Zirconium
Complexes Supported by an <i>N-</i>Perfluoro-Arylated Diamidopyridyl
Ligand: Synthesis of Hydrazinediido Complexes
- Publication date
- Publisher
Abstract
The <i>N-</i>perfluoro-phenylated
pyridyldiamine H<sub>2</sub>N<sub>2</sub><sup>PFP</sup>N<sub>py</sub> (<b>1</b>) has been prepared by a palladium-catalyzed coupling
of hexafluorobenzene and the diamine (H<sub>2</sub>NCH<sub>2</sub>)<sub>2</sub>C(CH<sub>3</sub>)(2-C<sub>5</sub>H<sub>4</sub>N) using
the palladacycle <i>trans</i>-di(μ-acetato)bis[<i>o</i>-(di-<i>o</i>-tolylphosphino)benzyl]palladium(II)
as catalyst. Reactions of H<sub>2</sub>N<sub>2</sub><sup>PFP</sup>N<sub>py</sub> and Zr(NMe<sub>2</sub>)<sub>4</sub> at room temperature
or 90 °C led to the complexes [(N<sup>PFP</sup>N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)ZrF(NMe<sub>2</sub>)] (<b>2</b>) and
[(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)ZrF<sub>2</sub>] (<b>3</b>) in which one or two dimethylamido groups replaced one or
two ortho fluorine atoms of the pentafluorophenyl groups in the ligand.
Reaction of Me<sub>3</sub>SiX (X = Cl, I) with [(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)ZrF<sub>2</sub>] (<b>3</b>) resulted
in the formation of mixed halogenated complexes [(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)ZrFI] (<b>4</b>) and [(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)ZrFCl] (<b>5</b>) in which the
axially bound fluorido ligand is substituted. Reaction of [(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)ZrF<sub>2</sub>] (<b>3</b>) with LiNHNPh<sub>2</sub> afforded the monohydrazido(1−)
complex [(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)ZrF(NHNPh<sub>2</sub>)] (<b>6</b>) which was converted to the dimeric fluoro-potassium
bridged hydrazinediido complex [Zr(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)FNNPh<sub>2</sub>K]<sub>2</sub> (<b>7</b>) using KHMDS.
The corresponding reaction with LiHMDS yielded the monomeric, donor
free complex [Zr(N<sub>2</sub><sup>TFAP</sup>N<sub>py</sub>)NNPh<sub>2</sub>] (<b>8</b>)
