Spectroscopic (FT-IR, FT-Raman) investigations and quantum chemical calculations of 4-hydroxy-2-oxo-1,2-dihydroquinoline-7-carboxylic acid

• IR, Raman, NBO analysis and MEP were reported.
• The wavenumbers are calculated theoretically using Gaussian09 software.
• The wavenumbers are assigned using PED analysis.
• The geometrical parameters are in agreement with the reported literature.

Quinoline derivatives have good nonlinear optical properties and have been extensively studied due to their great potential application in the field of organic light emitting diodes. Quantum chemical calculations of the equilibrium geometry, harmonic vibrational frequencies, infrared intensities and Raman activities of 4-hydroxy-2-oxo-1,2-dihydroquinoline-7-carboxylic acid in the ground state were reported. Potential energy distribution of normal modes of vibrations was done using GAR2PED program. The synthesis, 1H NMR and PES scan results are also discussed. Nonlinear optical behavior of the examined molecule was investigated by the determination of first hyperpolarizability. The calculated HOMO and LUMO energies show the chemical activity of the molecule. The stability of the molecule arising from hyperconjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated geometrical parameters are in agreement with that of similar derivatives.

In this work, the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy for 4-hydroxy-2-oxo-1,2-dihydroquinoline-7-carboxylic acid. The computations were performed at HF and DFT levels of theory to get the optimized geometry and vibrational wavenumbers of the normal modes of the title compound. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution and using Gaussview software. The calculated HOMO and LUMO energies show the chemical activity of the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated geometrical parameters are in agreement with that of similar derivatives. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis.Figure optionsDownload as PowerPoint slide