The Flash Photolysis of Water and Aqueous Solutions

Abstract

Transient species absorbing in the ultraviolet are produced in the flash photolysis of aerated water and a variety of aqueous solutions. The flash irradiation of water alone and of aerated water and dilute aerated solutions of methanol produces hydrogen peroxide in amounts consistent with the primary production of H and HO from the photolysis of water. The transient absorption at 254 m mu produced in dilute aerated methanol solutions shows second-order decay kinetics, and the decay rate is enhanced considerably by the presence of Cu/sup 2+/. The observations are consistent with the absorption being due to the radical HO/sub 2/. Rate constants for the processes HO/sub 2/ + HO/sub 2/ and Cu/ sup 2/ + HO/sub 2/ have been obtained. (auth)