Counterion effect in SDS–calix[4]resorcinarene micelles

Here we report the clouding phenomenon, conductivity, 1H NMR spectroscopy and dynamic light scattering data of mixed sodium dodecylsulfate–calix[4]resorcinarene micellar solutions in combination with tetrabutyl-, tetraethyl-, tetramethylammonium bromides and choline chloride. The NMR data reveal tight (the binding constant is about 104) guest–host binding of calix[4]resorcinarene in alkaline conditions with tetraethyl-, tetramethylammonium and choline cations. This binding occurs at rather small concentrations of the external quaternary salts (0–0.0005 M) and leads to dramatic increase of the cloud point temperature. The obtained data are discussed in the correlation with the micellar size changes, caused by the ion exchange due to the variation of quaternary salt concentrations.

Peculiarities of the counterion effect in the SDS-calix[4]resorcinarene micelles is caused by the host–guest binding of tetrabuthyl-, tetramethyl-, tetraethylammonium and choline cations with calix[4]resorcinarene.Figure optionsDownload as PowerPoint slide