Solvent effects on the nitrogen and β-hydrogen hyperfine splitting constants of aminoxyl radicals obtained in spin trapping experiments

Abstract

The nitrogen and β-hydrogen hyperfine splitting constants (hfsc) for phenyl, 4-nitrophenyl, 4-pyridyl, benzoyl, and trichloromethyl spin adducts of α-phenyl tert-butyl nitrone (PBN) as well as for the tert-butoxyl adduct of 5,5-dimethylpyrroline-N-oxide (DMPO) have been obtained as a function of solvent (30 solvents). A useful linear relationship between the β-H hfsc and the N-hfsc of each aminoxyl is found except for the benzoyl adduct of PBN. Some speculations regarding the structural significance of these correlations is presented.