Iodine monofluoride

Iodine monofluoride is an <a href="/facts/Interhalogen_compound/TBED2c9B">interhalogen compound</a> of <a href="/facts/Iodine/JlfMecMf">iodine</a> and <a href="/facts/Fluorine/YUV0Fb8m">fluorine</a> with formula IF. It is a chocolate-brown solid that decomposes at 0 °C, <a href="/facts/Disproportionation/67QMkXrV">disproportionating</a> to elemental iodine and <a href="/facts/Iodine_pentafluoride/fKRhn5NA">iodine pentafluoride</a>:

5 IF → 2 I2 + IF5
However, its molecular properties can still be precisely determined by <a href="/facts/Spectroscopy/mj71FuNK">spectroscopy</a>: the iodine-fluorine distance is 190.9 pm and the I−F <a href="/facts/Bond_dissociation_energy/wdDb5yHN">bond dissociation energy</a> is around 277 kJ mol−1. At 298 <a href="/facts/Kelvin/E3trzC4C">K</a>, its <a href="/facts/Standard_enthalpy_change_of_formation/UFgGC7UQ">standard enthalpy change of formation</a> is ΔfH° = −95.4 kJ mol−1, and its <a href="/facts/Gibbs_free_energy/bvenDuzh">Gibbs free energy</a> is ΔfG° = −117.6 kJ mol−1.
It can be generated, albeit only fleetingly, by the reaction of the elements at −45 °C in <a href="/facts/Trichlorofluoromethane/bx7YxsjC">CCl3F</a>:

I2 + F2 → 2 IF
It can also be generated by the reaction of iodine with <a href="/facts/Iodine_trifluoride/pAnsUKaG">iodine trifluoride</a> at −78 °C in CCl3F:

I2 + IF3 → 3 IF
The reaction of iodine with <a href="/facts/Silver(I)_fluoride/2tLglyn5">silver(I) fluoride</a> at 0 °C also yields iodine monofluoride:

I2 + AgF → IF + AgI

Iodine monofluoride open-in-new

Iodine monofluoride