Concept of homolytic and herterolytic fission

Organic reactions usually involve making and breaking of covalent bonds. Fission of bonds can take place in two ways:

Homolytic Fission

When the cleavage of covalent bond between two atoms takes place in a manner, which enables each atom to retain one electron of the shared pair, it is known as homolytic fission. This fission is symmetrical and leads to the formation of atoms or groups of atoms having unpaired electrons, called free radicals. The free radicals are denoted by putting dot over the symbol of atom or group of atoms. For example,

Heterolytic Fission

Heterolytic fission is unsymmetrical wherein one of the fragments takes both the electrons of the shared pair, leaving none on the other. This results into two charged particles as: