Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an, 710069, P. R. China.
Dalton Trans. 2011 Mar 21;40(11):2509-21. doi: 10.1039/c0dt01206h. Epub 2011 Feb 4.
Along with our recent investigation on the flexible ligand of H(2)ADA (1,3-adamantanediacetic acid), a series of Zn(II) and Cd(II) metal-organic frameworks, namely, Zn(3)(ADA)(3)(H(2)O)(2)·5nH(2)O (1), Zn(ADA)(4,4'-bipy)(0.5) (2), Zn(2)(ADA)(2)(bpa) (3), Zn(2)(ADA)(2)(bpa) (4), Zn(2)(ADA)(2)(bpp) (5), Cd(HADA)(2)((4,4'-bipy) (6), Cd(3)(ADA)(3)(bpa)(2)(CH(3)OH)(H(2)O) (7), and Cd(2)(ADA)(2)(bpp)(2)·7nH(2)O (8) have been synthesized and structurally characterized (where 4,4'-bipy = 4,4'-dipyridine, bpa = 1,2-bis(4-pyridyl)ethane and bpp = 1,3-bis(4-pyridyl)propane). Due to various coordination modes and conformations of the flexible dicarboxylate ligand and the different pyridyl-containing coligands, these complexes exhibit structural and dimensional diversity. Complex 1 exhibits a three-dimensional (3D) framework containing one-dimensional (1D) Zn(II)-O-C-O-Zn(II) clusters. Complex 2 exhibits a 2D structure constructed by 1D double chains based on [Zn(2)ADA(2)] units and a 4,4'-bipy pillar. Complexes 3 and 4 possess isomorphic 2D layer structures, resulting from the different coordination modes of carboxylate group of ADA ligands. Complex 5 features a 2D 4(4) layer in which ADA ligands and Zn(II) atoms construct a 1D looped chain and the chains are further connected by bpp ligands. Complex 6 is composed of 1D zig-zag chains that are entangled through hydrogen-bonding interactions to generate a 2D network. Complex 7 is a rare (3,5)-connected network. Complex 8 possesses a 3D microporous framework with lots of water molecules encapsulated in the channels. The structural diversity of the complexes perhaps mainly results from using diverse secondary ligands and different metal centre ions, and means the assistant ligand and metal centre play important roles in the design and synthesis of target metal-organic frameworks. This finding revealed that ADA could be used as an effective bridging ligand to construct MOFs and change coordination modes and conformational geometries in these complexes. The thermogravimetric analyses, X-ray powder diffraction and solid-state luminescent properties of the complexes have also been investigated.
除了我们最近对 H(2)ADA（1,3-金刚烷二乙酸）的柔性配体的研究，我们还合成并结构表征了一系列 Zn(II)和 Cd(II)金属有机框架，即 Zn(3)(ADA)(3)(H(2)O)(2)·5nH(2)O（1）、Zn(ADA)(4,4'-bipy)(0.5)（2）、Zn(2)(ADA)(2)(bpa)（3）、Zn(2)(ADA)(2)(bpa)（4）、Zn(2)(ADA)(2)(bpp)（5）、Cd(HADA)(2)((4,4'-bipy)（6）、Cd(3)(ADA)(3)(bpa)(2)(CH(3)OH)(H(2)O)（7）和 Cd(2)(ADA)(2)(bpp)(2)·7nH(2)O（8）（其中 4,4'-bipy = 4,4'-联吡啶，bpa = 1,2-双(4-吡啶基)乙烷，bpp = 1,3-双(4-吡啶基)丙烷）。由于柔性二羧酸配体的各种配位模式和构象以及不同的含吡啶辅助配体，这些配合物表现出结构和维度的多样性。配合物 1 表现出含有一维（1D）Zn(II)-O-C-O-Zn(II)簇的三维（3D）框架。配合物 2 表现出由基于 [Zn(2)ADA(2)]单元和 4,4'-bipy 支柱的一维双链构成的 2D 结构。配合物 3 和 4 具有同构的 2D 层状结构，这是由于 ADA 配体的羧基的不同配位模式所致。配合物 5 具有 2D 4(4)层，其中 ADA 配体和 Zn(II)原子构建了一个 1D 闭环链，链进一步由 bpp 配体连接。配合物 6 由 1D 之字形链组成，这些链通过氢键相互缠绕形成二维网络。配合物 7 是一种罕见的（3,5）连接网络。配合物 8 具有三维微孔骨架，其中封装了大量水分子。这些配合物的结构多样性可能主要源于使用不同的辅助配体和不同的金属中心离子，这意味着辅助配体和金属中心在目标金属有机骨架的设计和合成中发挥着重要作用。这一发现表明 ADA 可作为有效的桥连配体来构建 MOFs，并改变这些配合物中的配位模式和构象几何形状。还对配合物的热重分析、X 射线粉末衍射和固态发光性能进行了研究。
