Synthesis and spectroscopic characterisation of closo-Ru-4(CO)(12)(mu(4),eta(2)-HC2Ph) and closo-Ru-4(CO)(9)(mu-CO)(2)(mu(4),eta(2)-HC2Ph)(mu(4)-Se). Crystal structure of closo-Ru-4(CO)(12)(mu(4),eta(2)-HC2Ph)

Abstract

Reaction of the chalcogen stabilised butterfly cluster Fe-2(CO)(6){mu-SeC(H)=C(Ph)Se} with Ru-3(CO)(12) occurs under thermal conditions affording the clusters FeRu2(CO)(9)(mu-Se)(2) (2), closo-Ru-4(CO)(12)(mu(4) eta(2)-HC2Ph) (3) and closo-Ru-4(CO)(9)(mu-CO)(2)(mu(4),eta(2)-HC2Ph)(mu(4)-Se) (4) in 30%, 22% and 18% yield respectively. They were characterised by IR and H-1, C-13 and Se-77 NMR spectroscopy. Compound 3 was further characterised by X-ray methods: space group P2(1)/n, a = 20.138(4), b = 9.333(2), c = 26.219(6) Angstrom, beta = 97.43(2)degrees, Z = 8, rho(calc) = 2.291 gcm(-3). The structure was solved using direct methods and was refined to the final values of the residuals R = 0.0377 and R-w = 0.0455. The molecule consists of a butterfly arrangement of four ruthenium atoms with a quadruply bridged alkyne ligand. Compound 4 was characterised by comparison of its spectroscopic data with that of the analogous S-compound.