Interhalogen Compounds

INTERHALOGEN COMPOUNDS

Interhalogen compounds are the binary compounds of halogens among themselves.

There are four such types of compounds are known

• AX
• AX3
• AX5
• AX7

They are regarded as halides of the more electropositive components. 'A' - Central should be more electropositive w.r.t. substituent - 'X'. In this way, fluorine can never be a central halogen while iodine can never be a substituent due to the above contradiction.

The ClF is called chlorine monofluoride and ICl3 is called iodine trichloride as they are regarded as halides of the more electropositive component.

The halogen atom in an interhalogen compound is linked by covalent bonds in exactly the same manner as halogen atoms among themselves to form molecules. The bonds are essentially covalent due to a small electronegativity difference. But as a result of the small electronegativity difference between A and X halogen atoms, the interhalogen compounds show polarity in bonds.

Thus ICl, ICl3, and BrF3 show certain ionic character in their molecule. The compound formed AX and AX3 groups are those where the electronegativity difference is not too great. The higher valencies AX5 and AX7 are shown by large atoms such as Br and I associated with small atoms such as F. This is because it is possible to pack more small atoms around a large one