Containing Activated Oxygen

Acyclic alcohols can be deoxygenated easily by this two-step reaction sequence (first, reaction of the alcohols with dicyclohexylcarbodiimide, then 

---

When an alkaline earth peroxide is dissolved in arsenic acid and the solution is evaporated under reduced pressure at a low temperature, a perarsenate is said to be produced,1 and if an alkali sulphate is added to the solution before evaporation, a solution of the alkali perarsenate is- obtained. The latter may be obtained with scarcely any loss of active oxygen by careful evaporation to dryness under reduced pressure. Using the above method of desiccation, however, Coons 2 could not obtain any compound containing active oxygen either by this method or by the electrolytic method. 

When an alkali perarsenate is added to aqueous solutions of metallic salts, precipitates containing active oxygen are obtained thus salts of the alkaline earths, zinc, cadmium, silver, mercurous mercury, lead and bismuth yield white precipitates, mercuric salts give red precipitates, copper blue, manganese pink, nickel greenish-white and ferrous salts bluish-green. With auric chloride oxygen is liberated, and with ferric chloride feme hydroxide is precipitated. 

Properties White, amorphous powder of unknown constitution containing active oxygen. Evolves oxygen gas when dissolved in water hygroscopic. 

There are some examples in the literature where tertiary phosphines have been used as substrates to follow 0-transfer in synthetic models of these metalloenzymes. In Table 12 we show examples of enzymes which contain activated oxygen intermediates with could be potential targets for tertiary phosphines. We have also included details of the reactivity of model compounds with phosphines where known. Note that phosphines could interfere with electron transport in other ways, for example by binding to Fe at the haem site (see Sect. 4.5) or by acting as an electron acceptor or donor (see Sect. 4.3). 

Activated carbons contain chemisorbed oxygen in varying amounts unless special cate is taken to eliminate it. Desired adsorption properties often depend upon the amount and type of chemisorbed oxygen species on the surface. Therefore, the adsorption properties of an activated carbon adsorbent depend on its prior temperature and oxygen-exposure history. In contrast, molecular sieve 2eohtes and other oxide adsorbents are not affected by oxidi2ing or reducing conditions. 

The commercial product is a powder containing a minimum of 96% Na202 and approximately 20% active oxygen. It is made commercially by oxidizing the molten metal with either oxygen or air enriched in oxygen. Early industrial history (1) and manufacturing details (3) are available. Sodium... 

Strontium Peroxide. Commercial strontium peroxide contains about 85% Sr02 and 10% active oxygen. It can be made by heating strontium oxide ia the preseace of oxygea gas uader 20 MPa (200 atm) pressure, or by reactiag a soluble stroatium salt with hydrogea peroxide. The only substantial appHcation for this compound is ia pyrotechnics (qv). Strontium peroxide [1314-18-7] produces a red color ia flames. 

The commercial product is a dull yeUow powder containing about 90% Ba02 and about 8.5% active oxygen the remainder is mainly barium carbonate and barium hydroxide. The principal use is in pyrotechnics, but there are also small uses in the curing of polysulftde mbbers and in the production of certain titanium—aluminum alloys. 

The commercial product is a white powder containing a minimum of 13% of active oxygen and up to 15% of anhydrous sodium carbonate. The solubihty ia water at 20°C is about 150 g/L. 

Sodium perborate tnhydrate, NaBO 3H2O or Na2B2(02)2(0H)4 4H2O, triclinic, contains 11.8 wt % active oxygen (96). It has been claimed to have better thermal stabiUty than the tetrahydrate but has not been used commercially. The tnhydrate can be made by dehydration of the tetrahydrate or by crystallization from a sodium metaborate and hydrogen peroxide solution in the present of tnhydrate seeds. Between 18 and 50°C the tnhydrate is more stable but slower to crystallize than the tetrahydrate. Below 15°C the tnhydrate is spontaneously converted into the tetrahydrate. 

Of the many tests which have been submitted, the determination of active oxygen or peroxide content seems to give rather good correlation of data. During the oxidation of fat, certain oxygen-containing compounds are formed which are active in the sense that they are capable of liberating iodine from potassium iodide (19). The liberated iodine may be determined quantitatively and it thus becomes a measure of rancidity. 

---