日本ゼオライト学会　刊行物 Publication of Japan Zeolite Association

Metal-Organic Framework (MOF) with structurally well-defined nanoscale cavities are of great　interest because of their characteristic properties, such as gas storage, separation, and catalysis.　Numerous types of MOF have been synthesized and constructed with judicious choices of metals and　designed bridging ligands affording tailored open channels and cavities. The interesting aspect found in　those open spaces is their framework's flexibilities, where pore shapes and sizes change in response to　penetrating guest molecules with maintaining of the framework in the solid state, which is rarely　observed in other classes of porous materials such as zeolites and activated carbons. In this manuscript,　we will briefly show the history, synthetic strategy, problem, and development about MOF, for the　scientists and engineers who have never dealt with MOF. Especially, unique adsorption isotherms　associated with the framework's flexibilities are shown focusing on our recent results.