A stable metal cluster-metalloporphyrin MOF with high capacity for cationic dye removal

A metalloporphyrin Cu-5-cluster based MOF (metal-organic framework), [Cu-4.5((H(4)TZPP)(TZPP)Cl-2)(H2O)(0.5)]center dot CH3NH2CH3 center dot 7EtOH center dot 8H(2)O (LIFM-WZ-3) was synthesized from the tetrapodal ligand 5,10,15,20-tetrakis[4-(2,3,4,5-tetrazolyl)phenyl]porphyrin (H(6)TZPP) and copper chloride. LIFM-WZ-3 exhibits a rare 2D + 3D -> 3D interpenetration topology, of which the frl-type 3D MOF and a layered 2D HOF (hydrogen bond organic framework) are intertwined, leading to an anionic framework with 1D spindle-like channels. Powder X-ray diffraction analysis reveals that the framework is stable in acid, base and various organic solvent environments. LIFM-WZ-3 exhibits moderately high separation performances for CO2/CH4, CO2/N-2, C3H6/CH4, C2H6/CH4, and C2H4/CH4 at room temperature. Specifically, the anionic framework in LIFM-WZ-3 containing dimethylamine cations can selectively adsorb cationic organic dyes from aqueous pollutants for recycle purpose. The high adsorption capacity for methylene-blue (MB+, 983 mg g(-1)) and crystal violet (CV+, 713.5 mg g(-1)) ranks the highest among those MOFs ever reported.