SYNTHESIS OF [M3H(CO)9(MU-3-SIGMA-ETA(2)-ETA-2-C6H7)] (M = RU OR OS) - MOLECULAR AND CRYSTAL-STRUCTURE OF THE RUTHENIUM CLUSTER

The dienyl cluster compounds [M3H(CO)9(mu3-sigma:eta2:eta2-C6H7)] (M = Ru or Os) have been synthesised from [Os3H2(CO)10] or [M3(CO)10(MeCN)2] (M = Ru or Os) with cyclohexa-1,3-diene. The molecular and crystal structure of [RuH(CO)9(C6H7)] has been established by single-crystal X-ray diffraction analysis: monoclinic, space group P2(1), a = 8.487(6), b = 12.031(3), c = 9.073(2) angstrom, beta = 92.43(4)-degrees and Z = 2. The cyclohexadienyl ligand is involved in one sigma and two pi interactions with the metal triangle, while the H (hydride) ligand bridges the long Ru-Ru bond [3.052(1) angstrom]. The other two Ru-Ru bond lengths are the same [2.837(l) angstrom] and comparable to those observed in [Ru3(CO)9(mu3-eta2:eta2:eta2-C6H6)]. The H(hydride) position afforded by the diffraction experiment has been compared with the result of potential-energy minimization procedures. The molecular organization within the lattice has been explored by means of atom-atom packing potential-energy calculations showing the presence of a network of C-H ... 0 intermolecular hydrogen-bonding interactions.