Rethinking the Nature and Extent of Inductive Effects in Organic Compounds

The inductive effect is generally taught as being transmitted through the σ-bond framework in organic molecules, diminishing with each bond. This historical position does not align with more recent studies, and we show that the inductive effect in neutral molecules is effectively limited to one bond. Evidence of onward transmission (e.g., 13C NMR chemical shifts) should be viewed with scepticism. In charged species, where an electron-donating functional group is coupled with a suitably disposed electron-withdrawing substituent, the effect is transmitted over more bonds. These examples should be considered as polarizability rather than ‘purely’ inductive. Examples that are commonly described as a through-space field effect are better explained by polarizability/orbital perturbation. This work presents a more complete view of the inductive effect and its interface with polarizability.