Single crystals of [(H₂O)⊂(DB18C6)(μ₂-H₂O)2/2][(H₃O)⊂(DB18C6)(μ₂-H₂O)2/2]I₃ 1 were shown to possess ideally stacked crown ether molecules which form channels running in one direction through the solid state structure. By immersion of single crystals of 1 into NaOH, ion exchange takes place to yield the compound...