Sticked-Layer Strategy to a Flexible-Robust Hydrogen-Bonded Organic Framework for Efficient C₂H₂/CO₂ Separation

Flexible-robust hydrogen-bonded organic frameworks (HOFs) are attracting increasing interest due to their excellent separation performance for important industrial gases, but the construction remains challenging. Herein, a sticked-layer strategy is first proposed to construct a flexible-robust HOF, HOF-FJU-8, from a donor (D)-pi-acceptor (A) molecule 4,4',4 '',4'''-(pyrrolo[3,2-b]pyrrole-1,2,4,5-tetrayl)tetrabenzonitrile (DP-4CN). HOF-FJU-8 is a microporous three-dimensional framework composed of two kinds of DP-4CN molecules, one acting as building units for the two-dimensional layer via C N center dot center dot center dot H-C hydrogen bond dimers and another as the sticks to link the layers along channels through D-A pi center dot center dot center dot pi interactions. The activated framework HOF-FJU-8a possesses flexible-robust pore characteristics, as determined by the gas adsorption and in situ gas-loaded powder X-ray diffraction. HOF-FJU-8a exhibits adaptive adsorption and stronger binding affinity to C2H2 rather than CO2 due to the flexible-robust nature, which can effectively separate acetylene and carbon dioxide mixtures. [GRAPHICS] .