Heterometallic In(III)–Pd(II) Porous Metal–Organic Framework with Square-Octahedron Topology Displaying High CO2 Uptake and Selectivity toward CH4 and N2

The targeted synthesis of metal–organic frameworks (MOFs) with open metal sites, following reticular chemistry rules, provides a straightforward methodology toward the development of advanced porous materials especially for gas storage/separation applications. Using a palladated tetracarboxylate metalloligand as a 4-connected node, we succeeded in synthesizing the first heterobimetallic In(III)/Pd(II)-based MOF with square-octahedron (soc) topology. The new MOF, formulated as [In3O(L)1.5(H2O)2Cl]·n(solv) (1), features the oxo-centered trinuclear clusters, [In3(μ3-O)(−COO)6], acting as trigonal-prismatic 6-connected nodes that linked together with the metalloligand trans-[PdCl2(PDC)2] (L4–) (PDC: pyridine-3,5-dicarboxylate) to form a 3D network. After successful activation of 1 using supercritical CO2, high-resolution microporous analysis revealed the presence of small micropores (5.8 A) with BET area of 795 m2 g–1 and total pore volume of 0.35 cm3 g–1. The activated solid shows high gravimetric (92.3 cm3 ...