A robust indium(III)-potassium(I) MOF with high CO2/C2- hydrocarbons over CH4 separation performance

A heterometallic MOF, [NH2(Me)(2)](5)[K3In8L8(H2O)(6)]center dot 13DMA center dot 12H(2)O (1), has been synthesized under solvothermal conditions by employing a pyridyl-decorated tetracarboxylate ligand, 2,2'-(pyridine-2,5-diyl)diter-ephthalic acid (H4L). Structural analysis demonstrates that 1 is a 3D microporous framework based on three kinds of inorganic secondary building units (SBUs), which shows an unprecedented 5-nodal (3,4,4,7,7)-connected topology. Especially, 1 possesses high chemical stability in pH = 2-13 aqueous solutions. The desolvated structure of 1 contains a highly polar pore system decorated with open metal sites, diethylammonium cations, and free pyridine atoms, leading to a high CO2/C-2-hydrocarbons over CH4 separation performance.