Comparative vibrational spectroscopic studies of 7-chloro-4- hydroxy-3-quinolinecarboxylic acid based on density functional theory

Abstract

The experimental and theoretical vibrational spectra (FT-IR and FT-Raman) of 7-chloro-4-hydroxy3-quinolinecarboxylic acid (7C4H3QCA) are investigated. The experimental FT-IR (400–4400 cm −1 ) and FTRaman spectra (100–3500 cm −1 ) spectra of the molecule are recorded. In the whole study the CS point group symmetry has been used. Theoretical Vibrational frequencies and geometric parameters (bond lengths and bond angles) were calculated using ab initio Hartree Fock (HF) and density functional B3LYP method with 6-31+G (d, p) basis set. The complete vibrational assignments of wave numbers were made on the basis of potential energy distribution. The scaled B3LYP/6-31+G (d, p) results show the best agreement with the experimental values over the other methods.