Interhalogen compounds are formed by the direct combination of two halogen atoms with differing electronegativities, represented as XyN, where X has lower electronegativity. They can be synthesized through direct combination or by reacting lower interhalogen compounds with higher ones. These compounds have diverse applications, including as non-aqueous solvents, catalysts, and fluorinating agents, with varied structures and bonding based on hybridization principles.

1. INTER HALOGEN COMPOUNDS
DEPARTMENT OF CHEMISTRY
SEMBODAI R.V. ARTS AND SCIENCE COLLEGE
SEMBODAI – 614 809, VEDARANIAM – DT, NAGAPATTINAM – DT

2. INTERHALOGEN COMPOUNDS
DEFINITION
Compounds Produced By the Direct Combination of two halogen
atom of different electronegativity are called as inter halogen
compounds.
In General they are represented as
XYn
Where n= 1,3,5 or 7
X= Halogen atom with lower electronegativity and bigger size
Y= halogen atom with higher electronegativity and smaller size
Examples
ClF,BrF,BrF3,IF5,IF7,
Halogen F Cl Br I
EN Decreases
Size Increases

3. Types of Inter halogen Compounds
AX AX3 AX5 AX7
Diatomic IC Tetra-atomic IC Hexa-atomic IC Octa-atomic
IC
e.g. ClF, BrF, IF e.g. ClF3 BrF3 IF5 BrF5 IF7
Inter halogen Compounds are named as name of first halogen followed by
name of second halide with number of atoms i.e. ending –ine of halogen is
replaced by –de
e.g. i) ClF is named as Chlorine monofluoride.
ii) ClF3 is named as Chlorine trifluoride.
iii) BrF5 is named as Bromine pentafluoride.

4. Methods of Synthesis of Inter halogen Compounds.
There are two general methods of synthesis of Interhalogen Compound.
1) By direct Combination of two halogen molecules at particular temperature
condition.
e.g. when equal volume of chlorine and fluorine react together at 473K ,
chlorine monofluoride formed.
2) Halogen molecule react with lower IC to give higher IC at particular
temperature condition.
e.g. molecular fluorine react with iodine pentafluoride at 543K to give higher IC
iodine hepta fluoride

5.  Synthesis of Chlorine monofluoride:- (ClF)
Chlorine monofluoride is prepared by the direct combinition of molecular
chlorine with fluorine at 473K.
Reaction:- F2 + Cl2 2ClF
 Chlorine monofluoride is a colorless gas with melting point117K.
 It is covalent molecule and diamagnetic in nature.
 It is more reactive than normal halogen as the molecule is polar in nature.

6.  Synthesis of Iodine mono chloride (ICl)
Iodine mono chloride is formed by passing chlorine gas over solid iodine
at temperature 273K.
Reaction:-
 It is red-brown chemical compound melt near room temperature.
 ICl is highly polar molecule due to difference in electronegativity.
 In organic synthesis, estimation of Iodine number of oils as a source of
I+.

7. Synthesis of Bromine trifluoride (BrF3 )
Bromine trifluoride is produced by the mixing of bromine vapor and
fluorine in a stream of nitrogen at 293K
Reaction:-
 It is straw colored liquid with pungent odor
 It is powerful fluorinating agents
 It is used to produce uranium hexafluoride UF6 in the processing and
reprocessing of nuclear fuel.

8. Synthesis of Chlorine trifluoride (ClF3 )
Chlorine trifluoride is synthesized by the mixing of molecular chlorine and
fluorine at 473-573K in copper vessel.
Reaction:- Cl2 + 3F2 2ClF3
 Chlorine trifluoride is a colorless gas which condenses to give pale green
liquid.
 It is hydrolyzed by water to give ClOF.
 When chlorine trifluoride is reacted with molecular fluorine it gives higher
inter halogen compound ClF5.
 Shape of Chlorine trifluoride is bent T type due to two lp of electrons.

9.  Synthesis of Bromine pentafluoride (BrF5 )
Bromine pentafluoride is prepared by the direct reaction of molecular
bromine with excess of fluorine at temperature 423K.
Reaction:-
 Bromine pentafluoride is pale yellow liquid.
 It is an extremely effective fluorinating agent, converting most uranium
compound to the hexafluoride at room temperature.

10.  Synthesis of Iodine pentafluoride ( IF5 )
Iodine pentafluoride is prepared by the direct combination of Iodine with
excess of fluorine.
Reaction:- I2 + 5F2 2IF5
 Iodine pentafluoride is a colorless liquid with melting point 283K.
 It is good conductor of electricity.
 It is hydrolyzed by water to give halogen acid and oxyacid of larger
halogen atom.
 Iodine pentafluoride has square pyramidal shape with one lp of electron.

11.  Synthesis of Iodine heptafluoride (IF7)
Iodine heptafluoride is synthesized by passing a mixture of iodine
pentafluoride vapors and fluorine through a platinum tube at 573K.
Reaction:-
 Iodine heptafluoride is a colorless gas.
 It is used as strong oxidizing agent.
 It is used to prepare periodic acid.

12.  Applications of Inter halogen Compounds
 Inter halogen compounds are used as non-aqueous solvents in many
chemical reaction.
 They are used as Catalyst in chemical reaction.
 Inter halogen compounds are used as fluorinating agents in several
chemical reactions.

13. Structure and Bonding in Interhalogen Compounds
A) Diatomic IC (AX type)ClF, ICl, IBr etc.
 Structure and Bonding in Interhalogen Compounds can be explain on the
basis of Hybridization.
 Valence shell EC of Central atom Chlorine is 3s2 3p5
 Diatomic IC 7+7=14 e/8 i.e. 1bp and 3lp
 Central atom Chlorine undergo sp3 Hybridization
 According to VSEPR theory, Shape of ClF is linear as it contain two atoms
only
 Out of four hybridized orbital, three contain lp of electron and one is bp
having linear structure

14. B) Structure and Bonding in Tetra-atomic IC (AX3 type)
e.g. ClF3, BrF3, IF3, ICl3
 Structure of Chlorine tri-fluoride can be explain on the basis of
hybridization.
 In, ClF3 central atom Chlorine has valence shell EC 3s23p5
 In tetra-atomic IC 7X4=28e/8 i.e. 3bp and 2lp
 Central atom Chlorine undergo sp3d hybridization resulting Trigonal
bipyramidal geometry
 According to VSEPR theory, shape of ClF3 is bent T shape as it contain
three bp and two lp
 Out of five hybridized orbital three contain bp and two contain lp

15. C) Structure and Bonding in Hexa-atomic IC (AX5 type)
e.g. BrF5 IF5 etc.
 Structure and bonding in IF5 can be explain on the basis of Hybridization
 In IF5 Central atom Iodine has valence shell EC 5S25P5
 In hexa-atomic IC , IF5 7x6=42/8=5bp and one lp
 In IF5 ,Central atom Bromine undergo sp3d2 hybridization resulting
Octahedral geometry
 According to VSEPR theory, Shape of IF5 is Square pyramidal due to 5 bp
and one lp
 Out of six hybridized orbital five are bp and one is lp decreasing bond angle
to 81.9

16. D) Structure and Bonding in Octa-atomic IC (AX7 type)
e.g. IF7
 Structure and bonding in IC can be explain on the basis of hybridization
 In IF7, Central atom Iodine has valence shell EC 5s25p2
 In octa-atomic IC ,like IF7 8x7=56/8 i.e. 7bp and zero lp.
 In IF7 central atom iodine undergo sp3d3 hybridization resulting in
pentagonal bipyramidal geometry.
 According to VSEPR theory lp is zero therefore IF7 has regular shape i.e.
pentagonal bipyramidal shape.
 In IF7 all the seven hybridized orbital forms seven covalent bond with
fluorine atom having regular shape.