Vibrational Spectral Study of 3,4,5-Trichlorophenol with Density Functional Theory, NBO, NMR and Homo-LUMO Analyses

Abstract

A systematic vibrational spectroscopic assignment and analysis of 3,4,5-trichlorophenol has been carried out by using FTIR and FT-Raman spectral data. The vibrational analysis was aided by electronic structure calculations, density functional methods (B3LYP) performed in 6-31+G (d, p) and 6-311++G (d, p) basis sets. The assignment proposed based on the experimental IR and Raman spectra have been reviewed and complete assignment of the observed spectra has been proposed. The geometrical, thermodynamic parameters and ¹H,¹³C NMR chemical shift  was compared with the experimental data. Finally the molecular and electronic properties, thermodynamic properties have also been determined. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The predicted first hyperpolarizibility also show that the molecule might have a reasonable good Nonlinear optical (NLO) behavior.