Catharina C. Quitmann

Crystal Structure of Di[(μ‐benzoato‐O,O′)bis(η5‐methylcylopentadienyl)ytterbium(III)]

Transparent orange-red crystals of [Yb(MeCp)2(O2CPh)]2 obtained by oxidation of Yb(MeCp)2 with Tl(O2CPh) in tetrahydrofuran have a dimeric structure with bridging bidentate (O,O′)-benzoate groups and eight-coordinate ytterbium.

Divalent Europium in 1∞[Eu(Pz)2(Pz-H)2]: The First Unsubstituted Pyrazolate and Cp Analogous Pyrazole Complex of a Rare Earth Element in One

Abstract Bright yellow crystals of 1∞[Eu(Pz)2(Pz-H)2] were obtained by the reaction of europium metal with a melt of pyrazole. According to single crystal X-ray analysis the compound exhibits a onedimensional chain structure including both unsubstituted pyrazolate anions as well as unsubstituted neutral pyrazole molecules as ligands. The latter are isoelectronic with the cyclopentadienyl anion and link two adjacent Europium(II) centers in an η1-σ -bridging as well as Cp analogous η5-π-binding mode, whilst the pyrazolate anions are N-η1-coordinating terminal ligands. In addition to the crystal structure, MIR, FarIR, Raman and UV/vis spectroscopic data are presented.