Synthesis of [M3H(CO)9(µ3-σ:η2:η2-C6H7)](M = Ru or Os). Molecular and crystal structure of the ruthenium cluster

Abstract

The dienyl cluster compounds [M₃H(CO)₉(µ₃-σ:η²:η²-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 [Ru₃H(CO)₉(C₆H₇)] has been established by single-crystal X-ray diffraction analysis: monoclinic, space group P2₁, a= 8.487(6), b= 12.031(3), c= 9.073(2)Å, β= 92.43(4)° and Z= 2. The cyclohexadienyl ligand is involved in one σ and two π interactions with the metal triangle, while the H(hydride) ligand bridges the long Ru–Ru bond [3.052(1)Å]. The other two Ru–Ru bond lengths are the same [2.837(1)Å] and comparable to those observed in [Ru₃(CO)₉(µ₃-η²:η²:η²-C₆H₆)]. The H(hyride) 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 ⋯ O intermolecular hydrogen-bonding interactions.