Hydrogen peroxide Methylene Blue oxidant

Sansoni prepared several samples of polycondensates of resorcinol, formaldehyde and Methylene Blue and tested their redox properties by repeated oxidation reduction cycles,9 with ammoniacal sodium dithionite as the reductant and acidic hydrogen peroxide as the oxidant. The best resins had a redox capacity of. 5 5 8 meq of Fe(lll) per gram. This novolac type of condensation was later used th azo dyes to give thermosetting colored coating compositions. When dye molecules are available with two condensable... 

The photosensitized results are from I.B.C. Matheson and J. Lee 118h It is seen that the quantum yields in photosensitized oxidation depend on the concentrations of luminol and base, and on temperature. At higher temperature (50°) and low luminol concentrations, the quantum yields reached those of hemin-catalyzed hydrogen peroxide oxidation of luminol in aqueous-alkaline solution. Primary products of the photosensitized oxidation are singlet oxygen (1Ag02) or a photoperoxide derived from methylene blue, but neither of these is directly responsible for the luminol chemiluminescence. 

The oxidation reactions of 2,4,5-triphenylimidazole (lophine) have received considerable attention. With chromic acid it gives benzamide and benzanilide, but even more interest has centred on its involvement in the phenomenon of chemiluminescence. Some of this material has been discussed earlier (Sections 4.06.3.6, 4.07.1.2.1 and 4.07.1.2.3). The oxidative decomposition of lophine in the presence of air is accompanied by the emission of light, and it is the excited singlet state of the diaroylarylamidine (12 Scheme 2) which is the light emitter. The radical (46) derived from oxidation of lophine with aqueous ferricyanide and ethanolic KOH forms a hydroperoxide with hydrogen peroxide with consequent luminescence. When 2,4,5-tri- and 1,2,4,5-tetra-phenylimidazoles are oxidized in dilute methanol solution in the presence of methylene blue, the dibenzoylbenzamidine is also formed under circumstances in which hydroperoxides cannot be intermediates (B-76MI40701). 

The oxidation of ascorbic acid still attracts attention and a mechanism has been proposed for the reaction with photochemically produced H02 radicals. An analogous reaction with hydrogen peroxide affords a means of access to L-threonic acid. Heating D-isoascorbic acid in aqueous pyridine in the presence of boric acid gives the decarboxylation products D-arabinose and D-ribose. Two Russian papers have reported on the oxidation of ascorbic acid with copper(ll) in the presence and absence of oxygen and light. As part of a basic study of the action of oxidase and reductase enzymes, the reduction of Methylene Blue by ascorbic acid has been examined, in the presence of surfactants added to mimic the effects of the protein parts of the enzymes. ... 

The reaction of a crystalline turnip peroxidase has been shown to proceed with hydrogen peroxide and any of a group of electron acceptors, cytochrome C, methylene blue, or ferric iron in place of oxygen (Yamazaki and Souzi, 1960). A mechanism was proposed in which both hydrogen peroxide and the other oxidant participate in sequential steps of the oxidation of indoleacetic acid. When oxygen is the second oxidant, it is reduced to hydrogen peroxide, which, therefore, plays a catalytic role. 

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