Two Isomeric Magnesium Metal–Organic Frameworks with [24-MC-6] Metallacrown Cluster

Two novel Mg-based metal–organic framework isomers with the formula [Mg2(HCO2)2(NH2-BDC)­(DMF)2]n (NH2-BDC = 2-amino-1,4-benzenedicarboxylate) have been synthesized based on a 6-connected [24-MC-6] metallacrown secondary building unit (SBU), which display a two-dimensional (2D) 36 net (1) and three-dimensional primitive rhombohedral net (2) derived from a different extended orientation of SBU, respectively. The 2D framework of 1 exhibits relevant thermal stability, solvents stability, high CO2 adsorption, and strong luminescent properties.