  The host-guest interaction between benzene or azine with the newly
synthesized ExBox4+ complex is studied with the help of DFT. The solvent phase
interaction energy is found to decrease with gradual substitution of methine
group of guest benzene ring with N atom in the resultant azine@ExBox4+ complex.
The nature of bonding interaction is studied with the help of newly developed
NCI plot program package along with energy decomposition analysis (EDA) and
charge decomposition analysis (CDA). The interaction is mostly pi-type van der
Waals interaction.
