Rearrangements of [C(6)H(7)Si](+) cations. A radiochemical and quantum chemical study.

Nucleogenic cations were formed by beta-decay of phenylsilane tritiated at ortho- and para-positions of the benzene ring as well as at the silyl group and the products of their reactions with methyl tert-butyl ether were analyzed by radiochromatography. We found that the o-silatolyl cation was isomerized into the silabenzyl cation while the p-silatolyl cation was not. Furthermore, the silabenzyl cation was not converted into other isomers.

Methylation of thymine and uracil with free methyl cations formed due to beta-decay of tritiated methane: possible implication in mutagenesis and carcinogenesis.

Exposure of solid thymine and uracil at room temperature to free methyl cations, produced due to beta-decay of tritiated methane, resulted in formation of their 1-, O2-, 3-, O4-, and 6-methyl derivatives. In addition, uracil formed a 5-methyl derivative (thymine); tritium-containing thymine and uracil were also detected. Both thymine and uracil formed predominantly unidentified products which resulted presumably from their oligomerization.