A Selective Fluorescent Sensing of H2PO4- by the Formation of Anion Induced Self-Assembly Supramolecular Polymer

The utilization of anions to induce the formation of self-assembled supramolecular polymers in solution is an undeveloped area of host–guest chemistry. We report in this manuscript a comparative study of two tripodal anion receptors by hydrogen or halogen bonding interactions to form self-assembly supramolecular structures induced by the presence of anions. DOSY NMR and DLS experiments provided evidence for the formation of supramolecular structures in solution in both halogen and hydrogen bond donor with H2PO4- anion. The nucleation and elongation constants obtained by the thermodynamic model indicate that the polymers grow following an isodesmic mechanism. Emission studies demonstrate that only the formation of the supramolecular polymer between halogen bond donor receptor and H2PO4- anions results in the apparition of the excimer emission band