Synthesis, Structure And Magnetic Properties Of Multi-Spin System

Crystal engineering, property and functional study of polynuclear complex is one of the most active subjects in the field of coordination chemistry. In this thesis,12 compounds complexes have been synthesized by the reactions of polydentate Schiff-base ligands with transition metallic and/or lanthanides ions. The crystal structures of the compounds were characterized, and the magnetic property for some of them were measured. This thesis could be divided into four chapters:In the first chapter, as spin carriers, nitroxide radicals not only show interesting properties at solid state, but also serve as bridging ligands and form the inorganic-organic hybrid magnetic materials with the transition metallic ions. The thesis is focused on the charasteristics of the nitroxide radicals and devoted to the research of the crystal structures and magnetic properties of the nitroxide radicals and their complexes. The main results are summarized as follows: NIToPy was synthesized, a series of mononuclear Mn complexes was obtained, and the single-crystal structure analysis of them were conducted。In the second chapter, a series of binuclear complexes have been synthesized by Schiff-base ligands. The single-crystal structure analysis and the magnetic properties have been studied in further. Magnetic measurements revealed that dominant anti-ferromagnetic interactions existed between the two nuclears.In the third chapter, a discrete dysprosium cubane has been prepared and structurally characterized. Slow relaxation of magnetization in this complex is observed, which may stimulate further investigations into the dynamics of magnetization in lanthanide clusters with different topologies.In the fourth chapter, a series of 3d-4f tetranuclear complexes were obtained. According to the contrast study, the structures of the complexes may be affected by many factors, such as the structures and properties of the ligands, the coordination requirements and the characteristics of the metallic ions, the geometrical configurations and the properties of the anions. Various structure types may be obtained by changing these factors.