Vibrational spectra, molecular structure, natural bond orbital, first order hyperpolarizability, TD-DFT and thermodynamic analysis of 4-amino-3-hydroxy-1-naphthalenesulfonic acid by DFT approach

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2013-04, Vol.107, p.167-178
• Main Authors: Sebastian, S., Sylvestre, S., Sundaraganesan, N., Amalanathan, M., Ayyapan, S., Oudayakumar, K., Karthikeyan, B.
• Format: Article
• Language: English
• Subjects: NBO; NLO; Sulfonic acid; TD-DFT; TED; Vibrational spectra
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2013.01.041

[Display omitted] ► A detailed interpretation of infrared and Raman spectra of 4A3HNSA were reported. ► The first order hyperpolarizability of 4A3HNSA were calculated. ► NBO, HOMO and LUMO analysis were also performed by DFT approach. Vibrational spectral analysis of 4-amino-3-hydroxy-1-naphthalenesulfonicacid (4A3HNSA) molecule were carried out using FT-IR and FT-Raman spectroscopic techniques. The equilibrium geometry, harmonic vibrational wavenumbers, various bonding features have been computed using density functional B3LYP method with 6-31G(d,p) as basis set. The Non-Linear Optical (NLO) behavior of 4A3HNSA has been studied by determination of the electric dipole moment (μ) and hyperpolarizability β using HF/6-31G(d,p) method. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in σ* and π* antibonding orbitals and second order delocalization energies (E2) confirms the occurrence of Intramolecular Charge Transfer (ICT) within the molecule. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) complements with the experimental findings. The simulated spectra satisfactorily coincide with the experimental spectra.