Iodine monofluoride is an interhalogen compound of iodine and fluorine with formula IF. It is a chocolate-brown solid that decomposes at 0 ðC, disproportionating to elemental iodine and iodine pentafluoride:
However, its molecular properties can still be precisely determined by spectroscopy: the iodine-fluorine distance is 190.9 pm and the IâÂÂF bond dissociation energy is around 277 kJ mol<sup>âÂÂ1</sup>. At 298 K, its standard enthalpy change of formation is ÃÂ<sub>f</sub>Hð = âÂÂ95.4 kJ mol<sup>âÂÂ1</sup>, and its Gibbs free energy is ÃÂ<sub>f</sub>Gð = âÂÂ117.6 kJ mol<sup>âÂÂ1</sup>.
It can be generated, albeit only fleetingly, by the reaction of the elements at âÂÂ45 ðC in CCl<sub>3</sub>F:
It can also be generated by the reaction of iodine with iodine trifluoride at âÂÂ78 ðC in CCl<sub>3</sub>F:
The reaction of iodine with silver(I) fluoride at 0 ðC also yields iodine monofluoride:
Iodine monofluoride is used to produce pure nitrogen triiodide: