Nitrogen splittings

The majority of the spin density is on nitrogen due to the high electronegativity of the sulfoxide sulfur. This is shown by the low g factor and high proton and nitrogen splitting compared to the bis(dimethylamino)sulfide cation. 

ENDOR spectrum exhibited chlorine and nitrogen splittings indicating a carotenoid-quinone radical adduct formation. 

When radicals are produced electrochemically in the same solvents and under similar conditions again only one nitrogen splitting is observed in the e.s.r. spectrum. The change to a non-protic solvent. 

The ESR spectra of the anion radicals 246 derived from a series of 4-dicyanom ethyl idene-4//-thiopy ran sulfones show clearly resolved hyperfine structure centred around g values of ca. 2000. Large nitrogen splitting of 1.0-1.5 mT and FI-3 and FI-5 splitting of 0.3-0.93 mT are observed <1995JOC1674>. 

Bimethylamine absorbs nitrogen, splitting off water in ratios that likewise indicate the formation of hexamethylenetetramine. 

The behavior of pyridines with the mesomerically electron-withdrawing groups nitro, acetyl, and cyano is, by contrast with the foregoing, very different. In these radicals the substituent rather than the heterocycle becomes the primary site for unpaired electron density. For example, in the three mononitropyridine anions the heterocyclic nitrogen splitting is much... 

The anion-radical of cycl[3.2.2]azine (pyrido[2,l,6-ct/]pyrrolizine) (181) has been known many years.598,599 The observed nitrogen splitting is very... 

Nitrogen splittings, like 0-splittings, are dependent upon the spin densities at the adjacent atoms, and interpretation of their magnitude is therefore difficult. Nevertheless, the variation of in a series of radicals, as a function of solvent and substituents, can provide information about both intra- and inter-molecular effects. 

The nitrogen-splittings in iminoxy radicals, R R C=N—O, are 30 G, which is very much larger than in nitroxides and probably reflects the fact that there is a significant spin density at nitrogen in an... 

The nitrogen splitting for 6 in acetonitrile may be compared with those for the nitro groups in the anion-radicals of nitrobenzene and the three nitropyridines in the same solvent (Part I Section III,A,l,b). The relative orders of magnitude are 2-nitrofuran > nitrobenzene > 3-nitropyridine >... 

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