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>.