Phosphane coordination to rare earth metal centers: monomeric, solvent-free complexes of type Cp′2LnX with phosphanoethyl substituted cyclopentadienyl ligands

The reaction of phosphanoethyl substituted cyclopentadienides [C5H4CH2CH2PR2]M, R=Me, Cy, t-Bu, Ph, M=Li, K with LnX3 (Ln=rare earth metal, X=Cl−, CF3SO3−) afforded twofold substituted metal complexes of the type [C5H4CH2CH2PR2]2LnX. Using the dianionic ligand Li2[(C5H4CH2CH2)2PMe] phosphano bridged ansa metallocene derivatives [(C5H4CH2CH2)2PMe]LnX (Ln=Y, Lu; X=Cl−, CF3SO3−) were isolated. The complexes are soluble in toluene, monomeric and free of solvent. According to X-ray studies on [C5H4CH2CH2PMe2]2YCl, a distorted trigonal bipyramid with two axial phosphano groups and two equatorial cyclopentadienyl moieties is the structural motif, the third equatorial site being occupied by the halide ligand.