ESR evidence regarding the structures of some simple nitrogen-centered radicals in aqueous solution
✍ Scribed by Richard W. Fessenden
- Publisher
- Elsevier Science
- Year
- 1974
- Tongue
- English
- Weight
- 541 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
The ESR specuum of the radical obtained by reaction of e; ,cribed by the parameters aN = wit1 N-brotioacetamidc in aqueous solution is des-10.40, aH(CHs) = oH(OH) = 1.42 G, :md g = 2.00326. 'These values show that the stable structure is CHaC(OH)=fi, i.e., mothylene iminc type, and is not CHsC(=O)fiH. l?ie OH proton dissociates.
yith a pK of 6.3 and the resulting anion CHaC(C-)=I? shows magneic parameters also consistent with an imino type. The unpaired electron in these radicals is in a nitrogen p orbital in thz plane of the heavy atoms. The previously re-,, ported radicals -02CNH and CHsOC!(=O)~ derived from OH + OCiy and e; + CHaOC(=O)NHCI respectively, have higher g factors (and a large proton splitting in the case of -02CNH) whit 3, sugpst they are of the amino or a&do structure with the unpaired electron in a nitrogen p orbitd at &h t angles to the plane of the heavy atoms. Together, these radicak illustrate two different sites of piotanation and two different structures for the -(CON): group.
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