Synthesis, characterization, hydrolase and catecholase activity of a dinuclear iron(III) complex: Catalytic promiscuity

• Published in: Journal of inorganic biochemistry 2015-05, Vol.146, p.77-88
• Main Authors: Camargo, Tiago P., Maia, Fernanda F., Chaves, Cláudia, de Souza, Bernardo, Bortoluzzi, Adailton J., Castilho, Nathalia, Bortolotto, Tiago, Terenzi, Hernán, Castellano, Eduardo E., Haase, Wolfgang, Tomkowicz, Zbigniew, Peralta, Rosely A., Neves, Ademir
• Format: Article
• Language: English
• Subjects: Catalysis; Catalytic promiscuity; Catechol Oxidase - chemistry; Dinuclear iron(III) complex; DNA - chemistry; DNA cleavage; Ferric Compounds - chemical synthesis; Ferric Compounds - chemistry; Hydrolases - chemistry; Iron Compounds - chemical synthesis; Iron Compounds - chemistry; Oxidation-Reduction; Substrate Specificity
• ISSN: 0162-0134; 1873-3344
• DOI: 10.1016/j.jinorgbio.2015.02.017

Herein, we report the synthesis and characterization of the new di-iron(III) complex [(bbpmp)(H2O)(Cl)FeIII(μ-Ophenoxo)FeIII(H2O)Cl)]Cl (1), with the symmetrical ligand 2,6-bis{[(2-hydroxybenzyl)(pyridin-2-yl)methylamino]methyl}-4-methylphenol (H3bbpmp). Complexes 2 with the unsymmetrical ligand H2bpbpmp — {2-[[(2-hydroxybenzyl)(2-pyridylmethyl)]aminomethyl]-6-bis(pyridylmethyl) aminomethyl}-4-methylphenol and 3 with the ligand L1=4,11-dimethyl-1,8-bis{2-[N-(di-2-pyridylmethyl)amino]ethyl}cyclam were included for comparison purposes. Complex 1 was characterized through elemental analysis, X-ray crystallography, magnetochemistry, electronic spectroscopy, electrochemistry, mass spectrometry and potentiometric titration. The magnetic data show a very weak antiferromagnetic coupling between the two iron centers of the dinuclear complex 1 (J=−0.29cm−1). Due to the presence of labile coordination sites in both iron centers the hydrolysis of both the diester model substrate 2,4-BDNPP and DNA was studied in detail. Complex 1 was also able to catalyze the oxidation of the substrate 3,5-di-tert-butylcatechol (3,5-DTBC) to give the corresponding quinone, and thus it can be considered as a catalytically promiscuous system. The synthesis, X-ray structure and catalytic promiscuity (diesterase and catecholase activity) of a new dinuclear FeIII complex are here reported. [Display omitted] •Dinuclear Iron(III) complex using a symmetric ligand•Synthesis, X-ray structure, magnetic properties and solution studies of the dinuclear catalyst•Ability of the complex to catalyze different reactions (catalytic promiscuity)