Construction And Magnetic Properties Of Cyano-bridged Molecule Magnets Between Zero-dimensional Clusters And Two-dimensional Layers

In the 21st century, the research community has witnessed a prominent growth of information technology, however, memory units based on conventional inorganic magnetic materials limit the further development of this area due to size effect, thereby developing materials with ultra-high data storage density has risen to the forefront of materials chemistry. Single-molecule magnets ?SCMs? and single-chain magnets ?SMMs?, with the nature of expressing magnetism on sole molecule, offer the potential to improve storage density by reducing storage size to molecular level. Inspired by the Prussian-blue complexes, the molecular magnetic materials with cyano-bridges have attracted widespread concern. Cyano-group, as a so called "chemical bridge", is able to deliver the magnetic coupling interaction between spin carriers efficiently. Through the self-assembly of different cyanometalate precursors, transition metal ions and organic ligands, various kinds of metal-organic molecule magnets can be achieved with architectures ranging from discrete polynuclear complexes to multi-dimensional assemblies, which providing a great deal of experimental materials for the study of magneto-structural correlation. Nonetheless, it is still a challenge task to design and construct cyano-bridged SMMs and SCMs. Too much work need to be done to increase the intramolecule spin ground state, enhance the magnetic coupling interactions and eliminate the intermolecule interactions, which ultimately improving the Curie temperature. Based on the above aspects, this dissertation includes two sections as follows:?1? Using tricyanometalates [Fe?L??CN?₃]-?L=Tp, pzTp, Tp*? as precursors to react with transiton metal ions ?Cu?, Co?, Mn?? and auxiliary ligands, six discrete polynuclear complexes were synthesized, including a dinuclear complex ?1?, two trinuclear complexes ?2, 3?, two tetrannuclear complexes ?4,5? and a hexanuclear complex ?6?. Studies on the magnetic properties of these complexes showed an intramolecule antiferromagnetic coupling in complexes 1,2,4 and an intramolecule ferrimagnetism in complexes 3,5,6.?2? Using tetracyanometalate precursors [Fe?bpy??CN?₄]-to coordinate with Cu?, Co? and the ditopic ligand ?btab?, two 2D layered complexes 7 and 8 were obtained. The layers were composed of the cyano-bridged double zigzag chains which were further linked by the bridging ligand?btab?. Complex 7 showed a strong intrachain ferromagnetic coupling and 8 showed both field-induced metamagnetic property and single chain magnet behavior.