Viologen chemically modified

Photochemical hydrogen production via oxidative quenching of [Ru(bipy)3 2+ by chemically modified viologens... 

In this section the effect of chemically modified viologens on the model system is described. Their role in the system is identical to that of MV2- in the model system and hence the results of these modifications are collected in Table 8. Some of the findings are discussed below in more detail. 

Hayashi T, Takimura T, Ogoshi H (1995) Photoinduced singlet electron transfer in a complex formed from zinc myoglobin and methyl viologen artificial recognition by a chemically modified porphyrin. J Am Chem Soc 117 11606-11607... 

J. G. Gaudiello, P. K. Gosh, and A. J. Bard, Polymer films on electrodes. 17. The application of simultaneous electrochemical and electron spin resonance techniques for the study of two viologen-based chemically modified electrodes, J. Am. Chem. Soc. 107, 3027-3032 (1985). 

Microelectronic technologies have also been used in nitrite biosensors and electrochemical sensors (Suzuki and Taura, 2001 Adhikari and Majumdar, 2004). Ameida et al. (2013) have also developed a method of electrochemical nitrite measurement by means of a gold working electrode covered with 1,2-diaminobenzene (DAB) integrated in a FIA system. This sensor helps improve selectivity, repeatability, stability, and sensitivity. A Nafion/lead-ruthenate pyrochlore electrode chemically modified for determination of NO2 oxidation and NO reduction based on AC-impedance spectroscopy and FIA has also been tested (Zen et al., 2000). Quan and Shin (2010) also tested an electrochemical nitrite biosensor based on co-immobilization of copper-containing nitrite reductase and viologen-modified chitosan (CHIT-V) on a glassy carbon electrode (GCE). 

Fig. 18b.9. Example cychc voltammograms due to (a) multi-electron transfer redox reaction two-step reduction of methyl viologen MV2++e = MV++e = MV. (b) ferrocene confined as covalently attached surface-modified electroactive species—peaks show no diffusion tail, (c) follow-up chemical reaction A and C are electroactive, C is produced from B through irreversible chemical conversion of B, and (d) electrocatalysis of hydrogen peroxide decomposition by phosphomolybdic acid adsorbed on a graphite electrode.

Figure 6.38 Electron flow diagram of the switching processes that take place for an electrochromic window based on viologen/Ti02 and phenothiazine/Sn02-Sb modified electrodes. Reprinted with permission from D. Cummins, G. Boschloo, M. Ryan, D. Corr, S. N. Rao and D. Fitzmaurice, /. Phys. Chem., B, 104, 11449 (2000). Copyright (2000) American Chemical Society...

As shown in this symposium, interest in chemical modification of electrode surfaces has been extended in many directions, including the study of light-assisted redox reactions, and the use of modified electrodes in electrochromic devices (1,2). Our own studies have centered on the study of metal and metal oxide electrodes modified with very thin films of phthalocyanines (PC) and on the electrochromic reaction of n-heptyl viologen on metal oxide electrodes, and on the effect on these reactions of changing substrate chemical and physical composition (A,5). 

Further studies of the n-heptyl viologen reaction on modified surfaces are reported elsewhere (25). It is clear that the interaction of ion-beams or plasmas with the electrode surface can be a powerful modification tool, complementary to chemical modification procedures for application to either photoelectrochemical or electrochromic reactions. 

Figure 23F-3 Functional groups formed on a metal or carbon surface by oxidation. Often, linking agents such as orgaonsilanes are bonded to the functionalized surface. Reactive components, such as ferrocenes, viologens, and metal bipyridine complexes, are then attached to form the modified surfaces shown in Figure 23F-4. (From A. J. Bard, Integrated Chemical Systems. New York Wiley, 1994. This material is used by permission of John Wiley Sons, Inc.)...

Figure 14.2.3 Cyclic voltammograms of electrodes modified by covalent attachment of monolayers of different types, a) Pt electrode with attached ferrocene, 200 mV/s. [Reprinted with permission from J. R. Lenhard and R. W. Murray, J. Am. Chem. Soc., 100, 7870 (1978). Copyright 1978, American Chemical Society.] (b) Graphite with attached py-Ru(NH3)5, 5 V/s. [Reprinted with permission from C. A. Koval and F. C. Anson, Anal. Chem., 50, 223 (1978). Copyright 1978, American Chemical Society.] (c) Glassy carbon with attached viologen, 100 mV/s. [Reprinted from D. C. S. Tse, T. Kuwana, and G. P. Royer, J. Electroanal. Chem., 98, 345 (1979), with permission from Elsevier Science.]...

Figure 5.17 Cyclic voltammograms of the viologen-substituted polyvinylpyridine modified Au electrode with 25 mM nitrate. 0.1 M phosphate buffer (pH 7.5) in the presence (solid line) and absence (broken line) of NR (A) sweep rate 2 mV s and (B) sweep rate 100 mV s". Reprinted with permission from ref. 103. Copyright 2003 American Chemical Society.

Fig. 36.1 Schematic representation of the construction of CP5-stabilized AuNPs and their supramolecular self-assembly by adding viologen molecules (I and II) (a) 5 min and (c) 24 h after the addition of viologen I (10 mM) into a solution of CP5-modified AuNPs (b) 5 min after the addition of viologen I (75 mM) into the solution of CP5-modified AuNPs (d) 5 min and (e) 24 h after the addition of viologen II (3.8 mM) into a solution of CP5-modified AuNPs (Reprinted with permission from Ref. [27], Copyright 2013 American Chemical Society)...

Chemical structures of viologen side group modified PEDOT (PolyViolEDOT), polyethylene-dioxythiophene (PEDOT), and polymeric viologens (PolyViol). 

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