Andrew P. Abbott, Cherie S. M. Cheung, Gillian R. Lonergan, Pavel Koovský, Irena G. Stará and Ivo Starý
The redox behaviour of the binaphthyl unit in quaternary ammonium salts with an appended crown ether (3) is dramatically affected by the presence of metal cations and this effect can be used as an analytical tool to detect micromolar concentrations of alkali metal ions.