Interhalogen compounds exhibit various chemical properties and reactivities. AX-type interhalogens like ICl hydrolyze to form hydrogen halides and hypohalous acids. ClF3 and BrF3 can fluorinate metal oxides to form metal fluorides and oxygen. Higher interhalogens like ClF5 and IF7 can ionize to form polyatomic ions. IF7 reacts with water to form IOF5 and HF, and with silicon dioxide to form IOF5 and silicon tetrafluoride.

1. Chemical properties of Interhalogen
compounds
Dr. Mithil Fal Desai| Shree Mallikarjun and Shri Chetan Manju Desai College
Canacona, Goa

2. Reactivity
Interhalogens are more reactive than halogens (except F2)
Hydrolysis
ICl + H2O HCl + HIO
Cl2 + H2O HCl + HClO
hypoiodous acid
hypochlorous acid
BrF5 + 3H2O 5HF + HBrO bromic acid
Fluorinate metal oxides
UO2 + 4BrF5 3UF4 + 2Br2 +3O2
3UF4 + ClF3 UF6 + ClF

3. AX type interhalogen compounds and chemical
reactivity
Fluorination
6ClF + 2 Al 2AlF3 + 3Cl2
6ClF + U UF6 + 3Cl2
6ClF + S SF6 + 3Cl2
Simultaneous Chlorination and Fluorination
ClF + CO COClF
ClF + SF4
SClF5
ClF + SO2
SO2ClF
Wij’s reagent
R
1
R
2
ICl
R
1
R
2
I
Cl
Chlorination and iodination
OH
O
OH
ICl vapour
ICl in nitrobenzene
iodination chlorination
Addition compounds with alkali halide
NaBr + ICl Na[BrICl]
KI + ICl K[I2Cl]
ClF
BrF
IF
BrCl
ICl
IBr

4. AX3 type interhalogen compounds and chemical
reactivity
ClF3 BrF3
IF3 (ICl3)2
ClF3 + Cl2
3ClF
3ClF3 + U UF6 + 3ClF
4ClF3 + 6MgO 6MgF2 + 2Cl2 +3O2
4ClF3 + 2Al2O3 4AlF3 + Cl2 + 2ClF
2ClF3 + 2AgCl 2AgF2 + Cl2 + 2ClF
2ClF3 + 2NH3 6HF + Cl2 + N2
ClF3 + BrF3 [ClF2]+
+ [BF4]-
ClF3 + SbF5 [ClF2]+
+ [SbF6]-
ClF3 + PtF5 [ClF2]+
+ [PtF6]-
4ClF3 + 3N2H4 12HF +3N2 + 2Cl2

5. AX3 type interhalogen ccompounds and chemical
reactivity
ClF3 BrF3
IF3 (ICl3)2
BrF3 + 3SiO2 3SiF4+ 2Br2 + 3O2
BrF3 + 3TiO2 3TiF4+ 2Br2 + 3O2
BrF3 as non-aqueous solvent
-m.p 8.8 ° C and b. p. 126 °C
- Not violent
- Considerable self ionisation than ClF3
2BrF3
[BrF2]+
+ [BrF4]-
Order of reactivity
ClF3 > BrF5 > IF7 > ClF > BrF3 > IF5 > BrF > IF3 > IF

6. AX5 type interhalogen ccompounds and chemical
reactivity
ClF5 BrF5
IF5
3ClF5 + 2H2O FClO2 + 4HF
BrF5 + 3H2O HBrO3 + 5HF
BrF5 + SiO2 SiF4+ 5BrF3 + O2
BrF5 + CsF Cs[BrF6]
IF5 + KI K[IF6]
IF5 [IF4]+
+ [IF6]-

7. AX7 type interhalogen ccompounds and chemical
reactivity
IF7
Preparation
KI + 4F2 IF7 + KF
PdI2 + 8F2
2IF7 + PdF2
Reactions
IF7 + H2O IOF5 + HF
IF7 + SiO2
2IOF5 + SiF4
IF7 + CsF Cs[IF8]