Spectroscopic investigations, DFT computations and other molecular properties of 2,4-dimethylbenzoic acid

Abstract

The molecular vibrations of 2,4-dimethylbenzoicacid (DMBA) have been investigated by recording Fourier transform infrared (FTIR) and FT-Raman spectroscopy. The complete vibrational assignment and analysis of the fundamental modes of the compound have been carried out using the experimental data and quantum chemical studies from DFT calculations employing MPW1PW91 and B3LYP methods employing 6-311++G(d,p) basis set. The ¹H and ¹³C NMR chemical shifts have been calculated with the GIAO method using the optimized parameters obtained from B3LYP/6-311+G(d,p) method. Important thermodynamic properties and electronic properties have been calculated. Low value of HOMO-LUMO energy gap suggests the possibility of intramolecular charge transfer in the molecule. Furthermore, the first hyperpolarizability and total dipole moment of the molecule have been calculated.