om980762r_si_001.cif (57.38 kB)
Synthesis, Structure, and Reactivity of Unsolvated Triple-Decked Bent Metallocenes of Divalent Europium and Ytterbium
dataset
posted on 1999-03-19, 00:00 authored by William J. Evans, Matthew A. Johnston, Michael A. Greci, Joseph W. ZillerThe europium and ytterbium complexes of formula [(C5Me5)Ln]2(μ-η8:η8-C8H8) 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.
YbI2(THF)2 reacts with KC5Me5 and K2C8H8 in THF to form [(C5Me5)Yb(THF)]2(μ-η8:η8-C8H8),
1, in 80% yield. 1 can be readily desolvated at 30 °C and 10-7 Torr to afford [(C5Me5)Yb]2(μ-η8:η8-C8H8), 2, in 80% yield. 2 crystallizes from toluene and consists of two divalent [(C5Me5)Yb]+ moieties bridged by a (C8H8)2- unit with 159° and 161° (C5Me5 ring centroid)−Yb−(C8H8 ring centroid) angles. [(C5Me5)Eu(THF)2]2(μ-η8:η8-C8H8), 3, can be desolvated at
55 °C and 10-7 Torr to afford [(C5Me5)Eu]2(μ-η8:η8-C8H8), 4, in 90% yield. 4 crystallizes with
a molecule of toluene and has 149.3° and 148.9° (C5Me5 centroid)−Eu−(C8H8 centroid) angles.
Complex 2 reacts with 1,3,5,7-cyclooctatetraene to form (C5Me5)Yb(C8H8), 5.
