Solvation spectra. Part 32.—Variation in the e.s.r. linewidths of ClO2 and SO –2 in water-butyl alcohol mixtures

Abstract

Because of the dependence of the e.s.r. linewidths on T/η, the predominant relaxation mechanism for both ClO₂ and SO^–₂ is taken to be the motional modulation of spin-rotational interactions. This is more efficient for ClO₂ than for SO^–₂ in water, but the effect of added t-butyl alcohol is markedly different for the two isoelectronic radicals. Whereas the linewidth for SO^–₂ roughly follows T/η, as expected theoretically, that for ClO₂ is independent of viscosity η in the 0-0.1 mol fraction region. These differences are discussed in terms of the clathrate theory of hydration.