An NMR Study on Complexation of p-tert-Butylcalix[6]arene Ester Derivatives with Ethylammonium Picrate

Abstract
Complexation of p-tert-butylcalix[6]arene ester derivatives with ethylammonium ion was investigated via measurement of their proton relaxation times and chemical shifts in CDCl3. The results suggest that the endo-type complexes are formed and the overall rotation of these complexes is more rapid than that of the corresponding free hosts.