The cleavage of a @C01384@ so that both bonding electrons remain with one of the two fragments between which the bond is broken, e.g.
Heterolytic bond fission is a feature of many @M03989@ reactions in solution (e.g.@E02020@ substitution, @N04249@ substitution).
See also:
heterolytic bond-dissociation energy
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1120 [Terms] [Paper]