Preparation and structural investigations of fluorinated tungsten(vi) alkoxides

The preparation and characterization of compounds of composition Cl6-xW(OCH2CF3)x (x = 1−6) and X4W[OC(CH3) (CF3)2]2 (X = Cl,F) together with 19F NMR spectra are reported. An X-ray structure analysis of Cl4W[OC(CH3)(CF3)2]2 shows a W-O-C angle of 173.6°, which is unusually large for metal alkoxides, and a short W-O distance of 181.9 pm. A discussion on structural aspects and a comparison with related tungsten-nitrogen compounds are presented. Cl4W[OC(CH3) (CF3)2]2 is monoclinic, space group C2/m, with a = 820.3(2), b = 1059.2(2), c = 1071.6(2) pm, β = 99.72(2)°, Z = 2 and was refined to R = 0.031 for 848 observed reflections.