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

Abstract

A novel two-dimensional coordination polymer with a negatively charged framework named {[(CH₃)₂NH₂][Zn₂(L)₂]·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.