Kinetics of β-Carotene Oxidation in the Presence of Highly Active Forms of µ-Carbido Diiron(IV) Tetraphenylporphyrinate
- Authors: Simonova O.R.1, Zaitseva S.V.1, Tyulyaeva E.Y.1, Zdanovich S.A.1, Koifman O.I.1,2
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Affiliations:
- Krestov Institute of Solution Chemistry, Russian Academy of Sciences
- Ivanovo State University of Chemistry and Technology
- Issue: Vol 92, No 11 (2018)
- Pages: 2128-2134
- Section: Chemical Kinetics and Catalysis
- URL: https://journals.rcsi.science/0036-0244/article/view/170190
- DOI: https://doi.org/10.1134/S0036024418110390
- ID: 170190
Cite item
Abstract
The oxidative destruction of β-carotene in the presence of highly oxidized forms of µ-carbido-bis[(5,10,15,20-tetraphenyl-21H,23H-porphyrinato)iron(IV)] (1 → 3) or its analog with axially coordinated imidazole (2 → 4) obtained under the action of tert-butyl hydroperoxide tBuOOH was studied by spectrophotometry. It was found that compound 3 is the oxo form of compound 1 singly oxidized at the macrocyclic ligand (π radical cation) under the action of which β-carotene is oxidized with a rate constant k = 3.3 L2 mol–2 s–1. A conclusion is drawn that short-lived compound 4 has unique EAS and is capable of oxidizing tBuOOH to form O2, which makes it possible to consider it the model of peroxidase. The value of k for the reaction with the participation of β-carotene and compound 4 (k = 10.3 L2 mol–2 s–1) is three times higher than that with the participation of compound 3. If a new portion of β-carotene is added, the process of its oxidative destruction in the presence of compounds 3 or 4 occurs without additives of the dimeric complex and peroxide. A possible nature of compound 4 is discussed, as well as the influence of N-base in the coordination sphere of the complex on the nature of active intermediates and the rate of β-carotene decomposition.
About the authors
O. R. Simonova
Krestov Institute of Solution Chemistry, Russian Academy of Sciences
Email: teu@isc-ras.ru
Russian Federation, Ivanovo, 153045
S. V. Zaitseva
Krestov Institute of Solution Chemistry, Russian Academy of Sciences
Email: teu@isc-ras.ru
Russian Federation, Ivanovo, 153045
E. Yu. Tyulyaeva
Krestov Institute of Solution Chemistry, Russian Academy of Sciences
Author for correspondence.
Email: teu@isc-ras.ru
Russian Federation, Ivanovo, 153045
S. A. Zdanovich
Krestov Institute of Solution Chemistry, Russian Academy of Sciences
Email: teu@isc-ras.ru
Russian Federation, Ivanovo, 153045
O. I. Koifman
Krestov Institute of Solution Chemistry, Russian Academy of Sciences; Ivanovo State University of Chemistry and Technology
Email: teu@isc-ras.ru
Russian Federation, Ivanovo, 153045; Ivanovo, 153000