Thiothionyl fluoride
Thiothionyl fluoride is a chemical compound of fluorine and sulfur and an isomer of disulfur difluoride. Preparation. Thiothionyl fluoride can be obtained from the reaction between disulfur dichloride with potassium fluoride at about 150 °C or with mercury(II) fluoride at 20 °C. Another possible preparation is by the reaction of nitrogen trifluoride with sulfur. It also forms from disulfur difluoride when in contact with alkali metal fluorides. Properties. Thiothionyl fluoride is a colorless gas. At high temperatures and pressures, it decomposes into sulfur tetrafluoride and sulfur. With hydrogen fluoride, it forms sulfur tetrafluoride and hydrogen sulfide