NEUTRAL PTAG2 CLUSTERS CONTAINING UNSYMMETRICAL MU(3)-SIGMA AND MU-ETA(2),SIGMA ALKYNYL GROUPS - CRYSTAL-STRUCTURE OF [PTAG2(C6F5)(2)-(MU-ETA(2),SIGMA-C-CPH)(MU(3)-SIGMA-C-CPH)(PPH(3))(2)]CENTER-DOT-0.25CH(2)CL(2)

The reaction between [{PtAg2(C6F5)(2)(C=CR)(2)}(n)] and triphenylphosphine in a molar ratio of 1:2 has resulted in a good yield of the trinuclear mixed-metal complexes [PtAg2(C6F5)(2)(mu-eta(2),sigma-C=CR)(mu(3)-sigma-C=CR)(PPh(3))(2)] (R = Ph 3 or Bu(t) 4), and the crystal structure of 3 revealed that they contain two different types of unsymmetrical mu(3)-sigma and mu-eta(2),sigma-edge-bridging alkynyl ligands.