Selective Separation of Water, Methanol, and Ethanol by a Porous Coordination Polymer Built with a Flexible Tetrahedral Ligand

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 water from
bioethanol, which is a mixture of water, methanol, and ethanol.