Water-Stable Europium 1,3,6,8-Tetrakis(4-carboxylphenyl)pyrene Framework for Efficient C₂H₂/CO₂ Separation

Compound {(Me 2 NH 2 ) 3 [Eu 7 (μ 3 -O) 2 (TBAPy) 5 (H 2 O) 6 ]·12.5DMF} n ( JXNU-5 ), constructed from the 1,3,6,8-tetrakis(4-carboxylphenyl)pyrene (TBAPy 4– ) ligand and one-dimensional (1D) europium carboxylate rods, is presented. JXNU-5 has a three-dimensional framework with 1D channels. The strong coordination bonds between Eu III ions with high charge densities and carboxylate O atoms as well as strong π···π-stacking interactions between pyrenes lead to a water-resistant JXNU-5, which was verified by powder X-ray diffraction and surface area measurements. The breakthrough simulations and experiments demonstrate that an efficient C 2 H 2 /CO 2 (50/50 mixture) gas separation at ambient conditions was achieved with JXNU-5 . The calculation results show that the dominating interactions between the absorbed C 2 H 2 molecules and host framework are hydrogen bonds associated with the carboxylate O atoms exposed on the pores. Thus, an elegant example of a water-stable metal–organic framework for effective C 2 H 2 /CO 2 separation is demonstrated.