Di(alkyl- and 4,4,4-trifluorobutylimidazolium) quaternary halides of p-tert-butylcalix[4]arene, 5a-8a and 11a, were prepared and characterized. Metathetical reactions of these compounds with LiN(SO2CF3)(2) and KPF6 in methanol and water gave the corresponding new quaternary salts 5b-8b and 11b and 5c-8c and 11c, respectively, with high thermal stabilities. Compounds 5a-d, 6b, and 11a-c exhibit melting points <100 degreesC. On the basis of H-1 NMR and 13 C NMR spectral measurements, all of the new quaternary calix[4]arene salts were found to exist in a cone conformation. H-1 NMR titration experiments and electrospray MS spectra support the encapsulation of K+ in the ionophoric cavity of 11c.