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


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

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.

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.


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