Di-tert-butylcyclopentadienyl complexes of europium and ytterbium: synthesis and crystal structures of (1,3-But2C5H3)2 Eu·THF, (1,3-But2C5H3)(C5Me5)Yb·THF, and\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$\left( {1,3 - Bu^t _2 C_5 H_3 } \right)_2 Yb(\mu _2 - Cl)_2 Li(THF)_2 $$ \end{document}

The (1,3-But2C5H3)2Eu·THF complex was prepared by the reaction of 1,3-But2C5H3Na with Eul2 in tetrahydrofuran. The mixed-ligand (1,3-But2C5H3)(C5Me5)Yb·THF complex was obtained by the reaction of YbI2 with C5Me5Na and 1,3-But2C5H3Na. The reaction of 1,3-But2C5H3Li with YbCl3 afforded the (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$\left( {1,3 - Bu^t _2 C_5 H_3 } \right)_2 Yb(\mu _2 - Cl)_2 Li(THF)_2 $$ \end{document})ate-complex. The structures of the title compounds were established by X-ray diffraction analysis.