Kinetics and Mechanism of the Reaction of Coherently Synchronized Oxidation and Dehydrogenation of Cyclohexane by Hydrogen Peroxide

Abstract

Inducing effect of hydrogen peroxide on synchronous oxidation reaction is accompanied by the occurrence of two interconnected and interacting reactions. The reaction of Н 2 O 2 decomposition (primary) generates the leading active • OH and HO • 2 free radicals in a system. During the interaction of active and free radicals with the substrate, the conversion of the substrate occurs in the secondary reaction, coherently-synchronized with the primary one. The mechanism of such coherently synchronized reactions is being examined in the process of cyclohexane oxidation with hydrogen peroxide in homogeneous and heterogeneous systems.The process of coupling dehydrogenation of cyclohexane to cyclohexene and cyclohexadiene with hydrogen peroxide was carried out without catalyst. This process was also carried out at a fairly low temperature in a heterogeneous catalytic system.Biomimetic catalyst, which simulates the basic functions of the enzyme group of oxidoreductase - catalase and monooxygenase, was used as the catalyst here. Characterised by its highly active and selective action these biomimetic catalysts are synthesized based on iron-porphyrin complexes simulating the active component of cytochrome P-450.Based on this experimental researches, the complex reaction, consisting of parallel-sequential oxidation and dehydrogenation reactions, which are coherently synchronized, proceeds during the process of cyclohexane oxidation with biomimetic catalyst. Depending on the reaction parameters it is possible to deliberately adjust the direction of oxidation reaction and reaction rate.