A very labile monomeric 1,5-cyclooctadiene complex of W(II) and its transformation to dimeric [(μ-Cl)2W2(GeCl3)2(CO)6(NCMe)2]

The photochemical oxidative addition of 1 equiv. of GeCl4 to [W(CO)4(η2,η2-1,5-C8H12)] affords the very labile seven-coordinate complex of tungsten(II) [WCl(GeCl3)(CO)3(η2,η2-1,5-C8H12)] (1). The structure of compound 1 has been established by IR and 1H NMR spectroscopic methods. A very labile 1,5-cyclooctadiene ligand of 1 in dichloromethane/acetonitrile solution leaves the coordination sphere of tungsten to give a dimeric seven-coordinate compound of tungsten(II) [(μ-Cl)2W2(GeCl3)2(CO)6(NCMe)2] (2). The crystal structure of a new dimeric compound containing W–Ge bonds (2) was determined by X-ray diffraction studies.