Infrared intensities as a quantitative measure of intramolecular interactions. Part XXXIV. Quantitative relations between conjugation and strain energies and σ°R values: rotational barriers in monosubstituted benzenes

Abstract

Known rotational barriers for substituents in monosubstituted benzenes are correlated with ring–substituent resonance interactions and strain energies. Rotational barriers are estimated for a variety of other substituents. σ Constants are related directly to the energy scale.