Quantification and visualization of the anisotropy effect in NMR spectroscopy by through-space NMR shieldings
- The anisotropy effect of functional groups (respectively the ring-current effect of aryl moieties) in H-1 NMR spectra has been computed as spatial NICS (through-space NMR chemical shieldings) and visualized by iso-chemical-shielding surfaces of various size and low(high) field direction. Hereby, the anisotropy/ring-current effect, which proves to be the molecular response property of spatial NICS, can be quantified and can be readily employed for assignment purposes in proton NMR spectroscopy-characteristic examples of stereochemistry and position assignments (the latter in supramolecular structures) will be given. In addition, anisotropy/ring-current effects in H-1 NMR spectra can be quantitatively separated from the second dominant structural effect in proton NMR spectra, the steric compression effect, pointing into the reverse direction, and the ring-current effect, by far the strongest anisotropy effect, can be impressively employed to visualize and quantify (anti) aromaticity and to clear up standing physical-organic phenomena asThe anisotropy effect of functional groups (respectively the ring-current effect of aryl moieties) in H-1 NMR spectra has been computed as spatial NICS (through-space NMR chemical shieldings) and visualized by iso-chemical-shielding surfaces of various size and low(high) field direction. Hereby, the anisotropy/ring-current effect, which proves to be the molecular response property of spatial NICS, can be quantified and can be readily employed for assignment purposes in proton NMR spectroscopy-characteristic examples of stereochemistry and position assignments (the latter in supramolecular structures) will be given. In addition, anisotropy/ring-current effects in H-1 NMR spectra can be quantitatively separated from the second dominant structural effect in proton NMR spectra, the steric compression effect, pointing into the reverse direction, and the ring-current effect, by far the strongest anisotropy effect, can be impressively employed to visualize and quantify (anti) aromaticity and to clear up standing physical-organic phenomena as are pseudo-, spherical, captodative, homo-and chelatoaromaticity, to characterize the pi-electronic structure of, for example, fulvenes, fulvalenes, annulenes or fullerenes and to differentiate aromatic and quinonoid structures.…
Author details: | Erich KleinpeterORCiDGND |
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DOI: | https://doi.org/10.1016/B978-0-12-800184-4.00003-5 |
ISBN: | 978-0-12-800184-4 |
ISSN: | 0066-4103 |
Title of parent work (English): | Annual reports on NMR spectroscopy |
Title of parent work (English): | Annual Reports on NMR Spectroscopy |
Publisher: | Elsevier |
Place of publishing: | San Diego |
Editor(s): | GA Webb |
Publication type: | Review |
Language: | English |
Year of first publication: | 2014 |
Publication year: | 2014 |
Release date: | 2017/03/27 |
Tag: | Anisotropy effect; Aromatic or quinonoid; Aromaticity; Binding pocket position; Chelatoaromaticity; Diastereomers assignment; Ring-current effect; Stereochemistry; Supramolecular compounds; Through-space NMR shielding (TSNMRS) |
Volume: | 82 |
Number of pages: | 52 |
First page: | 115 |
Last Page: | 166 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |