A new calix[4]arene based nucleobase for cation recognition

A novel calix[4]arene linked nucleobase molecular receptor bearing two adenine moieties has been synthesized and characterized by UV, IR, NMR and ESI–MS analyses. The synthesized receptor can recognize biologically important Zn2+ and Mn2+ ions through 1:1 binding stoichiometry. The evaluation of binding constants suggests that adenine alone, in an appropriate supramolecular network, can exhibit efficient binding for Zn2+ ions without the presence of any phosphate or sugar unit.