Rate of hydrated electron reaction with neutral and anionic scavengers in concentrated salt solutions

The rate constants, k/sub obsd/, of the e/sub aq/- reaction with nitrobenzene, IrCl62-, and Fe(CN)63- have been measured in water, and in LiCl and CsCl solutions up to a concentration of 14 M LiCl and 6 M CsCl and were found to be diffusion controlled. The viscosity of CsCl solutions is independent of CsCl concentration whereas in the case of LiCl solutions the logarithm of the viscosity decreases linearly with concentration. Since the logarithm of the rate constant, log k/sub obsd/, with nitrobenzene decreases linearly with LiCl concentration the viscosity is the rate-determining parameter. In CsCl solutions the rate constants do not vary with salt concentration. Iridate and ferricyanide behave like neutral species at LiCl concentrations above 1 and 6 M, respectively; above these LiCl concentrations the dependence of their rate constants and that of nitrobenzene on salt concentration is Smoluchowski--Debye equation at high salt concentration