Hybrid DFT study on non-covalent interactions and their influence on pK a 's of magnesium-carboxylate complexes.

The electronic structure, stability, acidity, topological properties and charge transfer of octahedral magnesium-carboxylate complexes have been investigated at M05-2X/6-311G** level of theory. The interaction energy studies confirm the stability of the pentahydrated magnesium compounds. The calculated pKa values using SMD solvation model through the deprotonation of metal-ion bound water molecule vary from 15.08 to 19.36, enunciate the role of Mg-O bonds on the acidity of the Mg+2 complexes. The closed shell ionic interactions of Mg-ligand bonds are assessed by the atoms in molecules (AIM) and the electron localization function (ELF) analyses. A reduced density gradient approach is utilized to explore the weak interactions including dihydrogen bonds.