Preparation and structure of fully caesium exchanged zeolite A and of the linear (Cs4)3+ cation

Fully dehydrated, fully Cs+-exchanged zeolite A has been prepared by reducing the Na+ ions in dehydrated zeolite 4A with caesium vapour at 623 K, to give Cs12–A·1/2Cs which contains (Cs4)3+, followed by baking the occluded caesium atoms out at 1273 K to give Cs12–A; both structures were determined by single crystal X-ray diffraction methods.