Recognition of 5’-GMP through a supramolecular assembly
Organized assembly of molecules through non-covalent interactions is a powerful tool for generating defined molecular architectures. Although such assemblies have been effectively utilized in host–guest chemistry, metallocyclophanes have rarely been utilized as receptors for nucleotides in aqueous solution. Of all the nucleotides, the recognition of guanosine 5’-monophosphate (5’-GMP) is vital because it acts as an intermediate in the synthesis of nucleic acids and plays important roles in several metabolic processes. An anthracene based ligand was synthesised which forms a novel water-soluble supramolecular metallocyclophane in the presence of CuCl2, as compared to other metal ions. This metallocyclophane, containing a rigid and well defined cavity, uniquely functions as a selective host for 5’-GMP in aqueous solution. Uniquely, this metallocyclophane supramolecular assembly selectively recognizes 5’-GMP as compared to other nucleotides and nucleosides and signals the event through changes in the fluorescence intensity utilizing the synergistic effects of electrostatic, -stacking and coordinative interactions inside the cavity (Chem. Commun. 2009, 6352-6354 – as hot article with cover page).