کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1232252 | 1495280 | 2012 | 8 صفحه PDF | دانلود رایگان |
Efavirenz, (S)-6-chloro-4-(cyclopropylethynyl)-1,4-dihydro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one, is an anti HIV agent belonging to the class of the non-nucleoside inhibitors of the HIV-1 virus reverse transcriptase. A systematic quantum chemical study of the possible conformations, their relative stabilities and vibrational spectra of efavirenz has been reported. Structural and spectral characteristics of efavirenz have been studied by vibrational spectroscopy and quantum chemical methods. Density functional theory (DFT) calculations for potential energy curve, optimized geometries and vibrational spectra have been carried out using 6-311++G(d,p) basis sets and B3LYP functionals. Based on these results, we have discussed the correlation between the vibrational modes and the crystalline structure of the most stable form of efavirenz. A complete analysis of the experimental infrared and Raman spectra has been reported on the basis of wavenumber of the vibrational bands and potential energy distribution. The infrared and the Raman spectra of the molecule based on DFT calculations show reasonable agreement with the experimental results. The calculated HOMO and LUMO energies shows that charge transfer occur within the molecule.
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► FT-IR and FT-Raman spectra were recorded and compared with the theoretical results.
► The PED calculation regarding the normal modes provides a strong support for the frequency assignment.
► The theoretical calculations were made using B3LYP/6-311++G(d,p) method.
► By using TD-DFT/6-31G method, electronic spectra for title compound have been predicted.
► The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule.
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 88, March 2012, Pages 116–123