Selective Adsorption of Water, Methanol, and Ethanol by Naphthalene Diimide-Based Coordination Polymers with Constructed Open Cu²⁺ Metal Sites and Separation of Ethanol/Acetonitrile

The selective separation of ethanol/acetonitrile by porous materials has rarely been observed owing to their similar physicochemical properties. In this work, we report a new coordination network, [Cu2(4-pmntd)2(opd)2]­(4-pmntd = N,N′-bis­(4-pyridymethy)­naphthalene diimide, opd = disodium 1,2-benzenedicarboxylate), which exhibits selective separation of ethanol over acetonitrile. The weak coordination bonds formed by unsaturated Cu2+ sites and hydroxyl groups are the key to such performance