Oxidizing capability

Although ammonium nitrate does not itself bum, it is a strong oxidizer capable of supporting the combustion of numerous substances when heated. It can support and intensify a fire even when air is excluded. Fires involving ammonium nitrate also present a toxic hazard from the release of nitrogen oxides, even though the soHd itself is generally considered not to be toxic. 

The oxidizing capability of Ce(IV) has also been used for block copolymer synthesis starting from hydroxyl functional azo compounds, but not proceeding via the formation of MAIs vide infra). 

Spectroscopy of the PES for reactions of transition metal (M ) and metal oxide cations (MO ) is particularly interesting due to their rich and complex chemistry. Transition metal M+ can activate C—H bonds in hydrocarbons, including methane, and activate C—C bonds in alkanes [18-20] MO are excellent (and often selective) oxidants, capable of converting methane to methanol [21] and benzene to phenol [22-24]. Transition metal cations tend to be more reactive than the neutrals for two general reasons. First, most neutral transition metal atoms have a ground electronic state, and this... 

Partial oxidation reactions are usually carried out over transition metal oxides capable of changing their valent state during their interaction with reacting molecules. Naturally, zeolites with their alumina-silicate composition did not prove themselves as good oxidation catalysts. They failed also to serve as efScient catalyst supporters, since transition metals being introduced into the zeolite matrix lose their ability to activate dioxygen [3,4],... 

Ozone is known to be a powerful oxidant capable of both initiating peroxidation in lipids and reacting with... 

The ring-opening of the cyclopropane nitrosourea 233 with silver trifiate followed by stereospecific [4 + 2] cycloaddition yields 234 [129]. (Scheme 93) Oxovanadium(V) compounds, VO(OR)X2, are revealed to be Lewis acids with one-electron oxidation capability. These properties permit versatile oxidative transformations of carbonyl and organosilicon compounds as exemplified by ring-opening oxygenation of cyclic ketones [130], dehydrogenative aroma-tization of 2-eyclohexen-l-ones [131], allylic oxidation of oc,/ -unsaturated carbonyl compounds [132], decarboxylative oxidation of a-amino acids [133], oxidative desilylation of silyl enol ethers [134], allylic silanes, and benzylic silanes [135]. 

Probably, the little ciurent in the first few cycles is due to the lack of electrocatalytic activity for the oxidation of methanol to COad on the tin-rich surface, although the svuface has the oxidation capability for COad ot lower potentials as shown in the previous section. As more platinum became exposed, the more COad is likely to form, followed by the early oxidation of COad on Pt-Sn surface. Further removal of tin, however,... 

The reactions of aldehydes at 313 K [69] or 323 K [70] in CoAlPO-5 in the presence of oxygen results in formation of an oxidant capable of converting olefins to epoxides and ketones to lactones (Fig. 23). This reaction is a zeolite-catalyzed variant of metal [71-73] and non-metal-catalyzed oxidations [73,74], which utilize a sacrificial aldehyde. Jarboe and Beak [75] have suggested that these reactions proceed via the intermediacy of an acyl radical that is converted either to an acyl peroxy radical or peroxy acid which acts as the oxygen-transfer agent. Although the detailed intrazeolite mechanism has not been elucidated a similar type IIaRH reaction is likely to be operative in the interior of the redox catalysts. The catalytically active sites have been demonstrated to be framework-substituted Co° or Mn ions [70]. In addition, a sufficient pore size to allow access to these centers by the aldehyde is required for oxidation [70]. 

It is unknown what role is played by ligand environments in proteins and in synthetic analogues in stabilizing different species as it is also unknown which species represent active oxidants capable of transfering oxygen atoms to substrate in the enzyme systems. Moreover, it is not known how a binuclear metal active site might differ tom a mononuclear active site or if there is one type of reaction mechanism that operates in all or most of the monooxygenase enzymes or if each type of enzyme follows a different mechanism. 

Shidlovskiy has pointed out that metal-fluorine compounds should also have good oxidizer capability. For example, the reaction... 

In fact, as we shall see in more detail later in the chapter, peroxo metal complexes are very versatile oxidants capable of reacting with a variety of substrates through different reaction mechanisms, either polar or radical Thus, it would be of great help to be... 

It is very reactive substance. A trace amt (0.05% by wt) of F203 dissolved in liq oxygen makes the resultant oxidizer capable of hyper-golic ignition with common hydrocarbons, amine base fuels or hydrogen and provides more stable combstn... 

The strong oxidative capabilities of acetic acid bacteria are also harnessed for the production of other flavour acids from their corresponding alcohols, such as propanoic acid, butanoic acid, 2-methylpropanoic acid, 2-methylbutanoic acid and 3-methylbutanoic acid (Scheme 23.1). 

Many of the reactions with hydrazines are complicated multistep sequences which sometimes require the presence of an oxidizing agent. Oxidizing capability can come from adventitious 02, sacrificial reduction of the metal or the hydrazine itself (equations 134-136). 

The activation of DMSO by electrophilic reagents such as oxallyl chloride or trifluoroacetic anhydride (TFAA) (among many others) produces an oxidant capable of oxidizing primary alcohols to aldehydes in high yields. This oxidation is called the Swern oxidation and yields the aldehyde (oxidized product) by reductive elimination of dimethylsulfide (reduced product) and proceeds under mild, slightly basic conditions. It is a second widely used and effective oxidative method for the production of aldehydes from primary alcohols. 

Metal (IV) species - Oxidation of the carbonyls to metal(IV) derivatives requires oxidants capable of transferring oxygen atoms. Best characterized are the p-oxobis[oxometal(IV)] complexes directly accessible with alkylhydroperoxides or dioxygen/2,3-dimethylindole (path e). Other metal(IV) derivatives, e.g. bis-alkoxides or oxometal(IV) complexes, are formed from the dioxometal(VI) porphyrins mentioned below. 

The largest class consists of those oxides which are reduced to the metal, or a lower oxide, capable of producing a catalytic effect which is superposed upon the initial oxidation. The oxides of nickel and cobalt, of lead (PbOjj, Pb304, PbO), of copper (CuO, Cn20), at 350° belong to this class the reduced metals in these cases have a dehydrogenating effect upon the alcohol, and aldehyde results. 

Irritant dermatitis does not involve an immune response and is typically caused by contact with corrosive substances that exhibit extremes of pH, oxidizing capability, dehydrating action, or tendency to dissolve skin lipids. In extreme cases of exposure, skin cells are destroyed and a permanent scar results. This condition is known as a chemical burn. Exposure to concentrated sulfuric acid, which exhibits extreme acidity, or to concentrated nitric acid, which denatures skin protein, can cause bad chemical bums. The strong oxidant action of 30% hydrogen peroxide likewise causes a chemical bum. Other chemicals causing chemical bums include ammonia, quicklime (CaO), chlorine, ethylene oxide, hydrogen halides, methyl bromide, nitrogen oxides, elemental white phosporous, phenol, alkali metal hydroxides (NaOH, KOH), and toluene diisocyanate. 

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