Crystal and Molecular Structure of Calix[4]arene Originating from Pyrogallol

First example of X-ray diffraction analysis of the crystal structure of calix[4]pyrogallolarene is reported. The compound was prepared by acid-catalyzed condensation of pyrogallol with propionaldehyde in a water-alcohol medium, and it gave rise to a system of host-guest type. Calixarene molecules in a cone conformation are packed in molecular layers; therewith each host molecule contains an ethanol molecule in the cavity. Hydroxy groups, ethanol and water molecules form a hydrophilic layer between two layers; as a result arises an endless bilayer structure.