Dithiophosphinates of gold(I); oxidative addition of Cl-2 to a neutral, dinuclear gold(I) dithiophosphinate complex, and X-ray crystal structures of [AuS2P(C2H5)(2)](2), [AuS2PPh2](2), Au-2(CH2)(2)PMe2(S2PPh2), and Au2Cl2[(CH2)(2)PMe2][S2PPh2]

The formation and characterization of dinuclear gold(I) dialkyl- and diaryl -dithiophosphinate complexes of the type [AuS2PR2](2) are described. The co mplexes are readily prepared from the reaction between a chloro-gold(I) sta rting material and the corresponding dithiophosphinate salt. The structures of the complexes show both the absence (R = Et, 1) and presence (R = Ph, 2 a) of intermolecular Au . . . Au interactions as confirmed by X-ray crystal lographic study in the solid state. Reaction between [AuS2PPh2](2) and [Au( CH2)(2)PMe2](2) in CH2Cl2 solution leads to a ligand transfer reaction to f orm the hetero-bridged complex [Au-2{(CH2)(2)PMe2S2PPh2}] (3a) in high yiel d. Additionally, the latter complex reacts with Cl-2 to form the oxidative addition product [Au2Cl2{(CH2)(2)PMe2S2PPh2}] (4), the first gold(II) compl ex with a S-P-S bridging moiety. The X-ray crystal structure of both 3a and 4 exhibit rare boat conformations in the solid state, and 4 has a formal A u(II)-Au(II) single bond of 2.5611(5) Angstrom. Reaction between [AuS2PPh2] (2) and dppm (dppm = Ph2PCH2PPh2) leads to a sparsely soluble three-coordin ate dinuclear gold(I) complex with the molecular formula [Au-2{dppmS(2)PR(2 )}(2)](n) (n = 1 or infinity) (5).