Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2014-01-24

Structural features of the 2-amino-5-nitrobenzophenone by means of vibrational spectroscopy HF and DFT, first order hyperpolarizability, NBO, HOMO-LUMO and theromodynamic properties.

V Balachandran, G Santhi, V Karpagam, V K Rastogi

Index: Spectrochim. Acta. A. Mol. Biomol. Spectrosc. 118 , 835-46, (2014)

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Abstract

The FT-IR and Raman spectra of 2-amino-5-nitrobenzophenone (ANBP) molecule have been recorded using Brucker IFS 66 V spectrometer in the range of 4000-100 cm(-1). The molecular geometry and vibrational frequencies in the ground state are calculated using the Hartree-Fock (HF) and B3LYP with 6-311+G(d) basis set. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The isotropic HF and DFT analysis showed good agreement with experimental observations comparison of the fundamental vibrational frequencies with calculated results by HF and B3LYP methods indicates that B3LYP/6-311+G(d) is superior to HF/6-311+G(d) for molecular vibrational problems. The electric dipole moment (μ) and first hyper polarizability (β) values of the investigated molecule were computed using density functional theory calculations. Stability of the molecule arising from hyperconjucative interactions leading to its bioactivity, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The calculated HOMO-LUMO energies shows that charge transfer occur within the molecule. The thermodynamic functions (heat capacity, internal heat energy, Gibbs energy and entropy) from spectroscopic data by statistical methods were obtained for the range of temperature 100-1000 K. The observed and calculated frequencies are found to be in good agreement.Copyright © 2013 Elsevier B.V. All rights reserved.