The crystal and molecular structure of [ η5-C 5H 3(SiMe 3) 2] 2Yb(THF

Abstract

[ η 5-C 5H 3(SiMe 3) 2] 2Yb(THF has been structurally characterized. The compound crystallizes in the orthorhombic space group Pbcn with a = 11.345(4), b = 13.552(4), c = 21.185(6) A ̊ , and D calc = 1.354 mg m −1 for Z = 4 . The Yb and O atoms reside on a crystallographic two-fold axis. The formally seven-coordinate Yb(II) ion is symmetrically coordinated to the Cp″ ligands with an average Yb-C bond length of 2.67(2) Å. The YbO bond length and centroid-Yb-centroid angle are 2.34(1) Å and 136°, respectively. The calculated effective ionic radius of the Cp″ ligand, 1.59 Å, is at the low end of those calculated for 18 Cp″ lanthanide, lanthanum, or scandium compounds.