Self-assembled flexible metallo-supramolecular film based on Fe(II) ion and triphenylamine-subsituted alkyl terpyridine towards electrochromic application

Abstract A new metallo-supramolecular film was prepared by a liquid–liquid interface self-assembly method based on the metal ion Fe(II) in water solution and a star-shaped ligand of triphenylamine-substituted alkyl terpyridine in organic solvents. The film obtained exhibited excellent flexibility due to the presence of flexible alkyl arms, and could tightly adhere to the surface of ITO glass with very smooth surface morphology via SEM characterization. Spectroelectrochemical experiments demonstrated that the film displayed the electrochromism with purplish color in the neutralized state at 0 V vs Ag/AgCl turning to yellow-green color in the oxidized state at 1.2 V vs Ag/AgCl. This work further indicates that the liquid–liquid interfaciad self-assembly method is a promising strategy to prepare the metallo-supramolecular film towards electrochromic applications.