Synthesis And Characterization Of Amidinate Lanthanide And Their Catalytic Behavior

In this article, eight amidinate lanthanide complexes were synthesized by the reaction of anhydrous LnCl3 with amidinate lithium and well characterized by X-ray diffraction for two of them. The catalytic behaviors of homoleptic amidinate complexes were investigated both for homopolymerizations and copolymerizations ofε-CL, TMC and DTC and for Tishchenko reaction and cyclotrimerization of benzolnitrile as well.1. Homoleptic amidinate lanthanide complexes [MeC(NCy)₂]₃La (1). [MeC(NCy)₂]₃Sm(2) [MeC(NCy)₂]₃Yb(3) [PhC(NCy)₂]₃La(4) [PhC(NCy)₂]₃Sm (5) and [PhC(NCy)₂]₃Nd( 6),were prepared in good yield by the reaction of anhydrous LnCl3 with amidinate lithium in 1:3 molar ratio. All these complexes were characterized by elemental analysis. the molecular structures of complexes 1 and 2 were further determined by X-ray diffraction, IR spectroscopy and 1H NMR spectroscopy.2. Two bis(amidinate) lanthanide halide [MeC(NCy)₂]₂Yb(μ-Cl)2Li (7) and [MeC(NCy) ₂]₂Nd(μ-Br)₂Nd[(NCy)₂CMe]₂ (8), were prepared and the molecular structures of complexes 8 was further determined by X-ray diffraction.3. It was found that homoleptic amidinate lanthanide complexes can efficiently catalyze the ring-opening polymerization ofε-CL, TMC and DTC as single-component initiators. The effect of temperature,time and the structure of these complexes for ring-opening polymerization of TMC was studied. Among them, [CyNC(Me)NCy]₃La shows the highest catalytic activity. The polymerization mechanism was also investigated.4. Homoleptic amidinate lanthanide complexes show high activtity for the ring-opening copolymerization of TMC withε-CL and DTC withε-CL.5. Tishchenko reaction of aldehydes using homoleptic amidinate lanthanide complexes as catalyst was investigated for the first time. The homoleptic...