ISSN:
0030-4921
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Changes in 13C and 14N chemical shifts of the nitro derivatives of nitrogen heterocycles upon ionization (anion or cation formation) are twofold - first a uniform paramagnetic or in the case of protonation, a uniform diamagnetic shift of all the ring resonances that parallels the changes in the respective ultraviolet spectra and must be caused by changes in the molecular excited states, and second - the influence of the conjugated nitro group. About one third of the total negative anion charge may be localized on the nitro group, which causes unusually large shifts of the ring 13C resonances in this case.
Additional Material:
4 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1270040202