Unexpected C–H Bond Activation Promoted by
Bimetallic Lanthanide Amido Complexes Bearing a META-Phenylene-Bridged
Bis(β-diketiminate) Ligand
- Publication date
- Publisher
Abstract
Treatment
of META-[Na(THF)<sub>2</sub>]<sub>2</sub> (<b>1</b>; META =
{[2,6-<sup><i>i</i></sup>Pr<sub>2</sub>C<sub>6</sub>H<sub>3</sub>NC(Me)C(H)C(Me)N]<sup>−</sup>}<sub>2</sub>-(<i>m-</i>phenylene)] with 1 equiv of {Ln[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>2</sub>(μ-Cl)(THF)}<sub>2</sub> (Ln = Y, Yb) in
toluene at 110 °C afforded bimetallic lanthanide amido complexes
bridged by a chloride and a phenyl group, {Ln[N(SiMe<sub>3</sub>)<sub>2</sub>]}<sub>2</sub>(META′)(μ-Cl) (Ln = Y (<b>2</b>), Yb (<b>3</b>)), which formed via unexpected C–H bond
activation of the arene ring. However, the same reactions carried
out in both THF and toluene at room temperature gave the bimetallic
lanthanide amido–chloro complexes {Ln[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>2</sub>}META{Ln[N(SiMe<sub>3</sub>)<sub>2</sub>]Cl(THF)}
(Ln = Y (<b>4</b>), Yb (<b>5</b>)). When they were heated
to 110 °C in toluene, complexes <b>4</b> and <b>5</b> were converted to complexes <b>2</b> and <b>3</b> via
amine elimination. All of these complexes were confirmed by elemental
analysis, FT-IR, and X-ray structure analysis and by NMR analysis
in the cases of complexes <b>1</b>, <b>2</b>, and <b>4</b>
