Exploration of the Mutual Effects Between Cation–π and Intramolecular Hydrogen Bond Interactions in the Different Complexes of Mesalazine with Metal Cations of Alkali and Alkaline-Earth: A DFT Study

Abstract

In the current research, a comparative study of the interplay effects between cation–π and intramolecular hydrogen bond (IMHB) interactions is performed on the complexes of mesalazine with Li+, Na+, K+, Be2+, Mg2+ and Ca2+ cations using density functional theory (DFT). For this purpose, the mesalazine analogue and the equivalent values of 3-aminobenzoic acid complexes with the cited cations are selected as a set of reference points. In order to understand the mutual effects between these interactions, the descriptors of geometrical, binding energies, topological properties and charge transfer values are examined on complexes using the atoms in molecules (AIM) and natural bond orbital (NBO) analyses. Results indicate that with the exception of Be2+ complex, the coupling simultaneously weakens both of the interactions. Finally, the physical properties such as energy gap, chemical hardness as well as electronic chemical potential of complexes are systematically analyzed by using frontier molecular orbitals.