title: A synthetic model of the putative Fe(II)-iminobenzosemiquinonate intermediate in the catalytic cycle of o-aminophenol dioxygenases.
abstract: The oxidative ring cleavage of aromatic substrates by nonheme Fe dioxygenases is thought to involve formation of a ferrous-(substrate radical) intermediate. Here we describe the synthesis of the trigonal-bipyramdial complex Fe((Ph2)Tp)(ISQ(tBu)) (2), the first synthetic example of an iron(II) center bound to an iminobenzosemiquinonate (ISQ) radical. The unique electronic structure of this S = 3/2 complex and its one-electron oxidized derivative ([3](+)) have been established on the basis of crystallographic, spectroscopic, and computational analyses. These findings further demonstrate the viability of Fe(2+)-ISQ intermediates in the catalytic cycles of o-aminophenol dioxygenases.
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Bittner
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Lindeman
authors.forename: Adam T
authors.initials: AT
authors.lastname: Fiedler
mesh_terms: D000627:Aminophenols / Q000378:metabolism*; D016227:Benzoquinones / Q000737:chemistry* / Q000378:metabolism; D040761:Biomimetic Materials / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis; D018360:Crystallography, X-Ray; D049308:Dioxygenases / Q000378:metabolism*; D004583:Electrons; D005296:Ferrous Compounds / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D010084:Oxidation-Reduction; D013057:Spectrum Analysis
chemical_list: D000627:Aminophenols; D016227:Benzoquinones; D005296:Ferrous Compounds; C027667:2-aminophenol; D049308:Dioxygenases