Ruthenium Acetate Cluster Amphiphiles and Their Langmuir-Blodgett Films for Electrochromic Switching Devices

We synthesized a long-chain phenylazopyridine ligand and used it to obtain three new amphiphilic trinuclear ruthenium acetate clusters. The amphiphilicity and anisometric form of the long-chain ligand allowed the complexes to self-assemble at the liquid-air interface and enabled their deposition by the Langmuir-Blodgett technique. We obtained the linear complex [Ru3O(C2H3O2)(6)(py)(2)L](+) [L = 4-(4-dodecyloxyphenylazo)pyridine, py = pyridine], which was more stable than the triangular [Ru3O(C2H3O2)(6)L-3](+) and more suitable for application in electrochromic switching devices, as attested by its fast switching and optical changes in the near-IR region. Indeed, our electrochromic device remained stable for hundreds of switching cycles.