Isoreticular Synthesis of Mesoporous Metal-Organic Polyhedra with Permanent Porosity to Gas and Water.

Abstract

Synthesis of mesoporous metal-organic cages or polyhedra (MOCs or MOPs) that retain their porous functionality in the solid state remains challenging, given their tendency to collapse upon desolvation. Herein, we report the use of the isoreticular expansion approach to synthesize two permanently porous Rh(II)-based octahedral MOPs within the mesoporous regime. Our mesoporous MOPs, featuring internal cavities of up to 12.5 nm³, withstand the activation process, enabling their use as solid-state adsorbents for gases and water. In particular, the larger mesoporous MOP, named BCN-17, captures up to 0.47 gwater·gMOP-1 and exhibits an S-shaped water-sorption isotherm with a hysteresis loop, characteristic of mesoporous materials.