ISSN:
0749-1581
Keywords:
ESR
;
1,3,2-Dithiazol-2-yl radicals
;
Pyrazine
;
Quinoxaline
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Several symmetrical 1,3,2-dithiazol-2-yl radicals have been examined that have in common nitrogen-containing substituents at the 4- and 5-positions, namely 4,5-dicyano-1,3,2-dithiazol-2-yl, [15N2]-1,3,2-dithiazolo [4,5-b] pyrazin-2-yl and 1,3,2-dithiazoleo [4,5-b] quinoxalin-2-yl. The ESR spectrum of the 4,5-dicyano radical does not reveal any 14N splittings from the cyanide groups; however, the pyrazine and the quinoxaline derivatives do have multi-lined well resolved spectra arising from substantial hyperfine interactions with these nuclei. The interactions are sufficiently large to be observed in the powder spectra of the latter. The presence of proton hyperfine interactions shows that unpaired-electron spin density is delocalized over all the rings. It has been found that the radicals attached to pyrazine and quinoxaline can be incorporated into single crystals of naphthalene and phenazine, respectively.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260300814
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