Inversion barriers in para-substituted anilines from ab initio molecular orbital theory

Abstract

The effects of para-substituents (NO₂, CH₃, F, OH, NH₂) on the barrier to inversion and the geometry at the nitrogen atom in aniline have been studied using ab initio molecular orbital theory; substituents which are π-electron acceptors lower the barrier and lead to a slight flattening of the nitrogen pyramid while π-electron donors raise the barrier and increase the pyramidalization of the bonds at the nitrogen atom.