The reactivity of tungsten hexachloride with tetrahydrofuran and 2-methoxyethanol

The ring opening polymerization reaction of tetrahydrofuran (thf) by WCl6 was investigated under different conditions, and the polymeric material was characterized by NMR and SEC (Size Exclusion Chromatography) analyses. The mixed valence complex [(thf)2(?-H)][{WOCl3(thf)}2(?-O)], 3, was isolated from the reactions of WCl6 with 4-8 equivalents of thf in dichloromethane at room temperature, and crystallographically characterized. The formation of 3 was preceded by that of WOCl4(thf), 2, while Cl(CH2)4Cl and Cl(CH2)4O(CH2)4Cl were identified as the prevalent organic side products. The 1:1 M reaction of WCl6 with MeO(CH2)2OH, in CH2Cl2 at room temperature, afforded the complexes (WOCl4)2(?-?2-1,4-dioxane), 4, and WCl5(OCH2CH2OMe), 5, in admixture with Cl(CH2)2Cl, MeO(CH2)2OMe and MeCl. Also complex 4, resulting from a Csingle bondO bond forming process, was characterized by X-ray crystallography.