Metal–Organic Frameworks with Triazine and Amine Functional Groups for Iodine Removal and Sensitive Detection of Cu²⁺ and Fe³⁺ Ions

Abstract

Water pollution, especially industrial or nuclear wastewater, has become a global environmental problem and poses a serious threat to human life and health. Efficient treatment of wastewater is still a huge challenge. Herein, we report two new metal–organic frameworks (MOFs), [Me2NH2]­[Sr4­(tatab)3­(DMF)0.4­(H2O)1.6]·guest (1) and [Me2­NH2]5­[La3­(μ-O)­(tatat)2]·guest (2) (H3tatab = 4,4′,4″-((1,3,5-triazine-2,4,6-triyl)­tris­(azanediyl))­tri­benzoic acid, DMF = N,N-di­meth­yl­formamide, and H6­tatat = 5,5′,5″-(1,3,5-triazine-2,4,6-triyl)­tris-(azanediyl)­tri­iso­phthalic acid), with triazine and amine functional groups. Both of them contain anionic host frameworks and Me2NH2 + as counter cations in the pores. By virtue of the strong host–guest interactions between the triazine/imine functional groups on the framework and I2, both 1 and 2 are able to effectively remove iodine from the solution. Also, interestingly, 1 and 2 exhibit different luminescence properties, and the prominent 2 possesses sensitive fluorescence quenching behavior toward Cu2+ or Fe3+ ions, which can be used to effectively detect these ions in water.