Experimental and Theoretical Spectroscopic Properties of Quinazoline

摘要

In the present study. FT-IR and FT-Raman spectra of quinazoline were recorded and the observed vibrational frequencies were completely assigned. The vibrational frequencies, infrared intensities and Raman scattering activities of the quinazoline were computed using DFT (B3LYP) and HF methods with basis set 6-311++G(d,p) and the corresponding results were tabulated. The calculated and scaled wave number shows good agreement with the experimental values. The influence of the presence of N atom in the skeletal ring on the vibrations of the molecules have been discussed. Moreover, the chemical shifts of the compound were calculated from ~(13)C NMR and ~1H NMR by using the Gauge Independent Atomic Orbital (GIAO) method. A UV-visible spectra of the molecule was also experimentally recorded and stimulated by HF and DFT methods and analysis on the electronic properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were reported. The calculated HOMO and LUMO energies and the energy gap analysis shows the charge transformation within the molecule. The polarizability and hyperpolarizability of the compound were also calculated and the results indicates that the chosen compound is a good non-linear optical (NLO) material. The thermodynamic properties such as thermal energy, heat capacity and entropy of the quinazoline were calculated in gas phase.