Vibrational study on the molecular interaction of L-Proline and Para-Aminobenzoic acid

In the current work, the interaction of Para-Aminobenzoic acid (PABA) and L-Proline are studied for the first time from the experimental and theoretical point of view. Spectral characterization of the bio-molecular complex is made by vibrational techniques such as Raman and FTIR techniques. The optimization of molecules and theoretical calculation is carried out in the gas phase using B3LYP/6-31G (d, p) model. Further complete vibrational assignment, HOMO-LUMO energy gap, Natural Bond Orbital (NBO) analysis, Molecular Electrostatic Potential (MEP) and Non-Linear Optical (NLO) properties are reported. The calculated quantum chemical parameters show high reactivity and non-linear properties of L-Proline + PABA compound compared to individualistic t-Proline and PABA respectively. The experimental data of Raman and IR spectra are found satisfactorily agree with the theoretical calculation. The molecular docking study of t-Proline shows the highest binding energy of -5.18 kcal/mol. (C) 2019 Elsevier B.V. All rights reserved.