Facile E-E and E-C bond activation of PhEEPh (E = Te, Se, S) by ruthenium carbonyl clusters: Formation of Di- and triruthenium complexes bearing bridging dppm and phenylchalcogenide and capping chalcogenido ligands

Reactions of [Ru-3(CO)(10)(mu-dppm)] (1) and its ortho-metalated derivative [Ru-3(CO)(9){mu(3)-eta(3)- P(C6H5)CH2P(C6H5)(C6H4)}] (11) with PhEEPh (E = Te, Se, S) have been investigated. Treatment of 1 with PhTeTePh at room temperature afforded the dinuclear compound [Ru-2(CO)(4)(mu-TePh)(2)(mu-dppm)] (2) and the 54-electron triruthenium compounds [Ru-3(CO)(6)(mu(3)-Te)(2)(mu-TePh)(2)(mu-dppm)] (3) and [Ru-3(CO)(6)(mu(3)-Te)(mu-TePh)(3)(eta(1)-COPh)(mu-dppm)] (4). Analogous reactions of 1 with PhEEPh (E = Se, S) led to [Ru-2(CO)(4)(mu-EP[Ru-3(CO)(6)(mu(3)-E)(2)(mu-EPh)(2)(mu-dppm)])(2)(mu-dppm)] (E = Se, 5; E = S, 8) and the 54-electron triruthenium compounds (E = Se, 6; E = S, 9), and [Ru-3(CO)(6)(mu(3)-E)(mu-EPh)(3)(Ph)(mu-dppm)] (E = Se, 7; E = S, 10). Reactions of the ortho-metalated complex 11 with PhEEPh (E = Te, Se, S) in refluxing THF gave exclusively [Ru-3(CO)(6)(mu-EPh)(2)(mu(3)-eta(3)-P(C6H5)CH2P(C6H5)(C6H4)}] (E = Te, 12; E = Se, 13; E = S, 14). The new compounds have been characterized by a combination of analytical and spectroscopic methods, and molecular structures of 2-4, 7, 10, and 13 have been determined by single-crystal X-ray diffraction studies. Compounds 2, 5, and 8 have the classical "sawhorse" structure with two bridging EPh (E = Te, Se, S) moieties and one bridging dppm ligand. Compounds 3, 6, and 9 contain a Ru-3 framework with two bridging EPh (E = Te, Se, S) groups, one bridging dppm ligand, and two capping chalcogenido ligands. Compound 4 contains an Ru-3 core with a capping tellurido ligand, three bridging TePh moieties, one bridging dppm ligand, and a terminally coordinated benzoyl group, formed from multiple fragmentation of the PhTeTePh ligand and migratory insertion of a Ph group into a CO ligand. Compounds 7 and 10 comprise a capping chalcogenido ligand, three bridging EPh (E = Se, 7; E = S, 10) moieties, a bridging dppm ligand, and a terminally coordinated a-bonded phenyl group. In compounds 12-14, the coordination of ortho-metalated diphosphine ligand is the same as in 11 and both the EPh moieties bridge the same unbridged Ru-Ru edge. Compounds 3, 6, 7, and 10 exhibit restricted fluxional behavior involving the mu-EPh moieties.