Hydroperoxide peroxide

The conversion of hydroperoxide/peroxide to superoxide is a one-electron redox reaction and requires the presence of transition metals having accessible multiple oxidation states as in biological iron or manganese clusters (e.g., Fe(II, III, IV) clusters of monooxygenase or the Mn(II, HI, IV) clusters of photosystems). Ti is usually not reduced at ambient temperatures. The various possibilities that could facilitate the transformation of hydroperoxo/peroxo to superoxo species are as follows ... 

Inifiation. The trick here is to get the reaction started. Usually a catalyst is used, typically an organic peroxide such as ditertiary butyl hydroperoxide. Peroxide molecules are somewhat unstable, and when they re heated, they decompose and turn into highly reactive free radicals. As you ll recall, a radical is an almost-complete molecule, but all the valence requirements are not satisfied. So it is very anxious to meet up with some other molecule to satisfy its valence needs. The free radical, in the presence of an abundance of monomers, say a million to one ratio, will react with a monomer molecule. It becomes part of the molecule. In doing so, the unsatisfied valence condition now transfers to the end of the monomer. A new radical is formed. That s the start of the initiation step. 

The elution factors in normal-phase TLC and RP-HPLC, using a fixed set of chromatographic parameters, were determined for a series of saturated triacylglycerides with TCN from C30 to Ceo, serving as reference compounds and various oxidation derivatives of analogous unsaturated triglycerides, including hydroperoxides, peroxides, epoxides, core aldehydes and their DNP derivatives. From these measurements, a series of incremental... 

Temperature-programmed thermal desorption particle beam MS of collected secondary aerosol particles shows that the major ozonization products of normal alkenes in an environmental chamber include organic hydroperoxides, peroxides, final ozonides and monocarboxylic acids. Attempts to analyze these compounds by GC result in their decomposition to simpler molecules". 

A Perkin-Elmer Model 21 infrared spectrophotometer was used to detect and to estimate the hydroxylic and carbonyl functions in the oxidized product mixtures. The organic hydroperoxide and peroxide functional groups in the product mixtures were determined by an iodine liberation and titration procedure (11). In order to get reproducible results, it is necessary to pretreat the olefins with about 10 weight % activated silica or alumina for several hours with agitation to remove adventitious peroxides and impurities. Sodium bisulfite solution rapidly destroys hydroperoxides but does not destroy peroxides completely. The hydroperoxides and peroxides decomposed extensively during attempted distillation at about 1 mm. of Hg partial vacuum. We had some success in concentration by liquid chromatography over silica gel the unconverted olefins are eluted with n-hexanes, and a hydroperoxide-peroxide... 

Synonyms Dihydrogen dioxide hydrogen dioxide hydrogen oxide hydroperoxide peroxide... 

Straight acetylene can be used as an explosive when in liquefied or solidified form (see Acetylene as an Explosive) (See also Acetylene Condensation or Polymerization Products, Acetylene Derivatives, Acetylene Hydroperoxides Peroxides, Acetylene-Nitric Acid Reactions, Acetylene Reactions, Acetylenic Compounds, Acetylides, Cuprene and Halogenated Acetylenes)... 

Other authors took advantage of the use of ozone in the object of block copolymerization. Smets et al. ozonized polypropylene and studied the obtained hydroperoxides/peroxides ratios [124, 125] vs ozonization time. They show that hydroperoxide content is favored by long ozonization time (Table 1). 

Redox reactions occur with hydroperoxides, peroxides, peresters, persulfates, hydrogen peroxide, and other peroxides. A wide variety of metal ions may be used as reducing agents. Ions which are commonly used include Co +, Fe +, Cr ", and Cu+. 

The conversion of hydroxamic acids into the corresponding amides is believed to involve initial formation of amidyl radicals by nitrogen-oxygen bond homolysis. Photodecomposition of hydroperoxides, peroxides and ozonides has also been examined. 

The reaction proceeds until the free radicals are destroyed by inhibitors or by side-reactions which eventually break the chain. The rancid odour which is a characteristic of oxidised fats and oils is due to aldehydes, ketones and short-chain fatty acids which are the breakdown products of the hydroperoxides. Peroxides (ROOR ) and hydroperoxides (ROOH) are photolabile, breaking down to hydroxyl (HO ) and/or alkoxyl (RO ) radicals, which are themselves highly oxidising species. The presence of residual peroxides in polyoxyethylene glycols (PEGs) is a cause for concern when these excipients are used in formulation, as for example in the case of fenprostalene. ... 

ACD has been associated with ethoxylated alcohol surfactants. Though not by themselves known to cause ACD, ethoxylated surfactants are polyethers and are easily air oxidized to hydroperoxides, peroxides, and carbonyl compounds (including formaldehyde and acetaldehyde), substances that do cause ACDJ22 251 The irritant components of surfactants and other chemicals present in formulated products facilitate the absorption of the ACD causing decomposition products of ethoxylated alcohols and thus exacerbate their effects. F61 This is yet another example of lipophilic compounds enhancing the absorption of hydrophilic compounds (the decomposition products of ethoxylated alcohols) and hence increasing the toxic effect beyond that predicted. 

Total concentration of hydroperoxides, peroxides and peracids The iodometric method described by Carlsson Wiles (16) was applied. Note tertiary BuOOBu is not measured under these conditions ... 

S. Korcek (Ford Motor Company) found that the hydroperoxides/peroxides formed during the oxidation of a simple n-paraffin of molecular weight close to that of a lube base stock, namely, hexadecane, were extremely complex and... 

Denison and Condit19 previously postulated how sulfur compounds inhibit base stock oxidation. In this mechanism the hydroperoxide/peroxides intermediates reacted with sulfur compounds to give products that could not propagate further by the free radical mechanism. In their oxidation preventative role, the peroxides oxidized the sulfur compounds first to sulfoxides and these in turn could be further oxidized to sulfones ... 

Synonyms/Trade Names High-strength hydrogen peroxide, Hydrogen dioxide, Hydrogen peroxide (aqueous). Hydroperoxide, Peroxide ... 

In this work, we develop a consistent set of oxygenated peroxy-hydrocarbon and acetylene-alcohol groups derived from the thermodynamic properties data of a set of hydroperoxides, peroxides, ethers and alcohols determined in previous chapters. 

In conclusion, the salient features of the light-induced oxidation of polymers are the formation of hydroperoxide, peroxide, and carbonyl groups, the latter in the form of both aldehyde and keto groups. Moreover, certain reactions, such as reaction (d) in Scheme 7.20 and reaction (b) in Scheme 7.21, result in main-chain cleavage as far as the oxidation of linear macromolecules is concerned. Main-chain cleavage leads to a deterioration in certain important mechanical properties. Therefore, the photo-oxidation of polymers is deleterious and should be avoided in commercial polymers. Appropriate stabilization measures are discussed in Section 9.3. 

Perfluoroalkyl Hypohalites, Fluoroperoxides, Hydroperoxides, Peroxides, and Trioxides. More worthwhile reading concerning hypofluorous acid (history, isolation, chemical and physical properties, molecular parameters, etc.) is available in the form of a review entitled Nonexistent Compounds Two Case Histories (half... 

Ethyl chloroformate, ClCOOC Hg-i Methyl trichloroacetate Diethyl oxalate Ethyl malonate Orthoformic acid esters. Ethyl orthoformate (RCO) O (CH CO) O, (C fiO)fi, (CF,COkO n-Octanoic anhydride (C,H,C0),0 R-OOH,C,Hg-OOH Cumene hydroperoxide Peroxides... 

The determination of peroxides has two goals one is to monitor peroxide concentration used as initiator and catalysts and the other is to detect formation of hazardous peroxides formed as autoxidation products in ethers, acetals, dienes, and alkylaromatic hydrocarbons. A sample is dissolved in a mixture of acetic acid and chloroform. The solution is deaerated and potassium iodide reagent is added and let to react for 1 h in darkness. The iodine formed in reaction is measured by absorbance at 470 nm and result calculated to active oxygen in the sample. The method can determine hydroperoxides, peroxides, peresters, and ketone peroxides. Oxidizing and reducing agents interfere with flic determination. 

Free radical polymerization initiators are compounds with bonds that easily undergo thermal homolytic scission, e.g., hydroperoxides, peroxides, peresters, azo compounds, and strongly sterically hindered ethane derivatives ... 

From the hydroperoxide, peroxides, acids, aldehydes, and numerous adducts may form. Alcohols, such as ethanol in the case of ethyl ether, are also present as a result... 

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