Some phosphine exchange and oxidative addition reactions of complexes of the type trans-[RhX(CO)L2](X = Halide; L = dimethylphenyl-phosphine or -arsine)

Abstract

Some new complexes of the type trans-[RhX(CO)L₂](X = Cl, Br, l, or N₃; L = tertiary phosphine or tertiary arsine) are described. Oxidative addition reactions of methyl, acyl, allyl, or sulphonyl halides with these complexes to give adducts of the type [RhX₂R(CO)L₂](X = Cl or Br; R = Me etc.) are described. The methyl–rhodium complex [RhBr₂Me(CO)(PMe₂Ph)₂] reacts with carbon monoxide to give the acetyl–rhodium complex. The configurations (I) of these adducts were determined by the methyl resonance pattern of the phosphine or arsine ligands. N.m.r. and infrared data are given and discussed. The effects of adding PMe₂Ph to solutions of trans-[RhCl(CO)(PMe₂Ph)₂] were studied by n.m.r. and J(P–CH₃) for free and complexed PMe₂Ph shown to be of opposite sign.