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 N-2 and CH4.