Anion binding by pyrrole-pyridine-based macrocyclic polyamides

The synthesis, characterisation and anion-binding properties of new pyrrole-pyridine-based macrocyclic polyamides 7a and 7b are presented. Chloride anion templation in the macrocyclisation reaction has been shown to control [1+1] acylation. The anion-binding properties of the receptors have been determined by UV-vis titrations in a DMSO solution and compared with systems with a similar design. The new receptors have been found to display a 10-fold selectivity for hydrogensulphate, dihydrogenphosphate and acetate anions over other anions studied.