Tetranuclear Cu II Cluster as the Ten Node Building Unit for the Construction of a Metal-Organic Framework for Efficient C 2 H 2 /CO 2 Separation.

Rational design of high nuclear copper cluster-based metal-organic frameworks has not been established yet. Herein, we report a novel MOF (FJU-112) with the ten-connected tetranuclear copper cluster [Cu 4 (PO 3 ) 2 (μ 2 -H 2 O) 2 (CO 2 ) 4 ] as the node which was capped by the deprotonated organic ligand of H 4 L (3,5-Dicarboxyphenylphosphonic acid). With BPE (1,2-Bis(4-pyridyl)ethane) as the pore partitioner, the pore spaces in the structure of FJU-112 were divided into several smaller cages and smaller windows for efficient gas adsorption and separation. FJU-112 exhibits a high separation performance for the C 2 H 2 /CO 2 separation, which were established by the temperature-dependent sorption isotherms and further confirmed by the lab-scale dynamic breakthrough experiments. The grand canonical Monte Carlo simulations (GCMC) studies show that its high C 2 H 2 /CO 2 separation performance is contributed to the strong π-complexation interactions between the C 2 H 2 molecules and framework pore surfaces, leading to its more C 2 H 2 uptakes over CO 2 molecules.