Highly porous metal–organic framework sustained with 12-connected nanoscopic octahedra

Two dicopper(II)-paddlewheel-based metal-organic frameworks (PCN-81 and -82) have been synthesized by using tetratopic ligands featuring 90°-carbazole-dicarboxylate moieties. Both adopt 12-connected tfb topology with nanoscopic octahedra as building units. The freeze-dried PCN-82 shows Brunauer-Emmett-Teller (BET) and Langmuir surface areas as high as 4488 and 4859 m(2) g(-1), respectively. It also exhibits high H(2)-adsorption capacity at low pressure (300 cm(3) g(-1) or 2.6 wt% at 77 K and 1 bar), which can be attributed to its high surface area, microporosity, and open metal sites.