Formation of fluorescent metal complexes and nanofibers self-assembled from Cu(II) and Ag(I) ions with bis-thia-bis-quinoline ligands

In this study, we have examined the formation of metal complexes from newly synthesized bis-thia-bis-quinoline ligand (1) and their self-assembly in water. When various metal ions were mixed with 1 in water, Cu(II) and Ag(I) ions induced significant spectral changes, indicating the formation of metal complexes. Interestingly, fluorescence intensity of 1 was remarkably enhanced upon the addition of Cu(II) ions. In contrast, Ag(I) ions caused quenching of the ligand fluorescence. In electron microscopy, fibrous nanostructures were observed for Ag(I)/1 complex. Thus, the ligand 1 acts as a multi-task transducer which gives varied structural and spectral features depending on the metal ions. The present approach would lead to the development of an information transformation system for aqueous metal ions.