Photochemical reactions of 2-(pentamethyldisilanyl)furan and 2-(pentamethyldigermanyl)furan. Formation of a radical pair

Article abstract of DOI:10.1016/0022-328X(94)87043-8

Photochemical reactions of 2-(pentamethyldisilanyl)furan and 2-(pentamethyldigermanyl)furan have been investigated by chemical trapping experiments and laser flash-photolysis.On irradiation, the furylated catenates of Group 14 elements undergo silicon-silicon ? bond and germanium-germanium ? bond homolysis to give a pair of silyl radicals and germyl radicals, respectively.In CCl4, these radicals are converted to the corresponding chlorides by abstraction of a chlorine atom.In nonhalogenated solvents (cyclohexane and other hydrocarbons), the silyl radical pair undergoes a disproportionation to give as main products a monosilane and a silene.The trimethylgermyl radical mainly couples at the ipso-position of the furyl group of the pairing radical to yield the corresponding diradical.This diradical undergoes elimination of a divalent species, dimethylgermylene, with concomitant formation of 2-(trimethylgermyl)furan. Key words: Photochemistry; Silanyl; Germanyl; Radical