Teaching 1H NMR Spectrometry Using Computer Modeling
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Yoichi Habata [1] ; Sadatoshi Akabori [1]
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[1] Toho University
Toho University
Japón
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 78, Nº 1, 2001, pág. 121
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
Use of computer modeling for teaching 1H NMR spectroscopy is described. The direction of the induced magnetic field is clarified by displaying the electrostatic potential on the molecule, when the magnetic anisotropy effect is taught. It is possible to show a clear reason why the induced magnetic field occurs in the H-C-C-H direction in acetylene. By viewing an electrostatic potential map, which displays electrostatic potential on the electron density, it is possible for students to visually understand the shielding effect by the electronegativity. This map gives understanding of the difference in chemical shift between CHX3, CH2X2, and CH3X, depending on the number of halogen atoms. Although long-range coupling between the protons arranged in a W shape in the bicyclic systems has been introduced in many textbooks of 1H NMR spectroscopy, there is no clear description of why they happen. A display of the highest occupied molecular orbital aids understanding of why long-range coupling happens in bicyclic systems.
