PUB - Publikationen an der Universität Bielefeld

The synthesis of tris(pentafluoroethyl)germanium derivatives is described. The reaction of germanium tetrachloride with three equivalents of the pentafluoroethylation reagent LiC2F5 does not lead selectively to the formation of tris(pentafluoroethyl)chlorogermane, (C2F5)(3)GeCl. Here the introduction of a diethylamino function as a protecting group was beneficial. Thus, treatment of Cl3GeNEt2 with LiC2F5 smoothly afforded (C2F5)(3)GeNEt2. The replacement of the amino substituent by halides was accomplished by reaction with HBr or HCl on a multigram scale. The combination of (C2F5)(3)GeCl with Ag2CO3 gave rise to the formation of the digermoxane [(C2F5)(3)Ge](2)O. An obtuse Ge-O-Ge angle of 150.2(1)degrees was determined by X-ray diffraction. Attempted hydrolysis of the digermoxane leads to an equilibrium mixture of the precursor, (C2F5)(3)GeOH, and water.