کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1411719 | 1501875 | 2008 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Synthesis and NMR characterization of seven new substituted pyridine N-oxides
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
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چکیده انگلیسی
Seven 3-substituted (alkylamino, alkylnitramino and alkylnitrosoamino) derivatives of pyridine N-oxide have been prepared and their 1H, 13C and 15N NMR chemical shifts assigned based on PFG 1H, 13C HMQC and PFG 1H, X (X = 13C or 15N) HMBC experiments. In the sterically most crowded congener, 3-ethylnitramino-4-nitropyridine N-oxide, chemical non-equivalence or diastereotopicity of the N–CH2 protons was observed probably due to the chirality of the adjacent amino nitrogen caused by its restricted inversion. The coalescence temperature for the 1H NMR chemical shifts of these geminal protons has been determined and the corresponding ΔG∗ for the energy barrier of the dynamic process has been estimated.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 889, Issues 1–3, 29 October 2008, Pages 371–375
Journal: Journal of Molecular Structure - Volume 889, Issues 1–3, 29 October 2008, Pages 371–375
نویسندگان
K. Laihia, A. Puszko, E. Kolehmainen, J. Lorenc,