Transport properties of solid state crown ether channel systems

Single crystals of [(H2O)⊂(DB18C6)(μ2-H2O)2/2][(H3O)⊂(DB18C6)(μ2-H2O)2/2]I31 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 [(Na)⊂(DB18C6)(μ2-H2O)2/2][(Na)⊂(DB18C6)(μ2-OH)2/2]I32, with slightly but significantly different cell parameters. Both compounds were tested for transport properties through these channels by using two different devices, one for water transport, the other for NaOH transport, through single crystals of 1 and 2, respectively. The results indicate that transport can take place via a hopping mechanism.

Graphical abstractMeasuring the water and ion transport through single crystals containing one-dimensional channel systems formed with dibenzo-18-crown-6 seems to confirm a hopping process in the solid state.Figure optionsDownload full-size imageDownload as PowerPoint slide