MP2 study on the variation of stacking interactions in aniline and some para substituted aniline systems

The use of appropriate level of theories for studying weak van der Waal interactions such as 8-8 stacking interactions of aromatic molecules has been an important aspect, since the high level methods have limitations for application to large molecules. The differences in the stacking energies of various aromatic molecular structures are found significant. It is also very important for identifying the most favored stacked models of aniline and some of the p-substituted aniline molecules. The effect of basis set in the stacking energies of MP2 calculations is small. The values for HF and MP2 level of theories calculate less electron correlation energy whereas CCSD (T) methods may be used for the calculation of better electron correlation energy. 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 studies, it has been investigated by using MP2 and DFT methods, to study the 8-8 stacking interaction energies for the minimized stacked models of aniline and some psubstituted aniline systems.