MULTI-SITE BONDED HYDROCARBYLS ON OSMIUM CLUSTERS. THE REACTIONS OF HYDRIDOACETYLIDE AND HYDRIDOVINYLIDENE-OSMIUM CLUSTERS WITH 2 AND OF (η-C5H5)2Ni2(HC2But) WITH OSMIUM CARBONYLS. SYNTHESIS AND CRYSTAL STRUCTURE OF (η-C5H5)Ni(μ-H)Os3(CO)9(μ4-η2-C=CHBut)

Article abstract of DOI:10.1016/S0022-328X(00)98734-5

The heterometallic cluster (η-C5H5)Ni(μ-H)Os3(CO)9(C=CHBu^t) has been obtained in low yield by treating hydridoacetylide- or hydridovinylidene-osmium clusters with <(C5H5)Ni(CO)>2 under hydrogen.The structure of this complex has been determined by X-ray methods.The crystals are monoclinic, space group P2₁/n with a 15.412(9), b 16.916(10), c 9.088(6) Angstroem, β 94.22(4) deg and Z = 4.The structure was solved from diffractometer data by direct and Fourier methods and refined by full matrix least squares to a R = 0.037 for 2210 observed reflections.The metal cluster consists of a butterfly arrangement with the Ni atom occupying the wing tip site.The vinylidene is ?-bonded to two Os and the Ni atoms and η-coordinated to the third Os atom.An Os-Os edge is bridged by a hydridic hydrogen atom.The structure of this complex is very similar to that of the previously reported Ru-Ni analogues; a comparison is made between the bonding parameters for the vinylidene and related ligands in the different clusters.These butterfly complexes are structurally related to the iron clusters involved in the Fischer-Tropsch reaction; the formation mechanism of the vinylidene butterfly derivatives and the role of molecular hydrogen in their formation reactions are discussed.