Transition-metal carbonyl derivatives of the germanes. Part 17. Tetracarbonylgermyl(trimethylgermyl)iron, [Fe(CO)4(GeH3)(GeMe3)], its conversion into [{Fe(CO)4(GeH2)}2], and hence to [Co4Fe2Ge2(CO)21](characterised by X-ray crystallography)via[Co4Fe2Ge2(CO)22]

Abstract

The synthesis and spectroscopic characterisation of the mixed germane derivative [Fe(CO)₄(GeH₃)(GeMe₃)](3) are described. This compound eliminates GeMe₃H to give quantitatively [{Fe(CO)₄(GeH₂)}₂](4), which has a Fe₂Ge₂ four-membered ring. The GeH₂ units of (4) react with [Co₂(CO)₈], eliminating H₂ and CO, to give [Co₄Fe₂Ge₂(CO)₂₂](7). Quantitative loss of CO from (7) gives [Co₄Fe₂Ge₂(CO)₂₁](8) which has been shown by an X-ray crystal structure determination to contain linked Co₂Ge and Fe₂Ge triangles.