Some organic derivatives of lead and germanium

Abstract

This thesis describes a study into the reactions of organics and inorganic halides of germanium and lead with organo-lithium and Grignard reagents, and also an investigation into the formation of compounds containing germanium and bonded to transition metals. Such compounds had not previously been described. Triphenylgermyl-triphenylphosphinegold(I), Ph(_3)Ge-AuPPh(_3), and similar copper end silver compounds were prepared by reacting triphenylgormyl-lithium with the corresponding tertiary phosphine - metal halide complex. 1,2-Idbromoethane cleaved the metal - metal bond to give ethylene, bromotriphenylgermane and the corresponding metal halide –phosphine complex; and phenyl-lithium gave the unstable salt, lithium bis(triphenylgarmyl)aurate(1) etherate, Li(^+)[(Ph(_3)Ge)(_2)Au](^-). 4Et(_2)0, which was converted into the more stable tetraethylammonium salt. Germanium(II)iodide reacted with phenyl-lithium to give, not diphenylgermanium(II), but yellow to red polymeric materials, intermediate in composition between PhGe and Ph(_2)Ge, containing Ph(_3)Ge, PH(_2)Ge, PhGe and Gs groupings. A reaction path involving “metal-halogen” exchange reactions is put forward. Tetraphenylgermyl and triphenylgermane were also isolated from these reactions. Triphenylgermyl-lithium reacted with germanium(II)iodide to give the lithium salt, lithium tris(triphenylgermyl)germane. In contrasr, lead (II) bromide reacted with mesitylmagnesium bromide to give solutions involving the equilibrium: Ms(_2)Pb + MeMgEr ↔ Me(_3)PbMgBr, Ms – 1,3,5 – (CH(_3))(_3)C(_6)H(_2). This equilibrium could be displaced by carbonation, as shown by bromination studies. The formation of digermanes, (R(_6)Ge(_2)), from the interaction of germanium(IV)chloride with Grignard reagents has been suggested to involve germanium(II) chloride as intermediate. In this work, however, the formation of digermanes has been shown to involve the germyl-Grignard reagent, H(_3)GeMgX. This may be formed predominantly by the reaction between the halide R(_3)GeMgX and the magnesium metal remaining from the Grignard preparation, through in cases of sterically hindered Grignard preparation, through in cases of sterically hindered Grognard reagents the exchange reaction R(_3)Gex + RMgX → R(_3)GeMgX + RX can occur. The reactions of lithium diphenylphosphide with germanium (IV)chloride and organogermanium halidies, (R(_n)GeX(_4-n),n = 1, 2, 3), and properties of the germanium – phosphoris bond in the resulting compounds are also described.