Anion binding can be achieved by neutral receptors through hydrogen bonding or by positively charged ligands through electrostatic interaction.1 Some examples of both types of receptors based on calixarene structures have already been published.2
We report here the synthesis of two new positively charged calixarene derivatives substituted at the lower rim by two and four triphenylphosphonium butyl groups, respectively. The first results of UV and NMR experiments concerning their ability to complex tetrahedral oxyanions (ClO4 -) and iodide will also be presented.
1. P. D. Beer and P. A. Gale, Angew. Chem. Int. Ed. Engl. 2001, 40, 486.
2. S. E. Matthews, P. D. Beer, in "Calixarenes 2001", Z. Asfari, V. Bohmer, J. Harrowfield, J. Vicens Eds., Kluwer Academic Publishers, Dordrecht, 2001, p. 421-439.