A Microporous Mn(II) MOF Based on 5-(4H-1,2,4-triazol-4-yl) Isophthalic Acid for CO 2 /N 2 Separation.

Removal of carbon dioxide (CO 2 ) from a CO 2 /N 2 mixture by utilizing CO 2 -selective sorbents is important from the perspective of energy security and environmental sustainability. Herein, a microporous metal-organic framework (MOF) composed of manganese(II) and a bifunctional linker 5-(4 H -1,2,4-triazol-4-yl)benzene-1,3-dicarboxylic acid (H 2 L), [Mn(HL) 2 ] ( 1 ) is designed and synthesized using a hydrothermal method. Characterized by single-crystal X-ray diffraction (SCXRD), a microporous channel was found in the structure of compound 1 along the a -axis. Attributed to hydrogen-binding interactions between CO 2 molecules and N- and O-donor ligands in its microporous one-dimensional (1D) channel, compound 1 exhibits favorable adsorption of CO 2 over N 2 . Further, verified by experimental breakthrough tests, the CO 2 /N 2 mixture can be separated efficiently. This work provides potential guidance for designing CO 2 -selective MOFs for CO 2 /N 2 separation.