Rhodium(I) complexes containing mono- and ditertiary phosphines and arsines

Article abstract of DOI:10.1021/ic50071a028

Rhodium dicarbonyl chloride dimer, [Rh(CO)₂Cl]₂, reacts with cis- and trans-β-styryldiphenylarsine, cis-β-styryldiphenylphosphine, bis(1-propynyl)phenylphosphine, and tris(ferrocenyl)phosphine to give complexes of the type [Rh(CO)ClL₂] (L = phosphine or arsine). Using an excess of cis-1,2-bis(diphenylphosphino)ethylene or bis(diphenylphosphinomethyl) ether, ionic complexes of the type [Rh(L-L)₂]X (L-L = diphosphine, X = anion) are obtained. Polymeric complexes of formula [Rh(CO)Cl(L-L)]_n (L-L = diphosphine) result from the reaction with trans-1,2-bis(diphenylphosphino)ethylene and bis(diphenylphosphino)acetylene. By contrast, complexes of the same empirical formula prepared from bis(diphenylphosphino)methane and its arsenic analog are dimers. When used in a 2:1 molar ratio, cis-1,2-bis(diphenylphosphino)ethylene and [Rh(CO)₂Cl]₂ give [Rh(L-L)₂][Rh(CO)₂Cl₂] (L-L = diphosphine). An analogous reaction with the arsenic analog gives [Rh(CO)(L-L)₂] [Rh(CO)₂Cl₂] (L-L = diarsine). A number of bromo analogs were also prepared. Conductance and infrared spectral data are presented and the structures of the complexes are discussed.