Theoretical And Experimental Studies On Vibration Spectrum Of Quinolone Antibiotics

This article takes the fourth-generation quinolone antibiotics gatifloxacin and moxifloxacin as research objects,because the infrared and Raman spectra are complementary in the information that characterizes the molecular structure.At the same time,The theoretical calculation of the spectrum has important guiding significance for the experimental spectrum.therefore,based on infrared spectroscopy and Raman spectroscopy technology combined with density functional theory method,this paper makes qualitative analysis and research on drugs,and reserves basic data for the detection of infrared and Raman spectroscopy of gatifloxacin and moxifloxacin.Technology provides references and applications in the field of drug identification.The experimental measurements of conventional Raman and infrared spectra of Gatifloxacin and Moxifloxacin drugs show that the drug molecules have obvious Raman and infrared activities in the range of 3800cm^-1?2800cm^-1 and 1800cm^-1?400cm^-1,and identify the peak position of the vibration spectrum.In Gauss software,the vibration mode of molecular chemical bonds can be accurately presented,and the spatial structure parameters such as the bond length,bond angle,and dihedral angle of the gatifloxacin and moxifloxacin molecules are given.Then,based on the density functional theory,Gaussian view05 software was used to construct the spatial structure of the gatifloxacin and moxifloxacin molecules.Under the B3LYP functional 6-31G basis set,the two molecules were structurally optimized to obtain a more stable and stable For accurate molecular structure,the gatifloxacin molecule is in the 6-311+G?d?basis group,and the moxifloxacin molecule is optimized again in the 6-311++G?d?structure.Then in the basis set mode of the second optimized structure,the theoretical vibration frequency was calculated in the range of 4000cm-1?400cm-1,and the theoretical infrared and Raman spectra of gatifloxacin and moxifloxacin were also given.By comparing the theoretical spectrum,it is found that most of the vibration modes with Raman and infrared activity are mostly represented by the stretching and bending vibrations of the C=O bond,C—H bond and O—H bond of the molecule.The theoretical spectrum is corrected and compared with the experimental spectrum.The results show that the infrared and Raman vibrational spectrum peak frequencies have a good matching degree.Then,the vibration modes of infrared and Raman active peak positions in the experimental spectrum are assigned.