Thionyl Fluoride

image [7783‐42‐8] SOF 2 (MW 86.061) InChI = 1S/F2OS/c1‐4(2)3 InChIKey = LSJNBGSOIVSBBR‐UHFFFAOYSA‐N (reagent used for fluorination, nucleophilic acyl substitutions including one‐pot peptide coupling and introduction of S(O)F group) Alternative Names: sulfinyl fluoride, sulfur difluoride oxide, sulfur difluoride monoxide, sulfurous oxyfluoride, thionyl difluoride. Physical Data: mp −129.5 °C, bp −43.8 °C, d 1.758 g cm −3 . Solubility: soluble in ethanol, ether, and benzene. Hydrolyzes in water. Form Supplied in: colorless gas packaged in cylinders, commercially available. Analysis of Reagent Purity: singlet in 19 F NMR at δ −72.2. 1,2 IR (cm −l ) 1333, 808, 748, 530, 410, 390. 3 Preparative Methods: thionyl fluoride is typically generated from thionyl chloride and a fluoride salt followed by condensation of the resulting gas. 4 More conveniently, it can be generated ex situ, bubbled in various organic solvents, and used directly or kept as a stock solution. 5 It is also one of the major decomposition products of sulfur hexafluoride under electric discharges, by hydrolysis of sulfur tetrafluoride in air. 6 Purification: fractionated distillation through a low‐temperature column. Handling, Storage, and Precautions: toxic gas that should be handled in a well‐ventilated fume hood.