Electron spin resonance study of oxygen-17 enrichedN,N-dimethyl-4-nitroaniline radical anion

Abstract

N,N-Dimethyl-d6-4-nitroaniline enriched to approximately 11 atom. per cent in oxygen-17 has been prepared and the oxygen-17 isotropic hyperfine interaction in the corresponding radical anion has been examined. In dry dimethylformamide solution we find a O = -8·85 ± 0·02 and a N = 11·39 ± 0·10 gauss, while in moist acetonitrile solution a O = -8·82 ± 0·07 and a N = 12·23 ± 0·11 gauss. These results substantiate the recent suggestion that the isotropic oxygen-17 splittings in π-radicals may be described by a single parameter equation analogous to McConnell's relation for aromatic proton splittings, i.e. a O = Q OρO π, where Q O = -41 ± 3 gauss.