Molecular Structure, Vibrational Spectroscopic Analysis of Levofloxacin by Density Functional method

The Fourier transform infrared (FT-IR) spectra of Levofloxacin has been recorded and analysed. The equilibrium geometry, bonding features and harmonic frequencies of the title molecule is investigated with the help of ab initio and density functional theory (DFT) method using B3LYP levels employing 6-31 G(d,p) basis sets. The difference between the observed and scaled wavenumber values is very small. The first order hyperpolarizability (β) and other related properties (α and µ) of Levofloxacin have been examined using density functional theory (DFT). The calculated values show that the molecule might have non-linear optical (NLO) behaviour with non-zero values. The molecular HOMO-LUMO composition, their respective energy gaps, MESP Contours and Surfaces has also been drawn to explain the activity of Levofloxacin. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound were calculated. In general, there is a good agreement between experimental and calculated normal modes of vibration have been observed.