A triazine-functionalized nanoporous metal–organic framework for the selective adsorption and chromatographic separation of transition metal ions and cationic dyes and white-light emission by Ln3+ ion encapsulation

Abstract

In this study, a triazine-based nanoporous metal–organic framework (MOF1) using the tricarboxyl ligand 5,5′,5′′-((1,3,5-triazine-2,4,6-triyl)tris(azanediyl))tris(2-methylbenzoic acid) was solvothermally synthesized. High thermal and chemical stability of MOF1 was established by thermogravimetric and powder X-ray diffraction analysis. Owing to its porous structure with potential nitrogen chelating sites, MOF1 could selectively adsorb the Cu²⁺ ions over the Mn²⁺, Ni²⁺, Co²⁺, and Zn²⁺ ions, and the chromatographic separation of the Co²⁺ ion was achieved from a mixed solution containing Co²⁺ and Cu²⁺. Moreover, MOF1 could selectively adsorb and separate cationic dyes on the basis of ionic selectivity rather than size selectivity. Furthermore, the nanoporous MOF1 was used as a host to encapsulate luminescent species, and it displayed a characteristic luminescent color (green for Tb³⁺ and red for Eu³⁺); moreover, we tuned the luminescence properties of the MOF1 to achieve white light emission with good color quality.