n‐Heptylviologen Radical Cation Films on Transparent Oxide Electrodes

Abstract

The cosmetic and kinetic properties of n‐heptylviologen dihydrogenphosphate radical cation films deposited on transparent oxide electrodes, in particular tin oxide, are dependent upon the initial condition of the oxide‐electrode surface. The implication is a strong interaction of the electrode surface with the first layer(s) of radical cation film deposited.

The Influence of Supporting Electrolyte on Kinetics of Electroreduction Process of Poly(methylviologen), Poly(methylviologen)‐Nafion Complex, and Poly(methylviologen)‐Poly(p‐styrenesulfonate) Complex Coated on Electrodes

“…Balzer recently described advances in scientific understanding of reaction mechanism in the field of electroorganic chemistry (11). Swann and Alkire have indexed several thousand organic compounds which may be synthesized by electrolysis (12). Beck et al discussed evaluation of several electro-organic process candidates (13).…”

“…The "poly(viologen)"-coated electrodes prepared by the various types of immobilization of polymeric viologen materials on the surfaces of conductors and semiconductors have been getting considerable interest as electrontransfer mediators or catalysts (1)(2)(3)(4), as promising electrochromic materials (5), as a potential means of solar energy conversion via the photoelectrochemical reduction of viologen itself (6,7,(9)(10)(11), and as electrode materials for electrochemical deionization (8). The immobilization of polymeric viologen materials on electrodes can be achieved by the formation of insoluble films of the reduced viologen on electrodes (12)(13)(14)(15), the formation of the intermolecular polymer complexes (e.g., Nafion| xylylviologen) (PXV) and poly(p-styrenesulfonate) (PXV-PSS) (1,2,16), the incorporation of monomeric methylviologen into anionic polyelectrolytes (such as Nation and PSS) coated on electrode surfaces (1,2,16,17), the physical adsorption of viologen polymer itself (3,4,11,16), the chemical bonding of polymeric films of organosilane derivatives by metal -O-Si-linkages to electrode surfaces (9,10,18), and the formation of polymeric viologens prepared by electropolymerization of monomeric viologen derivatives possessing vinyl groups (e.g., Vinyldiquat | (19). From the previous data (3,4,16) concerning the "homogeneous" charge transport within the poly(viologen) coatings on electrodes in these various cases, it is obvious that the apparent diffusion coefficients (Dapp) characterizing the charge transport, actually described as a diffusion process, are functions of the polymer, solvent, electrolyte, concentration of viologen site in coatings, the conditions of coating preparation, temperature, etc.…”

Combined Spectroscopic Ellipsometry and Voltammetry of Tetradecylmethyl Viologen Films on Gold

“…Our electrode interfaces are characterized in situ using spectroscopic ellipsometry in combination with traditional electrochemical methods . Previous investigations focused on the study of viologen optical properties using thin layer transmission cells with transparent electrodes ,, or UV−vis reflectance. ,, While the measurements provided valuable data on the prevailing viologen species close to the electrode surface, these techniques cannot distinguish between optical absorption by the surface film and absorption by the adjacent solution boundary layer. We employ spectroscopic ellipsometry, which has enhanced sensitivity to the optical properties and thickness of the surface films.…”

Accelerating the discovery of materials for clean energy in the era of smart automation

“…Electrochromic materials have a long history, and various material classes, such as viologens (both in solution or as polymer films) [137][138][139][140] and conjugated conducting polymers [141][142][143] , have been extensively studied. For a more comprehensive overview, we refer the interested reader to REFs 144,145 and the references therein.…”