A DFT theoretical investigation on the interplay effects between cation-π and intramolecular hydrogen bond interactions in the mesalazine ••• Fe2+ binary complex

A detailed study on mesalazine center dot center dot center dot Fe2+ complex is performed using density functional theory calculations to show the interplay effects of cation-pi and intramolecular hydrogen bond (IMHB) interactions in the presence of the different solvents. To achieve better insight on the mentioned interactions, the complex of benzene and the mesalazine analogue is chosen as a set of reference points. For this purpose, the analyses of atoms in molecules and natural bond orbital are applied to study the nature of the bonding. The results exhibit that the coexistence of IMHB and cation-pi interactions decreases the IMHB strength and increases the cation-pi interactions. The electronic properties, stability and reactivity of the studied complex in the various solvents are also evaluated by frontier molecular orbitals, chemical hardness as well as electronic chemical potential.