Schiff Base Zn/Dy Molecular Magnets And Their Structure Optimization

Single-molecule magnets(SMMS)have attracted increased attention in the field of quantum computers,information storage devices,molecular switches etc.due to their intrinsic properties such as slow magnetic relaxation and quantum tunneling(QTM).After more than 20 years of research,lanthanide single-molecule magnets(Ln-SMMs)based on high spin ground states and strong anisotropy have rapidly development.At the same time,Ln-SMMs still face challenges in the optimization of the coordination field environment.In this paper three types of Schiff base ligands are used.These ligands are N,N'-bis(3-methoxysalicylidene)ethylenediamine derivative,N,N',N",N'"-tetra_salicylidene-3,3',4,4'-tetraaminodiphenyl,and covalent organic framework(COF)AzaCMP.Moreover,eight complexes were formed from these ligands.Through X-ray single crystal diffraction,XRD and molecular magnetic testing,the relationship between magnetic and structure of the complex was studied.The main research work is as follows:1.A series of Zn-Ln heteronuclear SMMs constructed from hexadentate compartment Schiff base Zn-precursor and lanthanide ions were structurally and magnetically characterized,in which the two[Zn-Ln]moieties are bridged by series of hydroxamic acid and resulting in double deck tetranuclear complexes.The magnetic measurement shows that complexes 1-3 display obvious slow magnetic relaxation under zero field.In order to explore the magnetic fluorescent bifunctional materials,the magnetic test and fluorescence test of complex 4 under an external magnetic field were carried out.Complex 4 exhibit dual-functional properties of magnetic fluorescence.2.The hexadentate Schiff base ligand L3 was used to react with ?-diketone lanthanide salt,and ?-diketone was used to adjust the Dy center coordination environment to construct three heterobinuclear Zn-Dy complexes.Magnetic tests show that complexes 5-7 exhibit SMM behavior under an applied field.3.Dysprosium acetylacetonate was loaded on Aza-CMP COF by coodination bond,and the hybrid material Aza-CMP@Dy(acac)3 was prepared,and the behavior of slow magnetic relaxation was observed.