Quantum Mechanical Studies on the π-π Stacking Interactions of Aniline and Water-assisted Aniline in Gas and Aqueous Phases
The quantum mechanical study of weak interactions such as π-π stacking interactions of aromatic molecules has been an important aspect, since high level methods have limitations for application to large molecules. The differences in the stacking energies of various aromatic molecular structures are found quite significant. It has also been found significant for identifying the most favoured stacked models of aniline and some of the substituted aniline molecules. There observed a remarkable change in interaction energies for both gas and solvent phases for the same stacked models. The effect of basis set in the stacking energies of the second order Møller-Plesset perturbation method (MP2) calculations is very small. The moderately accurate calculations, MP2 level of theories were found feasible for most of the simple aromatic systems such as benzene, pyridine, aniline etc. In our study, the investigation was on the π-π stacking interaction energies for stacked models of aniline and water-assisted aniline systems both in gas and aqueous phases.