Chemical reactions of interhalogens

1. Interhalogens
Dr. Mithil Fal Desai| Shree Mallikarjun and Shri Chetan Manju Desai College
Canacona, Goa

2. Chemical properties of
Interhalogen compounds

3. 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

4. AX type interhalogen ccompounds 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
ICl
Chlorination and iodination
OH
O
OH
ICl vapourICl in nitrobenzene
iodination chlorination
Addition compounds with alkali halide
NaBr + ICl Na[BrICl]
KI + ICl K[I2Cl]
ClF
BrF
IF
BrCl
ICl
IBr

5. AX3 type interhalogen ccompounds 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

6. 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

7. 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]-

8. 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]