A pacs-type metal-organic framework based on [Cd3(OH)] clusters for effective C2H2/CO2 separation and fluorescent detection of TNP in water

Abstract Metal-organic frameworks (MOFs) have become a versatile platform for gas capture/separation and luminescent sensing of toxic pollutants, and the combination of both of these properties depends on the robust framework and pre-designed pore functionality which is critical to achieve the targeted applications. In this work, a novel Cd(II)-MOF {(NH2Me2)[Cd3 (μ3-OH) (tpt) (TZB)3](H2O)2 (1,4-dioxane)5}n (1, H2TZB ​= ​4-(1H-tetrazol-5-yl)benzoic acid, tpt ​= ​2,4,6-tri (pyridin-4-yl)-1,3,5-triazine) comprising of a {Cd3(OH)}5+ cluster-based unit (SBU) has been solvothermally formed from nitrogen-rich and highly fluorescent organic ligands. The porous structure 1 is composed of cages and segments which are affixed by high density of free nitrogen atoms. The activated Cd(II)-MOF (1a) exhibits a relative high C2H2 sorption capacity than that of CO2 which endows it with a C2H2/CO2 sorption selectivity of 7.26 ​at room temperature. Furthermore, complex 1 could behave as a luminescent sensor for highly discriminative detection of explosive 2,4,6-trinitrophenol (TNP) via remarkable fluorescence quenching (Ksv ​= ​6.16✕104 ​M−1).