The Primary Process ClO3- (+hν) ClO- + O2 in the Photolysis of Aqueous ClO3- Solutions

Article abstract of DOI:10.1021/j100155a046

The quantum yield, Φ₁, in the primary process ClO3^- (+hν) <*> ClO^- + O2 (1) and the sum of the quantum yields Φ₁ + Φ₂ in the primary processes ClO3^- (+hν) <*> ClO2 + O^- (2) and ClO3^- <*> ClO2^- + O(³P) (3) were measured in the steady state photolysis of aqueous ClO3^- solutions at 214 and 229 nm.The ratio of the yields of ClO^- and ClO3^- in the reactions ClO2 <*> ClO^- + O2 and ClO2 + O^- <*> ClO3^- (4) was determined by γ-radiolysis of aqueous solutions of ClO2 at varying pH.The finding that the ratio between the yields of ClO^- and ClO3^- in reactions 4 equals the ratio between Φ₁ and the quantum yield, Φ₀ = 1 -Φ₁ - Φ₂ - Φ₃, for ClO3^- returning to the ground state is taken as evidence that process 1 results from a cage-back reaction.This result combined with recent studies of the radiolysis of KClO3 crystals suggest that the primary processes in the photolysis of aqueous ClO3^- originate in a common process by which O^- is expelled from ClO3^- upon photoexcitation.The expelled O^- may escape the solvent cage containing ClO2 (process 2), or react in cage-back reaction (process 0 and 1).During the expulsion of O^- the photoproducts may convert to ClO2^- and O(³P) (process 3).