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Synthesis of Functional Metal-Organic Frameworks via Secondary Linker Installation and Primary Linker Design

Yuchen Hu, University of Nebraska - Lincoln

Abstract

The past two decades have witnessed the explosive development of metal-organic frameworks (MOFs) as a class of highly porous crystalline materials. To exploit more applications and potentials of MOFs, it is significant to introduce the functionalities and increase the complexity without destructing their ordered structures. One strategy to achieve this is to design, synthesize and modify the primary ligands with various functionalities, another one is to incorporate different secondary linkers at the precise positions in the crystalline lattice via post-synthetic stepwise insertion. In this dissertation, Zr-MOFs and Ln-MOFs with various functionalities are constructed via secondary linkers installation and primary ligands design. Firstly, we rationally decreased the size of the primary ligand used in NPF-300, a Zr-MOF with scu topology (NPF = Nebraska Porous Framework), and synthesized its isostructural NPF-320. NPF-320 exhibits optimized pocket sizes which allow to post-synthetically installed three secondary linkers in all six permuted sequences via both linker exchange and installation, forming a final quinary MTV-MOFs via single-crystal to single-crystal transformation. Secondly, we synthesized a series of RE (rare earth)-tetracarboxylate MOFs (Eu, Tb, Y, and Gd) with 8-connected hexanuclear clusters by using additional modulators. The RE-MOFs show scu topology which provides open pockets for secondary linker insertions. Two fluorescent secondary linkers can be inserted to construct fluorescent MTV MOFs for energy transfer study. Thirdly, isostructural lanthanide MOFs are synthesized through the self-assembly of a ligand with blue fluorescent and lanthanide ions (Eu3+, Tb3+, Y3+). With careful adjustment of the relative concentration of the lanthanide ions, the color of the luminescence can be modulated, and white light-emission can be achieved. At last, three unique angular carbazole ditopic ligands were used to construct a series of microporous MOFs. One of them shows interesting inverse selective ethane/ethylene separation properties.

Subject Area

Chemistry|Chemical engineering|Organic chemistry

Recommended Citation

Hu, Yuchen, "Synthesis of Functional Metal-Organic Frameworks via Secondary Linker Installation and Primary Linker Design" (2022). ETD collection for University of Nebraska - Lincoln. AAI29168125.
https://digitalcommons.unl.edu/dissertations/AAI29168125

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