ASYMMETRIC MONOCATIONIC AND DICATIONIC GOLD(II) COMPLEXES - X-RAY STRUCTURE OF UOH2](CLO4)(2)CENTER-DOT-2CH(2)CL(2)CENTER-DOT-H2O

The reaction of [(tht)Au(CH(2)PPh(2)CH(2))(2)Au(tht)](ClO4)(2) (tht = tetrahydrothiophene) with [Ag(OClO3)PR(3)] (PR(3) = PPh(3), PPh(2)Me o r P(4-MeOC(6)H(4))(3)) gives [R(3)PAu(CH(2)PPh(2)CH(2))(2)Au(tht)](ClO 4)(2). Displacement of weakly coordinated ligands gives new dicationic ([R(3)PAu(CH(2)PPh(2)CH(2))(2)AuL](ClO4)(2) (L = py, AsPh(3), PPh(2)M e or OH2)) or monocationic complexes ([R(3)PAu (CH(2)PPh(2)CH(2))(2)Au X]ClO4 (X = Cl, S2CN(CH(2)Ph)(2) or OClO3)). The structure of [MePh(2) PAu(CH(2)PPh(2)CH(2))(2)Au(OH2)]ClO4 was confirmed by single-crystal X -ray diffraction analysis. The (197)AU Mossbauer spectra of [Ph(3)PAu( CH(2)PPh(2)CH(2))(2)Au(tht)](ClO4)(2) is reported and compared with ot her symmetric or asymmetric dinuclear gold(II) complexes.