The NMR spectra of salts formed from calix[4]arene and aliphatic amines in CD3CN are in agreement with a exo-calix position of the ammonium cation. The chemical shifts (d) of aromatic and methylenic hydrogens of calix[4]arene were almost the same for the amines utilized. The coalescence temperatures (t c) were obtained and fall in the range between 32 and 38 ºC, and is higher for more basic amines, and was not observed dependence with the shape of the amine.
calixarenes; molecular complexes; ammonium cations
