SEQUENTIAL ELECTROLYSIS

Polyaniline/poly(N-vinyl carbazole), polypyrrole/poly(N-vinyl carbazole) and polypyrrole/polyaniline films (or reverse order of each pair in the films) were synthesised on platinum foil electrodes by sequential electrolysis. Confocal Raman microprobe spectroscopy was used to characterise both the solution sides and the electrode sides of the films. Two types of film were observed, depending on the conditions. Either the second polymer was incorporated into the initially coated layer or a doublelayer film with a well-defined interface was formed. Electrolysis of pyrrole and aniline monomer mixtures gave films rich in pyrrole when the pyrrole aniline molar ratios were greater than 0.12. However, polymerisation of N-vinyl carbazole and pyrrole monomer mixtures gave only polypyrrole over a wide range of molar ratios. 19 refs. 

Figure 3.58 A-H Spectroelectrochcmical studies of Re(dmbpy)(CO)3CI in CHjCN/0.4 M letra-butylammonium perchlorate. (A) Prior to electrolysis. (B) after applying a potential of - 1,7 V vs. SSCfc. (C- H) Sequential spectra after holding the potential at —1.7 V. From Breikss...

In Chapter 21, Hawley has formulated a series of questions about the mechanism of an electrode reaction. Complete diagnosis of the mechanism includes knowledge of the electrode reaction products and the sequential steps (E and/ or C) by which they are formed. If a chemical reaction follows rapidly upon an electron transfer, the new (secondary) product may be produced close to the electrode, and may be subject to further electrochemistry. If the secondary products are formed slowly, after the primary electrolysis product has diffused away from the electrode, their formation will ordinarily not influence the electrode mechanism, except in bulk electrolysis. We limit our treatment to reactions occurring on the CV time scale, approximately 20 s to 10 ms for routine technology. Ultramicroelectrode technology (Chap. 12) extends the short-time limit to below 1 ps. 

Electrolysis of diethyl phosphite in MeCN containing tetraethylammonium salts in the presence of chloroacetonitrile and aldehyde gives the corresponding a,P-unsaturated nitriles in satisfactory yields as a mixture of (E)- and (Z)-isomers, indicating that the cyanomethylphosphonate carbanion is generated then reacted during sequential Michaelis-Becker and Homer-Wadsworth-Emmons reactions. ... 

Primary structure (covalent bond lengths and bond angles) is determined by microstructure of the amino acid repeating units along the chain. Numerous procedures, including sequential degradation, gel electrolysis, dye binding, and immunoassays have been used to determine sequences. 

For a sequential reaction without any branching pathways (such as decomposition of a reactive intermediate), one would expect [35] to see isosbestic points in the thin-layer electrolysis, as in Fig. 2. It is an excellent idea to carry out several oxidation-reduction cycles to test the stability of the spectral responses, in other words, to see if the starting material is always fully regenerated. If not, the kinetics of the follow-up chemical reactions could be explored as described below. 

Fig. 1 Scheme of the sequential degradation of chlorinated ethenes by anaerobic and aerobic metabolism of microorganisms. Biostimnlatirat is achieved by providing electron drator and acceptor by electrolysis of groundwater. At the cathode (—) hydrogtat as an electron drator and at the anode (+) oxygen as an electron acceptra ate produced... 

In the first step, a highly reactive and unstable organic cation Al" " is generated from its precursor A1 by low-temperature flow electrolysis (the cation flow method). In the flow system, A1+ is reacted with nucleophile B1 to obtain product Al-Bl. Then, by flow switching Al is reacted with nucleophile B2 to produce A1-B2. In the third step, A1+ is reacted with nucleophile B3 to produce A1-B3. Then, the precursor of a cation is switched to A2, and A2, which is generated by flow electrolysis of A2, is reacted with nucleophiles Bl, B2, and B3 sequentially to give A2-B1, A2-B2, and A2-B3, respectively. Then, the precursor of the cation is... 

Yan, D., Yang, X.W., Yuan, W.Q., 2015. Electricity and H2 generation from hemicellulose by sequential fermentation and microbial fuel/electrolysis cell. Journal of Power Sources 289, 26-33. 

Water electrolysis is a method to generate hydrogen. The water electrolysis process can be treated as a superposition of concurrent or sequential electrochemical reaction occurring in the vicinity of electrodes (half reactions) whose overall effect is to split water molecule under the influence of a direct electric current and separate gaseous products (hydrogen and oxygen) [80]. 

In a certain country with an emerging economy, a governmental decision has been made to establish a polymer industry based on native resources. No oil refineries or coal tar operations exist. Cotton (pure cellulose) and sugar are the major raw materials. In addition, electrolytic processes can be used, since hydroelectric power abounds. Your first step is to set up plants to produce from sugar, sequentially ethyl alcohol, acetic add, and butadiene. Erom electrolysis you now have NaOH, CI2, HCN, and HCl. Sulfuric and nitric acids are also produced locally. 

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