The Mechanism of ESR Relaxation in Peroxylamine Disulfonate Ion ·ON(SO3)22−

Abstract

Abstract The mechanism of ESR relaxation in ·ON(SO3)22− is discussed. As the line width in an aqueous solution is plotted against the concentration, it is almost concentration independent in the range lower than 7×10−3 mol/l, but the dependence increases in the higher range. Powles and Moseley showed that the anisotropy of the g-value contributes to the line width in the lower concentration range, but the line width in the higher-concentration range, which is investigated in the present investigation, can not be accounted for by the g-tensor anisotropy. Hence, it is supposed that electron spin exchange or nuclear quadrupole interaction contributes in the higher-concentration range. The latter can, however, be eliminated by the line width measurement in a deuterium measurement in a deuterium oxide solution, and so it may be concluded that electron spin exchange is the main contribution to the line width in the higher-concentration range. This is in accordance with the proposal of Jones. Furthermore, we could show that, by calculation of the line shape for Bloch’s equation, including exchange interactions, the exchange frequency of 5.4×107 sec−1 can give a line fitting the observed line shape for the 7.8×10−2 mol/l solution. This result can be taken as another evidence showing that the electron spin exchange is the main source of the line width in the higher-concentration range.