Ssa-type MOFs constructed from dicopper paddlewheels and bent diisophthalate ligands exhibit a promising potential for gas adsorption which benefits from their rich open copper sites and polyhedron-based cages with suitable sizes. However, the rational construction of such types of MOFs is exceedingly challenging because the bent diisophthalate ligands employed are inclined to exhibit various conformations and thus are prone to form MOFs with varied topologies. In this work, by pre-organizing the ligand's conformation, we successfully targeted an ssa-type MOF ZJNU-57 from a bent diisophthalate ligand. More significantly, ZJNU-57 exhibits excellent hydrolytic stability and high CH and CO uptake capacities as well as impressive CH/CH and CO/CH adsorption selectivities, indicating its promising potential for CH/CH and CO/CH separation, which are relevant to acetylene production and natural gas purification. This work not only provides a rare water-stable MOF based on the Cu(COO) cluster for highly selective adsorption of CH and CO from CH, but also demonstrates that the ligand conformation-controlled assembly strategy may be an efficient approach toward the construction of MOF materials with definite topologies for specific applications.

A microporous MOF based on a heterotopic ligand was successfully synthesized under solvothermal conditions and fully characterized using single‐crystal and powder X‐ray diffraction, TGA, FTIR, and microanalyses. Single‐crystal X‐ray diffraction analyses showed that the title MOF contains rich inorganic nitrate ions decorating the channel surface that can serve as C2H2 recognition sites. Its selective gas adsorption properties towards C2H2 over CO2 and CH4 were evaluated by single‐component equilibrium adsorption measurements and IAST calculations, establishing its promising potential for C2H2 separation and purification. At ambient conditions, the C2H2 uptake capacity reaches 92.2 cm3 (STP) g–1, while the IAST‐predicted adsorption selectivities are up to 30.6 and 4.5 for the equimolar C2H2‐CH4 and C2H2‐CO2 binary gas mixtures, respectively. Furthermore, DFT computation studies revealed that the inorganic nitrate ion plays a very important role for preferential adsorption of C2H2 over CO2 and CH4.

ABSTRACT. A new fabrication of {[H3O][Cu6(tpta)3(DMA)4(COO)]•12H2O•7DMA}(1) was used as a drug vehicle of 5-fluorouracil (5-FU) for drug delivery. The incorporation of the drug 5-FU into the 1 was around 47.3 wt% per gram of dehydrated 1. Cargo release behavior and material degradation profile were also investigated under different mdeium. 5-FU is released in a highly controlled and progressive manner with 92% of the drug release after 96 h at acidic condition and with 88% after 96 h at PBS. In vitro cytotoxicity assays indicated that the 1 possesses no obvious cytotoxicity. The results provide a new avenue for MOFs to be used as potential drug delivery.

Two NbO-type MOFs were constructed as a platform to reveal the effect of ligand-originated MOF isomerization on selective C2H2/CH4 and CO2/CH4 adsorption properties.

Evaluating the effect of the substituents on structural stabilities and gas adsorption properties of MOFs is fundamentally important for rational design and synthesis of new MOFs with better performance. For this purpose, three isoreticular copper-based MOFs (ZJNU-87, ZJNU-88 and ZJNU-89) with ssa-type topology were successfully constructed from bent diisophthalate ligands bearing different substituents. Permanent porosity studies reveal that the substituent has a significant effect on framework stabilities against desolvation. Utilizing nonpolar n-hexane as an activation solvent can give more optimized permanent porosity for nonpolar or less-polar substituent-modified ZJNU-88 and ZJNU-89. Furthermore, their gas adsorption properties with respect to C2H2, CO2 and CH4 were systematically investigated, revealing their promising potential for selective C2H2/CH4 and CO2/CH4 separations. In particular, methoxy-modified ZJNU-89 performs better than the methyl-modified ZJNU-88 in terms of uptake capacity and adsorption selectivity, which might be attributed to more suitable pore space of ZJNU-89.