Syntheses, Characterization, and Computational Study of WSF4 and WSF4-CH3CN

A new and improved synthetic route to WSF 4 was developed from the reaction of WF 6 and Sb 2 S 3 in anhydrous HF. Tungsten sulfide tetrafluoride was characterized by Raman and 19F NMR spectroscopy for the first time in HF solvent. Both studies provided evidence for its monomeric form in HF solution. In the solid state, WSF 4 was also characterized by Raman and infrared spectroscopy. The WSF 4 · CH 3 CN adduct was prepared from WSF 4 and CH 3 CN in anhydrous HF solvent and by the direct combination of WSF 4 with excess CH 3 CN, and was characterized by Raman and infrared spectroscopy in the solid state and 19 F NMR spectroscopy in CH 3 CN solution. The crystal structure of WSF 4· CH 3 CN was obtained and showed that CH 3 CN coordinates to W in an end-on fashion and trans to the W-S bond. Quantum-chemical calculations using B3LYP and PBE1 PBE methods were used to calculate the gas-phase geometries and vibrational frequencies of WSF 4 and WSF 4 · CH 3 CN.