Preparation of oligogermanes via the hydrogermolysis reaction

Article abstract of DOI:10.1021/om060115x

The hydrogermolysis reaction has been shown to be useful for the formation of germanium-germanium bonds. The Ge - Ge bond forming reaction involves a germanium amide and a germanium hydride and requires the use of acetonitrile as the solvent. A key factor in the formation of the Ge - Ge bond involves reaction of the germanium amide R₃GeNMe₂ with acetonitrile solvent to furnish an α-germylated nitrile R₃GeCH₂CN which contains a labile Ge - C bond. This species undergoes subsequent reaction with a germanium hydride R₃GeH to form the Ge - Ge bond. Using this method, the digermanes Buⁿ₃GeGePh₃ and Et ₃GeGePh₃ have been obtained and their X-ray crystal structures have been determined. The preparation of three synthons for stepwise oligogermane chain buildup, R₂Ge(NMe₂)CH ₂CH₂OEt (R = Et, Bu, Ph), has also been achieved. These synthons react with Ph₃GeH in CH₃CN to afford the corresponding digermanes, which in the case of R = Et and Bu undergo subsequent reaction with DIBAL-H to generate a digermane hydride. The ethyl and n-butyl digermane hydrides then are subsequently reacted with an additional equivalent of the appropriate synthon to produce the corresponding trigermanes, and repetition of these two steps furnishes the tetragermanes Ph ₃GeGe(R₂)Ge(R₂)Ge(R₂)CH ₂CH₂OEt (R = Et, Bu). Thus, in this study two new series of oligomeric organogermanium species have been prepared and fully characterized.