Cation-pi versus anion-pi interactions: a comparative ab initio study based on energetic, electron charge density and aromatic features

Abstract

[eng] Several complexes of benzene with cations and hexafluorobenzene with anions have been optimized at the MP2/6-31++G**, B3LYP/6-31++G** and HF/6-31++G** levels of theory. Different aspects of the cation-p interaction have been compared to those of anion-p, including changes in the aromaticity of the ring upon complexation, charge-transfer effects using the Merz-Kollman charges and the contribution of dispersion energies by comparing the complexation energies computed at the B3LYP and MP2 levels of theory.