Electronic Effects

Electronic effects — the influence of substituent electron-donating or electron-withdrawing character on a molecule's reactivity, acidity or basicity, and...

Electronic effects — the influence of substituent electron-donating or electron-withdrawing character on a molecule's reactivity, acidity or basicity, and binding interactions — are systematically explored during SAR analysis through the introduction of substituents with defined electronic character, such as electron-withdrawing halogens or nitro groups versus electron-donating alkyl or alkoxy groups, at defined structural positions, with the resulting change in biological activity interpreted in the context of Hammett-type electronic parameters where a sufficiently large, systematically varied analogue series is available. Electronic effects are of particular importance where a binding interaction depends on the precise electronic character of a specific functional group, such as a hydrogen-bond acceptor whose strength is modulated by the electron density of an adjacent aromatic ring.