[SCAN] Macrobicyclic architectures for recognition of anions in aqueous solution

SCAN

Title: Macrobicyclic architectures for recognition of anions in aqueous solution

Speaker: Rita Delgado

Affiliation: Coordination and Supramolecular Chemistry Lab, ITQB NOVA

Abstract:

Polyamine macrobicyclic compounds (or cryptands) are very versatile architectures, as their protonated forms can directly interact with anions, their neutral forms can coordinate metal ions, and both ammonium groups and metal centres combined can cooperatively bind anions.

Recognition of anions in water remains a key challenge in supramolecular chemistry, but is essential for applications in biology, medicine, and environment. In the chemistry of life processes, anion binding plays a central role. For instance, the recognition, signaling and transport of anions is crucial in the metabolism and in cell function regulation. Additionally, anions can also have a negative impact on the environment.

In our work we took advantage of the ease modification of the macrobicyclic architecture and by small structural modifications we tried to rigidify their structure in order to increase the preorganization. A family of almost unexplored polyamine cryptands were thoroughly studied as anion receptors, in aqueous solution and in the solid state. It was not only possible to achieve selectivity between inorganic substrates of similar size and shape but also build new compounds appropriate for the binding of more complicated substrates such as the dicarboxylates and amino acids. Several examples will be presented.