基于Dy3三角结构基元新型单分子磁体的构筑与性质研究

Lanthanide ions have unique electronic structrues and their high spins and significant electron anisotropy make these ions ideal elements for constructing molecular magnets. The relation of magnetism-structure of the rare earth single molecular magnets is complex, and the theory is not perfect, while the blocking temperature of the existing single molecular magnets is much lower than the room temperature. so the directed synthesis of high blocking temperature rare earth single molecular magnets is still a challenging topic and one of difficulty in the research field of chemistry and material. The newly discovered Dy3 cluster-containing molecular magnets possess a circular spin structure and exhibit an unusual chiral nature of the ground non-magnetic doublet. The resonant quantum tunnelling of magnetization at the crossings of the discrete energy levels of these new materials opens new perspectives in quantum computation and data storage using the molecular nanomagnets. In this research proposal, we would like to synthesize new rare earth Dy3 cluster containing sinlge molecular magnetic functional materials. First, we would like to identify and syntehisze ligands which favor the formation of Dy3 clusters. Then, we use the synthesized Dy3 clusters as building units to construct new single molecular magnets. Finally, we would like to study in detail their optical, electrical and magnetic properties and explore their applications as single molecular magnets. We would like to establish the correlation between structure and magnetic property to perfect the Dy3 triangle magnetic theory, to better understand the relaxation process of the single molecular magnets, and to set up a solid background for future synthesis of more new molecular magnetic materials with high blocking temperature.

稀土离子具有较多单电子、显著的各向异性，是设计单分子磁体的理想选择。稀土单分子磁体磁构关系复杂，理论相对不完善，探索合成单分子磁体还带有一定的偶然性，现有单分子磁体的阻塞温度还远低于室温。因此，定向合成高阻塞温度稀土单分子磁体仍是化学与材料研究领域中具有挑战性的课题和难点之一。本项研究中，我们围绕稀土磁功能材料的研究方向，在原有研究成果的基础上，以具有环形自旋结构，表现出独特的自旋手性现象Dy3单分子磁体为研究原始模型，设计合成新型适合形成Dy3的配体，并以Dy3为构筑基元，设计合成新型单分子磁体，研究所获材料在光、电、磁、非线性光学等方面的性能和应用。从结构的角度，利用磁性理论基础知识，系统的研究结构类型和磁性质之间的关系，从而理解和调控单分子磁体弛豫过程，为定向合成高阻塞温度分子磁性材料奠定基础。

本项研究中，我们围绕稀土磁功能材料的研究方向，以稀土金属离子(4f)和有机配体作为结构单元，设计合成具有特定Dy3结构和磁学性质的功能基元。通过功能性基元的可控组装和结构优化，制备新型稀土金属分子基材料。深入研究反应物和反应条件对产物结构的影响，探索稀土分子基材料的合成规律和新的合成方法；从结构的角度，利用磁性理论基础知识，系统的研究结构类型和磁性质之间的关系，重点研究该体系不同电子载体间的磁相互作用本质以及分子内和分子间相互作用与性能的关系。考察体系在外界温度、压力、辐射、磁场微扰下的动力学行为，探讨由此而产生的新现象和新机理，从而理解和调控单分子磁体弛豫过程。寻找具有实用价值的分子基磁性材料。本项目侧重开展稀土金属分子基材料的可控合成、磁构关系及磁性能调控的基础研究工作，为实现多功能分子基磁性材料在可控制备方面提供有价值的依据，为合成高阻塞温度分子磁性材料奠定基础。