Iodine(I) fluorosulfonate is an inorganic compound of iodine, sulfur, fluorine, and oxygen with the chemical formula . This is a monovalent compound of iodine from the group of fluorosulfonates.
Like the other halofluorosulfonates, iodine(I) fluorosulfonate can be obtained from iodine and peroxydisulfuryl difluoride:
Reaction with iodine at 85 ðC can convert iodine(I) fluorosulfate to triiodine fluorosulfonate.
When dissolved in carbon tetrachloride, iodine monochloride, peroxydisulfuryl difluoride, and phosgene are formed:
However, carbon dioxide can also be produced instead of phosgene:
The compound forms black crystals.