Distinct Temperature-Dependent CO₂ Sorption of Two Isomeric Metal–Organic Frameworks

Abstract

Two isomeric metal–organic frameworks, consisting of Co-triazolate layers and positional isomeric dicarboxylate pillars, both show distinct temperature-dependent CO2 sorption behaviors. Because of the pores functionalized by amino groups, both materials have high CO2 uptake and highly selective sorption of CO2 over CH4 and N2.

Creating Giant Secondary Building Layers via Alkali-Etching Exfoliation for Precise Synthesis of Metal–Organic Frameworks

“…To test whether this nanosheet can be used as giant SBLs to construct other functional MOFs, a family of ligands (Figure a) with different functional groups including 1,4-benzene dicarboxylic acid (BDC), 2,5-dihydroxy terephthalic acid (DOBDC), 2-aminobenzene-1,4-dicarboxylic acid (NH 2 -BDC), and 1,4-naphthalene dicarboxylic acid (1,4-NDC) were chosen for the self-assembly study. PXRD patterns (Figure ) and N 2 adsorption isotherms (Figure ) confirmed the successful syntheses of the corresponding MOFs Zn–TRZ–BDC, Zn–TRZ–DOBDC, Zn– TRZ–NH 2 -BDC, and Zn–TRZ–1,4-NDC with high crystallinity and porosity. , In addition, Zn–TRZ–BPDC and Zn–TRZ–BCPT can also be obtained based on this giant SBL when we turned to longer pillars such as 4,4′-biphenyldicarboxylic acid (BPDC) and 3,5-bis­(4′-carboxy-phenyl)-1,2,4-triazole (BCPT) . Interestingly, even a monocarboxylate ligand, 4- nitrobenzoic acid (4-NBA), can be installed onto Zn–TRZ layer giant SBLs where the 4-NBA ligands are intercalated into adjacent layers with carboxylate groups coordinated with Zn­(II) centers while the nitro groups connect with TRZ through hydrogen bonds (Figure c) .…”

“…PXRD patterns (Figure 6) and N 2 adsorption isotherms (Figure 7) confirmed the successful syntheses of the corresponding MOFs Zn−TRZ−BDC, Zn−TRZ−DOBDC, Zn− TRZ−NH 2 -BDC, and Zn−TRZ−1,4-NDC with high crystallinity and porosity. 38,39 In addition, Zn−TRZ−BPDC and Zn−TRZ−BCPT can also be obtained based on this giant SBL when we turned to longer pillars such as 4,4′biphenyldicarboxylic acid (BPDC) 40 and 3,5-bis(4′-carboxyphenyl)-1,2,4-triazole (BCPT). 41 Interestingly, even a monocarboxylate ligand, 4-nitrobenzoic acid (4-NBA), can be installed onto Zn−TRZ layer giant SBLs where the 4-NBA ligands are intercalated into adjacent layers with carboxylate groups coordinated with Zn(II) centers while the nitro groups connect with TRZ through hydrogen bonds (Figure 5c).…”

Ligand Symmetry Modulation for Designing Mixed-Ligand Metal–Organic Frameworks: Gas Sorption and Luminescence Sensing Properties

“…It should be noted that the two amino groups on the atz – ligands point to the opposite direction, which might be attributed to the minimization of the interaction energy in the “paddle-wheel” cluster. To our knowledge, the combination of the Hatz ligands and Zn­(II) ions tends to give Zn-triazolate layers, and 1 represents the first MOF based on the helical Zn-triazolate chain-like SBUs. − Compared with the MOF constructed from the same bpydb 2– ligand and datz – pillar, we can speculate that the asymmetry substituent group on the atz – ligand might be responsible for the formation of the helical chain. The Flack parameter of 1 is 0.01, which further demonstrates the validity of the absolute configuration.…”

Tuning the CO2 and C1/C2 Hydrocarbon Capture and Separation Performance for a Zn-F-Triazolate Framework through Functional Amine Groups

“…On the other hand, although the amine-functionalized MOFs have exhibited high CO 2 uptake performance, only a small number of them show outstanding selectivity for CO 2 over CH 4 . − Furthermore, the adsorption and separation of C2 hydrocarbons (C 2 H 2 and C 2 H 4 ) from CH 4 mixtures utilizing amine-functionalized MOFs has been much less explored. In fact, the separation of CO 2 and C2 hydrocarbons from CH 4 is important for the natural gas upgrading.…”