The Porous MOF Materials Based On Rigid Ligands And Templating Effects

Porous Metal-organic frameworks （MOF） as novel multifunctional materials, haveattracted more and more attention because of their flexible structures, various topologies,potential applications in gas storage, ion-exchange, adsorption, molecular recognization,catalysts, selective separation and chiral separation along with optics, electrics, magnetismand enantiomeric separation. These open frameworks possess not only crystalline porousstructure, but also better performance in gas sorption and storage comparing with traditionalzeolites. In addition, according to the principle of crystal engineering, it is possible thatrational design and synthesis of porous MOFs by selecting special organic ligands, metalsand templates.In this dissertation, we synthesize N-donor and carboxylate ligands, and use solventwith different size as templates to construct porous MOFs. We also investigate fluorescentproperty of the compound as multi-functional material with potential applications.Under hydrothermal and solvothermal conditions, we have synthesized23porousMOF. These compounds have been structurally characterized by the elemental analysis, IR,XRPD, TG,1H NMR and single-crystal X-ray diffraction. Moreover, the ions-exchange, N2absorption and fluorescence properties of some MOFs have been studied and discussed.These results include the following four issues:1. We synthesize a series of solvents with different size and then choose1,3,5-benzenetricarboxylate （BTC） coupled with metal ions to evaluating influence ofsolvents with different size. We successfully obtain twelve different3D porous MOFs:Zn₂（BTC）（NO₃）（DMA）₃（1）[Zn₁₁（BTC）₆（NO₃）₄·9DEE]（2）[Zn₁₁（BTC）₆（NO₃）₄·8DEP]（3）[Zn（BTC）][（CH₃）₂NH₂]·DMA （4）[Zn₃（BTC）₃][（CH₃）₂NH2]3·3DMA （5）[Zn₉（BTC）₆（OH）₂][（CH₃）₂NH₂]₂·3DMA （6）[Zn₉（BTC）₅（OH）₃（C₂O₄）][（CH₃）₂NH₂]₂·6DEE （7）[Cd（BTC）][（CH₃）₂NH₂]·DMA （8）Cd₂（BTC）（NO₃）·（DMA）₃（9）Cd₂（BTC）（NO₃）·（DEE）₃（10）Co₂（BTC）（NO₃）·（DMA）₃（11）Co₂（BTC）（NO₃）·（DEE）₃（12）Using solvents with different size as space-templating method, a cheap and easysynthesis approach have been successfully applied to synthesize MOFs. Not only does thisapproach can systematically control the pore size, but it also allows access to new structuresand topologies previously unrealized in MOFs. In general, that is ‘the larger the solventssize, the larger the pores’. The ion exchange behavior, gas absorbtion and the fluorescentproperty were studied and discussed. 2. By choosing organic amine cations as a template and different rigid carboxylateligands, we successfully obtain three different3D MOFs with anionic frameworks.[（CH₃）₂NH₂][Cd（BPDC）_1.5]·2DMA （13）[（CH₃）₂NH₂][Cd（BPDC）)_1.5]·2DMA （14）[Me₂NH₂]₂[Cd₂（NH₂BDC）₃]·4DMA （15）We found that these anionic frameworks are basically low-symmetric, which aredifferent with the neutral framework and easier to form chiral structures. The ion exchangebehavior, gas absorbtion and the fluorescent property are studied and discussed.3. By using rigid N-donor ligands such as3-BPH,4-BPH and so on, together with rigidcarboxylic acid ligands and transition metal ions, we synthesized four mixed ligand basedMOFs with different structures.Co₂（BPDC）₂（4-BPH）·4DMF （16）Cd（BPDC）（4-BPH）·2DMF （17）Co4（BTC）（C₂H₂N₂O₂）0.5（4-BPH）0.5（DMF）2·H₂O （18）Ni₂（BDC）₂（3-BPH）₂（H₂O）·4DMF （19）It shows that these MOFs possess flexible coordination modes. Through its adjustablespatial configuration and role of the coordination of nitrogen atoms, novel pillared MOFshave been synthesized. The gas absorbtion property are also studied and discussed4. Using multi N-containing ligands such as TPB, IP and so on, together with rigidcarboxylic acid ligands and transition metal ions, we synthesized four mixed ligand basedMOFs with different structures.[Cu （TPB）][SO₄] H₂O （20）Zn（TPB）（BDC）·2H₂O （21）Co₂（BPTC）（IP）₄·12H₂O （22）Ni（BPTC）（IP）₂·6H₂O （23）Study shows that the ligands TPB, IP are not easy to form three-dimensional porousframeworks. Unexpectedly, we get a stable supramolecular framework, where the pore size is1.2nm.