Chromic and fluorescence response system based on the dihydrophenanthroline-bipyridine skeleton: dynamic redox behavior and metal binding properties

The spiro-acridan/acridinium-based dynamic redox pair (1/22+) transduces the electrochemical input into UV–vis and fluorescence spectra, whereas the 2,2′-bipyridine units in 1 works as a bidentate ligand for metal ions. X-ray structural analyses of this redox pair and the corresponding Zn-complexes [1-ZnI2/22+-Zn2+(OTf−)4] demonstrate drastic structural changes upon electron-transfer, thus metal binding properties are modified by redox reactions.