Experimental and theoretical spectral investigations of 5-chloro-ortho-methoxyaniline using FT-IR, FT-Raman and DFT analysis

Abstract

Vibrational spectral analyses have been carried out using FT-IR and FT-Raman spectra for 5-chloro-ortho-methoxyaniline (5COMA). The fundamental vibrational frequencies and intensity of vibrational bands are evaluated using density functional theory. The vibrational spectra have been interpreted with the help of normal coordinate analysis based on scaled quantum mechanical force fields. The first-order hyperpolarizability and the anisotropy polarizability invariant have been computed with the numerical derivative of the dipole moment. The HOMO-LUMO energies, atomic charges, hardness, softness, ionization potential, electronegativity and electrophilicity index have been calculated. Natural atomic charges, nonlinear optical, ¹H NMR and ¹³C NMR data have been employed to study the electronic properties of 5COMA using the B3LYP functional with 6-311G** basis set. Molecular electronic potential and Mulliken’s charges have been obtained using the DFT calculation method. Electronic excitation energies, oscillator strength and nature of the respective excited states have been calculated by the closed-shell singlet calculation method.