Meso-tetraphenylporphyriniron(iii) chloride catalyzed oxidation of aniline and its substituents by magnesium monoperoxyphthalate in aqueous acetic acid medium

Raja Manickam,Karunakaran Kulandaivelu

doi:10.2478/v10026-012-0099-9

Abstract

Abstract The catalytic properties of the first generation catalyst meso-tetraphenylporphyriniron(III) chloride and magnesium monoperoxyphthalate (MMPP) as oxidant have been studied in the oxidation of aniline and its substituents in acetic acid medium. The thermodynamic parameters for the oxidation have been determined and discussed. It confirms the Exner relationship (only at the low range of temperatures) and also some of the activation parameters to the isokinetic relationships. The magnesium monoperoxyphthalate oxidation with 18 ortho- meta- and para-substituted anilines fulfills with isokinetic relationship but not to any of the linear free energy relationships. The reaction mechanism and the rate law were proposed.

Highlights

The cytochrome P450 is a large group of enzymes
For cytochrome P-450 the model catalyst metalloporphyrins could be used as the intermediate of oxygen carrier in biological systems
Metalloporphyrins have been widely used as catalysts for various oxidation reactions[1,2,3,4,5]

Summary

Introduction

The cytochrome P450 is a large group of enzymes. The most common reaction catalyzed by cytochromes P450 is a monooxygenase reaction. For cytochrome P-450 the model catalyst metalloporphyrins could be used as the intermediate of oxygen carrier in biological systems. Heme itself is very unstable in oxidations, and that is why the more robust metallo-tetraarylporphyrins were introduced. These complexes can catalyze the oxidation of aniline. Metalloporphyrin iron complexes have been the subject as a catalyst in a number of findings[7,8] and in the present study the first generation catalyst meso-tetraphenylporphyriniron(III) chloride (5,10,15,20-tetraphenyl-21h,23h-porphineiron(III) chloride) is added as a catalyst in the selective oxidation of aniline. The iron complexes with meso-tetraphenyl groups are considered as a model of the natural ironporphyrins due to their constructive properties such as catalytic and semi-conducting properties. The kinetics of the oxidation of anilines by a variety of oxidants has been reported[15,16,17,18,19] and few of them authenticate Hammet equation

Methods

Results

Conclusion