Reactions of silanes and germanes with iridium complexes. Part I. Reactions with Vaska's compound

Abstract

Vaska's compound, trans-carbonylchlorobis(triphenylphosphine)iridium(I), reacts with SiH₃X (X = H, Cl, Br, I) and with GeH₄ in benzene at room temperature to give insoluble 1 : 1 adducts. With GeH₃Y (Y = Cl, Br, I) and with Ge₂H₆, initial reaction gives soluble 1 : 1 adducts, whose stereochemistries have been determined from their n.m.r. spectra; after 30–60 min, insoluble adducts precipitate. Reaction with Si₂H₆ is more complicated and the product is not homogeneous; in every other case addition involves the breaking of Si–H or Ge–H bonds. The i.r. spectra and some of the reactions of the adducts are described. On prolonged standing, under an excess of SiH₃Cl, Vaska's compound gives SiH₂Cl₂ and a soluble silyl complex of six-co-ordinated iridium containing two Ir–H bonds; with the other halides, prolonged reaction leads to halogen exchange and to decomposition.