title: Ligand noninnocence in FeNO corroles: insights from β-octabromocorrole complexes.
abstract: The first FeNO octabromocorroles have been synthesized including four β-octabromo-meso-tris(p-X-phenyl)corrole derivatives Fe[Br8TpXPC](NO) (X = CF3, H, CH3, OCH3) and the β-octabromo-meso-tris(pentafluorophenyl)corrole complex, Fe[Br8TPFPC](NO). The last complex, which proved amenable to single-crystal X-ray structure determination, exhibits the geometry parameters: Fe-N(O) 1.643(8) Å, N-O 1.158(9) Å, and a FeNO angle of 176.4(6)°. The more electron-deficient complexes exhibit increased instability with respect to NO loss and also higher infrared NO stretching frequencies (νNO). Interestingly, DFT calculations and IR marker bands indicate a noninnocent {FeNO}(7)-(corrole˙(2-)) formulation for all FeNO corroles, both β-H8 and β-Br8, with essentially the same degree of corrole radical character. Instead, an electron-deficient corrole appears to exert a field effect resulting in reduced Fe-to-NO backdonation, which accounts for both the increased instability with respect to NO loss and the higher νNO's.
authors.affiliation: Department of Chemistry and Center for Theoretical and Computational Chemistry, UiT - The Arctic University of Norway, 9037 Tromsø, Norway. hugo.vazquez@uit.no abhik.ghosh@uit.no.
authors.forename: Hans-Kristian
authors.initials: HK
authors.lastname: Norheim
authors.affiliation: Department of Chemistry and Center for Theoretical and Computational Chemistry, UiT - The Arctic University of Norway, 9037 Tromsø, Norway. hugo.vazquez@uit.no abhik.ghosh@uit.no.
authors.forename: Jan
authors.initials: J
authors.lastname: Capar
authors.affiliation: Department of Chemistry and Center for Theoretical and Computational Chemistry, UiT - The Arctic University of Norway, 9037 Tromsø, Norway. hugo.vazquez@uit.no abhik.ghosh@uit.no.
authors.forename: Rune F
authors.initials: RF
authors.lastname: Einrem
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720-8229, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Gagnon
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720-8229, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Beavers
authors.affiliation: Department of Chemistry and Center for Theoretical and Computational Chemistry, UiT - The Arctic University of Norway, 9037 Tromsø, Norway. hugo.vazquez@uit.no abhik.ghosh@uit.no.
authors.forename: Hugo
authors.initials: H
authors.lastname: Vazquez-Lima
authors.affiliation: Department of Chemistry and Center for Theoretical and Computational Chemistry, UiT - The Arctic University of Norway, 9037 Tromsø, Norway. hugo.vazquez@uit.no abhik.ghosh@uit.no.
authors.forename: Abhik
authors.initials: A
authors.lastname: Ghosh