Ion exchange in bimetallic cage organosiloxanes incorporating copper and alkali metal atoms

The globular metallic cage organosiloxanes [RSiO2](12)[Cu4M4] (where R = Me, CH2=CH or Ph and M = Na or K) can be converted to the corresponding alkaline Li derivatives in an ion-exchange reaction with LiCl under mild conditions (in up to 79% yields). The [RSiO2](12)Cu4Li4 compounds have been synthesised and their structures have been studied by X-ray diffraction analysis.