Synthesis,Structures And Magnetic Properties Of Dy-Complexes With 8-hydroxyquinoline Derivatives

Dy-based single-ion magnets have been the research hospot because of their potential applications.This paper intends to study the magneto-structural correlation and slow magnetic relaxation mechanism of Dy-based single-ion magnets constructing from quinoline derivatives.We have investigated the synthesis method and conditions,providing the experiment examples for further designing and synthesizing of Dy-based single-ion magnets.In order to provide experiment basis and reference for the control of the structure and functions of the complexes,the mag;netic-structure relationship of the Dy-based single-ion magnets are systematically investigated through the modification ligands by introducing specific ftmctional groups.Different geometry symmetry around the Dy(?)center on the magnetic behavior of Dy-based single-ion magnets is under systematically investigation.The paper is of great theoretical and practical significance in aspect of expanding and deepening the studies on the Dy-based single-ion magnets,and developing the single-ion magnets systems with application value.The main research works of this thesis are listed below.1.Three new mononuclear Dy-based complexes[Dy(C10H6NOBr2)3(H2O)](1),[Dy(C10H6NOBr2)3(C10H7NOBr2)](2),[Dy(C10H6NOBr2)4]·(H20)(DMF)(HN(C2H5)3)(3)were synthesized and characterized by elemental analysis,IR spectra,and single-crystal X-ray crystal diffraction.The variable-temperatore magnetic susceptibility was measured in a temperature range from 300 to 2 K under 1 kOe applied field.The overall magnetic behavior of 1-3 is antiferromagnetic.Meanwhile,slow magnetic relaxation was observed in these complexes.A series of mononuclear Dy-based single-ion magnets were synthesized and magnetically characterized.The four molecules[Dy(C10H7NOBr2)2(CH3OH)Cl3](4),[Dy(C10H7NOBr2)2(C2H5OH)Cl3](5),[Dy(C10H6NOBr2)2(C10H7NOBr2)2(CH3OH)](6),and[Dy(C10H6NOBr2)2(C10H7NOBr2)2(C2H5OH)](7)all display remarkable magnetic relaxation behavior because of obviously frequency dependence observed in these complexes.The alternating current susceptibilities were further measured in a static dc field,all display field induced SMM behaviors.2.The reaction of 8-hydroxyquinoline derivatives with Dy(NO3)3 in the presence of triethylamine afforded a series of mononuclear dysprosium complexes[Dy(C10H6NOCl2)3(H2O)](8),[Dy(C10H6NOCl2)3(C10H7NOCl2)](9),[Dy(C10H6NOCl2)4]·(H2O)(DMF)(HN(C2H5)3)(10).The structures were determined by single-crystal X-ray diffraction,elemental analysis,and IR spectra.Variable-temperature magnetic susceptibilities measurements of 8-10 in the temperature 2-300 K indicated dominant antiferromagnetic exchange interactions.And alternating current susceptibility data indicated that 8-10 exhibit single-molecule magnetism behavior.