Guanidinium-Based Artificial Receptors for Binding Orthophosphate in Aqueous Solution

Receptors based on guanidinium‐ and pyrrole‐containing binding sites were designed and synthesized for selective recognition of orthophosphate in aqueous solution. Various analytical techniques were used to understand solution behavior and anion binding properties of the receptors in methanol and methanol/water mixtures. Binding studies revealed that the structure of pyrrole‐containing binding sites has great influence on selectivity of receptors for orthophosphate. The receptor with bulky substituents in the meso‐position of the dipyrrolylmethane core demonstrated the highest selectivity for orthophosphate over other inorganic anions. Selective recognition of orthophosphate in aqueous solution was achieved by receptors based on guanidinium and pyrrole binding sites. The structure of pyrrole‐containing binding sites has great influence on the selectivity of receptors for orthophosphate. The receptor with bulky substituents in the meso‐position of the dipyrrolylmethane core demonstrated the highest selectivity for orthophosphate