Synthesis and structures of new metallocene derivatives of lanthanides. Molecular structures of the complexes (C13H9)2Eu(THF)2 and (C5Me4H)2YbI(THF)

The divalent europium bis-fluorenyl complex (C13H9)(2)Eu(THF)(2) was synthesized by the metathesis reaction of EuI2(THF)(2) with two equivalents of fluorenylpotassium and by the protolytic substitution of the naphthalene ligand in the (C10H8)Eu(THF)(2) complex using the reaction with fluorene. According to X-ray diffraction data, the complex displays a skewed sandwich structure, in which one fluorenyl ligand is eta(5)-coordinated to the metal atom, whereas the eta(3)-coordination mode makes a great contribution to the coordination of another ligand. The (C5Me4H)(2)YbI(THF) complex was synthesized by the reaction of YbI3(THF)(2) With two equivalents of (C5Me4H)K. The structure of the complex was established by X-ray diffraction.