Unsymmetrical alkyne binding to a triruthenium centre: Oxidative-addition of diphenyl ditelluride to the furyne cluster [Ru3(CO)7(μ-H)(μ3-η2-C4H2O){μ-P(C4H3O)2}(μ-dppm)]

Oxidative-addition of PhTe2Ph to the furyne cluster [Ru3(CO)7(μ-H)(μ3-η2-C4H2O){μ-P(C4H3O)2}(μ-dppm)] (1) results in the isolation of four complexes; (i) the previously reported 54-electron cluster [Ru3(CO)6(μ3-Te)2(μ-TePh)2(μ-dppm)] (5) which results from elimination of trifuryl phosphine, (ii) the furenyl cluster [Ru3(CO)5(μ-η2-C4H3O){μ-P(C4H3O)2}(μ-TePh)2(μ-dppm)] (6) which results from carbon-hydrogen bond formation and (iii) two new 50-electron complexes [Ru3(CO)5(μ-H)(μ3-η2-C4H2O){μ-P(C4H3O)2}(μ-TePh)2(к2-dppm)] (7) and [Ru3(CO)4(μ-H){P(C4H3O)3}(μ3-η2-C4H2O){μ-P(C4H3O)2}(μ-TePh)2(к2-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.