Unsymmetrical alkyne binding to a triruthenium centre: Oxidative-addition of diphenyl ditelluride to the furyne cluster [Ru-3(CO)(7)(mu-H)(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-dppm)]

Oxidative-addition of PhTe2Ph to the furyne cluster [Ru-3(CO)(7)(mu-H)(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-dppm)] (1) results in the isolation of four complexes; (i) the previously reported 54-electron cluster [Ru-3(CO)(6)(mu(3)-Te)(2)(mu-TePh)(2)(mu-dppm)] (5) which results from elimination of trifuryl phosphine, (ii) the furenyl cluster [Ru-3(CO)(5)(mu-eta(2)-C4H3O){mu-P(C4H3O)(2)}(mu-TePh)(2)(mu-dppm)] (6) which results from carbon-hydrogen bond formation and (iii) two new 50-electron complexes [Ru-3(CO)(5)(mu-H)(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-TePh)(2)(kappa (2)-dppm)] (7) and [Ru-3(CO)(4)(mu-H){P(C4H3O)(3)}(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-T ePh)(2)(kappa(2)-dppm)] (8) both containing unsymmetrical furyne ligands. The structures of all the new compounds have been unambiguously established by single crystal X-ray crystallography. Further reactivity studies have provided a clear understanding of the relative sequence of the key oxidative-addition and reductive-elimination processes, showing that 6 is an intermediate in the formation of 7. DFT calculations have been used to shed light on the unsymmetrical binding of the furyne ligand in 7 and also to show that the adopted position of the heteroatom within the furyne ring can vary within complexes of this type. (C) 2010 Elsevier B.V. All rights reserved.