PREPARATION OF DOUBLY ACETYLIDE-BRIDGED BINUCLEAR PLATINUM PLATINUM AND PLATINUM PALLADIUM COMPLEXES - STRUCTURES OF [((DPPE)PT(CCPH)2)PT(C6F5)2] AND (PMEPH3)2[(C6F5)2PT(MU-CCPH)2PT(C6F5)2]

The reaction between [cis-Pt(C=CR)2L2] (R = Ph, (t)Bu; L2 = 2 PPh3, dppe, COD) and [cis-M(C6F5)2-(THF)2] (M = Pd, Pt; THF = tetrahydrofuran) in a 1:1 molar ratio affords neutral binuclear derivatives of the type [{L2Pt(C=CR)2}M(C6F5)2] in which the RC=C-Pt=CR group is acting as a bidentate ligand to "M(C6F5)2". In contrast, [cis-M(C6F5)2(THF)2] reacts with Q2[Cis-Pt(C6F5)2(C=CR)2] and Q2-[Pt(C6F5)(C=CR)3] (R = Ph, Q = PMePh3; R = (t)Bu, Q = NBu4) to give anionic diplatinum and platinum-palladium complexes of types Q2[(C6F5)2Pt(mu-C=CR)2M(C6F5)2] and Q2[(C6F5)(C=CR)Pt(mu-C=CR)2Pt(C6F5)2], respectively. The crystal structures of the complexes [{(dppe)Pt(C=CPh)2}Pt(C6F5)2] (3) and (PMePh3)2[(C6F5)2Pt(mu-C=CPh)2Pt(C6F5)2] (9) have been established by X-ray diffraction methods. 3 is a binuclear complex in which the unit "(dppe)Pt(sigma-C=CPh)2" acts as a chelate metallo ligand to "Pt(C6F5)2". In contrast, the crystal structure for 9 shows that two identical [(C6F5)2Pt-C=CPh] units are joined together through eta-2 bonding of C=CPh groups. This indicates that the complex is formed from the bis(sigma-alkynyl)bis(pentafluorophenyl)platinate and the synthon Pt(C6F5)2 via migration of one sigma-alkynyl group between the two platinum metal centers.