Conjugated Biradical Intermediates: Spectroscopic, Kinetic, and Trapping Studies of 2,2-Dimethyl-1,3-perinaphthadiyl
作者:Erich Hasler、Ernst Gassmann、Jakob Wirz
DOI:10.1002/hlca.19850680328
日期:1985.5.15
decay of this reactive intermediate which is persistent at 77 K in the triplet ground state (3a) and rather long-lived (400 μs) at room temperature. When formed in its lowest singlet state (1a), the biradical is too short-lived to undergo intersystem crossing to 3a or bimolecular reactions. Thus, 3a is formed exclusively from the excited triplet state of the precursor compounds, 31* or 33*. The monomolecular
所述双基-2,2-二甲基-1,3- perinaphthadiyl(一)是从两个不同的前体,所述naphthocyclopropane产生1和偶氮化合物2,并从每个由三个不同的途径(热解,直接光解,和三线态敏化,流程1)。来自闪速光解,低温光谱和产物分析的综合证据提供了这种活性中间体的形成和衰变的详细机理图,该中间体在三重态基态(3 a)下持续存在于77 K且寿命较长(室温下约400μs)。以最低的单重态(1 a),所述双基是过于短暂经历系间窜越到3一个或双分子反应。因此,3一从所述前体化合物的激发三重态,仅仅形成3 1 *或3 3 *。自旋势垒可阻止3 a的单分子衰减;3个一个发起丙烯腈聚合,并通过捕获3 Ò 2。