Nuclear magnetic resonance studies on metal complexes. Part V. Dimethylphenylphosphine and dimethylphenylarsine complexes of rhodium(III)

Rhodium trichloride and dimethylphenylphosphine react together in aqueous ethanol to give mer-[RhCl3(PMe2Ph)3], fac-[RhCl3(PMe2Ph)3], and the salt [PHMe2Ph][RhCl4(PMe2Ph)2]. Metathetical replacement reactions on mer-[RhCl3(PMe2Ph)3] under mild conditions give complexes of the type [RhCl2Y(PMe2Ph)3] configuration (IV; Y = Br, I, NCO, NCS, NO2, or N3) but under more vigorous conditions complexes of the type mer-[RhY3(PMe2Ph)3](Y = Br, I, NCO, NCS, or N3) are formed. The monothiocyanato-complex is N-bonded but on heating it gives the S-bonded linkage isomer. Methyl resonance data are given and are useful in assigning stereochemistry. The effects of ligands on methyl-resonance τ-values are discussed. Far-infrared data are given and rhodium–chlorine stretching frequencies assigned and discussed; they are useful in confirming the assigned stereochemistries.