Anion Effects to Electrochromic Properties of Ru-based Metallo-supramolecular Polymers

Abstract

Keywords: metallo-supramolecular polymer, electrochromism, anion effect IntroductionElectrochromic (EC) materials, which change the color by electrochemical redox, have attracted much attention due to the wide applications including electronic paper and smart windows.[1-3] As a new type of EC materials, we have investigated metallo-supramolecular polymers, which are synthesized by the 1:1 complexation of metal ions (Fe, Cu, Ru et al.) and ditopic ligands such as bis(terpyridine)s and bis(phenanthroline)s. [4][5][6][7][8][9][10][11] The polymers have a specific color based on the metal-to-ligand charge transfer (MLCT) absorption. We have revealed that the appearance/disappearance of the MLCT absorption can be reversibly controlled by the electrochemical redox of the metal ions in the polymer. The metallo-supramolecular polymers, which include many metal ions, are a cationic polymer and surrounded by the equivalent amount of counter anions to neutralize the positive charges. Therefore, it is anticipated that the counter anions influence to the EC properties of the polymers. Actually, Tieke et al. reported that introduction of electroactive anions to an organic polymer with Zn complex moieties changes the EC properties of the polymer.[12] Here we report the anion effects to the EC properties of metallo-supramolecular polymers for the first time.

Synthesis and characterization of metallo-supramolecular polymers from thiophene-based unimers bearing pybox ligands

“…The metal-to-ligand charge transfer transition (MLCT) at 580 nm was observed in the case of the iron salt. 44,45 Isosbestic points are present in both titrations with the mentioned ICs, indicating the presence of a coordinated (ligand-IC-ligand) symmetric form, referred to in the literature as a "buttery dimer", 46 and free ligand in solution. The equilibrium character of the mixture and an approximate character of the described model must always be kept in mind.…”

Solvent Effect on Electrochemical Properties of a Co(II)‐Based Metallo‐Supramolecular Polymer Film

“…According to our past study, anion is considered as the major ion species involving in the redox reaction of cationic metallo‐supramolecular polymer. The electrochemical reaction of polyCo can thus be generally written as follows: …”

Electrochromic Os(II)‐Based Metallo‐Supramolecular Polymers

“…Over the past 40 years, EC materials have received much attention for different applications, including colorful displays . Metallo‐supramolecular polymers are attracting considerable attention as EC materials during the last few years . Therefore, our aim was also to explore how the advent features of Os affect the electro‐optical properties, specifically the electrochromism of polyOss that have not been studied earlier.…”