Properties of (μ-Oxo)di-iron complexes and catalytic activity toward cyclohexane oxidation

Journal of the Brazilian Chemical Society

Gabrieli L. Parrilha²  Sarah S. Ferreira²  Christiane Fernandes²  Giselle C. Silva¹  Nakédia M. F. Carvalho¹  O. A. C. Antunes¹  Valderes Drago¹  Adailton J. Bortoluzzi¹  Adolfo Horn Jr.² 

[1] ,Universidade Estadual do Norte Fluminense Laboratório de Ciências Químicas Campos dos Goytacazes RJ ,Brazil

关键词: di-iron complex;    bridge;    methane monooxygenase;    cyclohexane oxidation;   

DOI  :  10.1590/S0103-50532010000400004

来源: SciELO

【 摘 要 】

We report herein the synthesis and characterization of two dinuclear μ-oxo iron compounds obtained through the reactions of FeSO4•7H2 O and FeCl3•6H2 O with 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol (L5), which resulted in the compounds [(SO4)(L5)Fe(μ-O)Fe(L5)(SO4 )]•6H2O, 1, and [Cl(L5)Fe(μ-O)Fe(L5)Cl]Cl2• 2H2O, 2. The electronic spectra of both compounds show absorption bands only in the UV range. The electrochemical analysis showed that the dinuclear unit is more stable under reduction in compound 1 than in compound 2, while the Mössbauer spectroscopy revealed that the monodentate ligands (sulfate and chloride) have a significant influence on the Mössbauer parameters determined for 1 and 2, particularly on the quadrupole splitting values. Both compounds were studied as catalysts in reactions of cyclohexane oxidation, using H2O2 and t-BuOOH as oxidants, in a substrate:oxidant:catalyst ratio of 1000:1000:1. Cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide, t-butyl cyclohexyl peroxide and adipic acid were formed during the process. The experiments revealed that compound 2 is, in general, more active than compound 1 in promoting cyclohexane oxidation.

【 授权许可】

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