title: Oxidative addition of carbon-carbon bonds with a redox-active bis(imino)pyridine iron complex.
abstract: Addition of biphenylene to the bis(imino)pyridine iron dinitrogen complexes, ((iPr)PDI)Fe(N(2))(2) and [((Me)PDI)Fe(N(2))](2)(μ(2)-N(2)) ((R)PDI = 2,6-(2,6-R(2)-C(6)H(3)-N═CMe)(2)C(5)H(3)N; R = Me, (i)Pr), resulted in oxidative addition of a C-C bond at ambient temperature to yield the corresponding iron biphenyl compounds, ((R)PDI)Fe(biphenyl). The molecular structures of the resulting bis(imino)pyridine iron metallacycles were established by X-ray diffraction and revealed idealized square pyramidal geometries. The electronic structures of the compounds were studied by Mössbauer spectroscopy, NMR spectroscopy, magnetochemistry, and X-ray absorption and X-ray emission spectroscopies. The experimental data, in combination with broken-symmetry density functional theory calculations, established spin crossover (low to intermediate spin) ferric compounds antiferromagnetically coupled to bis(imino)pyridine radical anions. Thus, the overall oxidation reaction involves cooperative electron loss from both the iron center and the redox-active bis(imino)pyridine ligand.
authors.affiliation: Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14850, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Darmon
authors.forename: S Chantal E
authors.initials: SC
authors.lastname: Stieber
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Sylvester
authors.forename: Ignacio
authors.initials: I
authors.lastname: Fernández
authors.forename: Emil
authors.initials: E
authors.lastname: Lobkovsky
authors.forename: Scott P
authors.initials: SP
authors.lastname: Semproni
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Karl
authors.initials: K
authors.lastname: Wieghardt
authors.forename: Serena
authors.initials: S
authors.lastname: DeBeer
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Chirik
mesh_terms: D002244:Carbon / Q000737:chemistry*; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D007094:Imides / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D005290:Ferric Compounds; D007094:Imides; D011725:Pyridines; D002244:Carbon