Synthesis and X-ray structures of [Os3Pt(CO)(9)(mu(4)-eta(2)-C CPh)-(eta(1)-C CPh)(L)] (L=4,4 '-dimethyl-2,2 '-bipyridine, 4,4 '-bis(tert-butyl)-2,2 '-bipyridine): New heterometallic clusters with a mu(4)-eta(2)- and an eta(1)-acetylide group on a spiked-triangular metal core

Treatment of [Os-3(CO)(10)(NCMe)(2)] with platinum bis(alkynyl) complexes c is-[Pt(C equivalent to CPh)(2)(L)] [L = 4,4'-dimethyl-2,2'-bipyridine (Me(2 )bipy), 4,4'-bis(tert-butyl)-2,2'-bipyridine (tBu(2)-bipy)] at room tempera ture readily affords the novel, spiked-triangular heterometallic cluster co mplexes [OS3Pt(CO)(9)(mu (4)- eta (2)-C drop CPh)(eta (1)-C drop CPh)(L)] ( L = Me(2)bipy 1, tBu(2)bipy 2) in moderate yields. X-ray analysis of both c omplexes reveals that one alkynyl moiety is coordinated to the metal atoms in a mu (4)-eta (2)(II) mode, accompanied by a concomitant transfer of an e ta (1)-C drop 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 .