Design and Synthesis of Porous Nickel(II) and Cobalt(II) Cages.

Coordination assemblies containing transition-metal cations with coordinatively unsaturated sites remain a challenging target in the synthesis of porous molecules. Herein, we report the design, synthesis, and characterization of three porous hybrid inorganic/organic porous molecular assemblies based on cobalt(II) and nickel(II). Precise tuning of ligand functionalization allows for the isolation of molecular species in addition to two- and three-dimensional metal-organic frameworks. The cobaltous and nickelous cage compounds display excellent thermal stabilities in excess of 473 K and Brunauer-Emmett-Teller surface areas on the order of 200 m2/g. The precise ligand functionalization utilized here to control phases between discrete molecules and higher-dimensional solids can potentially further be tuned to optimize the porosity and solubility in future molecular systems.