X-ray photoelectron spectroscopic (X-p.e.s.) studies on in situ photoinduced decomposition of inorganic molecular ions. Part 2.—Na[ClOx] system: mechanistic (x= 3, 4) and variable-temperature (x= 3) investigations

Abstract

The first-order rate constants for the decomposition of Na[ClO₃] and Na[ClO₄] when studied by X-p.e.s. are shown to have a linear dependence on the intensity of the ionising radiation used. A simple steady-state model, which emphasises the rôle of molecular excitons in the decomposition process, is constructed to explain this behaviour. Variable temperature studies in the range 293–113 K indicate that the rate of photo-induced decomposition of Na[ClO₃] increases as the temperature is lowered, and analysis of the mode of decomposition suggests that the temperature-dependence arises from thermal deactivation of the molecular exciton, [ClO^*₃]^–.