Preparation and characterization of cationic organolanthanides with less bulky ligands

摘要

The cationic complexes stabilized by methylcyclopentadienyl (MeCp ligands, i.e.[(MeCp)2Ln(THF)z][BPh4]?2THF (1, Ln=Sm; 2, Ln=Yb) have been preparedby oxidation of (MeCp)2Ln(THF) with AgBPH4 in tetrahydrofuran(THF) and characterized by elemental analyses, IR spectra, molarconductivities and TGDTA measurements. 2 was characterized byX-ray. The two centroids of methylcyclopentadienyl rings and thetwo oxygen atoms of THF molecules form a distorted tetrahedronaround the ytterbium atom with an average Yb-C(ring) bonddistance of 2.55? and Cen(1)-Yb-Cen(2) angle of 127.6°.Thestructural analysis indicates that the cationic complex with lessbulky ligands has a more open coordination environment aroundthe metal atom than that with bulky ligands. The results alsoconfirm that the stabilization of the cationic lanthanocenes can beachieved no matter how big or small the ligand is.