Density functional theory study of the interplay between cation–π and intramolecular hydrogen bonding interactions in complexes involving methyl salicylate with Li+, Na+, K+, Be2+, Mg2+, Ca2+ cations

Abstract

In the present study, the DFT (density functional theory) calculations are performed to gauge the effect of cation-π and intramolecular hydrogen bond (IMHB) interactions on each other in the formed complexes between methyl salicylate and Li+, Na+, K+, Be2+, Mg2+ and Ca2+ cations. The energetic, geometrical, topological parameters and the results of population analysis are applied to investigate these interactions. The calculations are carried out by using the atoms in molecules (AIM) and natural bond orbital (NBO) analyses. The computational results indicate that the presence of IMHB decreases/increases the binding energies in the mono/divalent complexes. On the other hand, the mutual influences of the IMHB and cation–π interactions decrease the IMHB strength of the studied systems. Finally, the frontier molecular orbital (FMO) analysis is employed to calculate the DFT-based global reactivity indices such as energy gap, chemical hardness and electronic chemical potential.