It is an isomer of disulfur difluoride (difluorodisulfane) F−S−S−F.

[1][2][clarification needed] Another possible preparation is by the reaction of nitrogen trifluoride with sulfur.

[1] It also forms from disulfur difluoride when in contact with alkali metal fluorides.

[3] S=SF2 can also be synthesized with the reaction of potassium fluorosulfite and disulfur dichloride: Thiothionyl fluoride is a colorless gas.

[5] It condenses with sulfur difluoride at low temperatures to yield 1,3-difluoro-trisulfane-1,1-difluoride.