Next Article in Journal
Hartee Fock Symmetry Breaking Effects in La2CuO4: Hints for connecting the Mott and Slater Pictures and Pseudogap Prediction
Next Article in Special Issue
A Critical Assessment of the Performance of Magnetic and Electronic Indices of Aromaticity
Previous Article in Journal
Inverse Supersymmetry Breaking in S1 × R3
Previous Article in Special Issue
Diagnosis of the σ-, π- and (σ+π)-Aromaticity by the Shape of the NICSzz-Scan Curves and Symmetry-Based Selection Rules
Article Menu

Export Article

Open AccessArticle
Symmetry 2010, 2(1), 418-436;

Computed NMR Shielding Effects over Fused Aromatic / Antiaromatic Hydrocarbons

Department of Chemistry and Biochemistry, University of North Carolina Wilmington, 601 South College Road, Wilmington, NC 28403-5932, USA
Author to whom correspondence should be addressed.
Received: 14 January 2010 / Revised: 17 March 2010 / Accepted: 19 March 2010 / Published: 22 March 2010
(This article belongs to the Special Issue Aromaticity and Molecular Symmetry)
Full-Text   |   PDF [529 KB, uploaded 22 March 2010]   |  


Through-space isotropic NMR shielding values of a perpendicular diatomic hydrogen probe moved in a 0.5 Å grid 2.5 Å above several polycyclic aromatic/antiaromatic ring and aromatic/aromatic hydrocarbons were computed with Gaussian 03 at the GIAO HF/6-31G(d,p) level. Combinations of benzene fused with cyclobutadiene, with the tropylium ion, and with the cyclopentadienyl anion were investigated. Subtraction of the isolated H2 isotropic value gave shielding increments(Δσ), which, when plotted against Cartesian coordinates of the probe over each hydrocarbon, gave representations of three-dimensional isotropic shielding increment surfaces. The results are related to the degree of bond length alternation, the extent of electron delocalization, and (for the ions) the NPA charge distribution. The shielding increment data are compared to NICS(1) values computed at the same level; both indicate the degree of aromaticity or antiaromaticity of the component rings. View Full-Text
Keywords: aromaticity; antiaromaticity; NMR shielding; fused hydrocarbons; GIAO; HF/6-31G(d,p); NICS(1) aromaticity; antiaromaticity; NMR shielding; fused hydrocarbons; GIAO; HF/6-31G(d,p); NICS(1)

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Share & Cite This Article

MDPI and ACS Style

Martin, N.H.; Teague, M.R.; Mills, K.H. Computed NMR Shielding Effects over Fused Aromatic / Antiaromatic Hydrocarbons. Symmetry 2010, 2, 418-436.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Symmetry EISSN 2073-8994 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top