Seisaku Kumai

The reaction of 1,2-diiodo-tetrafluoroethane with sulfur trioxide

Abstract As an extension of our studies on the reaction of I(CF 2 CF 2 ) n I (n = 2 and 3) with sulfur trioxide 1) , the reaction of 1,2-diiodo-tetrafluoroethane with sulfur trioxide was studied. 1,2-Diiodo-tetrafluoroethane was reacted with an excess of sulfur trioxide at reaction temperature ranging from 0°C to 115°C. The products were not the expected iododifluoroacetyl fluoride and/ or oxalyl fluoride, but thermally stable derivatives with polysulfate structures. These derivaties could be converted nearly quantitatively into iododifluoroacetyl fluoride and ethyl iododifluoroacetate by potassium fluoride and by ethanol, respectively. The possible structures of these derivatives will be discussed based on these results and 19 F-NMR studies.