A multi-functional two-dimensional Zn(<scp>ii</scp>)-organic framework for selective carbon dioxide adsorption, sensing of nitrobenzene and Cr2O72−

A novel two-dimensional coordination polymer with a negatively charged framework named {[(CH3)2NH2][Zn2(L)2]&#183;DMF}n (1) was solvothermally synthesized via the assembly of Zn(II) ions with the organic ligand H3L (2-(3,5-dicarboxylphenyl)-6-carboxyl-benzimidazole). 1 was characterized by IR spectroscopy, thermogravimetry, single-crystal, and powder X-ray diffraction methods. 1 possesses a 1D rectangle channel decorated by abundant uncoordinated imidazole N atoms and carboxylate O atoms, and is a better CO2 adsorbent and promising CO2/CH4 selective material, suggesting potential application in gas separation. Moreover, 1 can also serve as a multi-responsive sensing material for detecting nitrobenzene (NB) and Cr2O72−via a luminescence quenching effect with a low detection limit, and the mechanisms of the quenching effect and sensing properties of 1 are discussed in detail.