Molecular assembly of distal p-H-calix[4]dihydroquinone units

The solid-state self-assembly properties of distal dimethoxy-p-H-calix[4]dihydroquinone, 3, are described. Three different crystalline forms were obtained under different crystallization conditions. The cone conformation is maintained in all three crystalline forms, being favored by lower rim hydrogen bond formation. The first crystal, 3A, is constituted by mutual-inclusion calixarene trimers connected to each other by water molecules. The second and third ones (3B and 3C) are formed by alternate layers of crystallographically independent calixarene molecules