Crystal and molecular structure of the di-μ-hydroxo-dimolybdenum compound, [Mo(CO)2(OH)(C4H7)(3,5-diMepzH)]2•C6H6

Abstract

The synthesis and X-ray crystal analysis of a hydroxy-bridged molybdenum dimer are described. Crystals of di-μ-hydroxo-bis [dicarbonyl(3,5-dimethylpyrazole)(η3-2-methylallyl)molybdenum(II)] benzene solvate are monoclinic, P21/c, a = 7.508(1), b = 20.747(1), c = 20.717(3) Å, β = 99.536(6)°, Z = 4. The structure was determined by Patterson and Fourier methods and refined by full-matrix least-squares procedures to R = 0.022 for 3197 observed reflections. The dimeric molecule contains two distorted Mo coordination octahedra sharing an OH … OH edge to form a central folded four-membered Mo(μ-OH)2Mo ring. The pyrazole ligands form bent N—H … O intramolecular hydrogen bonds to the bridging OH groups, and the other ligands occupy positions which result in approximate C2 molecular symmetry. Two sets of Mo—OH bonds differ significantly in length, 2.237(2) and 2.140(2) Å; other molecular dimensions are within expected ranges. Molecules are linked into chains along a by O—H … OC hydrogen bonds, and benzene solvate molecules are well defined.