Nanoporous Frameworks with High Porosity and Unexpected Rigid Framework Topologies Based on Odd-Numbered...

Two tetracarboxylic linkers containing seven-membered rings are synthesized and utilized in metal-organic framework (MOF) syntheses, leading to the two new compounds DUT-184 and DUT-193. The introduced odd angles between carboxylates in a new dihydro-azepine-containing linker lead to exotic Zn-based MOFs: a 3D structure based on two catenated sets of 2D nets in DUT-184 and a cubic structure with so far unknown topology in the DUT-193 framework. The mesoporous DUT-193 shows high porosity upon adsorption of N₂, Ar, CH₄, and CO₂ at their standard boiling points. Grand canonical Monte Carlo simulations show good agreement between experimental and theoretical results and shine light on the microscopic adsorption mechanism at low pressure.