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

A great deal of attention has been directed toward the use of coordination polymers in the design and syntheses of new porous materials. These coordination polymers with open frameworks are widely regarded as attractive materials for applications in catalysis, separation, gas adsorption and molecular recognition. Compared with conventional porous materials such as zeolites or activated carbons, these coordination polymers have the higher potential because of designable framework, high microporosity and flexible framework based on a variety of coordination geometries of metal centers and multifunctionality of bridging organic parts.

In this paper, the gas adsorption properties of two-dimensional metal coordination polymer complexes synthesized by the reaction between copper salts and dicarboxylic acids, and three-dimensional metal complexes synthesized from the two-dimensional polymers and pillar ligands were characterized. The characterization by gas adsorption indicated that these coordination polymers have uniform micropores, high porosities and gas adsorption capacities. These properties depend on the kind of dicarboxylate and by changing it, the porosity and the pore size of polymer can be controlled. The measurements of methane adsorption isotherms revealed that all coordination polymers have methane adsorption capacities and especially three-dimensional polymers synthesized from copper styrene dicarboxylate and copper 4,4-biphenyl dicarboxylate, which have a ideal pore size and distribution for methane adsorption, have higher methane adsorption capacities than that of the theoretical maximum for activated carbon.