General Acid and Base Catalysis by Phosphate in Peroxyoxalate Chemiluminescence

Abstract

AbstractThe peroxyoxalate reaction, one of the most efficient chemiluminescent transformations, is widely utilized in analytical and bioanalytical assays. Although the mechanism of this transformation has been extensively studied, it is still not yet fully clarified. Furthermore, no detailed mechanistic studies have been performed in aqueous media, highly important for analytical applications. The light emission kinetic behaviour of the peroxyoxalate reaction is studied here in phosphate buffered binary 1,2‐dimethoxyethane/water mixtures at different pH values using three oxalic ester derivatives. The results indicate that conditions can be found where the chemiluminescent perhydrolysis is predominant over dark ester hydrolysis; the reactions are subject to general acid and base catalysis by phosphate ions; are reasonably reproducible, although, generally fast. However, chemiluminescence emission quantum yields are much lower than in organic solvents.