A leaving group that carries away the bonding electron pair. For example, in the hydrolysis of an alkyl chloride, Cl−
is the nucleofuge. The tendency of atoms or groups to depart with the bonding electron pair is called nucleofugality. The adjective is nucleofugal.
See also: electrofuge, nucleophile
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1145 (https://doi.org/10.1351/pac199466051077)