title: Diiron(II) mu-aqua-mu-hydroxo model for non-heme iron sites in proteins.
abstract: We have synthesized a diiron(II) complex with a novel aqua-hydroxo bridging motif, [Fe2(mu-H2O)(mu-OH)(TPA)2](OTf)3 (1). This is a new member of the diiron diamond core family. The complex is stable in solution in nonpolar solvents as well as in the solid state. Two high-spin iron(II) sites are antiferromagnetically coupled (J = -9.6 cm(-1)). The drastic difference of ca. 1 V in the redox potential between complex 1 and its bis(hydroxo)-bridged analogue Fe2(OH)2(TPA)3+ is accompanied by only a moderate difference in the dioxygen reactivity. This observation is consistent with the inner-sphere mechanism of iron(II)-dioxygen association rather than the outer-sphere electron transfer.
authors.affiliation: Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA.
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Korendovych
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Kryatov
authors.forename: William M
authors.initials: WM
authors.lastname: Reiff
authors.forename: Elena V
authors.initials: EV
authors.lastname: Rybak-Akimova
mesh_terms: D001665:Binding Sites; D015392:Chemistry, Inorganic / Q000379:methods; D004563:Electrochemistry / Q000379:methods; D004579:Electron Transport; D005296:Ferrous Compounds / Q000737:chemistry* / Q000378:metabolism; D006418:Heme / Q000737:chemistry / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010100:Oxygen / Q000737:chemistry; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014867:Water
chemical_list: D005296:Ferrous Compounds; D008024:Ligands; D011506:Proteins; D014867:Water; D006418:Heme; D007501:Iron; D010100:Oxygen