Design, synthesis, and control of metrics, functionality, and interpenetration in metal-organic frameworks and their application in hydrogen storage.

摘要

This thesis reports the isolation of both the interpenetrated [Zn₄O(TPDC)₃•(DEF)(H₂O)₅ (IRMOF-15)] and non-interpenetrated [Zn₄O(TPDC)₃•(DEF) ₁₇(H₂O)₂ (IRMOF-16)] forms of identical frameworks, demonstrating for the first time that interpenetration can be avoided even when it is topologically allowed. Additionally, a second series of frameworks, MOF-69A-C [Zn₃(BPDC)₂(OH)₂•(DEF) ₂(H₂O)₂ (MOF-69A), Zn₃(OH)₂(2,6-NDC) ₂•(DEF)₂(H₂O)₂ (MOF-69B), and Zn₃(OH)₂(BDC)₂•(DEF)₂(H ₂O)₂ (MOF-69C)] was synthesized. The unique aspect of these frameworks is the presence of rod building units that result in an underlying framework topology that forbids interpenetration, regardless of linker length. Rod building units were also identified in MOFs-71-73 [Co(BDC)(DMF) (MOF-71), Mn_1.5(BDC)_1.5(DEF) (MOF-72), Cd₃(1,3-BDC) ₄•(Me₂NH₂)₂ (MOF-73)]. Coupled with MOF-69A-C, MOFs-71-73 prompted consideration of new design strategies for the construction of stable, porous MOFs based on rod building units. Sorption studies indicate that MOF-72 is a microporous material, proving that rod-based MOF assemblies can indeed be highly stable.; This thesis also presents a study that relates SBU dimension to pH of reaction and shows specifically that the dimension of the SBU can increase with increasing pH. The description of Zn₃(1,4-BDC)₄•(DEF) ₂(Et₂NH₂)₂(Et₂NH)_1.5 (MOF-144) is detailed in these studies. In addition, this thesis uses knowledge of SBU formation to design MOFs with functionalized links: Zn ₃(TCPP)(H₂O)₂(DEF)₂•(DEF) ₁₁(H₂O)₁₁ (MOF-122) is the first microporous MOF that contains a porphyrin linker and Zn₄O(C₂₆H ₁₈O₄)₃•(DEF)₁₄(H₂O) _13.5 (IRMOF-17) is one of the first examples of a designed homochiral 3-D MOF.; Finally, inelastic neutron scattering spectroscopy of hydrogen sorbed Zn₄O(C₈H₄O₄)₃ (MOF-5) was used to identify the interactions between the adsorbed hydrogen molecules and the framework. It was found that favorable interactions exist between the adsorbed hydrogen and both the framework zinc atoms and the 1,4-benzenedicarboxylate linkers (C₈H₄O₄). Moreover, it was shown that the linkers contain several hydrogen binding sites. It was then shown that Zn₄O(C₁₂H₆O₄)₃ (IRMOF-8), which has a larger naphthalene linker, has quadruple the hydrogen uptake of MOF-5 (2.0 wt. %) at room temperature and 10 bar.