Ru(II) polypyridine complexes: photophysics, photochemistry, eletrochemistry, and chemiluminescence

Electrochromic tungsten oxide films: Review of progress 1993–1998

http://nathan.instras.com/MyDocsDB/doc-617.pdf

Electrochromic organic and polymeric materials for display applications

A review of electrochromic (EC) polymers and their applications in absorption/transmission, reflective, and patterned electrochromic devices (ECDs) is presented. Fundamental properties of EC materials such as optical contrast, coloration efficiency, switching speed, and stability are described along with the commonly used characterization methods. The origin of electrochromism in conjugated polymers is explained in terms of the electronic structure changes in the backbone upon doping/dedoping. The ability to tailor the EC properties of conjugated polymers and tune their color states via modification of the polymer structure is demonstrated. Multicolor electrochromic materials can be obtained by substitution of a parent polymer and controlled polymerization of comonomers and with blends and laminates of homopolymers. Absorption/transmission-type ECDs from complementarily colored polymers and reflective-type ECDs on metalized substrates are illustrated with several examples from the literature. Finally, sev...

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Multicolored Electrochromism in Polymers: Structures and Devices

The present invention relates to electrochromic polymeric solid films, manufacturing electrochromic devices using such solid films and processes for making such solid films and devices. The electrochromic polymeric solid films of the present invention exhibit beneficial properties and characteristics, especially when compared to known electrochromic media. The electrochromic polymeric solid films are transformed in situ from a low viscosity electrochromic monomer composition by exposure to electromagnetic radiation, and in so doing minimum shrinkage occurs. The electrochromic polymeric solid films of the present invention also perform well under prolonged coloration, outdoor weathering and all-climate exposure, and provide an inherent safety aspect not known to electrochromic media heretofore.

Electrochromic polymeric solid films, manufacturing electrochromic devices using such solid films, and processes for making such solid films and devices

An electrochromic device (100) with electrode surface confined complementary polymer electrochromic materials. The electrochromic material (20), able to change from a substantially colorless to a colored state upon oxidation, is surface confined onto one of the electrodes (25), which is on a glass substrate (30). For transmissive electrochromic devices, (25) is preferably transparent electrode such as ITO. For reflective electrochromic devices, (25) is preferably a Pt coating. The electrochromic material (20), and the electrochromic material (35) able to change from a substantially colorless state to a colored state upon reduction are physically separate from one another but ionically connected by means of an electrolyte. The two glass substrates (30) are placed together, with gaskets (45) keeping the respective glass substrates (30), with their respective electrochromic materials (20) and (35) apart.

Complementary surface confined polymer electrochromic materials, systems, and methods of fabrication therefor

Vibrational, electronic, and structural properties of cobalt, copper, and zinc octaethylporphyrin .pi. cation radicals

Preparation et caracterisation d'un nouveau materiau composite constitue d'une electrode d'or, de platine ou d'oxyde d'etain qui est modifiee par un film de polyaniline et de bleu de Prusse

Polyaniline‐Prussian Blue Novel Composite Material for Electrochromic Applications

Time-resolved resonance Raman (TR3) spectroscopy has been utilized to demonstrate that electronic excitation in the lowest metal-to-ligand charge-transfer (MLCT) excited states of many transition metal trisor bis(diimine) complexes in solution is localized on just one of the ligands.1-6 Therefore the MLCT state of Ru(bpy)3 (bpy ) 2,2′-bipyridine) is often represented as (bpy)2Ru(III)(bpy). As evidence for this localization, the correspondence of the TR3 spectrum of the excited complex to the ground state resonance Raman (rR) spectrum of 2,2′bipyridine radical anion (bpy•-) in solution is particularly persuasive.1b,6 This picture is supported by several other types of spectroscopic studies, most notably photoselection7 and timeresolved absorption polarization,8 and further evidence is available from the normal coordinate analysis of the ground and MLCT excited states of Ru(bpy)3 and of the bpy radical anion.9 Despite the strong similarities between the spectroscopic10 and electrochemical10,11 characteristics of the 1,10-phenanthroline (phen) complexes with Ru and those of their bpy analogs, definitive TR3 spectra of the MLCT states of Ru(phen)3 and other trisand bis(phen) complexes have been difficult to obtain.12 The TR3 spectrum of Ru(bpy)3 is markedly different from ground state scattering and is easily obtained by irradiating ∼10-4 M aqueous solutions with 354.7 nm pulses having a fluence of ∼6 × 106 W/cm2 (∼2 mJ, 10 ns/pulse, beam waist of ∼1 mm).1 Hopkins and co-workers recently reported13 that only the ground state spectrum of Ru(phen)3 can be observed under comparably low fluence conditions, in agreement with our own work.14 However they could observe a TR3 spectrum of excited Ru(phen)3 under the uncommonly large light fluence of 2 × 109 W/cm2 (100 μJ/pulse, 30 ps/pulse, beam waist 250 μm, 354.7 nm); it appears to be rather similar to the ground state spectrum.14 Kumar et al. earlier reported a very weak TR3 spectrum of Ru(phen)3 obtained with very large fluences (2 × 108 W/cm2 of highly focused 15 mJ, 10 ns pulses, assuming 0.5 mm beam waist); this spectrum also was similar to the ground state spectrum.15 For some time there has existed an obvious question: why should complexes with two such similar ligands produce TR3 spectra of such different intensities and appearance? In the absence of any spectroscopic measurements on phenanthroline radical anion, it was not possible to dismiss the possibility, however unlikely, that its rR spectrum coincidentally may be nearly identical to that of ground state phen. We report in this paper the electronic and resonance Raman spectra of phen•in THF solutions. Neither the electronic absorption spectrum of phen•nor the positions of its Raman bands match those of the ground state or of the lowest MLCT excited electronic state of Ru(phen)3. Implications of these results on the electron localization in the MLCT state of the complex will be discussed in a future publication.

Resonance Raman Spectrum of the Phenanthroline Anion: Implications on Electron Delocalization in the MLCT Excited State of Ru(phen)(3)(2+).

New Complementary Electrochromic System Based on Polypyrrole-prussian Blue Composite, a Benzylviologen Polymer, and Poly(vinylpyrrolidone)/potassium Sulfate Aqueous Electrolyte

Young C. Chung

Papers

Complementary surface confined polymer electrochromic materials, systems, and methods of fabrication therefor

Vibrational, electronic, and structural properties of cobalt, copper, and zinc octaethylporphyrin .pi. cation radicals

Polyaniline‐Prussian Blue Novel Composite Material for Electrochromic Applications

Resonance Raman Spectrum of the Phenanthroline Anion: Implications on Electron Delocalization in the MLCT Excited State of Ru(phen)(3)(2+).

New Complementary Electrochromic System Based on Polypyrrole-prussian Blue Composite, a Benzylviologen Polymer, and Poly(vinylpyrrolidone)/potassium Sulfate Aqueous Electrolyte