A leaving group that does not carry away the bonding electron pair. For example, in the nitration of benzene by
NO2+,
H+ is the electrofuge. The adjective of electrofuge is electrofugal.
See also: electrophile, nucleofuge
Source:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1109 (https://doi.org/10.1351/pac199466051077)