ISSN:
0749-1581
Keywords:
1H NMR
;
13C NMR
;
Fluorine-containing polycyclic aromatic hydrocarbons
;
Anomalous F-induced shifts and couplings
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 1H and 13C NMR spectra of several fluorine-substituted polycyclic aromatic hydrocarbons in which fluorine projects into a bay region were studied. Both protons and carbons of the sterically opposed CH bond show anomalously large F-induced shifts and couplings to fluorine. The magnitudes of the couplings (particularly the four-bond CF couplings which average 26 Hz) indicate a large through-space contribution due to direct overlap between fluorine and CH bond orbitals, whereas the F-induced shifts seem more likely to stem from diamagnetic anisotropy rather than F-induced CH bond polarization.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260270104
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