Molecular structure, vibrational spectra, first order hyper polarizability, NBO and HOMO-LUMO analysis of 2-amino-5-bromo-benzoic acid methyl ester

Abstract

An organic crystal of 2-amino-5-bromobenzoic acid methyl ester [abbreviated at 2A5BrBAMe], single crystal, belongs to the amino acid group, were grown by the slow evaporation solution growth technique at room temperature. The grown crystal had been subjected to single-crystal X-ray diffraction technique and cell parameters of the crystal were determined. The quantitative analysis on the crystal had been carried out using Fourier transform infrared (FTIR) and Fourier transform Raman (FT-Raman) spectral measurements. The molecular structures, vibrational wave numbers were calculated using DFT (B3LYP) method with 6-311++G(d,p) basis set. The formation of the hydrogen bond was investigated using NBO calculations. The calculated HOMO and LUMO energies show that charge transfer occur within the molecule. The dipole moment (μ) and polarizability (α0), anisotropy polarizability (Δα) and first order hyperpolarizability (β0) of the molecule have been reported.

Keywords: DFT; FT-Raman; FTIR; HOMO; LUMO; NBO.