论文总字数：41195字

摘 要

3d-4f异金属高核簇（3d-4f高核簇）不仅具有丰富的骨架结构，还具有独特的磁学性能，例如单分子磁体（SMMs），磁热效应（MCE）等，近年来已逐渐引起人们的极大关注，并成为磁性材料的研究热点。然而，由于3d和4f金属离子对同一配体的连接存在竞争关系，3d-4f高核簇的合成极具挑战，因此已报到的这类材料非常稀少。发展出新的合成策略、合成方法，制备更多具有结构新颖和性能优异的新型3d-4f高核簇材料，研究成簇机理是当前该领域所面临的首要任务。

本论文通过采用混合配体策略，成功合成了未见文献报道新型的3d-4f高核簇，通过单晶X-射线衍射分析、粉末X射线衍射、IR、TG等表征和磁性测试对上述化合物的结构和性质进行了系统研究。研究成果拓展了高核簇的种类，可为新型高核簇材料的探索合成提供指导性的设计策略。

主要研究混合配体策略的应用：首次以亚氨基二乙酸（IDA）和异烟酸（HIN）作为混合配体成功合成了两个具有灯笼状的高核3d-4f纳米簇合物: [Gd₅₂Ni₅₂(IN)₈(CH₃COO)₆(C₂O₄)₂(IDA)₄₆(μ₄-O)₆(μ₃-O)₁₈(μ₃-OH)₁₀₂(H₂O)₂₈]·27.5H₂O (1);

[Dy₅₂Ni₅₂(IN)₄(CH₃COO)₉(C₂O₄)₂(IDA)₄₆(NH₂CH₂COO)₃(μ₃-O)₁₆(μ₃-OH)₁₀₆(μ₂-OH)₁₀

(H₂O)₂₆]·25H₂O (2)。磁性测试表明，化合物(1)展现出了良好的磁热效应，在4.2 K，7 T下，最大磁熵变达到35.6 J kg^-1 K^-1，而化合物(2)在低温下显示出缓慢驰豫现象。实验结果表明混合配体策略在3d-4f高核簇合物的探索合成中是一个可供选择的优良方案。

关键词： 3d-4f高核簇 水热合成 晶体结构 磁热效应

ABSTRACT

High-nuclearity heterometallic complexes based on 3d-4f ions have been attracting considerable attention due to their fascinating structures as well as potential magnetic applications such as single molecule magnets (SMMs), magnetocaloric effect (MCE), and so forth. However, it also exists a big challenge to synthesize such clusters due to the competitive reactions between 3d and 4f metals chelating to the same ligand. The imperative task in this research topic is searching effective strategy to synthesize novel high-nuclearity complexes with fascinating structures and remarkable functional properties.

In this work, utlizing of a synthesis strategy: the mixed ligand strategy, we have synthesized unreported novel 3d-4f high-nuclearity clusters. Single crystal X-ray diffractions, elemental analysis, IR, powder XRD, TG were used to investigate the structures and their properties were measured as well. This work not only expands the richness of 3d-4f clusters, but also provides some instructional design strategies for seeking of new type of high-nuclearity clusters.

This paper mainly includes the application of the mixed ligand strategy: Two novel lantern-shaped high-nuclear clusters, [Gd₅₂Ni₅₂(IN)₈(CH₃COO)₆(C₂O₄)₂(IDA)₄₆(μ₄-O)₆(μ₃-O)₁₈(μ₃-OH)₁₀₂(H₂O)₂₈]·27.5H₂O (1) and [Dy₅₂Ni₅₂(IN)₄(CH₃COO)₉(C₂O₄)₂(IDA)₄₆(NH₂CH₂COO)₃(μ₃-O)₁₆(μ₃-OH)₁₀₆(μ₂-OH)₁₀(H₂O)₂₆]·25H₂O (2) are successfully isolated by the mixed-ligand approach. Magnetic studies show that (1) exhibits comparatively large MCEs, the maximum -∆S_m is 35.6 J kg^-1 K^-1 at 4.2 K, 7 T and (2) displays slow relaxation of the magnetization. The experiment result shows that the mixed ligand strategy is an effective way for seeking of 3d-4f clusters.

KEYWORDS: 3d-4f High-Nuclearity Clusters; Hydrothermal Synthesis; Crystal Structure; Magnetocaloric Effect

目 录

摘 要 I

ABSTRACT i

目 录 i

第一章 文献综述 1

1.1 绪论 1

1.2 3d-4f异金属构建的单分子磁体 2

1.2.1 3d-4f异金属簇合物单分子磁体 2

1.3 3d-4f异金属簇的磁热效应 4

1.3.1 3d-4f异金属构建的磁制冷材料 4

1.4 3d-4f金属构建的高核异金属簇 9

1.5 课题选择依据及内容 12

第二章 采用混合配体策略合成两个Ln-Ni (Ln = Gd, Dy)高核簇 14

2.1 引言 14

2.2 实验部分 15

2.2.1试剂 15

2.2.2仪器 16

2.3 化合物的合成 16

2.3.1[Gd₅₂Ni₅₂(IN)₈(CH₃COO)₆(C₂O₄)₂(IDA)₄₆(μ₄-O)₆(μ₃-O)₁₈(μ₃-OH)₁₀₂(H₂O)₂₈]·27.5H₂O (1)的合成 16

2.3.2[Dy₅₂Ni₅₂(IN)₄(CH₃COO)₉(C₂O₄)₂(IDA)₄₆(NH₂CH₂COO)₃(μ₃-O)₁₆(μ₃-OH)₁₀₆(μ₂-OH)₁₀(H₂O)₂₆]·25H₂O (2)的合成 16

第三章 结果与讨论 18

3.1 晶体结构 18

3.1.1[Gd₅₂Ni₅₂(IN)₈(CH₃COO)₆(C₂O₄)₂(IDA)₄₆(μ₄-O)₆(μ₃-O)₁₈(μ₃-OH)₁₀₂(H₂O)₂₈]·27.5H₂O (1)的结构描述 19

3.2 两种配体HIN和IDA在Ln-Ni高核簇形成中的作用 23

3.3 性质表征 23

3.3.1磁性测试 23

3.3.2 X-射线粉末衍射 26

3.3.3红外光谱 27

3.3.4热重分析 27

3.4 本章小结 28

第四章 结论与展望 30

4.1 结论 30

4.2 展望 30

参考文献 32

附录 37

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