Cyanide-, Hydroxy- And Azole-Bridged Complexes: Synthesis, Crystal Structures And Magnetic Properties

Molecular magnetism is to create new materials through chemistry especially coordination chemistry methods. These materials are applied to magnetic property research theoretically, for the purpose that promising progress will be made in material science and novel magical materials will benefit our whole society. It is an interdiscipline between physics, material science and chemistry, and it is still a research focus nowadays.In this graduation thesis, a series of one dimensional cyanide-bridged dimetallic complexes based on [M(CN)6]3- building blocks have been prepared. The research of their crystal structures and magnetic properties extended the current research in this area, helping to analyze the magnetic coupling interactions through the cyano group along the one dimensional orientation.The diversity of hydroxyl groups, oxime-, phenolic- and alcoholic- has been studied through several NiII and MnII/III/IV complexes. The oxime-bridge NiII12 cluster revealed a unique coordination mode of the oxime group and it is the first ferromagnetic complex with a ground state ST = 6. DFT calculation revealed the relationship between the coupling strength through NO-bridge and the torsion of Ni-N-O-Ni.Phenolic hydroxyl-bridge NiII2 / NiII3 complexes prove the relationship between ferromagnetic/antiferromagnetic coupling interaction and the value of angle Ni-O-Ni. One dimensional MnIII contains two kinds of hydroxyl groups, the phenolic- and isolate-hydroxyl, connecting the MnIII ions to become a chain structure. The mixed valence MnIIIMnIIMnIII complex contained a similar structure to the other substances previously, but revealed a significant difference in magnetic behavior. A list of comparability among these complexes was provided in the thesis.Through the research of azole groups, hydrothermal method was improved to start ring-closure reaction, which resulted in a quaternary ammonium salt. And several crystals were obtained based on these cationic ligands. It proves that a strong coordination tendence is able to overcome the electronic repulsion between the cation ligands and the metal ions. Another NiII8 cluster was obtained through pyrazole molecule, which contains a"cubane"structure and spin-canting phenomena potentially.