Fine-tuning the pore environment of isoreticular metal-organic frameworks through installing functional sites for boosting C₂H₆/C₂H₄ separation

Herein, we presented a strategy that tuning the pore environment via installing functional sites in the pores to boost C₂H₆/C₂H₄ separation performance of MOFs. To prove this strategy, four isoreticular MOFs [MAF-X10, -X10(Me), -X10(Cl), and -X10(F)] were designed and synthesized based on reticular chemistry principle, which featured the regulated pore environment and exhibited intriguing differences in C₂H₆ and C₂H₄ uptakes. Methyl group-modified nonpolar pores endow these MOFs with impressive C2H6-selective behavior and high C₂H₆ loadings (>110 cm³ g^-1), in which MAF-X10(F) with polar F sites exhibited the highest C₂H₆ uptake (140.5 cm³ g^-1) among four MOFs, ranking the top compared to the reported MOF materials. The polar sites-functionalized MAF-X10(Cl) and -X10(F) showed the significantly improved C2H6/C2H4 separation performances in comprehensive of selectivity, separation potential, C₂H₄ productivity, which were mainly contributed to the strong C-H ctdot;Cl/F interactions formed between the active sites (Cl or F) in MAF-X10(Cl)/(F) and C₂H₆, as revealed by molecular simulations.