Magnetic isotope effect in the photolysis of organotin compounds.
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.
Chemical Department of M. V. Lomonosov Moscow State University, Moscow 119992, Russia. abuchach@chph.ras.ru
Anatoly L
AL
Buchachenko
Vladimir L
VL
Ivanov
Vitaly A
VA
Roznyatovsky
Yuri A
YA
Ustynyuk
D005609:Free Radicals / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D007554:Isotopes; D008027:Light; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards; D008280:Magnetics; D015394:Molecular Structure; D009947:Organotin Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D010782:Photolysis; D012015:Reference Standards; D012680:Sensitivity and Specificity; D014001:Tin / Q000737:chemistry*
D005609:Free Radicals; D007554:Isotopes; D009947:Organotin Compounds; D014001:Tin