Illustrated Glossary of Organic Chemistry

Inductive effect: The effect on electron density in one portion of a molecule due to electron-withdrawing or electron-donating groups elsewhere in the molecule.

In a covalent bond between two atoms of unequal electronegativity, the atom with higher electronegativity withdraws electron density towards itself, causing the δ⁺ and δ^- charges of the bond dipole.

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Trifluoroacetate ion is a weaker base than formate ion, due to the electron-withdrawing inductive effect of the trifluoromethyl group (compared to the electroneutral hydrogen atom). The arrow indicates the direction of electron density shift.

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Acetate ion is a stronger base than formate ion due to the electron-donating inductive effect of the methyl group (compared to the electroneutral hydrogen atom). The arrow indicates the direction of electron density shift.