Phosphorylated Cavitands: Encapsulation of Hard Cationic Guests

The cone-shaped cavity of the calixresorcinolarene based cavitands opened the route to promising new receptors. Recent studies showed that it was possible to introduce phosphorus donor groups at the upper rim of these molecules. According to their structure the inward (i) and outward (o) orientations of the phosphorus substituents define the six stereoisomers iiii, iiio, iioo, ioio, iooo, oooo.