DEHYDROGENATIVE BUILDUP REACTIONS TO SILY L-SUBSTITUTED ALKALI-METAL GERMANIDES, STANNIDES, AND PHOSPHIDES - MOLECULAR-STRUCTURE OF NEOPENTASILANE

The build-up reaction between monosilane and dispersed sodium or potas sium in diethyleneglycol dimethyl ether leads to alkali metal silylsil anides of the composition (Na/K)-SiH3-n(SiH3)n (n = 0-3) (1, 1a-c; 2, 2a-c). By subsequent reactions with silyl nonafluorobutanesulfonate, C 4F9SO3-SiH3, benzenesulfonic acid, PhSO3H, and methyl p-toluenesulfona te the corresponding silanes SiH4-n(SiH3)n (n = 0-4) (3, 3a-d) and met hylsilanes CH3SiH3-n(SiH3)n (n = 0-3) (4a-d) were obtained in good yie ld. The molecular structure of neopentasilane (3d) has been determined by electron diffraction analysis. Treatment of group IV and V hydride s GeH4, PH3, and SnH4 with mixtures of sodium or potassium silylsilani des (1, 1a-c; 2, 2a-c) leads to silyl-substituted sodium or potassium germanides (Na/K)GeH3-n(SiH3)n (n = 1-3) (5a-c, 6a-c), phosphides KPH2 -n(SiH3)n (n = 1-2) (7a-b), and stannides NaSnH3-n(SiH3)n (n = 1-3) (8 , 8a-c).