Moisture-Stable Zn(II) Metal–Organic Framework as a Multifunctional Platform for Highly Efficient CO2 Capture and Nitro Pollutant Vapor Detection

A moisture-stable three-dimensional (3D) metal–organic framework (MOF), {(Me2NH2)­[Zn2(bpydb)2(ATZ)]­(DMA)­(NMF)2}n (1, where bpydb = 4,4′-(4,4′-bipyridine-2,6-diyl)­dibenzoate, ATZ = deprotonated 5-aminotetrazole, DMA = N,N-dimethylacetamide, and NMF = N-methylformamide), with uncoordinated N-donor sites and charged framework skeleton was fabricated. This MOF exhibits interesting structural dynamic upon CO2 sorption at 195 K and high CO2/N2 (127) and CO2/CH4 (131) sorption selectivity at 298 K and 1 bar. Particularly, its CO2/CH4 selectivity is among the highest MOFs for selective CO2 separation. The results of Grand Canonical Monte Carlo (GCMC) simulation indicate that the polar framework contributes to the strong framework–CO2 binding at zero loading, and the tetrazole pillar contributes to the high CO2 uptake capacity at high loading. Furthermore, the solvent-responsive luminescent properties of 1 indicate that it could be utilized as a fluorescent sensor to detect trace amounts of nitrobenzene in both solvent and vapor systems.