Self-Assembly, Structures, Gas Adsorption and Applications of Porous Metal–Organic Frameworks Constructed from Multi-pyridyl Ligands

Autor: Li-Wei Lee, 李立偉
Rok vydání: 2016
Druh dokumentu: 學位論文 ; thesis
Popis: 104
In this thesis, a series of porous metal–organic framework (MOFs) were synthesized by reacting rigid multi-pyridyl ligands, various dicarboxylate ligands and d10 metal ions (Zn2+ and Cd2+) under mild reaction conditions. The structures of these compounds range from one dimensional single-walled nanotubes, and two dimensional layers to three dimensional networks. The structure of the compounds {[Zn2(azpy)(aip)2]·2DMF}n (1), {[Zn2(dipytz)(aip)2]·DMF·MeOH}n (2), and {[Zn2(tpim)(aip)2]·2.5DMF·2H2O}n (3) assume a two-dimensional pillared-bilayer framework with 1D channels created inside the bilayers. Compounds {[Zn2(tpim)2(D-cam)2]·10H2O}n (4) and {[Zn2(tpim)2(L-cam)2]·10H2O}n (5) are composed of homochrial two-dimensional layers with a rectangle-like (4,4) topology. Compound {[Cd2(tpim)4(SO4)(H2O)2]·(SO4)·21H2O}n (6) shows a two-dimensional layer structure with a brick-wall-type (6,3) topology. Compound {[Zn(4-abpt)0.5(3,4-pydc)]·DMAc·1.5MeOH·0.5H2O}n (7) features a three-dimensional pillared-layer framework with a (3,4)-connected net. Compound {[Zn(4-pimp)(3,4-pydc)]·2DMAc}n (8) adopts a homochiral two-dimensional layered structure and {[Zn2(tpim)(3,4-pydc)2]·4DMF·4H2O}n (9) displays a homochiral three-dimensional pillared-layer network. Compound [Zn(tpim)(cis-1,4-chdc)]·3H2O (10) displays an independent 1D single-walled metal–organic nanotube and [Zn2(tpim)2(trans-1,4-chdc)2]·6H2O (11) shows a two-dimensional layered structure. All of the compounds are porous materials with different pore volumes and channel shapes. The pillared-bilayer frameworks of 1–3 have different pore volumes and channel shapes depending on the length and shape of the pillar ligands as well being feasible to tune the structural flexibility (1 and 2) or rigidity (3) through solvent-exchange processes. The resoluting MOFs exhibit a higher selective adsorption of CO2 over H2 and N2. It is noteworthy that the enantiopure compounds 4 and 5 showed an uncommon gate-opening effect on CO2 sorption and displayed a wide hysteresis loop upon desorption under ambient conditions. Compound 6 consists of a 2D layer structure with two types of sulfate anions and exhibits anion exchange capability with SCN− or N3− anions. Interestingly, the anion-exchanged products of 6 with SCN− or N3− are very different. Compound 7 adopted a three-dimensional porous pillared-layer framework with 1D honeycomb channels. Remarkably, the tetrahedral coordination environment of ZnII ions in 7 could be changed by the presence of other transition metal ions in a DMAc solution. Furthermore, compound 7 also displayed significant non-linear optical behavior. Compounds 8 and 9 crystallize in the homochiral orthorhombic space group P212121. Compound 8 adopted a 2D layer structure. Compound 9 showed a 3D pillared-layer framework with the rectangular-shape one-dimensional channels and revealed significant reversible the thermochromic behavior. Compounds 10 and 11 were constructed from the conformationally flexible 1,4-H2chdc (cis- or trans-) and tpim ligands under hydrothermal conditions and displayed different gas adsorption behaviors.
Databáze: Networked Digital Library of Theses & Dissertations
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