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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Kinetic studies on 2,6-lutidine catalyzed peroxyoxalate chemiluminescence in organic and aqueous medium: Evidence for general base catalysis

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Author(s):
Augusto, Felipe A. [1] ; Bartoloni, Fernando H. [2, 1] ; Cabello, Maidileyvis C. [1] ; dos Santos, Ana Paula F. [1] ; Baader, Wilhelm J. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Sao Paulo - Brazil
[2] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Santo Andre - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY; v. 382, SEP 1 2019.
Web of Science Citations: 1
Abstract

The peroxyoxalate reaction, base catalyzed perhydrolysis of activated aromatic oxalate esters in the presence of chemiluminescence activators, has widespread analytical and bioanalytical applications and is one of the most efficient chemiluminescence transformations known. We report here a kinetic study on this reaction using 2,6-lutidine as catalyst in organic (1,2-dimethoxyethane) and aqueous medium. In both media, experimental conditions can be designed which lead to reproducible results important for analytical applications. Observed rate constants (determined by observing the light emission intensity as well as absorbance variation due to phenol releases) show dependence on both the 2,6-lutidine and the hydrogen peroxide concentration, indicating their participation in the rate-limiting step of the transformation. The rate constants obtained from these kinetic studies proved to be at least one order of magnitude higher in water than in 1,2-dimethoxyethane as solvent. Kinetic experiments designed to distinguish between three different types of catalysis (nucleophilic, specific base and general base catalysis) clearly indicate that the role of 2,6-lutidine in this reaction is as general base catalyst in water as well as most likely in organic medium. (AU)

FAPESP's process: 14/22136-4 - Use of green solvents and their mixtures for optimizing chemical processes
Grantee:Omar Abou El Seoud
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 12/13807-7 - New tools for the study of electron transfer reactions in PS II model systems
Grantee:Fernando Heering Bartoloni
Support Opportunities: Regular Research Grants