Synthesis and characterization of dinuclear organolanthanide alkoxides, X-ray crystal structures of [(C 5H 5) 2Yb(μ-OCH 2CH 2CH 2CH 2CH 3)] 2 and [(C 5H 5)Yb(μ-OCH 2CH 2CH(Me) 2] 2

Abstract

The reaction of lanthanocenes Cp 3Ln (Cp  C 5H 5, Ln  Dy, Yb) with the equimolar alcohols HOR [R  CH 2CH 2CH 2CH 2CH 3,, CH 2CH 2CH(Me) 2] in THF forms three new dinuclear organolanthanide alkoxides, namely [Cp 2Yb(μ-OCH 2CH 2CH 2CH 2CH 3)] 2 ( I) and [Cp 2Ln(μ-OCH 2CH 2CH(Me) 2)] 2 [Ln  Dy ( II), Yb ( III)]. These three new complexes have been characterized by elemental analysis, IR and MS spectra, indicating they are oxygen-bridging dimers. Complexes I and II have also been studied by X-ray crystallography. The ytterbium atom is coordinated by two Cp rings and two oxygen atoms of bridging alkoxide groups to form a distorted pseudo tetrahedral geometry. The average YbC(Cp) distances in I and III are 2.59(2) and 2.60(2) Å, respectively. The average YbO distances for I and III are 2.18(1) and 2.197(6) Å, respectively.