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

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.