Study On The Synthesis And Their Catalytic Properties Of Rare Earth Schiff-base Complexes With Amino Acid Derivatives

Rare earth metal ions have 4 to 12 coordination number for the existence of d and f orbits,the complexes are easily synthesized from coordination of rare earth metal and multiplicate ligands.Among them,the lanthanide complexes with amino acid Schiff bases,which have various stable structures and the vital bioactivity and excellent luminescence,were widely used in the fields of catalysis and material etc.Amino acids are the basic unit of composition of the materials of life,amino acids and their derivatives with low toxicity and resistance are widely applied to chiral catalysis of various oganic reactions as natural and cheap chiral resource.Cyclic carbonates attained by chemical fixation of CO₂ are applied to the fields of oganic synthesis,gas separation,battery electromedium,metal extraction etc as chemical intermediate and polar organic solvent.In recent years,our group has been studying on symmetric and asymmetric synthesis of cyclic carbonates and the establishment of a variety of chiral and achiral catalytic systems.In my paper,eight new chiral schiff base ligands(H₂L¹ï½žH₂L⁵,H₃L⁶)were synthesized by the reaction of the mother ligand[(2-OH-3,5-di-^t-Bu-C₆H₂)CH=NCH₂CH₂]₂NH(H₂L)with the chiral amino acid derivatives,their lanthanide complexes prepared from the coordination of the ligands and Lanthanum compound(LaCl₃·7H₂O);The ligands and their lanthanide complexes were characterized by nuclear magnetic resonance, mass spectrometry,infrared spectroscopy and elemental analysis.Finally the catalytic properties of the complexes were studied on the coupling reaction of the epoxides and CO₂,and the results clearly pointed out what the next step of our work is.It made us further understanding affinity of material properties and structure.