New synthetic route to WSF4 and its solution-phase structure as determined by tungsten L(III)-edge extended X-ray absorption fine structure studies

Abstract

The compound WSF₄ was synthesized in one step by the reaction of WF₆ with (Me₃Si)₂S in solution at ambient temperatures. Solution-phase structural data have been obtained for the first time for it and related tungsten chalcogenide tetrahalides via a tungsten L(III)-edge EXAFS (extended X-ray absorption fine structure) study. This demonstrates that WOF₄, WOCl₄ and WSF₄ in acetonitrile or dichloromethane solution are monomeric. For WSF₄ analysis of the EXAFS data yielded bond lengths of 2.026(8)(WS) and 1.863(3)Å(W–F). The WS bond length is shorter than previously determined, by gas-phase electron diffraction, but is more consistent with that found in related structures.