Action of hydrogen peroxide

Hydrogen peroxide may react directiy or after it has first ionized or dissociated into free radicals. Often, the reaction mechanism is extremely complex and may involve catalysis or be dependent on the environment. Enhancement of the relatively mild oxidizing action of hydrogen peroxide is accompHshed in the presence of certain metal catalysts (4). The redox system Fe(II)—Fe(III) is the most widely used catalyst, which, in combination with hydrogen peroxide, is known as Fenton s reagent (5). 

D,L-Arahinitol can be prepared by the action of hydrogen peroxide in the presence of formic acid on divinyl carbinol (36) and, together with ribitol (Fig. ld),fromD,L-erythron-4-pentyne-l,2,3-triol,HOCH2CHOHCHOHC=CH (37). 

The action of hydrogen peroxide on freshly precipitated hydrated Ti(IV) oxide or the hydrolysis of a peroxide compound such as K2[Ti(02)(S0 2] yields, after drying, a yellow soHd, stable below 0°C, of composition TiO 2H2O. There is one peroxo group per titanium, but the precise stmcture is not known. The yellow soHd loses oxygen and water when heated and Hberates chlorine from hydrochloric acid. When freshly prepared, it is stable in acid or alkah, giving peroxy salts. 

A dimer is formed by the action of hydrogen peroxide on the quaternary salt of 3,4-dihydroisoquinoline (235). The other similar reactions are of small importance. 

The reaction is reversible and (24) can be recovered by the action of hydrogen peroxide. 

Preparing peracetic acid by the action of hydrogen peroxide on acetic acid is as hazardous. If the temperature is too low, compounds accumulate and cause the medium to detonate. Using peracetic acid solution as an oxidant causes detonations when its concentration is too high or if evaporation is attempted. An accident happened during such an operation (see reaction below). The best way to eliminate this peracid at the end of the reaction is to heat it in a water bath at a temperature that should not exceed 50°C and under reduced pressure. 

Action of hydrogen peroxide or permonosulfuric acid on acetone produces this dimeric acetone peroxide, which explodes violently on impact, friction or rapid heating. 

During isolation of the di-A-oxide of 2,5-dimethylpyrazine [1] and of the mono-/V-oxide of 2,2-bipyridyl [1], prepared by action of hydrogen peroxide in acetic... 

Bjorklund, G. H. et al., Trans. R. Soc. Can., (Sect. Ill), 1950, 44, 28 The solid peroxide produced by action of hydrogen peroxide and nitric acid on thiourea (and possibly a hydrogen peroxidate of thiourea dioxide) decomposed violently on drying in air, with evolution of sufur dioxide and free sulfur. 

By a procedure similar to that described for />-nitrobenzoyl peroxide, the following peroxides have been prepared w-nitro-benzoyl peroxide (m.p. 136-137°) in 90 per cent yield anisoyl peroxide (m.p. 126-127°) in 86-89 per cent yields -bromoben-zoyl peroxide (m.p. 144°) in 73 per cent yield and 3,4,5-tribromo-benzoyl peroxide (m.p. 186°) in 40 per cent yield.1 The procedure is not satisfactory for preparation of acetylsalicylyl peroxide, which is more conveniently prepared by action of hydrogen peroxide upon an acetone solution of the acid chloride. 

The influence of substituents on the rates of degradation of arylazo reactive dyes based on H acid, caused by the action of hydrogen peroxide in aqueous solution and on cellulose, has been investigated [43]. The results suggested that the oxidative mechanism involves attack of the dissociated form of the o-hydroxyazo grouping by the perhydroxyl radical ion [ OOH]. The mechanism of oxidation of sulphonated amino- and hydroxyarylazo dyes in sodium percarbonate solution at pH 10.6 and various temperatures has also been examined. The initial rate and apparent activation energy of these reactions were determined. The ketohydrazone form of such dyes is more susceptible to attack than the hydroxyazo tautomer [44]. 

With concentrated mineral acids azobenzene gives red salts, as may be shown by pouring hydrochloric acid on it. Addition of hydrogen leads to the re-formation of the hydrazo-compound. Oxygen is added on and the azoxy-compound formed by the action of hydrogen peroxide or nitric acid. The synthesis of asymmetrical aromatic azo-compounds from nitroso-compounds and primary amines was discussed above. 

Anilines are converted into nitrosoarenes ArNO by the action of hydrogen peroxide in the presence of [Mo(0)(02)2(H20) (HMPA)]224, whereas catalysis of the reaction by titanium silicate and zeolites results in the formation of azoxybenzenes ArN (0)=NAr225. Azo compounds ArN=NAr are formed in 42-99% yields by the phase-transfer assisted potassium permanganate oxidation of primary aromatic amines in aqueous benzene containing a little tetrabutylammonium bromide226. The reaction of arylamines with chromyl chloride gives solid adducts which, on hydrolysis, yield mixtures of azo compounds, p-benzoquinone and p-benzoquinone anils 234227. 

An interesting alternative to the use of chromium(VI) oxidants for the conversion of 1 to 2 involves the use of a low-valent iron reagent prepared in situ by the action of hydrogen peroxide on an iron(II) complex of 1 (73). Vinblastine (as the free base) is treated with 2 equiv of perchloric acid in acetonitrile at -20°C. Ferrous perchlorate is then added, followed by the addition of excess 30% hydrogen peroxide. Work-up of the reaction mixture with a saturated solution of ammonium hydroxide gives 2 in yields of 35-50% after chromatography. 

Triphenylarsine oxide has been prepared by the action of sodium hydroxide on triphenylarsine dibromide/ by the action of potassium permanganate on triphenylarsine, and by the action of hydrogen peroxide on triphenylarsine. The method described here is essentially that of Vaughan and Tarbell. ... 

Dihydroxo-tetrammino-platinic Chloride, [Pt(NH3)4(OH)2]Cl2, is prepared by the action of hydrogen peroxide on tetrammino-platinous chloride, or by decomposing the sulphate of the series with barium chloride. It crystallises in colourless monoclinic plates. 

Brandt and van Eldik30 review of the chemistry of sulfur(IV) oxidation, with emphasis on the catalytic role of metal ions such as Fe2+. We consider here only a simplified summary of the principal atmospheric oxidation processes. It is likely that oxidation is effected primarily through the action of hydrogen peroxide or ozone in water droplets in clouds, through the photochemical effect of ultraviolet light, or by heterogeneous catalysis of the S02-02 reaction by dust particles 9,30,31... 

Legler [86] was the first to prepare this substance by the action of hydrogen peroxide on ammonium salts in the presence of formaldehyde. Later, Girsewald [87] obtained it by the treatment of hexamethylenetetramine with hydrogen peroxide. 

The same compound was prepared by Leulier [89] by the action of hydrogen peroxide on hexamethylenetetramine in the presence of nitric acid, but in a lower yield than that in the Girsewald method. Leulier ascribed an incorrect formula to the substance as pointed out by Girsewald and Siegens [85]. 

This compound was obtained by Girsewald and Siegens [92] by the action of hydrogen peroxide and nitric acid on an aqueous solution of urea and formaldehyde. 

Finally, dithiocoumarins (e.g., 17, see p. 131) are converted into thiocoumarins by the action of hydrogen peroxide in acetic acid. ... 

Hoffmann, M.E. Meneghini, R. (1979) Action of hydrogen peroxide on human fibroblast in... 

Water is without effect on the element even at a red heat,3 but the combined action of water and ozone produces telluric acid at the ordinary temperature.4 The action of hydrogen peroxide upon tellurium is influenced considerably by the physical state of the element colloidal tellurium is readily oxidised, but crystalline tellurium is not readily attacked and has first to be dissolved in an aqueous solution of alkali hydroxide, when oxidation becomes possible with formation of tellurate.5 Hydrogen peroxide of 60 per cent, strength reacts very slowly with tellurium at a temperature of 100° C., but with increasing amount of telluric acid formed, the rate of dissolution increases. Amorphous tellurium as ordinarily prepared behaves in a similar manner to the crystalline variety, but if it is dried by treatment with alcohol and ether instead of by heating at 105° C. it will dissolve readily in a concentrated solution of hydrogen peroxide.6... 

Colorimetric Methods are used only for the estimation of very small percentages of vanadium, e.g. in vanadium steels and alloys. The most important depend on the intensity of the reddish-brown colour produced by the action of hydrogen peroxide on an acid vanadate solution.3 If chromium is present, an equal amount must be introduced into the standard vanadium solution under the same conditions of temperature, acid concentration, etc. Phosphoric acid is added to destroy any yellow colour due to ferric iron, and either hydrofluoric acid or ammonium fluoride to destroy any colour produced by titanium.4 A colorimetric method for the simultaneous estimation of small quantities of titanium and vanadium has also been worked out.5 Other colorimetric processes are based on (a) the formation of a yellow to black coloration, due to aniline black, in the presence of aniline hydrochloride and potassium chlorate or other oxidising agent,6 and (b) the orange coloration finally produced when an acid solution of a vanadate is brought into contact with strychnine sulphate.7... 

---