Trimethylsilymethyl complexes of platinum, gold, cobalt, manganese, and titanium have been obtained by interaction of the metal halide complexes with π-bonding ligands with the lithium or Grignard reagent from chloromethyltrimethylsilane. I.r. and n.m.r. spectra are reported and the stabillities of the compounds discussed with reference to other alkyl complexes. Platinum and gold neopentyl complexes have also been prepared.