Methanol persulfate oxidation

The most suitable oxidizing agent is potassium ferricyanide, but ferric chloride, hydrogen peroxide ia the presence of ferrous salts, ammonium persulfate, lead dioxide, lead tetraacetate or chromate, or silver and cupric salts may be useful. Water mixed, eg, with methanol, dimethylformamide, or glycol ethers, is employed as reaction medium. 

Dimethyl-4-nitropyridine-N-oxide-dimethyl sulfate adduct (220 g, 0.75 mole) was dissolved in methanol (1.0 Itr) and the solution heated to reflux. A solution of ammonium persulfate (140 gm) in water (200 ml) was added dropwise over 4 hours after which reflux was continued for 4 hours. Methanol was distilled off under reduced pressure and the residue was basified to pH 10 by addition of caustic lye (105 ml). The mixture was extracted with dichloromethane (2 times 400 ml). The dichloromethane layer was dried over sodium sulfate and filtered. The product was used as its solution in dichloromethane for the next reaction. 

A similar approach49 was used to prepare PAn/poly(alkylmethacrylate) composites. Sodium persulfate was used as the oxidant in acidic (HC1) media, and the composite was precipitated by the addition of methanol. Again, hot pressing was found to improve the mechanical properties, and conductivities of 2 S cm-1 were obtained. Although higher conductivities could be obtained with cold pressing, the mechanical properties were inferior. 

Pyrrole is dried with CaH2 for 24 h, followed by distillation under reduced pressure. Ammonium persulfate is used as an oxidant and dodecylbenzene sulfonate as the codopant. 0.15 mol of dodecylbenzene sulfonic acid and 0.3 mol of pyrrole are dissolved in 500 mL of distilled water with vigorous stirring. 0.06 mol of ammonium persulfate in 100 mL of distilled water are slowly added to the above solution whose temperature is maintained at 0 °C. The reaction is carried out for 40 h and terminated by pouring methanol. The resultant PPy powder is filtered and washed sequentially with distilled water, methanol and acetone several times, followed by filtering and drying in a vacuum oven at 25 °C for 12h. The apparent polymerization yield is 42%. This PPy can be dissolved by soni-cation into m-cresol in reasonable amounts. Another report describes the use of sodimn di(2-ethylhexyl)sulfosuccinate in analogous conditions. 

Oxidation State Studies. For the oxidation state studies polyaniline was chemically synthesized by addition of an ammonium persulfate solution (in 1.0 M HCl) to a stirred aniline solution (in 1.0 M HCl) over a two and one half-hour period. The temperature of the reaction mixture was controlled at -30 C. LiCl (6.0 M) was present to prohibit freezing. For this reaction, the aniline oxidant molar ratio was 2 1. The total reaction time was 24 hours after which the resultant emeraldine salt was washed with 6.0 L of deionized water. The emeraldine salt was deprotonated by stirring in 3 wt% NH40H for 25 hours and washed with 6.0 L deionized water. Oligomer was removed by stirring the emeraldine base in methanol for 45 minutes followed by rinsing with 6.0 L methanol. Gel permeation chromatography (polystyrene standards, N-methyl-2-pyrrolidinone/0.05 M LiBr as eluent, 80 C) was... 

A unique chemical polymerization technique for CP composites is solution evaporative polymerization. To cite an example, Han et al. [III.45] took a solution of FeCl3 (the oxidant) and PVA (the host polymer) in methanol, then added pyrrole monomer thereto. The oxidation potential of the solution, and hence the polymerization, could be changed and controlled via the proportion of FeClj to PVA as well as via evaporation of the solvent, and was optimally ca. +500 mV vs. SCE. Thus, simple casting of a film from this solution yielded P(Py) composite. The percolation threshold, for a saturation conductivity of ca. 10 S/cm, was claimed to be very sharp, at 5 w/w%. A method which appears to be a combination of solution evaporative polymerization and monomer-sorption polymerization is that carried out by Morita et al. [344] A P(Py)/PMMA composite, with nonhomogenous composition (a gradation of PMMA and P(Py) concentrations) was obtained in 0.1 to 10 pm thickness and 10 to 10 S/cm conductivity from combination of 2-butanone solutions of pyrrole, PMMA and benzoic acid with aqueous solutions of potassium persulfate. 

In 1992, Tomoda and Iwaoka reported the first catalytic chemical conversion of alkenes into allylic ethers and esters [310]. The reactions were performed anploy-ing 10 mol% of diselenides 455 or 456 (Fig. 7.27) and copper (11) nitrate trihydrate in methanol or acetic acid in the presence of excess of sodium persulfate as an oxidizing agent. The best results were achieved when using the diselenide 456 in the presence of molecular sieves 3 A in acetic acid (Scheme 7.69). This suggests that... 

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