Novel Iso-Reticular Zn(ii) Metal–Organic Frameworks constructed by Trinuclear-Triangular and Paddle-Wheel Units: Synthesis, Structure and Gas Adsorption

Abstract

Two novel Zn(II) metal–organic frameworks (MOFs) constructed by trinuclear-triangular and paddle-wheel units, namely {[Zn₅(dmtrz)₃(IPA)₃(OH)]·DMF·H₂O}_n (MAC-4, Hdmtrz = 3,5-dimethyl-1H-1,2,4-triazole, H₂IPA = isophthalic acid, DMF = dimethyl formamide) and {[Zn₅(dmtrz)₃(OH-IPA)₃(OH)]·DMF·5H₂O}_n (MAC-4-OH, OH-H₂IPA = 5-hydroxyisophthalic acid), were solvothermally synthesized. Single-crystal analyses reveal that MAC-4-OH is an iso-reticular framework of MAC-4 with channels functionalized by hydroxyl groups. Gas adsorption reveals that MAC-4-OH shows a significant enhancement for CO₂ uptake compared with that of MAC-4 due to the existence of electrostatic attractive interactions, though its surface area is lower than that of MAC-4.