Powerful Bipodal Anion Transporters Based on Scaffolds That Contain Different Chalcogens

A new family of bipodal anion transporters based on chalcogen-containing scaffolds has been designed and synthesized. Though structurally related to the well-studied tripodal anionophores, these molecules are simpler with only two anion-binding sites. However, the activities remain high. Anion transport could be facilitated by the new transporter at an exceptionally low loading of transporter/lipid ratio of 1:500000. This impressive efficiency is comparable with the most active one from the tren-based tripodal series. To investigate influences from different scaffolds and substituent groups, lipophilicity, anion-binding property, and transport activity of each molecule were studied. It was found that the bridge atom has a major impact on transport activities mainly as a result of anion-binding differences. The results also suggest that chalcogen can act as a key structural modulator to develop highly effective anion transporters and optimize their activities.