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Developing hydrogen‐bonded organic frameworks (HOFs) that combine functional sites, size control, and storage capability for targeting gas molecule capture is a novel and challenging venture. However, there is a lack of effective strategies to tune the hydrogen‐bonded network to achieve high‐performance HOFs. Here, a series of HOFs termed as HOF‐ZSTU‐M (M=1, 2, and 3) with different pore structures are obtained by introducing structure‐directing agents (SDAs) into the hydrogen‐bonding network of tetrakis (4‐carboxyphenyl) porphyrin (TCPP). These HOFs have distinct space configurations with pore channels ranging from discrete to continuous multi‐dimensional. Single‐crystal X‐ray diffraction (SCXRD) analysis reveals a rare diversity of hydrogen‐bonding models dominated by SDAs. HOF‐ZSTU‐2, which forms a strong layered hydrogen‐bonding network with ammonium (NH4+) through multiple carboxyl groups, has a suitable 1D "pearl‐chain" channel for the selective capture of propylene (C3H6). At 298 K and 1 bar, the C3H6 storage density of HOF‐ZSTU‐2 reaches 0.6 kg L−1, representing one of the best C3H6 storage materials, while offering a propylene/propane (C3H6/C3H8) selectivity of 12.2. Theoretical calculations and in situ SCXRD provide a detailed analysis of the binding strength of C3H6 at different locations in the pearl‐chain channel. Dynamic breakthrough tests confirm that HOF‐ZSTU‐2 can effectively separate C3H6 from multi‐mixtures. [ABSTRACT FROM AUTHOR]

Developing hydrogen‐bonded organic frameworks (HOFs) that combine functional sites, size control, and storage capability for targeting gas molecule capture is a novel and challenging venture. However, there is a lack of effective strategies to tune the hydrogen‐bonded network to achieve high‐performance HOFs. Here, a series of HOFs termed as HOF‐ZSTU‐M (M=1, 2, and 3) with different pore structures are obtained by introducing structure‐directing agents (SDAs) into the hydrogen‐bonding network of tetrakis (4‐carboxyphenyl) porphyrin (TCPP). These HOFs have distinct space configurations with pore channels ranging from discrete to continuous multi‐dimensional. Single‐crystal X‐ray diffraction (SCXRD) analysis reveals a rare diversity of hydrogen‐bonding models dominated by SDAs. HOF‐ZSTU‐2, which forms a strong layered hydrogen‐bonding network with ammonium (NH4+) through multiple carboxyl groups, has a suitable 1D "pearl‐chain" channel for the selective capture of propylene (C3H6). At 298 K and 1 bar, the C3H6 storage density of HOF‐ZSTU‐2 reaches 0.6 kg L−1, representing one of the best C3H6 storage materials, while offering a propylene/propane (C3H6/C3H8) selectivity of 12.2. Theoretical calculations and in situ SCXRD provide a detailed analysis of the binding strength of C3H6 at different locations in the pearl‐chain channel. Dynamic breakthrough tests confirm that HOF‐ZSTU‐2 can effectively separate C3H6 from multi‐mixtures. [ABSTRACT FROM AUTHOR]

Adsorptive separation of propylene/propane (C3H6/C3H8) mixture is desired for its potential energy saving on replacing currently deployed and energy‐intensive cryogenic distillation. Realizing efficient C3H6/C3H8 separation in the emerging hydrogen‐bonded organic frameworks (HOFs) is very challenging owing to the lack of functional sites for preferential gas binding. By virtue of crystal engineering, we herein report a functionalized HOF (HOF‐16) with free ‐COOH sites for the efficient separation of C3H6/C3H8 mixtures. Under ambient conditions, HOF‐16 shows a significant C3H6/C3H8 uptake difference (by 76 %) and selectivity (5.4) in contrast to other carboxylic acid‐based HOFs. Modeling studies indicate that free ‐COOH groups together with the suitable pore confinement facilitate the recognition and high‐density packing of gas molecules. The separation performance of HOF‐16 was validated by breakthrough experiments. HOF‐16 is stable towards strong acidity and water. [ABSTRACT FROM AUTHOR]

Adsorptive separation of propylene/propane (C3H6/C3H8) mixture is desired for its potential energy saving on replacing currently deployed and energy‐intensive cryogenic distillation. Realizing efficient C3H6/C3H8 separation in the emerging hydrogen‐bonded organic frameworks (HOFs) is very challenging owing to the lack of functional sites for preferential gas binding. By virtue of crystal engineering, we herein report a functionalized HOF (HOF‐16) with free ‐COOH sites for the efficient separation of C3H6/C3H8 mixtures. Under ambient conditions, HOF‐16 shows a significant C3H6/C3H8 uptake difference (by 76 %) and selectivity (5.4) in contrast to other carboxylic acid‐based HOFs. Modeling studies indicate that free ‐COOH groups together with the suitable pore confinement facilitate the recognition and high‐density packing of gas molecules. The separation performance of HOF‐16 was validated by breakthrough experiments. HOF‐16 is stable towards strong acidity and water. [ABSTRACT FROM AUTHOR]