Molecular Vibrational Spectroscopic Studies on “5-Chloro-7-Iodoquinolin-8-ol” by Density Functional Theory and HF method

Quantum chemical calculations of energy, geometrical structure and vibration wavenumbers of 5-Chloro-7-Iodoquinolin-8-ol were carried out by Ab initio HF and DFT (B3LYP) method with 3-21G (d) and LANL2MB as the basis set. The Fourier-Transform Infrared and Fourier-Transform Raman spectra of 5-Chloro-7-Iodoquinolin-8-ol were recorded in the region 4000-400 cm-1 and 3500-100cm-1.The thermodynamic functions of the title compound have been computed. A detailed interpretation of the vibration spectra of this compound has been made on the basis of the calculated potential energy distribution (PED). The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Natural bond order analysis of the title molecule was also carried out. Comparison of the stimulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibration mode.