Reaction of a heterotopic P,SAs ligand with group 10 metal(II) complexes: As-S bond cleavage and the formation of two unusual trinuclear structural isomers for Pd and Pt

The synthesis of the heterotopic P,SAs ligand, 1-Ph(2)AsSC(6)H(4)-2-PPh(2) (1) and its reaction with PdCl(2)(cod)], PtI(2)(cod)] (cod = 1,5-cyclooctadiene) and NiCl(2)·6H(2)O is reported. Cleavage of the As-S bond of 1 and coordination of the resulting phosphanylthiolato ligand (SC(6)H(4)-2-PPh(2))(-) (SC(6)H(4)-2-PPh(2) = P,S) was observed with formation of M(P,S)(2)] (M = Ni, Pd, Pt). In the case of Pd and Pt, not only the mononuclear complexes M(P,S)(2)] formed, but also the trimers of MX(P,S)] (MX{(μ-S-SC(6)H(4)-2-PPh(2))-κ(2)S,P}](3) M = Pd, X = Cl (2) and M = Pt, X = I (4)]). Formation of 2 and 4 was preceded by the trinuclear isomeric intermediates (cis-M{(μ-S-SC(6)H(4)-2-PPh(2))-κ(2)S,P}(2))-MX(2)-MX{(μ-S-SC(6)H(4)-2-PPh(2))-κ(2)S,P}] M = Pd, X = Cl (3) and M = Pt, X = I (5)]. The crystal structures of 1-5 and a possible reaction mechanism that leads to 2 and 4 are presented.