Exchange processes in halogen fluorides

Redistribution and Exchange Reactions in Groups IIB-VIIB

“…Halogen fluorides both alone and in admixture with other fluorides undergo rapid exchange of fluorine (33,93). Ionic or associative mechanisms have been proposed for both, but recently intramolecular mechanisms have been suggested for the halogen fluoride alone.…”

“…Iodine pentafluoride and bromine pentafluoride differed from the other halogen fluorides in requiring high temperatures for rapid halogen exchange (138). Activation energies were also higher than for halides of different symmetry, and the exchange was much less sensitive to impurities (93). Addition of potassium fluoride to iodine pentafluoride, which is thought to form the hexafluoroiodate (62), caused a rapid halogen exchange at room temperature (137,186).…”

“…Compounds most sensitive to exchange with fluorinecontaining impurities may in fact undergo catalyzed intermolecular exchange. Their reactivity makes it very difficult in practice to obtain extremely pure samples for analysis, and the information given in Table XX for chlorine trifluoride has been criticized on these grounds (93). Intramolecular exchange is not fully established except for the phosphorane, some group III compounds, and perhaps sulfur tetrafluoride.…”