Synthesis and tunable ion-recognition properties of novel macrocyclic triamides

In this work, we report synthesis of rigid macrocyclic triamides and their tunable ion-recognition properties as selective anion and metal receptors. Diphenylacetylene-containing cyclic triamide CTA-1b and three cyclic triamides bearing functional methoxy and pyrimidine moieties were prepared by Lithium Hexamethyldisilazide (LiHMDS)-assisted cyclocondesation. CTA-1b displayed strong binding affinity to Cl^– and I^– anions, while CTA-2b exhibited a good binding affinity to the La³⁺ and Eu³⁺ cations. The selective recognition ability of ions has been tuned by incorporating pyrimidine and methoxy groups into the macrocyclic amides.