ISSN:
0749-1581
Keywords:
Rotational barriers
;
π-electron density alternation
;
Mesomerism in pyrylium salts
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 13C NMR spectra and the temperature-dependent 1H NMR spectra of a series of NR2-substituted pyridines and pyrones were studied, and the 13C chemical shifts and the rotational barriers about the exocyclic partial C,N double bonds were compared with the corresponding values for suitable pyridinium, pyrylium and thiopyrylium salts. The NMR spectroscopic results are discussed in the light of the electronic state and mesomerism in the species studied; the salts in question should be named, from the electronic point of view, more realistically as bridged pentamethine cyanines rather than pyridinium, pyrylium and thiopyrylium salts.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260260813
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