The Syntheses,Structures And Properties Of Lanthanide And Transition Elements-Lanthanide Complexes

Shui-Dong Zhu（major in Inorganic Chemistry）,Directed by Professor Dr.He-Rui WenLanthanide has obvious advantages in building multifunctional materials because of its unique 4f electrons configuration.Choosing suitable ligands to construct 4f,d-4f heterometallic multifunctional coordination compounds shows potential application prospects in luminescence,high-density storage,spintronic devices,fuel cells,fluorescent sensors,etc.It has aroused great interest of chemists and material chemists and has become one of the hot spots in the research of functional coordination compounds.Therefore,in this paper,we used crystal engineering method to assemble novel 4f,3d-4f,4d-4f heterometallic coordination compounds by using chiral aminophenol ligands,2,2-bisimidazole ligands,lanthanide metal ions and transition metal ions(Cu²⁺,Cd²⁺).The magnetic properties,fluorescence,nonlinear optical properties and proton conductivity of these complexes were studied.The internal relationship between structure and these properties is explored.The main work and research results are summarized as follows:1.The synthesis,crystal structure and properties of 4d-4f complexes based on chiral aminophenol ligand（L）.Five pairs of chiral Cd-Ln heterometallic Chiral complexes were synthesized by solvent evaporation at room temperature.[Ln Cd₂（R,R/S,S-L）₂（H₂O）₆]（Cl O₄）₃2H₂O[Ln:Sm（1/2）,Eu（3/4）,Tb（5/6）,Dy（7/8）,Er（9/10）].The crystal structure of these compounds shows that they are Cd₂Ln trinuclear complexes,and crystalized in chiral space C222₁.We have studied the properties of these compounds.The results show that they have chiral optical properties,second-order nonlinear optical properties.Compounds 5 and 7 also have rare earth fluorescence,both compounds have field induced single molecule magnetic behavior.Compound 7 also showed a high proton conductivity.Complex 7 is the first multifunctional Cd ^II-Ln ^Ⅲcompound with second-order nonlinearity,fluorescence,proton conduction and single molecule magnet.There are few reports about the single molecule magnets and proton conductors of Cd ^II-Ln ^Ⅲsystem.Therefore,this study provides a new way to synthesize Cd ^II-Ln ^Ⅲheteronuclear metal compounds with optical,magnetic and electrical functions.2.The synthesis,crystal structure and properties of 3d-4f complexes based on chiral aminophenol ligand（L）.Four series of enantiomeric Cu-Ln complexes were synthesized by solvent evaporation at room temperature.I:[LnCu₂（R,R/S,S-L）₂（NO₃）₂]NO₃H₂O[Ln:Tb（11/12）,Dy（13/14）].II:[LnCu₂（R,R/S,S-L）₂（NO₃）（H₂O）₂]（NO₃）₂[Ln:Ho（15/16）,Er（17/18）,Yb（19/20）].Ⅲ:LnCu（R,R/S,S-L）（NO₃）₃（CH₃OH）₂[Ln:Tb（21/22）,Dy（23/24）].IV:[Ln₂Cu₄（R,R/S,S-L）₄（Cl O₄）₃（CH₃OH）₂]（Cl O₄）₃2H₂O[Ln:Tb（25/26）,Dy（27/28）,Ho（29/30）].X-ray single crystal testaments show that the structures of these compounds were trinuclear,Hexanuclear and one-dimensional chains,crystalized in chiral space P2₁2₁2₁,P2₁2₁2,P2₁,P2₁2₁2,respectively.The results show that the four series of Cu ^II-Ln ^Ⅲcompounds have chiral optical properties.Compounds 15,25 and 27 are monomolecular magnets.Compounds 11,13,21 and 23 exhibit slow magnetic relaxation.Compounds 13,15 and 25 also have proton conduction.The U_effof compound 27 is 55.1 K,which is the largest single molecule magnet in Cu ^II-Ln ^Ⅲsystem at the present time.Moreover,Complex 15 is the first Ho-based proton-conducting single molecule magnet.The spin polarized DFT calculation of local density approximation（LDA）+in-situ repulsion（U）shows that compound 23 has a net magnetic moment at low temperature,which is consistent with the experimental data of temperature magnetic susceptibility of compound 23.The combination of Cu ^IIwith chiral aminophenol ligands and lanthanide ion reaction provide a new method for the design and synthesis of novel and diversified new photoelectric magnetic multifunctional complexes.3.The synthesis,crystal structure and properties of rare earth coordination complex based on 2,2-bisimidazole ligand.A mononuclear Dy^Ⅲcomplex was synthesized by the reaction of 2,2-bisimidazole（H2bim）with Dy ^Ⅲsalt under solvothermal conditions.[Dy（H₂bim）₂（H₂O）₂（NO₃）₂]（NO₃）（31）.The compound exhibits a single ion magnet behavior,and it show a high proton conductivity as 10^–3S·cm–1 under 35^oC and 100（4）R.H.conditions.Compound 31 is the first proton-conducting SMM with mononuclear strucuture.