Zn‐MOFs Containing Pyridine and Bi­pyridine Carboxylate Organic Linkers and Open Zn²⁺ Sites

Abstract

Two Zn-based metal-organic frameworks (Zn-MOFs) were solvothermally synthesized using two pyridine-based carboxylate linkers to generate unique pore topologies, as evidenced by single-crystal XRD analysis. These Zn-MOFs provided coordinatively unsaturated Zn 2+ sites with squarepyramidal geometry, leading to an enhanced interaction with CO 2 , as demonstrated by sub-atmospheric pressure iso-

Enhanced CO2capture capacities and efficiencies with N-doped nanoporous carbons synthesized from solvent-modulated, pyridinedicarboxylate-containing Zn-MOFs

“…2), which was 0.14 larger than that of an individual ZnMOF-PDC crystal determined using single crystal XRD analysis. 27 Based on this discrepancy, we hypothesized that the low N eff of C ZnMOF-PDC may be due to a larger amount of DMF chemisorbed on the polycrystalline ZnMOF-PDC than that simulated, which potentially led to material collapse during pyrolysis due to the capillary effect. This capillary effect can render the framework geometry thermally vulnerable to structural collapse, 28,29 thus facilitating the loss of N-species during pyrolysis.…”

“…10 Therefore, to achieve a high loading of Lewis basic N dopants in the final carbon material, we synthesized ZnMOF-PDC as the carbon precursor, a pyridinedicarboxylatecontaining Zn-MOF recently synthesized in our lab (Table S2 †). 27 ZnMOF-PDC has an asymmetric base unit of Zn 2 IJPDC) 2 IJDMF) 1 , where PDC and DMF denote 2,5-pyridinedicarboxylate and N,N′-dimethylformamide, as evidenced by its single crystal X-ray diffraction (XRD) analysis (Fig. 1a).…”

“…1a). 27 As shown in Table 1, ZnMOF-PDC, which had an initial N content of 5.6 mmol N g −1 , was subsequently pyrolyzed at 1000 °C to form a porous carbon with a significant amount of bulk N (3.3 mmol N g −1 ) as well as a high surface area (850 m 2 g −1 ). However, in spite of incorporating the pyridine N source, pyrolyzed ZnMOF-PDC (C ZnMOF-PDC ) exhibited a relatively lower N efficiency (N eff of 58%) than that expected based on pyrolyzed pyridine IL results (Table S1 †).…”

“…One of the as-synthesized materials (BPyr-1) was subsequently analysed using single crystal XRD analysis. Interestingly, in spite of using mixed organic linker sources (PDC and 4,4′-bipyridine) that can be coordinated to Zn centers during the MOF synthesis, the single crystal of BPyr-1 was identical to ZnMOF-PDC, 27 where only the PDC linker was incorporated, and 4,4-bipyridine struts were not incorporated. ‡ In addition, as-synthesized materials were analysed using powder XRD prior to desolvation.…”

Synthesis of Zn-MOF incorporating titanium-hydrides as active sites binding H2 molecules

“…Metal-organic frameworks (MOFs) comprising of metal centers and organic linkers are versatile functional materials that can be applicable as a catalyst [1][2][3][4][5][6], an adsorbent [7,8], and a membrane [9]. In particular, the structures of Zn-based MOFs (ZnMOFs) have been controlled by varying organic struts coordinated to Zn nodes while providing a variety of free functionalities (-OH [10][11][12], -NH 2 [13], -CHO [14], and -CN [15]).…”