T. Lippmann et al., HOST-GUEST COMPLEXES BETWEEN CALIX[4]ARENES DERIVED FROM RESORCINOL AND ALKYLAMMONIUM IONS, Angewandte Chemie, International Edition in English, 32(8), 1993, pp. 1195-1197
Electrospray mass spectrometry was used to detect stable host-guest co
mplexes composed of cup-shaped calix[4]arenes 1 derived from resorcino
l and straight-chain trialkylammonium ions in the gas phase. The cryst
al structure of 1 . (Et3HN)2SO4 consists of alternating hydrophobic an
d hydrophilic layers.