Synthesis and structure of half-sandwich SmII and YIII cyclopentadienyl halide complexes with the penta(benzyl)cyclopentadienyl ligand

The exchange reactions of equimolar amounts of potassium penta(benzyl)cyclopentadienide Cp Bn 5K (Cp Bn 5 = C 5 (CH 2 Ph) 5 ) and SmI 2 (THF) 2 or YCl 3 afforded the corresponding half-sandwich derivatives [Cp Bn 5Sm(DME)(μ-I)] 2 ( 1 ) and [Cp Bn 5YCl 2 (THF)] 2 [KCl(THF) 2 ] ( 2 ). According to the X-ray diffraction data, the metal ions in complexes 1 and 2 are coordinated by Cp Bn 5 ligands in a η 5 -fashion. The difference is that there is a short contact between the Sm II cation and one benzyl group of the cyclopentadienyl ligand in structure 1 , whereas such interaction is absent in structure 2 .