Oxygenation with hydrogen peroxide

Oxygenation with Hydrogen Peroxide Hydrogen peroxide in super-acidic media is protonated to hydroperoxonium ion (H3O2+). Christe et al. reported the characterization and isolation of several peroxonium salts. The 

NMR spectrum of H3O2 has also been obtained. The hydroperoxonium ion may be considered as an incipient OH+ ion capable of electrophilic hydrox- 

In contrast with the radical oxidation processes, high selectivity is characteristic of electrophiUc oxidation of methane. It reacts with H2O2 in superacidic media (Magic Acid) above 0°C to give mainly methanol.2 The reaction is best explained by electrophilic insertion of the hydroperoxonium ion (H3O2 ) into the methane ( H bond [Eq. (6.48)]. A similar result was obtained with hydrogen peroxide-HSOsF at 60°C. In superacidic solution the product is protonated methanol (f M OH ), which is protected against further oxidation. 

The reaction proceeds via a pentacoordinate hydroxycarbonium ion transition state (66), which then cleaves to tert-butyl alcohol or the tert-butyl cation. Since 1 mol of isobutane requires 2mols of hydrogen peroxide to complete the reaction, one can conclude that the intermediate alcohol or carbocation reacts 

---

The superacid-catalyzed electrophile oxygenation of saturated hydrocarbons, including methane with hydrogen peroxide (via H302 ) or ozone (via HOs ), allowed the efficient preparation of oxygenated derivatives. 

Toxic or malodorous pollutants can be removed from industrial gas streams by reaction with hydrogen peroxide (174,175). Many Hquid-phase methods have been patented for the removal of NO gases (138,142,174,176—178), sulfur dioxide, reduced sulfur compounds, amines (154,171,172), and phenols (169). Other effluent treatments include the reduction of biological oxygen demand (BOD) and COD, color, odor (142,179,180), and chlorine concentration. 

A number of chemiluminescent reactions may proceed through unstable dioxetane intermediates (12,43). For example, the classical chemiluminescent reactions of lophine [484-47-9] (18), lucigenin [2315-97-7] (20), and transannular peroxide decomposition. Classical chemiluminescence from lophine (18), where R = CgH, is derived from its reaction with oxygen in aqueous alkaline dimethyl sulfoxide or by reaction with hydrogen peroxide and a cooxidant such as sodium hypochlorite or potassium ferricyanide (44). The hydroperoxide (19) has been isolated and independentiy emits light in basic ethanol (45). 

Classical chemiluminescence from lucigenin (20) is obtained from its reaction with hydrogen peroxide in water at a pH of about 10 Qc is reported to be about 0.5% based on lucigenin, but 1.6% based on the product A/-methylacridone which is formed in low yield (46). Lucigenin dioxetane (17) has been prepared by singlet oxygen addition to an electron-rich olefin (16) at low temperature (47). Thermal decomposition of (17) gives of 1.6% (47). 

Reaction takes place ia aqueous solution with hydrogen peroxide and catalysts such as Cu(II), Cr(III), Co(II), ferricyanide, hernia, or peroxidase. Chemiluminescent reaction also takes place with oxygen and a strong base ia a dipolar aprotic solvent such as dimethyl sulfoxide. Under both conditions Qcis about 1% (light emission, 375—500 am) (105,107). 

Weak to moderate chemiluminescence has been reported from a large number of other Hquid-phase oxidation reactions (1,128,136). The Hst includes reactions of carbenes with oxygen (137), phenanthrene quinone with oxygen in alkaline ethanol (138), coumarin derivatives with hydrogen peroxide in acetic acid (139), nitriles with alkaline hydrogen peroxide (140), and reactions that produce electron-accepting radicals such as HO in the presence of carbonate ions (141). In the latter, exemplified by the reaction of h on(II) with H2O2 and KHCO, the carbonate radical anion is probably a key intermediate and may account for many observations of weak chemiluminescence in oxidation reactions. 

The anhydride can be made by the Hquid-phase oxidation of acenaphthene [83-32-9] with chromic acid in aqueous sulfuric acid or acetic acid (93). A postoxidation of the cmde oxidation product with hydrogen peroxide or an alkaU hypochlorite is advantageous (94). An alternative Hquid-phase oxidation process involves the reaction of acenaphthene, molten or in alkanoic acid solvent, with oxygen or acid at ca 70—200°C in the presence of Mn resinate or stearate or Co or Mn salts and a bromide. Addition of an aHphatic anhydride accelerates the oxidation (95). 

Synthesis. Dialkyl peroxides are prepared by the reaction of various substrates with hydrogen peroxide, hydroperoxides, or oxygen (69). They also have been obtained from reactions with other organic peroxides. For example, dialkyl peroxides have been prepared by the reaction of hydrogen peroxide and alkyl hydroperoxides with alMating agents, eg, RX and olefins (33,66,97) (eqs. 24—27). 

Polymeric OC-Oxygen-Substituted Peroxides. Polymeric peroxides (3) are formed from the following reactions ketone and aldehydes with hydrogen peroxide, ozonization of unsaturated compounds, and dehydration of a-hydroxyalkyl hydroperoxides consequendy, a variety of polymeric peroxides of this type exist. Polymeric peroxides are generally viscous Hquids or amorphous soHds, are difficult to characterize, and are prone to explosive decomp o sition. 

Petoxycatboxyhc acids have been obtained from the hydrolysis of stable o2onides with catboxyhc acids, pethydtolysis of acyhinida2ohdes, reaction of ketenes with hydrogen peroxide, electrochemical oxidation of alcohols and catboxyhc acids, and oxidation of catboxyhc acids with oxygen in the presence of o2one (181). 

Thallic oxide can be prepared by reaction of thallium with oxygen or hydrogen peroxide and an alkaline thallium(I) solution. However, it is more easily made from the oxidation of thaHous nitrate by chlorine ia aqueous potassium hydroxide solution. It is insoluble in water but dissolves in carboxyUc acids to give carboxylates. 

Thiourea dioxide, or formamidine sulfinic acid, is an oxygenated thiourea derivative synthesized by the oxidation of thiourea with hydrogen peroxide. It has the chemical formula (NH2)NHCS02H and is tautomeric. 

PSS-SG composite film was tested for sorption of heme proteins hemoglobin (Hb) and myoglobin (Mb). The peroxidaze activity of adsorbed proteins were studied and evaluated by optical and voltammetric methods. Mb-PSS-SG film on PG electrode was shown to be perspective for detection of dissolved oxygen and hydrogen peroxide by voltammetry with linear calibration in the range 2-30 p.M, and detection limit -1.5 p.M. Obtained composite films can be modified by different types of biological active compounds which is important for the development of sensitive elements of biosensors. 

---