Transport properties of solid state crown ether channel systems

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 [(Na)⊂(DB18C6)(μ₂-H₂O)2/2][(Na)⊂(DB18C6)(μ₂-OH)2/2]I₃ 2, 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

From simple rings to one-dimensional channels with calix[8]arenes, water clusters, and alkali metal ions

The macrocycle 4-tert-butylcalix[8]arene (L) was reacted with alkali metal carbonates (Li₂CO₃, Na₂CO₃, K₂CO₃, Rb₂CO₃, and Cs₂CO₃) at the interface of a biphasic THF/water system. Needle-like crystals with a general formula [Ax(4-tert-butylcalix[8]arene-xH)(THF)y(H₂O)z] (with A=Li, Na, K, Rb, Cs, x=1, 2, y=4, 5, 8, and z=6, 7) were thereby obtained. The solid state structures were investigated by X-ray diffraction of single crystals and by TGA measurements. They do not appear to be maintained in solution