The structural dependence of the inductive effect. Part VI. The calculation of vicinal proton–proton spin–spin coupling constants in substituted ethanes

Abstract

The effects of substituents upon vicinal coupling constants between protons in individual rotational isomers of some substituted ethanes are analysed by a method analogous to that developed for nuclear shielding. Equations are given which enable such coupling constants to be calculated to a satisfactorily high degree of precision (±0·18–0·27 Hz) and which explain certain trends which were not explicable by previous treatments