the CIDNP 1H technique. The reactions proceeds by a two-step mechanism via the reversible formation of singlet biradicals, II. The triplet biradical (II), formed as a result of S-T conversion of (II)(S), irreversibly decomposes giving Me2E (E = Si, Ge). The insertion of Me2E into the CBr bond of PhCH2Br and the SnCl bond of Me3SnCl occurs via a radical mechanism, as deduced from the CIDNP effects observed
通过CIDNP 1 H技术研究了7-sila-和7-germa-降
冰片二
烯(Ia,b)的光
化学分解。反应通过可逆形成单线双自由基II的两步机制进行。由(II)(S)的
ST转化形成的三重双自由基(II)不可逆地分解,得到Me 2 E(E = Si,Ge)。从这些反应中观察到的CIDNP效应推论,Me 2 E插入到PhCH 2 Br的CBr键和Me 3 SnCl的SnCl键中是通过自由基机理发生的。