Oxidations NaClO

The ores are blended with Na2C03 and KNO3, then roasted. Part of the S and As are removed as volatile compounds, leaving Co, Ni, and Cu oxides, with some sulfates, and arsenates. The sulfates and arsenates are leached with HOH, then the oxides are dissolved in hot H2SO4. The solution is treated with the oxidant NaClO, and the hydroxides are selectively precipitated by careful... 

Further studies resulted in the development of a new system based on Yb catalysts (eq. (35)) (59). The advantages of this system over equations (33) and (34) are a more economical oxidant (NaClO) and an environmentally friendly solvent (H2O). 

Basic oxides of metals such as Co, Mn, Fe, and Cu catalyze the decomposition of chlorate by lowering the decomposition temperature. Consequendy, less fuel is needed and the reaction continues at a lower temperature. Cobalt metal, which forms the basic oxide in situ, lowers the decomposition of pure sodium chlorate from 478 to 280°C while serving as fuel (6,7). Composition of a cobalt-fueled system, compared with an iron-fueled system, is 90 wt % NaClO, 4 wt % Co, and 6 wt % glass fiber vs 86% NaClO, 4% Fe, 6% glass fiber, and 4% BaO. Initiation of the former is at 270°C, compared to 370°C for the iron-fueled candle. Cobalt hydroxide produces a more pronounced lowering of the decomposition temperature than the metal alone, although the water produced by decomposition of the hydroxide to form the oxide is thought to increase chlorine contaminate levels. Alkaline earths and transition-metal ferrates also have catalytic activity and improve chlorine retention (8). 

On an industrial scale, perchlorates are now invariably produced by the electrolytic oxidation of NaClOs (see Panel, p. 867). Alternative routes have historical importance but are now only rarely used, even for small-scale laboratory syntheses. 

When chlor-alkali electrolysis is conducted in an undivided cell with mild-steel cathode, the chlorine generated anodically will react with the alkali produced cathodically, and a solution of sodium hypochlorite NaClO is formed. Hypochlorite ions are readily oxidized at the anode to chlorate ions this is the basis for electrolytic chlorate production. Perchlorates can also be obtained electrochemically. 

It furnishes 47% of its weight as oxidant, which is much more than other common oxidants such as NaClO, KHSOs, and ROOH. 

Oxidation Studies. These studies were performed at 25+0.2°C in a carbonate buffered 0.1 M NaClO solution. The buffer was equilibrated with air or an 02/C02 gas mixture for at least 24 hours. The pH was adjusted to 8.3 using HCIO, NaOH, or Na2C03. Where y-FeOOH was present the suspension was deaerated by bubbling N2/C02 for 1 hour, the Mn(II) was added and was allowed to equilibrate with the solid for 30 minutes and then the oxidation was commenced by switching to 02/C02 or air bubbling. Where no solid was present the solution was not deaerated. The rate of oxidation was monitored by following the loss of filterable Mn. 

In freshwater, Mn(II) oxidation is slightly slower than in 0.1M NaClO. The difference between the Mn(II) oxidation rate in freshwater and 0.1M NaCIO, is greatest at pH 8.5, at this pH the rate of Mn(II) oxidation is only 40% lower in the freshwater than in 0.1M NaClO. In the estuarine-water at pH 8.5 the rate of Mn(II) oxidation is 20 times slower than in 0.1M NaCIO,. The speciation calculations indicate why the model predicts the oxidation is slower than in natural waters (see, for example Table VII). 

Figure 12. Burst strength of oxidized membrane that was soaked in NaClO of...

The most convenient and commonly employed method for promoting the generation of TEMPO-oxoammonium is instead the so-called Anelh procedure It resorts to NaClO as the regenerating oxidant in 1 1 molar ratio with the substrate, under co-catalysis by EUlr. In a two-phase CH2Cl2-water system at 0°C, the oxidation of a primary alkanol does take place, to give the aldehyde selectively and in good yields (entry 3) after a few minutes. In contrast, if the reaction is run in aqueous solution with 2 molar equivalents of... 

NaClO, or else in the two-phase system but with a quaternary ammonium (viz. AUquat) ion as a phase-transfer catalyst, overoxidation to the corresponding carboxylic acid is obtained (entry 4). Therefore, by proper choice of the experimental conditions, a synthetically useful distinction in products formation can be made for the oxidation of primary alcohols, even though we are far from a satisfactory understanding of the reason behind this different behaviour. In fact TEMPO, as a well-known inhibitor of free-radical processes is allegedly responsible for the lack of overoxidation of an aldehyde to carboxylic acid (entry 3) this notwithstanding, TEMPO is also present under those conditions where the overoxidation does occur (eutry 4). Moreover, a commou teuet is that the formation of the hydrated form of an aldehyde (in water solution) prevents further oxidation to the carboxylic acid however, both entries 3 and 4 refer to water-organic solutions, and their... 

Low-rank coals were oxidised with RuCl /aq. Na(IO )/CCl, and both aliphatic and aromatic acids were detected [158, 159]. The system RuClj/aq. NaClO yCCl -CHjCN was used for oxidation of Illinois No. 6 coal (see also arenes, 3.3.1, 3.3.3, Tables 3.4 and 3.5) [160]. 

Most sodium compounds tend to be quite hygroscopic, and therefore simple compounds such as sodium nitrate (NaNO 3), sodium chlorate (NaGlO 3), and sodium perchlorate (NaClO,) - combining the oxidizing anion with the metallic emitter - can not be used unless precautions are taken to protect against moisture... 

The supporting electrolytes were 0.1 M [n-Bu NlClO for CH3CN, EtOH, CH2C12, EtOH/toluene (1 1 v/v). sulfolane, and glacial acetic acid solvents, and 1.0 M NaClO /0.01-0.1 M HCIO for H2O, E. values for I oxidation were obtained at Pt... 

Uranium is deposited widely in the Earth s crust, hence it has few ores, notably the oxides uraninite and pitchblende. The ores are leached with H2SO4 in the presence of an oxidizing agent such as NaClOs or Mn02, to oxidize all the uranium to the (+6) state as a sulfate or chloride complex. On neutralization with ammonia a precipitate of yellow cake , a yellow solid with the approximate composition (NH4)2U207 is formed. This is converted into UO3 on ignition at 300 °C. This can be purified further by conversion into uranyl nitrate, followed by solvent extraction using tributyl phosphate in kerosene as the extractant. 

Chloryl fluoride can be prepared in high yield by the action of CIF3 on NaClOs. It is a colorless gas and a powerful oxidizing and fluorinating agent. " " It is the most common chlorine oxyfluoride and is typically encountered in reactions between CIF and oxides or hydroxides. 

Sodium Chlorite, NaClO, wh crysts, exists in anhyd tri-hydrated forms, mp 175 200° (decomp, temp dependent upon moisture content). The Solubility of NaClO is reported by Taylor et al(Ref 1), Commercial production of NaClO in the US is based upon the reduction of Ca(C10g)2 by HCl. The chlorate is reduced to chlorine dioxide, and the hydrochloric acid is oxidized to chlorine ... 

Figure 2. Salt Effect on the Pd(II) oxidation of ethylene fM varied by adding NaCl or NaClO-,...

Figure 3. Salt effects on the Tl(UI) oxidation of ethylene, varied with NaClO,. (HClOj, = 0.35 or 0.5M)...

Potassium peroxomonosulfate (Oxone ) is also an effective oxidizing agent for the epoxidation of various alkenes in the presence of Mn porphyrin and a PT catalyst [79]. The biphasic epoxidation of various olefins is readily catalyzed by Co and Ni" phthalocyanines with NaClO as the oxygen donor and Bu4N" Br" as the PT agent [80]. The PTC oxidation of alkenes with NaClO is also catalyzed by square-planar Ni complexes [81-83]. 

The synergism of the catalytic action of (tetraphenylpophyrinato)manganese(III) chloride [Mn" (TTP)Cl] and methyltrioctylammonium chloride was demonstrated by their joint appication for the PTC oxidation of benzyl alcohol with NaClO [88], Benzaldehyde is formed within several minutes in almost quantitative yield. The reaction proceeds much more slowly when only one of these catalysts is used. 

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