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The high yield syntheses of Me2GeHX (X = F, Cl, Br, I) and Me2GeHPs (Ps = CN, N3, NCO, NCS, OAc) are reported. The dimethylgermane derivatives are identified and characterized by various physical m...

The synthesis of a series of methylseleno-derivatives of Group IV, Me4 –nM(SeMe)n(M = Si, Ge, or Sn, n= 1–4), is reported. The preparative routes include reactions of methaneselenol with Group IV amines; the dehydrohalogenation of methaneselenol and a Group IV halide; and the reactions of Group IV halides with ‘methylselenolithium’, methylselenomagnesium iodide, lithium tetramethylselenoaluminate, and methylseleno(trimethyl)silane. The n.m.r. and vibrational spectra are reported and discussed. The reactions of the series Me3MSeMe with some protic reagents were studied.

Die symm. substituierten Disilylchalkogenide (I) werden durch Umsetzung der entsprechenden Iodo- oder Bromosilane mit H2O, HgS, LiA1(SeH)4 bzw. LiZTe dargestellt.

The silyl and germyl derivatives of selenophenol, SiH3(SePh), GeH3(SePh) and SiH2(SePh)2, and the methylated analogues MMenH3–n(SePh)(M = Si, n= 2 or 3; M = Ge, n= 1–3; M = Sn, n= 3) have been prepared and characterized. The comparative synthetic routes include reactions of halides with lithium benzeneselenolate, lithium tetra(phenylseleno) aluminate, and trimethyl(phenylseleno)silane, and also of selenophenol with bisgermylcarbodi-imides. The spectroscopic properties of these species are reported and discussed. The seleno-boranes, B(SePh)3 and B(SeMe)3, -phosphine, P(SePh)3, and -arsine, As(SePh)3, are formed by reactions of the corresponding chlorides with SiMe3(SePh) and SiMe3(SeMe). Reduction of B(SePh)3 by trimethylsilane is quantitative but a similar reaction with monosilane does not occur.

The molecular structures of the title compounds in the gas phase have been determined by electron diffraction. The analyses were based on the rg interatomic distances. For Me2GeF2 principal parameters are: rg(Ge–C) 1.928 ± 0.003 A, rg(Ge–F) 1.739 ± 0.002A; F–Ge–F 105.4 ± 2.0°, F–Ge–C 107.3 ± 0.7°, and C–Ge–C 121.0 ± 3.5°. For MeGeF3 principal parameters are: rg(Ge–F) 1.714 ± 0.002, rg(Ge–C) 1.904 ± 0.009 A; F–Ge–F 105.5 ± 0.9°, and F–Ge–C 113.2 ± 0.6°(uncertainties estimated to include both systematic and random errors). Observed variations in r(Ge–F) and r(Ge–C) are correlated with estimated bond polarities.

Bismethylgermanium and bismethylsilicon carbodi-imides have been prepared in high yield by halide metathesis reactions with lead(II), silver(I), or silicon(IV) species. The new derivatives in the series of general formula (MenH3 –nMN:)2C (MSi or Ge; n= 1, 2 or 3) have been characterised by 1H n.m.r., i.r., and Raman spectroscopy as well as mass spectrometry and cleavage reactions. The utility of the germanium carbodi-imides as synthetic intermediates is shown by ready cleavage of the Ge–N bond by Group VI and other protic species leading to the formation of chalcogeno-germanes and related derivatives of the type (MenH3 –nGe)2E (E = O, S, Se or Te) and Men H3 –n GeSR (R = Me, But, ph, MeC(O), or –CH2CH2–). Comprative studies show that in the silicon carbodi-imides the Si–N bond is not susceptible to protolysis by the heavier chalcogenols.

A sealed tube reaction is described for the preparation of iodogermane from the reaction of iodine with germane.