of hydrogen bonding interactions and freezing of rotameric equilibrium on the enhancement of photostability
作者:Barbara Golec、Krzysztof Nawara、Alexandr Gorski、Randolph P. Thummel、Jerzy Herbich、Jacek Waluk
DOI:10.1039/c8cp00726h
日期:——
which can exist only in the syn form, is more photostable in alcohols than similar, but non-rigid molecules. This additional photostability enhancement is due to the elimination of a slower channel of excited state deactivation in alcohol complexes, S0 ← S1 internal conversion. The dominant, faster channel of S1 depopulation is the excited state double proton transfer, manifested by the presence of low
12,13-dihydro-5 H-吲哚并[3,2- c ] ac啶(IA)是一种具有质子给体/受体官能团的刚性双官能吲哚衍生物,其光物理性质和光稳定性可被环境急剧改变。与醇形成氢键导致三重态形成效率的显着降低和光稳定性的提高。光降解产率被发现是大约200倍降低的甲醇和1-丙醇比Ñ正己烷或乙腈。已经报道了两种吲哚-萘啶核苷的相似作用,它们可以以顺式和反式的形式存在。我们证明了IA只能以合成形式存在的,在醇中的光稳定性高于类似但非刚性的分子。这种额外的光稳定性增强是由于消除了醇配合物中S 0 ←S 1内部转化的较慢的激发态失活通道。S 1减少的主要,较快的通道是激发态双质子转移,表现为低能互变异构荧光的存在。