Buchachenko Anatoly L, Ivanov Vladimir L, Roznyatovsky Vitaly A, Ustynyuk Yuri A
Chemical Department of M. V. Lomonosov Moscow State University, Moscow 119992, Russia.
J Phys Chem A. 2006 Mar 23;110(11):3857-9. doi: 10.1021/jp060592t.
Photolysis of organotin molecules RSnMe3 is shown to be a spin selective radical reaction accompanied by fractionation of magnetic, (117,119)Sn, and nonmagnetic, (118,120)Sn, isotopes between starting reagents and products. A primary photolysis process is a homolytic cleavage of the C-Sn bond and generation of a triplet radical pair as a spin-selective nanoreactor. Nuclear spin dependent triplet-singlet conversion of the pair results in the tin isotope fractionation. Experimentally detected isotope distribution unambiguously demonstrates that the classical, mass-dependent isotope effect is negligible in comparison with magnetic, spin-dependent isotope effect.
有机锡分子RSnMe3的光解被证明是一种自旋选择性自由基反应，伴随着起始试剂和产物之间磁性（117,119）Sn同位素和非磁性（118,120）Sn同位素的分馏。初级光解过程是C-Sn键的均裂，并产生作为自旋选择性纳米反应器的三重态自由基对。该对的核自旋依赖性三重态-单重态转换导致锡同位素分馏。实验检测到的同位素分布明确表明，与磁性、自旋依赖性同位素效应相比，经典的质量依赖性同位素效应可以忽略不计。
