The inclusion of tetramethylammonium and ditopic trimethylammonium cations by the water-soluble pentasulfonatocalixarene 1 has been studied at neutral pH by 1H NMR and compared with the homologous tetrasulfonatocalixarene 2. Unlike host 2, host 1 selectively binds the ditopic trimethylammonium ions by three different non-covalent interactions. Remarkably the flexible host 1 exhibits both more efficiency and selectivity in the complexation of ditopic methylammonium ions with respect to similar more preorganised calixarene receptors.
|Titolo:||Water-soluble pentasulfonatocalixarene: selective recognition of ditopic trimethylammonium cations by a triple non-covalent interaction|
|Data di pubblicazione:||2004|
|Appare nelle tipologie:||1.1 Articolo in rivista|