captodative effect

https://doi.org/10.1351/goldbook.C00795
Effect on the stability of a carbon-centred @R05066@ determined by the combined action of a captor (electron withdrawing) and a dative (electron releasing) substituent, both attached to the radical centre. The term is also used for certain unsaturated compounds.
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1092 [Terms] [Paper]