Journal ArticleDOI
Calculation of Nuclear Magnetic Resonance Spectra of Aromatic Hydrocarbons
C. E. Johnson,Frank A. Bovey +1 more
TLDR
In this article, the free electron model of Pauling was used to calculate the magnetic field around a benzene ring which is rotating rapidly about all axes in an external magnetic field.Abstract:
The free electron model of Pauling is used to calculate the magnetic field around a benzene ring which is rotating rapidly about all axes in an external magnetic field. It is assumed that the π electrons precess in two circular paths, one on each side of the ring, equal in radius to the C–C distance in the benzene ring. The separation of these rings is taken as 1.28 A, which gives a calculated value for the nuclear magnetic resonance shielding value for benzene protons equal to the observed value. The field thus calculated is employed to predict shielding values for other aromatic compounds. Agreement with experiment is in general good, but there are some exceptions.read more
Citations
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Journal ArticleDOI
NMR Studies of Cyclodextrins and Cyclodextrin Complexes
Book ChapterDOI
Chemical shifts as a tool for structure determination.
David S. Wishart,Brian D. Sykes +1 more
TL;DR: This chapter describes chemical shift standards and pointing out some of the necessary corrections and experimental recommendations that need to be followed so that the NMR community can exploit chemical shift information to the fullest.
Journal ArticleDOI
Dissected Nucleus-Independent Chemical Shift Analysis of π-Aromaticity and Antiaromaticity.
Paul von Ragué Schleyer,Mariappan Manoharan,Zhi-Xiang Wang,Boggavarapu Kiran,Haijun Jiao,Ralph Puchta,Nicolaas J. R. van Eikema Hommes +6 more
TL;DR: Analysis of the basic π-aromatic (benzene) and antiaromatic systems by dissected nucleus-independent chemical shifts (NICS) shows the contrasting diatropics and paratropic effects, but also reveals subtleties and unexpected details.
Journal ArticleDOI
Aromaticity and ring currents.
TL;DR: The idea of a ring current seems more secure now than it was 20 years ago, and it would appear that less apology or justification is needed for invoking it.
Journal ArticleDOI
Determination of the three-dimensional solution structure of the C-terminal domain of cellobiohydrolase I from Trichoderma reesei. A study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing.
TL;DR: The solution structure of a synthetic 36-residue polypeptide comprising the C-terminal cellulose binding domain of cellobiohydrolase I (CT-CBH I) from Trichoderma reesei was investigated by nuclear magnetic resonance (NMR) spectroscopy.
References
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Journal ArticleDOI
The Diamagnetic Anisotropy of Aromatic Molecules
TL;DR: In this article, the diamagnetic anisotropy of benzene and other aromatic hydrocarbon molecules is calculated on the basis of the assumption that the p_z electrons (one per aromatic carbon atom) are free to move from carbon atom to adjacent carbon atom under the influence of the impressed fields.
Journal ArticleDOI
Nuclear Resonance Spectra of Hydrocarbons: The Free Electron Model
J. S. Waugh,R. W. Fessenden +1 more
Journal ArticleDOI
Medium Effects in the Nuclear Magnetic Resonance Spectra of Liquids. III. Aromatics
TL;DR: The simple relationship between proton resonance line position and sample volume susceptibility applicable to mixtures of simple aliphatic compounds does not hold for mixtures containing an aromatic compound as a component as discussed by the authors.