Low-density, solid-state, porous supramolecular organic frameworks are constructed using pillarenes. The frameworks have a honeycomb-like structure, permanent porosity, high thermal stability, and selective and reversible sorption properties toward CO2. The exceptionally selective CO2-sorption properties (375/1, 339/1) of one framework over N-2 and CH4 indicate potential applications in CO2-capture for post-combustion power plants and natural gas sweetening.