10.1021/om980762r.s002
William J. Evans
William J.
Evans
Matthew A. Johnston
Matthew A.
Johnston
Michael A. Greci
Michael A.
Greci
Joseph W. Ziller
Joseph W.
Ziller
Synthesis, Structure, and Reactivity of Unsolvated
Triple-Decked Bent Metallocenes of Divalent Europium
and Ytterbium
American Chemical Society
1999
THF
C 8 H 8
centroid
KC
C 5
K 2 C 8 H 8
Yb
1999-03-19 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Synthesis_Structure_and_Reactivity_of_Unsolvated_Triple-Decked_Bent_Metallocenes_of_Divalent_Europium_and_Ytterbium/3783501
The europium and ytterbium complexes of formula [(C<sub>5</sub>Me<sub>5</sub>)Ln]<sub>2</sub>(μ-η<sup>8</sup>:η<sup>8</sup>-C<sub>8</sub>H<sub>8</sub>) have been
synthesized and structurally characterized to determine the dependence of the (ring
centroid)−metal−(ring centroid) angles on the size and electron configuration of the metal.
YbI<sub>2</sub>(THF)<sub>2</sub> reacts with KC<sub>5</sub>Me<sub>5</sub> and K<sub>2</sub>C<sub>8</sub>H<sub>8</sub> in THF to form [(C<sub>5</sub>Me<sub>5</sub>)Yb(THF)]<sub>2</sub>(μ-η<sup>8</sup>:η<sup>8</sup>-C<sub>8</sub>H<sub>8</sub>),
<b>1</b>, in 80% yield. <b>1</b> can be readily desolvated at 30 °C and 10<sup>-7</sup> Torr to afford [(C<sub>5</sub>Me<sub>5</sub>)Yb]<sub>2</sub>(μ-η<sup>8</sup>:η<sup>8</sup>-C<sub>8</sub>H<sub>8</sub>), <b>2</b>, in 80% yield. <b>2</b> crystallizes from toluene and consists of two divalent [(C<sub>5</sub>Me<sub>5</sub>)Yb]<sup>+</sup> moieties bridged by a (C<sub>8</sub>H<sub>8</sub>)<sup>2-</sup> unit with 159° and 161° (C<sub>5</sub>Me<sub>5</sub> ring centroid)−Yb−(C<sub>8</sub>H<sub>8</sub> ring centroid) angles. [(C<sub>5</sub>Me<sub>5</sub>)Eu(THF)<sub>2</sub>]<sub>2</sub>(μ-η<sup>8</sup>:η<sup>8</sup>-C<sub>8</sub>H<sub>8</sub>), <b>3</b>, can be desolvated at
55 °C and 10<sup>-7</sup> Torr to afford [(C<sub>5</sub>Me<sub>5</sub>)Eu]<sub>2</sub>(μ-η<sup>8</sup>:η<sup>8</sup>-C<sub>8</sub>H<sub>8</sub>), <b>4</b>, in 90% yield. <b>4 </b>crystallizes with
a molecule of toluene and has 149.3° and 148.9° (C<sub>5</sub>Me<sub>5</sub> centroid)−Eu−(C<sub>8</sub>H<sub>8</sub> centroid) angles.
Complex <b>2</b> reacts with 1,3,5,7-cyclooctatetraene to form (C<sub>5</sub>Me<sub>5</sub>)Yb(C<sub>8</sub>H<sub>8</sub>), <b>5</b>.