American Chemical Society
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Syntheses, Structures, and Reactions of Di-μ-hydroxo Dinuclear Complexes of Tungsten(IV) and Molybdenum(IV)

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journal contribution
posted on 1996-01-23, 00:00 authored by Jian-Guo Ren, Hideshi Tomita, Makoto Minato, Takashi Ito, Kohtaro Osakada, Mikio Yamasaki
The title compounds have been prepared in good yields by reaction of Cp2MH2 (M = W or Mo) with Cp2M(OTs)2 (OTs = p-CH3C6H4SO3) in aqueous acetone. The products were investigated by IR, 1H NMR, and 13C NMR spectroscopy as well as by X-ray crystallography. The molecules of the two compounds are isostructural. The structures comprise a planar four-membered ring consisting of alternating M and O atoms. In methanol solution, 1H NMR chemical shifts for the cyclopentadienyl units of the complexes are significantly deshielded with respect to those for the parent dihydrides. The reactions between these complexes and tertiary phosphines in alcoholic solvents yield novel alkoxo complexes [Cp2M(PR3)(R‘O)]+(OTs-) (2) (R = Et, Bun, and Ph; R‘ = Me, Et, Pri, CF3CH2, and Ph). The structure of the complex with (R = Bun and R‘ = CF3CH2, determined by a single-crystal X-ray diffraction study, exhibits a distorted tetrahedral geometry with Mo−P = 2.540 Å and internal angle CP1−Mo−CP2 (CP is the centroid of the cyclopentadienyl ligand) = 132.8°.