Blar i forfatter Artikler, rapporter og annet (kjemi) "Vazquez-Lima, Hugo"

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    • Comparing Isoelectronic, Quadruple-Bonded Metalloporphyrin and Metallocorrole Dimers: Scalar-Relativistic DFT Calculations Predict a > 1-eV Range for Ionization Potential and Electron Affinity 

      Conradie, Jeanet; Vazquez-Lima, Hugo; Alemayehu, Abraham; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-21)
      A scalar-relativistic DFT study of isoelectronic, quadruple-bonded Group 6 metalloporphyrins (M = Mo, W) and Group 7 metallocorroles (M = Tc, Re) has uncovered dramatic differences in ionization potential (IP) and electron affinity (EA) among the compounds. Thus, both the IPs and EAs of the corrole derivatives are 1 eV or more higher than those of the porphyrin derivatives. These differences ...

    • Infrared Spectroelectrochemistry of Iron-Nitrosyl Triarylcorroles. Implications for Ligand Noninnocence 

      Rahman, Md. Hafizur; Ryan, Michael D.; Vazquez-Lima, Hugo; Alemayehu, Abraham; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-13)
      Recent DFT calculations have suggested that iron nitrosyl triarylcorrole complexes have substantial {FeNO}<sup>7</sup> −corrole<sup>•2−</sup> character. With this formulation, reduction of Fe(C)(NO) complexes, where C = triarylcorrole, should be centered on the corrole macrocycle rather than on the {FeNO}<sup>7</sup> moiety. To verify this proposition, visible and infrared spectroelectrochemical ...

    • Ligand noninnocence in FeNO corroles: insights from β-octabromocorrole complexes 

      Norheim, Hans-Kristian; Capar, Jan; Einrem, Rune; Gagnon, Kevin J.; Beavers, Christine; Vazquez-Lima, Hugo; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-30)
      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) ...

    • Platinum Corroles 

      Alemayehu, Abraham; Vazquez-Lima, Hugo; Beavers, Christine M.; Gagnon, Kevin J.; Bendix, Jesper; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-06-09)
      Platinum has been inserted into corroles for the first time and three oxidized PtIV(corrole2)ArAr0 complexes have been structurally characterized. The Soret maxima of these complexes exhibit an unusually strong dependence on the meso-aryl substituents on the corrole, indicating aryl - corrole2 charge transfer character in these transitions.

    • Rare and Nonexistent Nitrosyls: Periodic Trends and Relativistic Effects in Ruthenium and Osmium Porphyrin-Based {MNO}7 Complexes 

      Demissie, Taye Beyene; Conradie, Jeanet; Vazquez-Lima, Hugo; Ruud, Kenneth; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-14)
      Relativistic and nonrelativistic density functional theory calculations were used to investigate rare or nonexistent ruthenium and osmium analogues of nitrosylhemes. Strong ligand field effects and, to a lesser degree, relativistic effects were found to destabilize {RuNO}<sup>7</sup> porphyrins relative to their {FeNO}<sup>7</sup> analogues. Substantially stronger relativistic effects account for ...

    • Unexpected Molecular Structure of a Putative Rhenium-Dioxo-Benzocarbaporphyrin Complex. Implications for the Highest Transition Metal Valence in a Porphyrin-Type Ligand Environment 

      Alemayehu, Abraham; Vazquez-Lima, Hugo; Teat, Simon J.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-18)
      A combination of quantum chemical calculations and synthetic studies was used to address the possibility of very high (>6) valence states of transition metals in porphyrin‐type complexes. With corrole as a supporting ligand, DFT calculations ruled out Re(VII) and Ir(VII) dioxo complexes as stable species. Attempted rhenium insertion into benzocarbaporphyrin (BCP) ligands on the other hand led to two ...