Calix[8]arene anions: solid state structure of an inclusion compound with a tetrabutylammonium cation

Octakis(dimethylsiloxy)-octa-p-tert-butylcalix[8]arene was prepared from the parent p-tert-butylcalix[8]arene and 1,1,3,3-tetramethyldisilazane. Desilylation of the siloxy-calix[8]arene with tetrabutylammonium fluoride hydrate under different conditions afforded di- and tetraanionic derivatives. Determination of the solid state structure of the dianion revealed the formation of an inclusion compound with one tetrabutylammonium cation inside the macrocyclic cavity.