| Inorganic microporous materials attract considerable attentions because they have potential applications in catalysis, adsorption and separation, as well as in advanced materials. There is always a general interest in exploring new open-framework materials in novel compositional domains.Germanates are of particular interest because they have metal-oxygen bond distances (≈1.76?) significantly greater than those in silicate-based materials (≈1.61?), and bond angles Ge-O-Ge (≈130o) smaller than Si-O-Si (≈146o), which lead to germanium can form GeO4, GeO5, and GeO6 coordinations. Therefore, these geometric factors have an important effect to form germanates with various structures. Recently, more attention has been paid to the synthesis of open-framework germanates, because germanium in the periodic table is an element which can be used as a silicon substituent to build various open-framework structures of zeolites and microporous materials. Particularly, some large and complicated second building units (SBUs) can be formed by the linkage of various Ge-centered polyhedra; typically, SBUs in germanates are Ge7, Ge9 and Ge10 clusters. Notable, some germinate structures with extra large pores and low framework densities are built up from those large clusters, such as ASU-12, ASU-16/SU-12, SU-8, SU-44, FDU-4, SU-M, and SU-MB. By using AASBU approach, it is possible to design more new open-framework germanates with large pores and low-framework density by using such large clusters as SBUs.The main body of this thesis focuses on synthesis and characterization of open-framework germanates with Ge7 cluster in solvothermal by using co-template and transferring the organic solvent. In addition, the corresponding structural characteristics and the roles of synthesis related to these compounds are also studied here.1. In this work, we firstly describe the synthesis of [M(en)3][GF6] (JLG-1,M=Ni,Co) using THF as a solvent, which is the first result when we attempt to synthesize germanates templated with chiral metal complexes based on in situ synthesis method. Interestingly, the [GeF6]2- anions interact with the chiral complex cations [M(en)3]2+ (M=Ni,Co) in such a way that pseudo-channels were formed along the 63 screw axis in a hexagonal, honeycomb arrays are created based on weak H-bonding of F···N atoms. It is believable that the chiral [M(en)3]2+ cations paired with [GeF6]2- anions in a D3 point symmetry is responsible for the fascinating arrangement in JLG-1(Ni) and JLG-1(Co). This work will be useful for the design of H-bonded pseudo-channel system.2. Using chiral metal complex as a template, a series of germanantes comprised of Ge7 cluster, 1-D chain-like germanate [Ni(dien)2]2[Ge7O13(OH)2F3]·Cl (JLG-7), 1-D tubular germanate of [Ni(1,2-PDA)3]2(HOCH2CH2CH2NH3)3(H3O)2[Ge7O14X3]3 (JLG-4), and 2-D layered [Ni(1,2-PDA)3][Ge7O14F2(OC2NH7)]·0.5H2O (JLG-3), and 2-D layered [Ni2(TEPA)2(en)](H2en)[Ge7O14F3]2·0.75H2O (JLG-6) have been synthesized under the synthesis conditions of GeO2-NiCl2·6H2O-H2O-T-S-HF (T= organic amines; S= ethanolamine, 2-amino-1-propanol, 3-amino-1-propanol). All of those germanates are co-templated by chiral metal complexes and other SDAs. Remarkably, JLG-4 is a 1-D germanate, which is the first tubular structure found in germanates. As for JLG-3, the organic amine C2NH6OH is covalently-bonded to one of five-coordinated germanium atoms to produce a chiral derivative of Ge7 cluster, such chiral Ge7 clusters are linked each other to generate an unusual chiral sheet with 10-rings. Under this synthesis conditions of germanates, the solvent play an important role. Especially, it plays a dual role of SDA and solvent in the synthesis of JLG-3 and JLG-4.3. Furthermore, by using pyridine as a solvent, a tubular germanate JLG-5 with 12-ring channels has been obtained by hydro(solvo)- thermal synthesis co-templated by 2-methylpiperazine and the (H2O)16 water cluster. Notably, an unique hydrogen-bonded (H2O)16 water cluster is present in each 68126 cavity and probably supports the formation of the cavity. In this thesis, we present a remarkable example of the templating role played by (H2O)n water clusters in the synthesis of open-framework materials. We believe that more extra germanate structures can be formed by using inorganic building units such as the Ge7 cluster or the different cavities built by the Ge7 cluster. Therefore, it is very important to understand well the formation of the building units and how to control the packing of such building units.4. It is important to understand the formation of the building units and to be able to control the packing of such building units. We summarized the various connection modes of Ge7 clusters which have been reported. And further researched germanate structures containing Ge7 cluster, four kinds of PBUs linked by Ge7 cluster can be found. From those PBUs, we design a series of 2-D sheets and 3-D open-framework germanate structures. We believe that more exotic germanate structures can be formed by using inorganic building units such as the Ge7 cluster or the different cavities built by the Ge7 cluster.In summary, by using AASBU approach, it is possible to design more new open-framework germanates by using Ge7 clusters as SBUs. So this thesis will be useful for the design of new open-framework germanates with large pores and low-framework density.
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