Elastic layer-structured metal organic frameworks (ELMs)

Elastic layer-structured MOFs (ELMs) have a novel feature of a flexible structure and a reversible expansion/shrinkage behavior and usefulness in applicability to CO 2 separation and CH 4 storage. Elastic layer-structured metal organic frameworks (ELMs) having flexible two-dimensional structure show a gate phenomenon in sorption/desorption of simple gas molecules. The gate phenomenon is accompanied by expansion/shrinkage of the layers. The gas sorption/desorption is not based on a physical adsorption, but on a chemical reaction, which includes high cooperativity. The cooperative reaction could be analyzed thermodynamically. The gate phenomenon showed advantages in separation of CO 2 from mixed gases and in storage of CH 4 owing to easy release of absorbed molecules.