A novel porous coordination polymer, CuII (mtpm) Cl2 [mtpm= tetrakis (m-pyridyloxy methylene) methane], has been synthesized, and its crystal structure has been determined. Its adsorption isotherms for water, methanol, and ethanol are totally different from each other. It adsorbs water at low humidity and shows gate-open behavior for methanol, but it does not adsorb ethanol. This compound has the capacity to separate both methanol and ...