Gated Channels in a Honeycomb-like Zinc−Dicarboxylate−Bipyridine Framework with Flexible Alkyl Ether Side Chains

Covalent functionalization of 1,4-benzenedicarboxylate (bdc) with methoxyethoxy groups induces conformational freedom in this molecule. Applying these 2,5-disubstituted bdc derivatives in metal−organic framework synthesis together with 4,4′-bipyridine as coligand yields novel honeycomb-like structures. The cylindrical channels of these materials are populated with flexible groups, which act as molecular gates for guest molecules. This allows highly selective sorption of CO2 over N2 and CH4.