Reactions of the hexaaquarhodium(III) cation with bis(benzimidazol-2-ylmethyl)methylamine and PPh3: syntheses and properties of new hydrido- and carbonylrhodium complexes

Hexaaquarhodium(III) perchlorate has been found to be an interesting starting material for the preparation of rhodium compounds. New mononuclear hydrido- and carbonylrhodium compounds with bis(benzimidazol-2-ylmethyl)methylamine (L) and PPh3 of the type [Rh(H)L(PPh3)2](ClO4)2 (1) and [Rh(CO)L(PPh3)2](ClO4) (2) have been synthesized. The monomeric Rh(II) compound was identified as an intermediate. Complexes 1 and 2 were characterized by elemental analysis, mass spectrometry and IR, and NMR spectroscopies. The fluxional behaviour of 2 was studied by variable-temperature 1H and 31P{H} NMR experiments.