Receptors for tetrahedral oxyanions

This review covers the field of anion recognition from the perspective of tetrahedral oxyanion recognition. The bulk of the attention is devoted to metal-free systems that are able to effect the recognition, binding or transport of phosphate and sulfate. Particular emphasis is devoted to design criteria that allow for discrimination and selectivity. In this context, a variety of recognition motifs are discussed and, within each receptor class, general paradigms that allow for the construction of receptor systems with high affinity and specificity are noted.