Theoretical Study on Ionization of Boric Acid in Aqueous Solution by Ab Initio and DFT Methods at T=298.15 K

Abstract

Objectives:

The aim of this research work was to theoretically calculate the pK _a value of boric acid in aqueous solution by theoretical methods at T=298.15 K.

Materials and Methods:

Boric acid has antifungal and antiviral properties. It is used in various prescription pharmaceutical products. The ab initio and density functional theory (DFT) methods were used in this research work.

Results:

To explain the determined acidic dissociation constant, the various molecular conformations and solute-solvent interactions of the species of boric acid were considered. The basis set at the B3LYP/6-31+G (d) level of theory was selected for DFT calculations. We analyzed the formation of intermolecular hydrogen bonds between several species of boric acid and water molecules through Tomasi’s method.

Conclusion:

The result showed that there was comparable agreement between the experimentally and theoretically determined pK _a values for boric acid.