Photochemical Synthesis of Tungsten Pentafluoride, WF₅

A new synthetic route for the synthesis of WF₅ utilizing a mercury photosensitized reduction of tungsten hexafluoride with H₂ is described. Crystals of WF₅ were studied using single-crystal X-ray diffraction, resulting in the first-reported crystal structure of WF₅. Powder X-ray diffraction studied at room-temperature showed the compound was phase-pure. The IR spectrum of WF₅ was reinvestigated and interpreted with the use of solid-state quantum-chemical calculations using the DFT-PBE0 density functional method. The compound synthesized herein was free of HF and moisture but may have contained minute amounts of WOF₄, that were only observed in the IR spectrum.