Synthesis and spectroelectrochemical properties of two new dithienylpyrroles bearing anthraquinone units and their polymer films

Colorless to Neutral Color Electrochromic Devices Based on Asymmetric Viologens

Electrochromic materials have extensively been investigated because of their potential fields of application, with a significant growing interest in expanding the provided colorations. However, among all palette of colors, colorless electrochromic devices (ECDs) that provide neutral-grayish colorations with a simple configuration remain a key challenge. The present study reports on the synthesis of asymmetrically 1-alkyl-1'-aryl-substituted viologens and their incorporation in PVA-borax gel polyelectrolytes for ECDs that constitute the simplest device architecture (glass/TCO/EC gel/TCO/glass). We demonstrate herein that these EC gels based on single asymmetric viologens provide more neutral-colored state than their corresponding symmetric viologens (a* and b* ≤ |15|), while maintaining satisfactory colorless bleached state (%T_b > 70% in the whole visible range), transmittance changes (i.e., ∼60%) and cyclability (i.e., ∼15 000 cycles). Additionally, the effect of the solvent on the observed coloration has also been investigated. This easy-to-make neutral-grayish color ECDs may significantly extend the potential of the electrochromic technology, because they adapt better aesthetically to the surrounding environment, as they are easier to implement in different applications.

Smart window application of a new hydrazide type SNS derivative

In this article the smart window application of a new type of thienylpyrrole derivative is presented.

Electrochemical synthesis, optical, electrochemical and electrochromic characterizations of indene and 1,2,5-thiadiazole-based poly(2,5-dithienylpyrrole) derivatives

PBDTA/PProDOT-Et₂ ECD showed high ΔT_max (43.8%) and satisfactory cyclic voltammetry stability, whereas P(BDTA-co-DTP)/PProDOT-Et₂ ECD showed high ΔT_max (44.0%) and coloration efficiency (504.6 cm² C⁻¹).

An experimental study of the electronic absorption and fluorescence spectral properties of new p-substituted-N-phenylpyrroles and their electrosynthesized polymers

Electronic absorption and fluorescence spectral properties of new p-substituted-N-phenylpyrroles (N-PhPys), including HOPhPy, MeOPhPy, ThPhPy, PhDPy, DPhDPy, PyPhThThPhPy, and their available, electrosynthesized polymers were investigated. Electronic absorption spectra, fluorescence excitation and emission spectra, fluorescence quantum yields (ΦF) and lifetimes (τF), and other photophysical parameters of these N-PhPy derivatives and their polymers were measured in DMF, DMSO diluted solutions and/or solid state at room temperature. The electronic absorption spectra of N-PhPy derivatives and their polymers included one to several bands, located in the 270-395 nm region, according to the p-phenyl substituent electron-donating effect and conjugated heteroaromatic system length. The fluorescence excitation spectra were characterized by one broad main peak, with, in most cases, one (or more) poorly resolved shoulder (s), appearing in the 270-405 nm region, and their emission spectra were generally constituted of several bands located in the 330-480 nm region. No significant shift of the absorption, fluorescence excitation and emission spectra wavelengths was found upon going from the monomers to the corresponding polymers. ΦF values were high, varying between 0.11 and 0.63, according to the nature of substituents(s) and to the conjugated system extension. Fluorescence decays were mono-exponential for the monomers and poly-exponential for PyPhThThPhPy and for polymers. τF values were relatively short (0.35-5.17 ns), and markedly decreased with the electron-donor character of the phenyl group p-substituent and the conjugated system extension.

Novel poly(2,5-dithienylpyrrole) (PSNS) derivatives functionalized with azobenzene, coumarin and fluorescein chromophore units: spectroelectrochemical properties and electrochromic device applications

The combination of strong chromophore units and a 2,5-dithienylpyrrole (SNS) monomer backbone resulted in interesting electrochemical and spectroelectrochemical behaviors.

Polypyrrole derivatives for electrochromic applications

This review provides a comprehensive assessment of recent progress in polypyrrole derivatives which are specially designed for electrochromic applications.

A FINE-TURNING COPOLYMER BASED ON TRIPHENYLAMINE AND 3,4-ETHYLENEDIOXYTHIOPHENE VIA ELECTROCHEMICAL POLYMERIZATION

Copolymer based on triphenylamine (TPA) and 3,4-ethylenedioxythiophene (EDOT) is polymerized electrochemically. The structure, morphology and electrochemical properties of the obtained copolymer are investigated by cyclic voltammetry and FT-IR spectroscopy. The results confirm the copolymerization of TPA/EDOT. UV-vis spectra show that the absorption peaks of the copolymer are different from those of Polytriphenylamine. Moreover, photoluminescence spectra of the copolymer exhibit great changes in emission color from pale blue to pale green with the variety of ratio of two monomers. Therefore, the monomer feed ratio plays important roles in the optical property of this copolymer.