Potassium superoxide,

Superoxides are used in breathing appHcations requiring no auxHiary source of oxygen. Sodium superoxide is ca 10 times as expensive as potassium superoxide because high temperature, high pressure autoclaves are required for its production. Use of calcium superoxide is experimental. Potassium superoxide is the most commonly used superoxide oxygen generator. 

Potassium superoxide is utilized primarily ia respiratory support equipment. The material is produced ia the United States (Gallery Chemical Company), France (Air Liquide), and China. 

Potassium superoxide is produced commercially by spraying molten potassium iato an air stream, which may be enriched with oxygen. Excess air is used to dissipate the heat of reaction and to maintain the temperature at ca 300°C. It can also be prepared ia a highly pure state by oxidizing potassium metal that is dissolved ia Hquid ammonia at —50° C. 

Of the binary peroxides made from hydrogen peroxide, calcium peroxide is the most important. World production is about 2000 t/yr, which is dominated by the dough-conditioning market in the United States. The markets for the other binary peroxides, such as those of zinc, magnesium, and strontium, total only a few hundred metric tons. Sodium peroxide and potassium superoxide are made from the alkaU metals and thek total markets are in the hundreds of tons. 

Primary and secondary alkyl haUdes and sulfonates react with potassium superoxide to form dialkyl peroxides (101,102) (eq. 28). Dia2oalkanes, eg, dia2omethane, have been used to alkylate hydroperoxides (66) (eq. 29). 

Phenols with bulky ortho- and para-substituents, eg, phenoHc antioxidants, do not undergo this reaction however, they scavenge radicals generated by thermolysis of diacyl peroxides and other peroxides. Diacyl peroxides react with potassium superoxide, KO2, forming singlet oxygen (207). 

Historically, potassium metal was used by the Mine Safety AppHances Company (parent company of Gallery Chemical Company) to develop potassium superoxide [12030-88-5] oxygen source in self-contained breathing equipment (see Oxygen-GENERATION systems). Greater understanding... 

Potassium Superoxide. Potassium, mbidium, and cesium form superoxides, MO2, upon oxidation by oxygen or air. Sodium yields the peroxide, Na202 lithium yields the oxide, Li20, when oxidized under comparable conditions. Potassium superoxide [12030-88-5] KO2 liberates oxygen in contact with moisture and carbon dioxide (qv). This important property enables KO2 to serve as an oxygen source in self-contained breathing equipment. 

Chemical Designations - Synonyms Potassium superoxide Chemical Formula K2O2. 

Oxygen masks for producing 02 in emergency situations contain potassium superoxide, K02. It reacts with C02 and H20 in exhaled air to produce oxygen ... 

Potassium superoxide is used in self-contained breathing devices for firefighters and miners. It reacts with the moisture in exhaled air to generate oxygen ... 

A self-contained breathing apparatus contains 248 g of potassium superoxide. A firefighter exhales 116 L of air at 37°C and 748 mm 1%. The volume percent of water in exhaled air is 6.2. What mass of potassium superoxide is left after the water in the exhaled air reacts with it ... 

Potassium chromate, 76,263 Potassium dichromate, 77-78 Potassium iodide, 499 Potassium permanganate, 17,288,549 Potassium superoxide, 543-544 Powell, H. M 175... 

Solutions of potassium superoxide-crown ether in dimethyl sulphoxide have been shown to cause oxidation of the solvent to the sulphone75 such a reaction could possibly be used synthetically. In the presence of water the reaction probably proceeds as shown ... 

The phosphorus-containing peroxy species obtained on reaction of potassium superoxide with diethylchlorophosphate, as shown in equation (23), has also been used to prepare sulphones from sulphoxides76 at 20 °C in reasonable yields. 

Unsymmetrical thiosulphinates and thiosulphonates are both oxidized by potassium superoxide in pyridine in the presence of 18-crown-6 ether to produce sulphinic and sulphonic acids and a disulphide, under mild conditions (equation 84)200,201. Sulphinic and sulphonic acids were produced from both the R and R substituents whilst the disulphide was derived only from the sulphenyl side of the reactant. Thus, the reaction mixture contained five products, making the reaction not synthetically useful. Pyrolysis of thiosulphinates also produces mixtures of products, one being the thiosulphonate again this is not a synthetically useful reaction202. 

L.6 Potassium superoxide, KC)2, is utilized in a closed-system breathing apparatus to remove carbon dioxide and water from exhaled air. The removal of water generates oxygen for breathing by the reaction 4 K02(s) + 2 H20(1) — 3 02(g) +... 

The carbon dioxide generated by the personnel in the artificial atmosphere of submarines and spacecraft must be removed from the air and the oxygen recovered. Submarine design teams have investigated the use of potassium superoxide, K02, as an air purifier because this compound reacts with carbon dioxide and releases oxygen (Fig. 4.16) ... 

FIGURE 4.16 When carbon dioxide is passed over potassium superoxide (the yellow solid), it reacts to form colorless potassium carbonate (the white solid coating the walls of the tube) and oxygen gas. The reaction is used to remove carbon dioxide from the air in a closed-system breathing environment. 

In the presence of air, there is very slow oxidation, which forms a layer of potassium superoxide as follows ... 

It violently reacts with strong oxidants such as ammonium perchlorate (ignition in contact with copper pip ), alkaline chlorates (detonation by heating, impact or friction powdered copper), ammonium nitrate (detonation molten ammonium nitrate and powdered copper) and potassium superoxide (copper glows). 

A zinc/potassium chlorate mixture is explosive on impact or friction. With potassium superoxide the metal glows. The same thing happens when a mixture of zinc and titanium oxide is heated or when nitric acid vapour is in contact with melted zinc ( 400°C). 

---