Disulfur difluoride
Disulfur difluoride is an inorganic compound with the chemical formula . It is a halide of sulfur. Structure 
Disulfur difluoride has a chain structure . The angle between the  and  planes is 87.9°, while the angles of  and  are equivalent, and are equal to 108.3°. Both  bonds are equivalent and their length is 163.5 pm, while the length of the  bond is 189 pm. This structure is referred to as gauche, and is similar to . There is a branched isomer of disulfur difluoride, thiothionyl fluoride, with the structure . Synthesis 
Silver(II) fluoride can fluorinate sulfur in a strictly dry container at , and the reaction produces :

Reactions 
Disulfur difluoride undergoes intramolecular rearrangement in the presence of fluorides of alkali metals, yielding the isomer S=SF2:

 Decomposing to sulfur tetrafluoride and sulfur when heated to 180 °C:

 Hydrolysis:

 Reacting with sulfuric acid at 80 °C:

 Reacting with sodium hydroxide:

 Reacting with oxygen at high pressure, using nitrogen dioxide as a catalyst:

References 

Disulfides
Nonmetal halides
Sulfur fluorides