Effect of Larger Pore Size on the Sorption Properties of Isoreticular Metal-Organic Frameworks with High Number of Open Metal Sites

Four isostructural CPO-54-M metal-organic frameworks based on the larger organic linker 1,5-dihydroxynaphthalene-2,6-dicarboxylic acid and divalent cations (M=Mn, Mg, Ni, Co) are shown to be isoreticular to the CPO-27 (MOF-74) materials. Desolvated CPO-54-Mn contains a very high concentration of open metal sites, which has a pronounced effect on the gas adsorption of N2 , H2 , CO2 and CO. Initial isosteric heats of adsorption are significantly higher than for MOFs without open metal sites and are slightly higher than for CPO-27. The plateau of high heat of adsorption decreases earlier in CPO-54-Mn as a function of loading per mole than in CPO-27-Mn. Cluster and periodic density functional theory based calculations of the adsorbate structures and energetics show that the larger adsorption energy at low loadings, when only open metal sites are occupied, is mainly due to larger contribution of dispersive interactions for the materials with the larger, more electron rich bridging ligand.

Robust high-connected rare-earth MOFs as efficient heterogeneous catalysts for CO2conversion

Two series of chemically and thermally stable rare-earth MOFs with a 12-connected hcp topology exhibit high catalytic activity towards the cycloaddition of CO₂and epoxides under mild conditions.

Construction of a polyhedron decorated MOF with a unique network through the combination of two classic secondary building units

A decorated metal–organic polyhedron based metal–organic framework with a unique 4,9-connected net is constructed, showing relatively strong interaction toward H₂and CO₂probably due to the presence of open metal sites in secondary building units.

Synthesis and stabilization of a hypothetical porous framework based on a classic flexible metal carboxylate cluster

A hypothetical porous network isomeric to MIL-88/MIL-101 has been realized by the introduction of terminal ligands and further stabilized by crosslinking.