SYNTHESIS AND REACTIVITY OF CARBONYLBIS(TRIPHENYLPHOSPHINE)RHODIUM(I) COMPLEXES OF WATER AND WEAKLY COORDINATING ANIONS

New complexes trans-Rh(PPh3)2(CO)OPOF2 and [trans-Rh(PPh3)2(CO) (OH2)]Z.nH2O (Z = SO3CF3, n = 1; Z = BF4, n = 2; Z = ClO4, n = 2) were prepared and characterized. Syntheses of the four species entailed metathesis of the Rh(I) chloride with AgPF6, AgSO3CF3, AgBF4, and AgClO4, respectively, in undried solvents. The water-free OPOF2 complex arises from hydrolysis of a spectroscopically detected Rh(I) PF6- species. Metathesis studies with [N(PPh3)2]+ salts and reactions with pyridine and CO showed the affinity of [Rh(PPh3)2(CO)]+ in CH2Cl2 for ligands L to follow the trend L = (O2CCF3)- > (ONO2)- > pyridine > (OPOF2)- >> H2O >> (SO3CF3)- almost-equal-to (BF4)- almost-equal-to (ClO4)-. Monoolefins such as C2H4 and PhCH = CH2 failed to displace the very weakly coordinating ligand H2O from [Rh(PPh3)2(CO)(OH2)]SO3CF3.H2O in CH2Cl2. The crystal structure of [Rh(PPh3)2(CO)(OH2)][BF4].1/2H2O.1/4C6H12 has been determined. The crystal belongs to the triclinic crystal system, space group P1BAR, with lattice constants a = 11.865 (2) angstrom, b = 17.235 (6) angstrom, c = 18.590 (5) angstrom, alpha = 91.95 (2)-degrees, beta = 101.62 (2)-degrees, gamma = 101.83 (2)-degrees, and Z = 4.