Quantum-chemical treatment of the linoleic acid molecule and two of its conjugated isomers

The structural, vibrational and electronic properties of die linoleic acid molecule and two of its conjugated isomers were investigated theoretically by performing the molecular mechanics (MM+ force field), the semi-empirical self-consistent-field molecular-orbital (PM3), and the density functional theory (B3LYP) calculations. The geometries of the considered molecules were optimized; the vibrational dynamics and the electronic properties were calculated in their ground states in the gas phase. It was found that the excess charge accumulated on hydrogen atoms bonded to double-bonded carbon atoms is relatively small, which may cause these hydrogen atoms to be easily abstracted.