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An unexpected in-situ hydrolysis reaction occurred during the solvothermal reaction of N,N′-bis(4-carboxy-2-methylphenyl)pyromellitic di-imide) and Ba(NO3)2, and a novel porous Ba-MOF, [H2N(CH3)​2]0.5[Ba1.5(L)(DMA)]·1.5DMA·1.5H2O (UPC-70, H3L = 2-(4-carboxy-2-methylphenyl)-1,3-dioxoisoindoline-5,6-dicarboxylic acid, DMA = N,N-dimethylacetamide), was obtained on the basis of the partial hydrolysate. The as-synthesized 3D network with 1D open channels of different sizes (24 A and 10 A) contains abundant open metal sites after removal of solvents, which is conducive to the preferential adsorption of CO2. The subsequent gas sorption measurement reveals the high separation selectivity of UPC-70 for CO2/CH4 (15) and CO2/N2 (32) at ambient conditions, and GCMC theoretical simulation provides good verification of the experimental results, indicating that UPC-70 is a potential candidate for CO2 capture from flue gas and natural gas.

Two Co(II)-MOFs with different structures were successfully synthesized under the premise of designing two ligands containing alkynyl functional groups. Complexes 1 ([Co(TEPA)(TPT)2/3]·2DMF·H2O) and 2 ([Co(EPA)(TPT)]·1.5DMF·1.5H2O) show excellent luminescence properties. Meanwhile, as fluorescent sensors, complexes 1 and 2 exhibit selectivity and sensitivity for Fe3+ with the Ksv of 1.520 × 104 L/mol and 3.543 × 104 L/mol, which can rapidly detect nitroaromatic compounds in methanol and ethanol, especially for 2,4-NPH through fluorescence quenching with high quenching efficiency. In particular, the Ksv value of complexes 1 and 2 towards 2,4-NPH can reach up to 1.627 × 105 L/mol and 9.600 × 104 L/mol, demonstrating that complexes 1 and 2 are good candidates for the identification and detection of Fe3+ and nitroaromatic compounds.

Three cadmium(II) metal-organic frameworks (MOFs) based on tetracarboxylate ligands, namely [Cd2(TTTA)(DMF)3]·2DMF (1), [Cd2(TB)(H2O)4]·3DMF·H2O (2) and [Cd(TEB)0.5]·2DMF·4H2O (3) have been designed and synthesized. Complex 1 is a 2-dimensional (2D) 3,4-connected network with 3,4L13 topology, complex 2 features a 3-dimensional (3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO2 over CH4. In addition, 2 shows fluorescence sensing of Fe3+ ion and rapid detection of nitroaromatic compounds (NACs) through fluorescence quenching.

A Co-based two-dimensional (2D) microporous metal-organic frameworks, [Co2(TMTA)(DMF)2(H2O)2]·NO3−·DMF (UPC-32) has been synthesized based on 4,4′,4′′-(2,4,6-trimethylbenzene-1,3,5-triyl)tribenzoic acid (H3TMTA). UPC-32 features a 2D microporous framework exhibits high adsorption of H2 (118.2 cm3/g, 1.05 wt%, at 77 K), and adsorption heat (Qst) of CO2 (34–46 kJ/mol). UPC-32 with narrow distance between layers (3.8 A) exhibits high selectivity of C3H6/CH4 (31.46) and C3H8/CH4 (28.04) at 298 K and 1 bar. It is the first 2D Co-MOF that showed selective separation of C3 hydrocarbon from CH4.