کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1235418 968847 2007 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Molecular structures and vibrational frequencies of xanthine and its methyl derivatives (caffeine and theobromine) by ab initio Hartree-Fock and density functional theory calculations
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Molecular structures and vibrational frequencies of xanthine and its methyl derivatives (caffeine and theobromine) by ab initio Hartree-Fock and density functional theory calculations
چکیده انگلیسی
The molecular structures, vibrational frequencies and corresponding vibrational assignments of xanthine and its methyl derivatives (caffeine and theobromine) have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-31G(d, p) basis set level. The calculations were utilized to the CS symmetries of the molecules. The obtained vibrational frequencies and optimised geometric parameters (bond lengths and bond angles) were seen to be well agreement with the experimental data. The used scale factors which have been obtained the ratio of the frequency values of the strongest peaks in the calculated and experimental spectra seem to cause the gained vibrations well corresponding to the experimental ones. Theoretical infrared intensities and Raman activities are also reported.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 67, Issue 2, June 2007, Pages 342-349
نویسندگان
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