Intramolecular and Intermolecular Reactivity of Localized Singlet Diradicals: The Exceedingly Long-Lived 2,2-Diethoxy-1,3-diphenylcyclopentane-1,3-diyl
作者:Manabu Abe、Waldemar Adam、Thomas Heidenfelder、Werner M. Nau、Xiangyang Zhang
DOI:10.1021/ja992507j
日期:2000.3.1
photodenitrogenation of the diethoxy-substituted diazene 3 in nonprotic solvents, e.g. n-hexane, benzene, and acetonitrile, afforded exclusively the housane 4 through the intermediary 2,2-diethoxy-1,3-diphenylcyclopentane-1,3-diyl diradical 2b. Alternatively, in the presence of methanol, the formation of the adduct 6 competed through trapping of the allylic cation 5. The intervention of the intermediates was corroborated
二乙氧基取代的二氮烯 3 在非质子溶剂(例如正己烷、苯和乙腈)中的直接和二苯甲酮敏化光脱氮反应,通过中间体 2,2-二乙氧基-1,3-二苯基环戊烷-1 仅提供 housane 4, 3-二基双基2b。或者,在甲醇存在下,加合物 6 的形成通过捕获烯丙基阳离子 5 竞争。二氮烯 3 的激光闪光光解实验证实了中间体的干预。双自由基中间体的特征在于其强瞬态545 nm 处的吸收,以微秒范围内的一阶寿命衰减。双自由基寿命按正己烷 (0.52 μs)、苯 (0.88 μs)、乙腈 (1.01 μs) 和氯仿 (3.73 μs) 的顺序增加。2的单线基态,