A Microporous Heterovalent Copper–Organic Framework Based on [Cu2I]n and Cu2(CO2)4 Secondary Building Units: High Performance for CO2 Adsorption and Separation and Iodine Sorption and Release

A microporous heterovalent Cu-based MOF, [(Cu 2 I)Cu 2 L 2 (H 2 O) 2 ] 2 2+ ·2NO 3 – ·5DMF ( 1 ) (H 2 L = 5-(4 H -1,2,4-triazol-4-yl)benzene-1,3-dicarboxylic acid, DMF = N, N -dimethylformamide), has been successfully synthesized using the mixed secondary building unit (SBU) strategy. Compound 1 was constructed from [Cu 2 I] n chain and Cu 2 (CO 2 ) 4 paddlewheel SBUs and exhibited a new (3,4,4)-connected topology. Although compound 1 possesses moderate surface area, it exhibits better CO 2 capture (91.9 cm 3 g –1 at 273 K) and separation ability (selectivity for CO 2 over CH 4 = 8.2 under 1 bar at 298 K) than most of the reported Cu x I y -based MOFs. Moreover, compound 1 is also a good candidate for the capture and release of iodine.