Article ID Journal Published Year Pages File Type
1235210 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2011 12 Pages PDF
Abstract

The Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of antiepileptic drug Ethosuximide (ETX) have been recorded and analyzed. In addition, the IR spectra in CCl4 at various concentrations of ETX are also recorded. The equilibrium geometry, bonding features and harmonic vibrational frequencies have been investigated with the help of Density Functional Theory (DFT) method. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the Gauge Including Atomic Orbital (GIAO) method. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the σ* and π* antibonding orbitals and second order delocalization energies E(2) confirms the occurrence of intramolecular charge transfer (ICT) within the molecule. UV–vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were performed by Time-Dependent Density Functional Theory (TD-DFT) approach. Finally the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with observed spectra.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► FTIR and FT-Raman spectra of Ethosuximide were recorded. ► 1H and 13C NMR chemical shifts were calculated using GIAO method. ► UV–vis spectrum was recorded and HOMO–LUMO energies were calculated by TD-DFT method. ► Ethosuximide is mainly used as antiepileptic and anticonvulsant drug.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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