Modeling the cis-Oxo-Labile Binding Site Motif of Non-Heme Iron Oxygenases: Water Exchange and Oxidation Reactivity of a Non-Heme Iron(IV)-Oxo Compound Bearing a Tripodal Tetradentate Ligand

The spectroscopic and chemical characterization of a new synthetic non-heme iron(IV)-oxo species [FeIV(O)(Me,HPytacn)(S)]2+ (2, Me,HPytacn=1-(2′-pyridylmethyl)-4,7-dimethyl-1,4,7-triazacyclononane, S=CH3CN or H2O) is described. Complex 2 was prepared by reaction of [FeII(CF3SO3)2(Me,HPytacn)] (1) wi...

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Detalhes bibliográficos
Autores: Company Casadevall, Anna, Prat Casellas, Irene, Frisch, Jonathan R., Mas-Ballesté, Rubén, Güell Serra, Mireia, Juhász, Gergely, Ribas Salamaña, Xavi, Münck, Eckard, Luis Luis, Josep Maria, Que, Lawrence, Costas Salgueiro, Miquel
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/12251
Acesso em linha:http://hdl.handle.net/10256/12251
Access Level:acceso embargado
Palavra-chave:Oxigenases
Oxygenases
Química bioinorgànica
Bioinorganic chemistry
Mecanismes de reacció (Química)
Reaction mechanisms (Chemistry)
Ferro
Iron
Descrição
Resumo:The spectroscopic and chemical characterization of a new synthetic non-heme iron(IV)-oxo species [FeIV(O)(Me,HPytacn)(S)]2+ (2, Me,HPytacn=1-(2′-pyridylmethyl)-4,7-dimethyl-1,4,7-triazacyclononane, S=CH3CN or H2O) is described. Complex 2 was prepared by reaction of [FeII(CF3SO3)2(Me,HPytacn)] (1) with peracetic acid. Complex 2 bears a tetradentate N4 ligand that leaves two cis sites available for binding an oxo group and a second external ligand but, unlike the related iron(IV)-oxo species with tetradentate ligands, it is remarkably stable at room temperature (t1/2>2 h at 288 K). Its ability to exchange the oxygen atom of the oxo ligand with water has been analyzed in detail by means of kinetic studies, and a mechanism is proposed on the basis of DFT calculations. Hydrogen-atom abstraction from C[BOND]H bonds and oxygen-atom transfer to sulfides by 2 have also been studied. Despite its thermal stability, 2 proves to be a very powerful oxidant that is capable of breaking the strong C[BOND]H bond of cyclohexane (bond dissociation energy=99.3 kcal mol−1)

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