Synthesis and X-ray Structures of [Os3Pt(CO)9(μ4-η2-C≡CPh)(η1-C≡CPh)(L)] (L = 4,4′-Dimethyl-2,2′-bipyridine, 4,4′-bis(tert-butyl)-2,2′-bipyridine): New Heterometallic Clusters with a μ4-η2- and an η1-Acetylide Group on a Spiked-Triangular Metal Core

Treatment of [Os3(CO)10(NCMe)2] with platinum bis(alkynyl) complexes cis-[Pt(C≡CPh)2(L)] [L = 4,4′-dimethyl-2,2′-bipyridine (Me2bipy), 4,4′-bis(tert-butyl)-2,2′-bipyridine (tBu2bipy)] at room temperature readily affords the novel, spiked-triangular heterometallic cluster complexes [Os3Pt(CO)9(μ4-η2-C≡CPh)(η1-C≡CPh)(L)] (L = Me2bipy 1, tBu2bipy 2) in moderate yields. X-ray analysis of both complexes reveals that one alkynyl moiety is coordinated to the metal atoms in a μ4-η2(||) mode, accompanied by a concomitant transfer of an η1-C≡CPh group from the platinum centre to the osmium atom to give a metal framework with an osmium atom apically bonded to an Os2Pt triangle.