Molecular structure, chemical reactivity, stability and vibrational spectroscopic investigation of stearic and palmitic acid using density functional theory

Abstract

The molecular structures of stearic acid and palmitic acid were simulated using density functional theory (DFT) at the B3LYP/6-31G*basis set level with a view to compare their reactivity and stability based on some theoretically calculated parameters. The energy gap between the HOMO and LUMO of both fatty acids were found to be similar (7.76 eV) and independent of alkyl residue. The total energy (absolute values) of stearic acid was found to be higher than that of palmitic acid. Values of global hardness and softness indicate significant chemical reactivity and stability of both molecules. Spectroscopic investigation gives similar spectral positions while slight differences in dipole moment values suggests higher reactivity of palmitic acid than stearic acid.