Investigations on organogermanium compounds. XIII: Synthesis of linear peralkylpolygermanes. Mechanism of the reaction of trialkylgermyl alkali metal compounds with trialkylhalogenogermanes

A full report is given of our investigations into the synthesis of a series of linear peralkylpolygermanes, both by reacting organohalogenogermanes with alkali metals and by coupling of organohalogenogermanes with trialkylgermyl alkali metal compounds2–4. The latter type of reaction always gives in addition to the asymmetric compound R3GeGeR3′, varying amounts of the symmetrical products R6Ge2 and R6′Ge2. Evidence is presented that these side-products are formed by a nucleophilic cleavage of the GeGe bond of the primary asymmetrical coupling products, rather than by a halogen-metal exchange reaction.