An intermediate cobalt(IV) nitrido complex and its N-migratory insertion product.

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Details zur Publikation

Autor(en): Zolnhofer E, Käß M, Khusniyarov M, Heinemann F, Maron L, Van Gastel M, Bill E, Meyer K
Zeitschrift: Journal of the American Chemical Society
Jahr der Veröffentlichung: 2014
Band: 136
Heftnummer: 42
Seitenbereich: 15072-8
ISSN: 1520-5126


Abstract

Low-temperature photolysis experiments (T = 10 K) on the tripodal azido complex [(BIMPN(Mes,Ad,Me))Co(II)(N3)] (1) were monitored by EPR spectroscopy and support the formation of an exceedingly reactive, high-valent Co nitrido species [(BIMPN(Mes,Ad,Me))Co(IV)(N)] (2). Density functional theory calculations suggest a low-spin d(5), S = 1/2, electronic configuration of the central cobalt ion in 2 and, thus, are in line with the formulation of complex 2 as a genuine, low-spin Co(IV) nitride species. Although the reactivity of this species precludes handling above 50 K or isolation in the solid state, the N-migratory insertion product [(NH-BIMPN(Mes,Ad,Me))Co(II)](BPh4) (3) is isolable and was reproducibly synthesized as well as fully characterized, including CHN elemental analysis, paramagnetic (1)H NMR, IR, UV-vis, and EPR spectroscopy as well as SQUID magnetization and single-crystal X-ray crystallography studies. A computational analysis of the reaction pathway 2 → 3 indicates that the reaction readily occurs via N-migratory insertion into the Co-C bond (activation barrier of 2.2 kcal mol(-1)). In addition to the unusual reactivity of the nitride 2, the resulting divalent cobalt complex 3 is a rare example of a trigonal pyramidal complex with four different donor ligands of a tetradentate chelate-an N-heterocyclic carbene, a phenolate, an imine, and an amine-binding to a high-spin Co(II) ion. This renders complex 3 chiral-at-metal.


FAU-Autoren / FAU-Herausgeber

Heinemann, Frank Dr.
Lehrstuhl für Anorganische und Allgemeine Chemie
Käß, Martina
Lehrstuhl für Anorganische und Allgemeine Chemie
Khusniyarov, Marat PD Dr.
Department Chemie und Pharmazie
Meyer, Karsten Prof. Dr.
Lehrstuhl für Anorganische und Allgemeine Chemie
Zolnhofer, Eva
Lehrstuhl für Anorganische und Allgemeine Chemie


Autor(en) der externen Einrichtung(en)
Max-Planck-Institut für Chemische Energiekonversion (MPI CEC) / Max-Planck-Institute for Chemical Energy Conversion
University of Toulouse


Zitierweisen

APA:
Zolnhofer, E., Käß, M., Khusniyarov, M., Heinemann, F., Maron, L., Van Gastel, M.,... Meyer, K. (2014). An intermediate cobalt(IV) nitrido complex and its N-migratory insertion product. Journal of the American Chemical Society, 136(42), 15072-8. https://dx.doi.org/10.1021/ja508144j

MLA:
Zolnhofer, Eva, et al. "An intermediate cobalt(IV) nitrido complex and its N-migratory insertion product." Journal of the American Chemical Society 136.42 (2014): 15072-8.

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Zuletzt aktualisiert 2018-23-07 um 18:08