Isonitrile-containing platinum-gold phosphine clusters

PtAu-phosphine clusters with an isonitrile ligand on Pt or both Pt and Au can be synthesized from [Pt(AuPPh3)8]2+. The reaction of one equivalent of RNC (R = i-Pr,t-Bu) with [Pt(AuPPh3)8]2+ results in the addition of RNC to the central Pt, to form [Pt(RNC)(AuPPh3)8]2+. The addition of an excess of RNC results in the replacement of one of the Au-bonded PPh3 ligands to give [Pt(RNC)(AuRNC)(AuPPh3)7]2+. Treatment of [Pt(CO)(AuPPh3)8]2+ with an excess of RNC does not result in displacement of the Pt-bonded CO ligand but only one of the Au-bonded PPh3 ligands, to yield [Pt(CO)(AuRNC)(AuPPh3)7]2+. Ag adducts of all of these compounds can be prepared by the addition of one equivalent of AgNO3.