Int. J. Mol. Sci. 2000, 1(4), 84-91; doi:10.3390/ijms1040084
Article

A New Graphical Model for Proton NMR (De)shielding over a Carbon-Carbon Double Bond to Replace the Shielding Cone Model

Ned H. Martin* email and Justin D. Brown
Department of Chemistry, University of North Carolina at Wilmington, Wilmington, NC 28403-3297 USA
* Author to whom correspondence should be addressed.
Received: 5 June 2000 / Accepted: 25 August 2000 / Published: 14 November 2000
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Abstract: The long-held “shielding cone” model of the through-space NMR shielding effect of a carbon-carbon double bond predicts only the effect of the magnetic anisotropy of the double bond; it ignores other important contributors to the overall shielding. GIAO-SCF and GIAO-MP2 calculations have been performed on a simple model system, methane moved sequentially above ethene or 2-methylpropene. These calculations permit the net NMR shielding surface to be mapped. Based on those results, a new and very different graphical model for predicting the effect of a proton’s position relative to a carbon-carbon double bond on its chemical shift is presented.
Keywords: NMR; shielding cone; isotropic shielding; GIAO-SCF; GIAO-MP2; alkenes

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Cite This Article

MDPI and ACS Style

Martin, N.H.; Brown, J.D. A New Graphical Model for Proton NMR (De)shielding over a Carbon-Carbon Double Bond to Replace the Shielding Cone Model. Int. J. Mol. Sci. 2000, 1, 84-91.

AMA Style

Martin NH, Brown JD. A New Graphical Model for Proton NMR (De)shielding over a Carbon-Carbon Double Bond to Replace the Shielding Cone Model. International Journal of Molecular Sciences. 2000; 1(4):84-91.

Chicago/Turabian Style

Martin, Ned H.; Brown, Justin D. 2000. "A New Graphical Model for Proton NMR (De)shielding over a Carbon-Carbon Double Bond to Replace the Shielding Cone Model." Int. J. Mol. Sci. 1, no. 4: 84-91.

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