Reactivity of [WCl6] with Ethers: A Joint Computational, Spectroscopic and Crystallographic Study

The reactions of [WCl 6 ] with a series of ethers have been performed in chlorinated solvent and elucidated by means of analytical, spectroscopic and DFT methods. The addition of tetrahydropyran (thp) or 1,4‐dioxane to [WCl 6 ] resulted in the reversible formation of the adducts WCl 6 ···L [L = thp ( 1a ), 1,4‐dioxane ( 1b )], detected in solution by NMR spectroscopy. The reaction of [WCl 6 ] with thp in a molar ratio of 1:2 in chloroform at reflux afforded [WOCl 4 (thp)] ( 2a ), which was isolated in 51 % yield. [WOCl 4 (OMe 2 )] ( 2b ) and [WOCl 3 (OMe 2 ) 2 ] ( 3a ) were isolated in yields of 53 and 18 %, respectively, from the reaction of [WCl 6 ] with an excess of dimethyl ether. [WOCl 3 (OEt 2 ) 2 ] ( 3b ) was the only identified metal compound produced from the reaction of [WCl 6 ] and OEt 2 (1:2 molar ratio). According to NMR studies, the oxide ligand in 2a , b and 3a , b was generated by double C–O bond cleavage involving one equivalent of organic reactant. The 1:1 reaction of [WCl 6 ] with 1,2‐diethoxyethane led to [WCl 5 (κ 1 ‐OCH 2 CH 2 OEt)] ( 4 ) and a minor amount of [WCl 4 (κ 2 ‐EtOCH 2 CH 2 OEt)] ( 5 ). The aryl oxide compound [WCl 5 (OPh)] ( 6 ) was prepared in 62 % yield from the reaction of [WCl 6 ] and anisole by selective C sp3 –O bond activation. The prolonged heating of a mixture of [WCl 6 ] and diphenyl ether in 1,2‐dichloroethane led to the isolation of the W V complex [WCl 5 (OPh 2 )] ( 7 ). The molecular structures of 2a and 3a were ascertained by X‐ray diffraction.