Introduction of cavities up to 4 nm into a hierarchically-assembled metal–organic framework using an angular, tetratopic ligandElectronic supplementary information (ESI) available: Synthesis and general characterizations (PXRD, IR and TGA), crystallographic data and additional structure figures. CCDC 735398. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c0cc00779j

Cavities up to 4 nm have been introduced into a hierarchically-assembled metal–organic framework by adopting an angular, semi-flexible tetratopic ligand. The resulting MOF possesses permanent porosity and exhibits stepwise sorption isotherms for O2and N2gases. [ABSTRACT FROM AUTHOR]