کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5372456 1388882 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
One and two dimensional 1H and 13C high resolution NMR investigation of lariat ethers and their alkali metal ionic complexes: A more tangible evidence for the presence of less common C-H⋯O hydrogen bonds
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
One and two dimensional 1H and 13C high resolution NMR investigation of lariat ethers and their alkali metal ionic complexes: A more tangible evidence for the presence of less common C-H⋯O hydrogen bonds
چکیده انگلیسی

The possible existence of less common hydrogen bonds in three lariat ethers and their alkali-metal ionic complexes have been investigated with one- and two-dimensional (1D and 2D) proton and carbon-13 high resolution liquid state NMR spectroscopy. The occurrence of hydrogen-bonding induced by the addition of metal ions has been identified with the observation of indirect dipolar coupling between the coupling partners involved in the hydrogen-bonding. The addition of metal ions, moreover, causes appreciable change of chemical shift of several protons and carbons. The chemical shift change depends on the ion radius, larger ions causing smaller change. Moreover, the change of chemical shift is in coincidence with the occurrence of hydrogen-bonding. The values of the coupling constants have been obtained for each of these hydrogen bonds and were used for evaluating the hydrogen-bond strength. An intriguing and surprising observation is that a C-H⋯O hydrogen bond identified in solution by this work was not found in the previous study with X-ray diffraction or other methods.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biophysical Chemistry - Volume 121, Issue 2, 20 May 2006, Pages 75-83
نویسندگان
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