Solvation spectra. Part 20.—Electron spin resonance studies of the alkali-metal derivatives of ortho- and meta-dinitrobenzenes in 1,2-dimethoxyethane

Line broadening has been observed in the electron spin resonance spectra of the alkali-metal derivatives of o- and m-dinitrobenzenes, and is discussed in terms of “fast” and “slow” rates of modulation of the isotropic hyperfine couplings of the nitrogen nuclei and certain protons. Methods are developed for predicting the amount of broadening of each line in these spectra, and it is shown that the relative signs of modulated coupling constants can be determined from the line broadening produced by “slow” modulation.