A study on quantum chemical calculations of 3-, 4-nitrobenzaldehyde oximes

Spectrochim Acta A Mol Biomol Spectrosc. 2011 Sep;79(5):1783-93. doi: 10.1016/j.saa.2011.05.057. Epub 2011 May 27.

Abstract

The molecular geometry, vibrational frequencies, 1H and 13C NMR chemical shifts, UV-vis spectra, HOMO-LUMO analyses, molecular electrostatic potentials (MEPs), , thermodynamic properties and atomic charges of 3- and 4-Nitrobenzaldehyde oxime (C7H6N2O3) molecules have been investigated by using Hartree-Fock (HF) and density functional theory (DFT/B3LYP) methods with the 6-311++G(d, p) basis set. The calculated optimized geometric parameters (bond lengths and bond angles), the vibrational frequencies calculated and 13C and 1H NMR chemical shifts values for the mentioned compounds are in a very good agreement with the experimental data. Furthermore, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) have been simulated and the transition states, energy band gaps and molecular electrostatic potential (MEP) maps for each oxime compound have been determined. Additionally, we also report the infrared intensities and Raman activities for the compounds under study.

MeSH terms

  • Benzaldehydes / chemistry*
  • Magnetic Resonance Spectroscopy
  • Models, Chemical*
  • Molecular Structure
  • Quantum Theory*
  • Spectrophotometry, Infrared
  • Spectrum Analysis, Raman
  • Vibration

Substances

  • Benzaldehydes
  • 4-nitrobenzaldehyde
  • 3-nitrobenzaldehyde