O-17 NMR spectra at natural isotopic abundance of two calix[n]arenes,
(n = 4, 6) and model phenols have been obtained in three different sol
vents. The difference in the hydrogen bond strength bem een calix[4]ar
ene and calix[6]arene is manifested in the O-17 NMR spectra. Copyright
(C) 1996 Elsevier Science Ltd