Three-dimensional Fe(II)-based metallo-supramolecular polymers with electrochromic properties of quick switching, large contrast, and high coloration efficiency

Printed Multicolor High-Contrast Electrochromic Devices

In this study, electrochemical responses of inkjet-printed multicolored electrochromic devices (ECD) were studied to evaluate the feasibility of presenting multiple colors in one ECD. Metallo-supramolecular polymers (MEPE) solutions with two primary colors were inkjet-printed on flexible electrodes. By digitally controlling print dosages of each species, the colors of the printed EC thin film patterns can be adjusted directly without premixing or synthesizing new materials. The printed EC thin films were then laminated with a solid transparent thin film electrolyte and a transparent conductive thin film to form an ECD. After applying a dc voltage, the printed ECDs exhibited great contrast with a transmittance change (ΔT) of 40.1% and a high coloration efficiency of 445 cm(2) C(-1) within a short darkening time of 2 s. The flexible ECDs also showed the same darkening time of 2 s and still had a high ΔT of 30.1% under bending condition. This study demonstrated the feasibility to fabricate display devices with different color setups by an all-solution process and can be further extended to other types of displays.

Cross-Linkable Fluorene-Diphenylamine Derivatives for Electrochromic Applications

Multicolor electrochromic systems based on heat cross-linkable arylamine-substituted fluorene derivatives, FD and FDOMe, are reported. These derivatives with pendant vinyl groups have been synthesized by the Buchwald-Hartwig amination reaction and were well-characterized using various analytical and spectroscopic techniques such as NMR, ESI-MS, and single-crystal X-ray diffraction analysis. FD and FDOMe exhibited thermally activated cross-linking above their melting temperatures, which was confirmed through absorption, differential scanning calorimetry (DSC), FT-IR, and wide-angle X-ray diffraction (WAXD) techniques. Cross-linked FD films (FD-X) on ITO showed two reversible redox peaks at 0.74 and 0.91 V (versus Ag/AgCl) that correspond to the formation of radical cations and dications, respectively. The corresponding redox peaks were observed at 0.6 and 0.8 V for cross-linked FDOMe films (FDOMe-X). Spectroelectrochemical studies of the electrochromic films on ITO revealed multicolor electrochromism of FD-X (colorless-yellow-dark cyan) and FDOMe-X (colorless-brick red-blue) with a color contrast of ∼44% at 485 nm for FD-X and ∼63% at 500 nm for FDOMe-X and good switching stability between the neutral and oxidized states (>300 cycles) with low switching voltages (<0.9 V for the first oxidation and <1.3 V for the second oxidation). Furthermore, fabrication of electrochromic devices using FD-X and FDOMe-X on FTO substrate with PMMA-based solid electrolyte was demonstrated, where the devices exhibited reasonably low switching time between the redox states (<30 s) with good optical contrast.

Synthesis of main-chain metal carbonyl organometallic macromolecules (MCMCOMs)

Synthesis of main-chain metal carbonyl organometallic macromolecules (MCMCOMs) is difficult, mainly due to the instability of metal carbonyl complexes. Despite its challenge a number of MCMCOMs has been prepared by strategically using organometallic, organic, and polymer synthetic chemistry. Main contributions to this research field were reported by the groups of Tyler, Pannell, and Wang and are briefly summarized in this article.

Effect of a three-dimensional hyperbranched structure on the ionic conduction of metallo-supramolecular polymers

3D metallo-supramolecular polymers exhibited 10–100 times higher ionic conductivity than their 1D equivalents due to the improved ion conduction pathway.

Highly emissive, solution-processable and dynamic Eu(iii)-containing coordination polymers

Preparation of new soluble dynamic coordination networks based on Eu(iii) and a new, rigid ditopic pybox-related ligand.