Metals tetraoxides

Mixtures of aluminium powder with liquid chlorine, dinitrogen tetraoxide or tetran-itromethane are detonable explosives, but not as powerful as aluminium-liquid oxygen mixtures, some of which exceed TNT in effect by a factor of 3 to 4 [1], Mixtures of the powdered metal and various bromates may explode on impact, heating or friction. Iodates and chlorates act similarly [2], Detonation properties of gelled slurries of aluminium powder in aqueous nitrate or perchlorate salt solutions have been studied [3], Reactions of aluminium powder with potassium chlorate or potassium perchlorate have been studied by thermal analysis [4],... 

Non-metal oxides MRH Carbon monoxide 6.44/42, dinitrogen tetraoxide 1.00/45,... 

Mixtures of potassium and solid carbon dioxide are shock-sensitive and explode violently on impact, and carbon monoxide readily reacts to form explosive carbonylpotassium (potassium benzenehexoxide) [1]. Dichlorine oxide explodes on contact with potassium [2], Potassium ignites in dinitrogen tetraoxide or dinitrogen pentaoxide at ambient temperature and incandesces when warmed with nitrogen oxide or phosphorus(V) oxide [3], At — 50°C, potassium and carbon monoxide react to give dicarbonylpotassium, which explodes in contact with air or water, or at 100°C. At 150°C, the product is a trimer of this, potassium benzenehexoxide. The just-molten metal ignites in sulfur dioxide [4],... 

Barium peroxide Metals Dinitrogen tetraoxide Metals MRH 12.97/50... 

Osmium tetraoxide and permanganate are the textbook example reactants for the direct addition of the hydroxyl function to double bonds as shown in Figure 1. Several reagents such as hydrogen peroxide, periodate, hexacyanoferrate(III) or recently also molecular oxygen [2-6] have been used to reoxidize the different metal-oxo compounds. 

The reaction mechanisms of these transition metal mediated oxidations have been the subject of several computational studies, especially in the case of osmium tetraoxide [7-10], where the controversy about the mechanism of the oxidation reaction with olefins could not be solved experimentally [11-20]. Based on the early proposal of Sharpless [12], that metallaoxetanes should be involved in alkene oxidation reactions of metal-oxo compounds like Cr02Cl2, 0s04 and Mn04" the question arose whether the reaction proceeds via a concerted [3+2] route as originally proposed by Criegee [11] or via a stepwise [2+2] process with a metallaoxetane intermediate [12] (Figure 2). 

Pentaborane(9), Reactive solvents, 0188 Calcium disilicide, Carbon tetrachloride, 3944 Fluorine, Halocarbons, 4310 Disilane, Non-metal halides, 4569 Dinitrogen tetraoxide, Halocarbons, 4747 Oxygen (Liquid), Halocarbons, 4832... 

Krypton difluoride, 4313 Potassium hexaoxoxenonate-xenon trioxide, 4674 Tetrafluoroammonium hexafluoroxenate, 4386 Xenon difluoride dioxide, 4322 Xenon difluoride oxide, 4319 Xenon difluoride, 4332 Xenon hexafluoride, 4377 Xenon tetrafluoride, 4353 Xenon tetrafluoride oxide, 4346 Xenon tetraoxide, 4863 Xenon trioxide, 4857 Xenon(II) fluoride methanesulfonate, 0443 Xenon(II) fluoride perchlorate, 3977 Xenon(II) fluoride trifluoroacetate, 0634 Xenon(II) fluoride trifluoromethanesulfonate, 0356 Xenon(IV) hydroxide, 4533 Xenon(II) pentafluoroorthoselenate, 4382 Xenon(II) pentafluoroorthotellurate, 4383 Xenon(II) perchlorate, 4110 See Other NON-METAL HALIDES, NON-METAL OXIDES... 

Cobalt is the 32nd most abundant element on Earth even though it makes up only 0.003% of the Earth s crust. It is not found in the free metallic state, despite being widely distributed in igneous rocks as minerals. Its two most common mineral ores are cobaltite (CoAsS) and erythrite [Co lAsO l ]. These ores are placed in blast furnaces to produce cobalt arsenide (COjAs), which is then treated with sulfuric acid to remove the arsenic. Finally, the product cobalt tetraoxide (Co O ) is reduced by heat with carbon (Co O + C — 3Co + 2COf resulting in cobalt metal. 

Vanadium pentoxide may be reduced to vanadium tetraoxide, trioxide, or vanadium metal by various reducing agents including hydrogen, carbon, and oxahc acid. Pentoxide may be reduced to metal by heating at high temperatures with calcium or magnesium. 

See Halogens or Interhalogens above Ammonium nitrate Metals Ammonium peroxodisulfate Iron Dinitrogen tetraoxide Metals Hydrogen peroxide Metals Nitryl fluoride Metals Peroxyformic acid Potassium dichromate Iron Potassium perchlorate Metal powders Sodium peroxide Metals... 

See Carbon dioxide, above Ammonium nitrate Metals Barium peroxide Metals Dinitrogen tetraoxide Metals Hydrogen peroxide Metals Lead(IV)oxide Metals Nitric acid Metals Oxygen (Liquid) Metals Potassium chlorate Metals Potassium perchlorate Powdered metals Sodium iodate Metals Sodium nitrate Magnesium See Halogens etc., above See Metal oxides, above See Metal oxosalts, above See Sulfur, etc., below... 

The oxidation catalyst is believed to be ruthenium tetraoxide based on work by Engle,149 who showed that alkenes could be cleaved with stoichiometric amounts of ruthenium tetraoxide. Suitable solvents for the Ru/peracid systems are water and hexane, the alkene (if liquid) and aromatic compounds. Complex-ing solvents like dimethylformamide, acetonitrile and ethers, and the addition of nitrogen-complexing agents decrease the catalytic system s activity. It has also been found that the system has to be carefully buffered otherwise the yield of the resulting carboxylic acid drops drastically.150 The influence of various ruthenium compounds has also been studied, and generally most simple and complex ruthenium salts are active. The two exceptions are Ru-red and Ru-metal, which are both inferior to the others. Ruthenium to olefin molar ratios as low as 1/20000 will afford excellent cleavage yields (> 70%). vic-Diols are also... 

The best known anhydrous oxides are listed in Table 18-E-2 the tetraoxides of Ru and Os are discussed later (Section 18-F-l). The oxides, generally rather inert to aqueous acids, are reduced to the metal by hydrogen, and dissociate on heating. There are mixed metal oxides, e.g., BaRu03, and platinum and palladium bronzes of formula MlPt304 (x = 0-1). Some oxides like MnPt306 have Pt—Pt bonds. Mixed oxides are used for electrodes in H2—02 fuel cells and in the chloralkali process. 

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