Kinetics and mechanism of the ferroxime(II)-catalysed biomimetic oxidation of 2-aminophenol by dioxygen. A functional phenoxazinone synthase model

Tatiana M. Simándi, László I. Simándi, Miklós Gyor, A. Rockenbauer, A. Gömöry

Research output: Contribution to journalArticle

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Abstract

[Fe(Hdmg)2(MeIm)2] (1), referred to as ferroxime(II), is the precursor of a selective catalyst for the oxidative dehydrogenation of 2-aminophenol (Hap) to 2-amino-3H-phenoxazine-3-one (apx) by dioxygen under ambient conditions. The superoxoferroxime(III) species has been detected by ES-MS, and a 4-substituted 2-aminophenoxyl free radical by the ESR technique. The kinetics of the reaction was followed spectrophotometrically and by monitoring dioxygen uptake at constant pressure. According to the proposed mechanism, solvolysis of 1 is followed by O2 binding to afford a superoxoferroxime, which abstracts an H-atom from Hap in the rate-determining step via an H-bonded intermediate, generating the free radical. This is supported by the observed primary deuterium kinetic isotope effect of 2.63. The system studied is a functional phenoxazinone synthase model.

Original languageEnglish
Pages (from-to)1056-1060
Number of pages5
JournalDalton Transactions
Issue number7
Publication statusPublished - Apr 7 2004

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Biomimetics
Free Radicals
Oxygen
Oxidation
Kinetics
Deuterium
Dehydrogenation
Isotopes
Paramagnetic resonance
Atoms
Catalysts
Monitoring
phenoxazinone
2-aminophenol
ferroxime(II)
phenoxazine

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Kinetics and mechanism of the ferroxime(II)-catalysed biomimetic oxidation of 2-aminophenol by dioxygen. A functional phenoxazinone synthase model. / Simándi, Tatiana M.; Simándi, László I.; Gyor, Miklós; Rockenbauer, A.; Gömöry, A.

In: Dalton Transactions, No. 7, 07.04.2004, p. 1056-1060.

Research output: Contribution to journalArticle

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