4 research outputs found

    Cobalt in a Bis-Ī²-diketiminate Environment

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    The reaction of Co<sub>2</sub>(mesityl)<sub>4</sub> with acetonitrile leads to the formation of a planar, low spin, bis-Ī²-diketiminate cobaltĀ­(II) complex, (1-mesitylbutane-1,3-diimine)<sub>2</sub>Co (<b>1</b>). EPR spectroscopy, magnetic studies, and DFT calculations reveal the CoĀ­(II) ion to reside in a tetragonal ligand field with a <sup>2</sup>B<sub>2</sub>(d<sub><i>yz</i></sub>)<sup>1</sup> ground state electronic configuration. Oxidation of <b>1</b> with ferrocenium hexafluorophosphate furnishes (1-mesitylbutane-1,3-diimine)<sub>2</sub>CoĀ­(THF)<sub>2</sub>PF<sub>6</sub> (<b>2</b>). The absence of significant changes in the metalā€“ligand bond metrics of the X-ray crystal structures of <b>1</b> and <b>2</b> supports ligand participation in the oxidation event. Moreover, no significant changes in Cā€“C or Cā€“N bond lengths are observed by X-ray crystallography upon oxidation of a Ī²-diketiminate ligand, in contrast to typical redox noninnocent ligand platforms

    Cobalt in a Bis-Ī²-diketiminate Environment

    No full text
    The reaction of Co<sub>2</sub>(mesityl)<sub>4</sub> with acetonitrile leads to the formation of a planar, low spin, bis-Ī²-diketiminate cobaltĀ­(II) complex, (1-mesitylbutane-1,3-diimine)<sub>2</sub>Co (<b>1</b>). EPR spectroscopy, magnetic studies, and DFT calculations reveal the CoĀ­(II) ion to reside in a tetragonal ligand field with a <sup>2</sup>B<sub>2</sub>(d<sub><i>yz</i></sub>)<sup>1</sup> ground state electronic configuration. Oxidation of <b>1</b> with ferrocenium hexafluorophosphate furnishes (1-mesitylbutane-1,3-diimine)<sub>2</sub>CoĀ­(THF)<sub>2</sub>PF<sub>6</sub> (<b>2</b>). The absence of significant changes in the metalā€“ligand bond metrics of the X-ray crystal structures of <b>1</b> and <b>2</b> supports ligand participation in the oxidation event. Moreover, no significant changes in Cā€“C or Cā€“N bond lengths are observed by X-ray crystallography upon oxidation of a Ī²-diketiminate ligand, in contrast to typical redox noninnocent ligand platforms

    Iron in a Trigonal Tris(alkoxide) Ligand Environment

    No full text
    Mononuclear FeĀ­(II) and FeĀ­(III) complexes residing in a trigonal trisĀ­(ditox) (ditox = <sup>t</sup>Bu<sub>2</sub>(Me)Ā­CO<sup>ā€“</sup>) ligand environment have been synthesized and characterized. The FeĀ­(III) ditox complex does not react with oxidants such as PhIO, whereas NMe<sub>3</sub>O substitutes a coordinated tetrahydrofuran (THF) in the apical position without undergoing oxo transfer. In contrast, the FeĀ­(II) ditox complex reacts rapidly with PhIO or Me<sub>3</sub>NO in THF or cyclohexadiene to furnish a highly reactive intermediate, which cleaves Cā€“H bonds to afford the FeĀ­(III)ā€“hydroxide complex. When generated in 1,2-difluorobenze, this intermediate can be intercepted to oxidize phosphines to phosphine oxide. The fast rates at which these reactions occur is attributed to a particularly weak ligand field imparted by the trisĀ­(alkoxide) ancillary ligand environment

    Iron in a Trigonal Tris(alkoxide) Ligand Environment

    No full text
    Mononuclear FeĀ­(II) and FeĀ­(III) complexes residing in a trigonal trisĀ­(ditox) (ditox = <sup>t</sup>Bu<sub>2</sub>(Me)Ā­CO<sup>ā€“</sup>) ligand environment have been synthesized and characterized. The FeĀ­(III) ditox complex does not react with oxidants such as PhIO, whereas NMe<sub>3</sub>O substitutes a coordinated tetrahydrofuran (THF) in the apical position without undergoing oxo transfer. In contrast, the FeĀ­(II) ditox complex reacts rapidly with PhIO or Me<sub>3</sub>NO in THF or cyclohexadiene to furnish a highly reactive intermediate, which cleaves Cā€“H bonds to afford the FeĀ­(III)ā€“hydroxide complex. When generated in 1,2-difluorobenze, this intermediate can be intercepted to oxidize phosphines to phosphine oxide. The fast rates at which these reactions occur is attributed to a particularly weak ligand field imparted by the trisĀ­(alkoxide) ancillary ligand environment
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