Syntheses,Structures And Magneto-optical Properties Of Polynuclear Lanthanide-Transition Metal Clusters Based On Acetate Ligand

The magneto-optical effect has received widespread attention since its discovery,especially the Faraday effect and the Kerr effect,but the current research on magnetooptical materials and devices is still in the development stage.The unique electron exchange between the metal ions in the rare earth-transition metal clusters will bring interesting magnetic and optical properties.The 4f-5d electron transfer present in them will cause a large Faraday rotation angle(FR),thereby enhancing the Faraday effect.This is very important for the preparation of magneto-optical devices.However,the formation of high-nuclearity rare earth-transition metal clusters is extremely complicated and it is still a challenge to explore the formation mechanism and reasonably design and synthesize the high-nuclearity rare earth-transition metal clusters.Based on the above research background,in this thesis,a series of multinuclear rare earth-transition metal clusters were obtained by using acetate ligand under the action of anion template,and their synthesis,structure and magneto-optical properties were studied.The details findings are following:1.Synthesis,structure and magneto-optical properties of Ln18Ni24 based on acetate ligand.We used acetate as a ligand and combined with the anionic template method to obtain two high-nuclear rare earth-transition metal clusters Ln18Ni24(Ln=Gd(1),Eu(2))constructed from Cubane-like unit.The magneto-optical properties show that compound 2 exhibits a stronger Faraday effect than 1,and the Faraday rotation efficiency of compound 2 is 44 times stronger than that of europium acetate.This result indicates that the construction of high-nuclear rare earth-transition metal clusters is beneficial to improve the Faraday effect of compounds.2.Synthesis,structure and magneto-optical properties of Co6Ln3 based on acetate and ethylenediamine ligands.Two multinuclear rare earth-transition metal clusters Co6Ln3(Ln=Gd(3),Dy(4))based on cubane-like structural units were obtained by acetate and ethylenediamine as the auxiliary ligand.The magneto-optical properties indicate that compound 4 exhibits a stronger Faraday effect than compound 3,and the Faraday rotation efficiency of compound 4 is better than that of dysprosium perchlorate,showing a stronger magneto-optical effect.3.Synthesis,structure and magneto-optical properties of Ln18Co7,Ln14Co30 and Ln30Co37 based on acetate and diethanolamine ligands.Based on the mixed-ligand strategy and anionic template method,with acetate and diethanolamine as mixed ligands,we have synthesized the double-propeller structures of Ln18Co7(Ln=Gd(5),Nd(6)),Capsule-shaped structures of Ln14Co30(Ln=Gd(7),Eu(8))and disc-shaped structures of Ln30Co37(Ln=Nd(9),Sm(10))were obtained.The magneto-optical properties show that these six compounds all exhibit obvious magnetic-circular dichroic signals,and the magneto-optical effect is enhanced as the number of nuclei increases.In addition,rare earth-transition metal clusters containing rare earth Nd ions exhibit stronger magneto-optical effects.