稀土基分子纳米磁体因其优异的磁学性质，成为了分子磁学领域的研究热点。本论文利用吡嗪氮氧酰腙席夫碱类配体与镝离子，构筑了21个结构新颖且具有动态磁行为的镝配位聚合物，深入研究了体系中配体的取代基、阴离子、溶剂分子、以及辅助配体的类型对于形成配合物中镝离子周围配位环境及其磁各向异性、镝离子间连接模式与磁相互作用的影响，并进一步探究了镝离子磁各向异性及镝离子间磁相互作用的变化对于配合物磁弛豫行为的影响。主要的研究内容及成果如下：

1、基于吡嗪氮氧酰腙席夫碱配体与镝盐，构筑得到了五例基于双核基元且具有典型慢磁弛豫行为的一维链状配合物。当调节双核间的桥连模式从单吡嗪氮氧到双吡嗪氮氧时，不仅使其一维结构从之字链变为了梯字形链，还使得磁弛豫能垒和阻塞温度分别从195 K和5 K提高到了399 K 和9 K。继续调节反应，得到了一例罕见的由双氯离子桥连接形成的一维稀土配合物，其零直流场下的磁弛豫能垒达到了556 K，通过磁-构关系研究结合理论计算，首次发现双核间通过氯离子桥传递的偶极相互作用能够有效地抑制单个镝离子的量子隧穿行为，促使配合物的磁弛豫路径通过第二激发态。

2、基于吡嗪氮氧酰腙席夫碱配体，结合不同类型的镝盐，并改变配体中取代基的类型，合成了三例氯离子配位的二维层状配合物和三例具有抗衡阴离子的二维层状配合物。有趣的是，水分子诱导下，三例氯离子配位的二维层状配合物发生可逆的单晶-单晶转化，并伴随着配位键的断裂与生成，形成了三例水分子参与配位的二维层状配合物。结构的变化使得镝离子的配位数从八变为了九，镝离子磁各向异性、配合物的磁驰豫能垒和量子隧穿行为发生了明显的改变，也开启了配合物的质子导电性质，体现了水分子对配合物结构和磁学、质子导电性质的调控作用。

3、基于镝-吡嗪氮氧席夫碱体系，引入金属氰根配体，构筑了七例基于双核基元且具有新颖kagomé结构的二维配合物。当配体中氯原子作为五位取代基，钴氰根作为第二配体时，构筑得到磁学性质最优异的配合物，其零直流场下的热弛豫能垒为608 K，在目前已报导的镝配位聚合物中能垒最高。磁构分析表明，抗磁钴氰根的引入，既能够增强镝离子的磁各向异性，也可以阻止体系中镝双核间的磁相互作用，使得其磁驰豫路径经过第三激发态。当运用顺磁铁氰根/铬氰根时，会引入镝与过渡金属离子间的相互作用，在低温诱导出另一个磁驰豫过程。当使用四位溴取代的配体时，得到了的kagomé结构能够在乙醇分子的诱导下，发生单晶-单晶的转化，使其磁弛豫能垒从325 K提高到366 K。此外，kagomé型配合物，因其特殊的阻挫晶格，在固态物理领域中具有广泛的应用前景。

Lanthanide-based molecular nanomagnets have aroused widespread interests in the field of molecular magnetism arising from their excellent magnetic properties. In this paper, twenty-one novel lanthanide complexes were successfully constructed by ultilizing pyrazine-N-oxide carbohydrazine Schiff-base and dysprosium ions. We have also investigated the effects of the type of substitutions in the ligands, anions, solvent molecules, and auxiliary ligands on the coordination environment and the magnetic anisotropy of Dy³⁺ ions and connection modes between the Dy³⁺ ions and magnetic interactions. We further explored the influence of magnetic anisotropy of Dy³⁺ ions and magnetic interactions between Dy³⁺ ions on slow magnetic relaxation behavior of lanthanide complexes. The main research contents and results include the following three parts:

1. Five novel dynamic dysprosium one-dimensional complexes based on dimeric units have been successfully synthesised via combining dysprosium ions with pyrazine-N-oxide carbohydrazine Schiff-base ligands. When the bridging mode was switched from a single pyrazine-N-oxide group to double groups, not only the one-dimensional structure changes from zigzag chain to ladder-like chain, but also the magnetic relaxation barrier and hysteresis temperature increased from 195 K and 5 K to 399 K and 9 K, respectively. A rare one-dimensional complex connected by double chloride bridges is obtained by adjusting the solubility of the system. Its thermal relaxation energy barrier is 556 K under zero direct-current field. The combination of magneto-structural correlations and theoretical calculations indicate that this is mainly due to the dipolar magnetic interactions between the adjacent dimers via chloride bridges, which can effectively suppress quantum tunneling rates and promote the magnetic relaxation path to the second-excited state of dysprosium ion.

2. Based on pyrazine-N-oxide carbohydrazine Schiff-base ligands, combining different types of dysprosium salts, and changing the types of substituents in the ligands, three isomorphic chloride-coordinated two-dimensional lanthanide complexes and three two-dimensional lanthanide complexes with counter anions in the crystal lattice have been successfully constrcuted. Interestingly, under the induction of water molecules, three chloride-coordinated two-dimensional lanthanide complexes can undergo a reversible single-crystal-to-single-crystal conversion behaviors, accompanied with the cleavage and generation of coordination bonds. Eventually, three new two-dimensional layered complexes were obtained in which water molecules participate in coordination. The structural change makes the coordination number of dysprosium ion changed from eight-coordination to nine-coordination. The magnetic anisotropy of dysprosium ions, the magnetic relaxation energy barrier and quantum tunneling behavior of the complex also have changed obviously. And the proton conductivity of the complex is also turned on, which reflects the regulation of water molecules on the structure, magnetism and proton conductivity of the complex.

3. Based on the system of dysprosium pyrazine-N-oxide carbohydrazine Schiff-base, seven two-dimensional kagomé-type lanthanide coordination polymers based on dimeric units were constructed by introducing [M(CN)₆]^3- (M = Cr, Fe, Co) as auxiliary ligands. When the chlorine atom is in the fifth position of the ligand as a substituent and [Co(CN)₆]^3- is used as auxiliary ligand, the obtained complex exhibited the best magnetic property with an effective energy barrier of 608 K under zero direct-current field, which is also the recording energy barrier in the lanthanide coordination polymers. Further magneto-structural correlations indicate that the introduction of diamagnetic [Co(CN)₆]^3- group into the system can not only enhance the magnetic anisotropy of dysprosium ions, but also prevent the magnetic interaction between the dysprosium dinuclear units in the system, so that the magnetic relaxation path passes through the third-excited state. When paramagnetic [M(CN)₆]^3- (M = Cr, Fe) were used, the magnetic interaction between dysprosium and transition metal ions is introduced, and another magnetic relaxation process is induced at low temperature. When the position of the substituent was changed to the fourth position, the obtained kagomé-type complexes can undergo single-crystal-to-single-crystal conversion under the induction of ethanol molecules. The magnetic relaxation barrier increased from 325 K to 366 K. In addition, kagomé-type complexes have a wide range of application prospects in the field of solid-state physics due to their special frustrated lattice.