title: O2 activation by bis(imino)pyridine iron(II)-thiolate complexes.
abstract: The new iron(II)-thiolate complexes [((iPr)BIP)Fe(II)(SPh)(Cl)] (1) and [((iPr)BIP)Fe(II)(SPh)(OTf)] (2) [BIP = bis(imino)pyridine] were prepared as models for cysteine dioxygenase (CDO), which converts Cys to Cys-SO(2)H at a (His)(3)Fe(II) center. Reaction of 1 and 2 with O(2) leads to Fe-oxygenation and S-oxygenation, respectively. For 1 + O(2), the spectroscopic and reactivity data, including (18)O isotope studies, are consistent with an assignment of an iron(IV)-oxo complex, [((iPr)BIP)Fe(IV)(O)(Cl)](+) (3), as the product of oxygenation. In contrast, 2 + O(2) results in direct S-oxygenation to give a sulfonato product, PhSO(3)(-). The positioning of the thiolate ligand in 1 versus 2 appears to play a critical role in determining the outcome of O(2) activation. The thiolate ligands in 1 and 2 are essential for O(2) reactivity and exhibit an important influence over the Fe(III)/Fe(II) redox potential.
authors.affiliation: Department of Chemistry, Johns Hopkins University , Baltimore, Maryland 21212, United States.
authors.forename: Yosra M
authors.initials: YM
authors.lastname: Badiei
authors.forename: Maxime A
authors.initials: MA
authors.lastname: Siegler
authors.forename: David P
authors.initials: DP
authors.lastname: Goldberg
mesh_terms: D007501:Iron / Q000737:chemistry*; D008024:Ligands; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D007501:Iron; C023666:pyridine; D010100:Oxygen