Mechanistic Studies on the Peroxyoxalate Chemiluminescence Using Sodium Salicylate as Base Catalyst

5 years ago

Mechanistic Studies on the Peroxyoxalate Chemiluminescence Using Sodium Salicylate as Base Catalyst

Wilhelm J. Baader, André P. Lang, Glalci A. Souza

Mechanistic studies on the peroxyoxalate chemiluminescence are often conducted with imidazole as base and nucleophilic catalyst. However, it is also known that this compound, at high concentrations, leads to a drastic reduction in the chemiluminescence quantum yields, apparently due to the destruction of the high-energy intermediate. Consequently, the search for new catalysts for this transformation is of importance for mechanistic studies as well as analytical application. Therefore, we report here a study on the mechanism of the peroxyoxalate reaction with sodium salicylate as base catalyst, which has already been utilized in this reaction; however, no detailed mechanistic investigation is known. In this work, a kinetic study on the sodium salicylate-catalyzed reaction of bis(2,4,6-trichlorophenyl) oxalate with hydrogen peroxide using 9,10-diphenylanthracene as activator is reported, where observed rate constants, singlet quantum yields and activation parameters are determined in different reaction conditions, leading to the formulation of a general mechanistic reaction scheme. The peroxyoxalate reaction is studied with sodium salicylate as catalyst which, contrarily to imidazole, acts only as base, not as nucleophilic, catalyst. Reproducible results are obtained, and a general reaction mechanism is proposed.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1111/php.12797