Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with N-piperidineethyl Substituted Fluorenyl Ligands

Synthesis, Structure and Catalytic Activity of Organolanthanide Complexes with N-piperidineethyl Substituted Fluorenyl Ligands
　　All experiments were carried out under the dry and oxygen-free argon atmosphere by using standard Schlenk techniques.Reaction of C5H10NCH2CH2Cl with 1 equiv of C13H9Li in Et2O at O°C yielded C5H10NCH2CH2C13H9(1)in 73%yield.Interaction of[(Me3Si)2N]3YbⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,after Special shape NdFeB magnets recrystallization from toluene,gave an ytterbium(Ⅱ)complex[η5;μ1-C5H10NCH2CH2C13H8]2YbⅡ(2)in 64%yield.Interaction of[(Me3Si)2N]3 EuⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,gave a europium(Ⅱ)complex[η5;η1-C5H10NCH2CH2C13H8]2EuⅡ(3)in 70%yield.Interaction of[(Me3Si)2N]3NdⅢ(μ-Cl)Li(THF)3 with 2 equiv of 1 in refluxing toluene for 24 hours,after recrystallization from toluene,gave a neodymium(Ⅲ)complex[η5;η1- C5H10NCH2CH2C13H8]2-NdⅢCl(4)in 47%yield;Interaction of 1 with 1 equiv ofn-BuLi in THF yielded C5H10NCH2CH2C13H5Li(THF)2(5)in 81%yield;Reaction of 5 with 0.5 equiv of YCl3 in THF yielded[η5;η1-C5H10NCH2CH2C13H8]2-yⅢCl(6)in 62%yield.All the complexes were fully characterized by elemental and spectroscopic analyses.The structures of complexes 3 and 5 were determined by X-ray diffraction.On the basis of the above experimental results,these experiments further certify that the internal donor ligands coordination promoted homolytic reaction of the Ln-N bond,The activities of the ytterbium(Ⅱ) and europium(Ⅱ)complexes http://www.999magnet.com/ as single-component catalysts in catalyzing MMA andε-CL polymerization were examined.It was found that the activities of the catalysts,stereo-regularity of PMMA,and the molecular weight of polymers were dependent on the solvents,temperature and the central metal of the catalysts.