【作者】 赵崇超；

【导师】 寇会忠；

【作者基本信息】 清华大学 ， 化学， 2008， 硕士

【摘要】 分子磁学是使用化学尤其是配位化学的手段,合成相关的化合物,供给物理学尤其是磁学进行理论的研究,并最终希冀获得在材料学上的进展,制备出多功能的分子基磁性材料,为人类社会的发展做出相应的贡献。它是一门涉及物理、材料、化学的交叉学科,在今天依然处于研究的热点之中。基于这个目的,在本论文中首先研究的是氰根桥联的配合物。基于六氰根构筑单元[M(CN)6]3-制得了三例双金属的一维链状配合物,对它们的结构和磁性进行了初步的研究。延续了在六氰根桥联配位这一个方向上的工作,为氰根桥联的双金属之间的磁偶合作用、尤其是在一维链方向上的磁偶合传递提供了更多的实例和更深入的研究。论文还重点探讨了羟氧官能团在配位中的特点,制备的三例NiII配合物和四例MnII/III/IV配合物展示了它的各种存在形式——肟、酚氧、醇氧、氢氧根。其中,肟桥联的十二核配合物NiII12具有肟桥基的独特的一种配位模式,它是第一例基态自旋值S = 6的铁磁偶合的十二核NiII簇合物,并且对它的DFT计算拟合揭示了NO-桥联的铁磁偶合强度是跟二面角Ni-N-O-Ni相关的。另外,酚氧桥联的双核NiII和三核NiIII配合物具有典型的酚氧桥联NiII的特点,通过它的Ni-O-Ni的键长、键角的数据跟文献报道的对照,进一步证实了酚氧桥联传递的磁偶合作用是跟该键角密切相关的。同时也得到了一例通过酚氧、氢氧根混合桥基桥联的一维MnIII配合物。而对于醇氧桥联的混合价三核锰MnIIIMnIIMnIII,它的结构跟文献类似,表现出强烈的反铁磁偶合。我们列举了这类型的结构,并且对它们的偶合常数进行了初步的比较。对于唑类小分子的研究,我们改进了一种溶剂热合成的关环方法,通过杂环上的氮季胺盐化而实现环合,并且得到了两例配体是阳离子的CuII/ZnII配合物,说明了即使电荷互斥作用,但强的配位作用仍能促进配位键的形成。另外,制得了一例吡唑桥联的八核NiII8簇合物,具有立方烷的骨架,磁性研究表明可能存在着自旋倾斜现象。更多还原

【Abstract】 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.更多还原