Chromium(III) and Chromium(II) Phenolate Complexes with Bulky Alkylcyclopentadienyl Ligands

Journal article


Publication Details

Author(s): Smytschkow I, Gidt W, Kunz C, Sun Y, Langer J, Oelkers B, Böttcher T, Sitzmann H
Journal: European Journal of Inorganic Chemistry
Publication year: 2019
Volume: 2019
Journal issue: 22
Pages range: 2742-2749
ISSN: 1434-1948


Abstract

The chromium(II) tricarbonyl methyl complex [Cp′′′Cr(CO)3CH3] (1, Cp′′′ = η5-C5H2tBu3-1,2,4) was obtained from chromium hexacarbonyl, NaCp′′′, and methyl iodide. 1 was found to establish an equilibrium with the dicarbonyl acetyl isomer [Cp′′′Cr(CO)2(COCH3)] in solution via reversible, slightly endothermic methyl migration from chromium to a carbonyl ligand with ΔH ca. 3.6 kJ/mol and Ea ca. 49.5 kJ/mol. Phosphorus pentachloride oxidized 1 to the green, dinuclear tetrachloro complex [Cp′′′CrCl(µ-Cl)]2 (2), which was crystallized as the blue-green chromium(III) half sandwich complex [Cp′′′CrCl2(THF)] (3) in the presence of tetrahydrofuran vapor. Attempted sublimation of the known chromium(II) iodo complex [4CpCr(µ-I)]2 resulted in a redox reaction with formation of the chromium(III) iodo dimer [4CpCrI(µ-I)]2, whose tri(tert-butyl)cyclopentadienyl derivative [Cp′′′CrI(µ-I)]2 (4) could also be prepared by oxidation of [Cp′′′Cr(µ-I)]2 with iodine. The chromium(III) bis(2,6-diisopropylphenolate) complex [4CpCr(OC6H3iPr2-2,6)2] (5) was obtained from chromium trichloride in a one pot reaction with sodium tetraisopropylcyclopentadienide, followed by sodium 2,6-diisopropylphenolate. The chromium(III) starting compound 2 reacted with 2,6-diisopropylphenolate to the Cp′′′ derivative [Cp′′′Cr(OC6H3iPr2-2,6)2] (6). The chromium(II) starting compound [Cp′′′Cr(µ-Br)]2 afforded the phenolate-bridged chromium(II) dimer [Cp′′′Cr(µ-OC6H5)]2 (7) upon treatment with sodium phenolate, while the product of the analogous reaction with 2,6-di(tert-butyl)phenolate was the mononuclear tetrahydrofuran adduct [Cp′′′Cr(OC6H3tBu2-2,6)(THF)] (8).


FAU Authors / FAU Editors

Langer, Jens Dr.
Lehrstuhl für Anorganische und Metallorganische Chemie


External institutions with authors

Albert-Ludwigs-Universität Freiburg
Technische Universität Kaiserslautern


How to cite

APA:
Smytschkow, I., Gidt, W., Kunz, C., Sun, Y., Langer, J., Oelkers, B.,... Sitzmann, H. (2019). Chromium(III) and Chromium(II) Phenolate Complexes with Bulky Alkylcyclopentadienyl Ligands. European Journal of Inorganic Chemistry, 2019(22), 2742-2749. https://dx.doi.org/10.1002/ejic.201900275

MLA:
Smytschkow, Igor, et al. "Chromium(III) and Chromium(II) Phenolate Complexes with Bulky Alkylcyclopentadienyl Ligands." European Journal of Inorganic Chemistry 2019.22 (2019): 2742-2749.

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Last updated on 2019-25-06 at 16:08