Polygermanes precurseurs d'especes du germanium a coordinance non usuelle

Abstract

Several thermal or photochemical α-elimination reactions of functional polygermanes lead to germylenes, R 2Ge. Photolysis of polygermanes, cyclopolygermanes and polygermylmercury compounds and also hydrogen abstraction from various organohydropolygermanes using t-BuO ., lead to the formation of polymetallated chains containing one or two germanium-centered radicals. These polygermyl radicals give germylenes, R 2Ge, germanium centered radicals ▪, α-digermyl diradicals (or digermenes) [ ▪ or ▪] and β- or γ-polygermyl diradicals via a homolytic monoelectronic α-elimination process. In some cases the formation of α-digermyl diradicals or digermenes can also be seen as occurring through dimerization of germylenes but with lower yields. All these intermediates have been characterized by several trapping reactions with dimethyl disulfide, 2,3-dimethylbutadiene or biacetyl.