Open Access

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

S. Gunasekaran, Department of Physics, Pachaiyappa’s college, Chennai,TN, India. K. Rajalakshmi, k_rajalakshmi123@yahoo.com
Department of Physics, Sri Chandrasekharendra Saraswathi Viswa MahaVidhyalaya, Enathur, Kanchipuram, TN, India. S. Kumaresan Department of Physics, Arignar Anna Government Arts college, Cheyyar , TN, India.

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Abstract

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.

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Reference

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Alkorta, I., Perez, J.J., Molecular polarization potential maps of the nucleic acid bases, Int. J. Quantum Chem., 57, 123-135 (1996).

http://dx.doi.org/10.1002/(SICI)1097-461X(1996)57:1%3C123::AID-QUA14%3E3.0.CO;2-9

Becke, A.D., Density-functional thermochemistry. III. The role of exact exchange, J. Chem. Phys., 98, 5648-5652 (1993).

http://dx.doi.org/10.1063/1.464913

Kawahara, S., Chemotherapeutic agents under study, Nippon Rinsho., 56, 3096-3099 (1998).

Kleinman, D.A., Nonlinear Dielectric Polarization in Optical Media, Phys. Rev., 126 , 1977(1962).

http://dx.doi.org/10.1103/PhysRev.126.1977

Lee, C., Yang, W., Parr, R.G., Development of the Colle-Salvetti conelation energy formula into a functional of the electron density, Phys.Rev. B., 37, 785-789 (1988).

http://dx.doi.org/10.1103/PhysRevB.37.785

Nelson, J.M., Chiller, T.M., Powers, J.H., Angulo, F.J., Fluoroquinolone-resistant Campylobacter species and the withdrawal of fluoroquinolones from use in poultry: a public health success story, Clin Infect Dis., 44, 977-80 (2007).

http://dx.doi.org/10.1086/512369

Padmaja, Amalanathan, M., Ravikumar,C., Hubert Joe, I., Density functional theory calculations and vibrational spectral analysis of 3, 5- (dinitrobenzoic acid), Spectrochim Acta. Part A., 74, 349-356 (2009).

http://dx.doi.org/10.1016/j.saa.2009.06.007