First example of X-ray diffraction analysis of the crystal structure of cal
ix[4]pyrogallolarene is reported. The compound was prepared by acid-catalyz
ed condensation of pyrogallol with propionaldehyde in a water-alcohol mediu
m, 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, etha
nol and water molecules form a hydrophilic layer between two layers; as a r
esult arises an endless bilayer structure.