SYNTHESIS AND CHARACTERIZATION OF RH(P(CH3)3)2(CO)CH3 AND RH(P(CH3)3)2(CO)PH

The new complexes Rh(P(CH3)3)2(CO)CH3 and Rh(P(CH3)3)2(CO)Ph were synthesized from Rh(P(CH3)3)2(CO)CI. The phenyl complex was synthesized by two routes, first by direct substitution of Rh(P(CH3)3)2(CO)CI Using diphenylmagnesium and second from the methyl derivative Rh(P(CH3)3)2(CO)CH3 by irradiation in the presence of benzene. Rh(P(CH3)3)2(CO)Ph reacts with HCI at low temperature to form the octahedral complex Rh(P(CH3)3)2(CO)(H)(Cl)Ph, which is unstable for extended periods at temperatures above 250 K and eliminates benzene to give Rh(P(CH3)3)2(CO)CI (t1/2 = 12.3 min at 265 K). The structures of Rh(P(CH3)3)2(CO)CI, Rh(P(CH3)3)2(CO)CH3, and Rh(P(CH3)3)2(CO)Ph were determined by X-ray crystallography. All three complexes are square-planar. Rh(P(CH3)3)2(CO)CH3 has a Rh-CH3 bond length of 2.130(9) angstrom, and Rh(P(CH3)3)2(CO)Ph has a Rh-C(phenyl) bond length of 2.096(4) angstrom. Crystals of Rh(P(CH3)3)2(CO)Cl are orthorhombic, space group Pcab, with a = 11.523(2) angstrom, b = 11.807(2) angstrom, c = 19.843(2) angstrom, V = 2699.7(6) angstrom3, and Z = 8. Crystals of Rh(P(CH3)3)2(CO)CH3 are monoclinic, space group P2(1)/n, with a = 9.944(5) angstrom, b = 10.136(3) angstrom, c = 13.266(6) angstrom, beta = 94.06(4)-degrees, V = 1334(1) angstrom3, and Z = 4. Crystals of Rh(P(CH3)3)2(CO)Ph are monoclinic, space group C2/c, with a = 13.406(6) angstrom, b = 11.797(4) angstrom, c = 11.033(7) angstrom, beta = 109.57(2)-degrees, V = 1644(2) angstrom3, and Z = 4.