title: A stable hyponitrite-bridged iron porphyrin complex.
abstract: The coupling of two nitric oxide (NO) molecules in heme active sites is an important contributor to the conversion of NO to nitrous oxide (N(2)O) by heme-containing enzymes. Several formulations for the presumed heme-Fe{N(2)O(2)}(n-) intermediates have been proposed previously, however, no crystal structures of heme-Fe{N(2)O(2)}(n-) systems have been reported to date. We report the first isolation and characterization of a stable bimetallic hyponitrite iron porphyrin, [(OEP)Fe](2)(mu-N(2)O(2)), prepared from the reaction of [(OEP)Fe](2)(mu-O) with hyponitrous acid. Density functional theoretical calculations were performed on the model compound [(porphine)Fe](2)(mu-N(2)O(2)) to characterize its electronic structure and properties.
authors.affiliation: Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, Oklahoma 73019, USA.
authors.forename: Nan
authors.initials: N
authors.lastname: Xu
authors.forename: Adam L O
authors.initials: AL
authors.lastname: Campbell
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Powell
authors.forename: Jana
authors.initials: J
authors.lastname: Khandogin
authors.forename: George B
authors.initials: GB
authors.lastname: Richter-Addo
mesh_terms: D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds; D006418:Heme / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D008958:Models, Molecular; D009573:Nitrites / Q000138:chemical synthesis / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D005290:Ferric Compounds; D009573:Nitrites; C025117:hyponitrite; D006418:Heme