Selenium oxides

Conversion of telluiium to the hexavalent form is complete. The extent of selenium oxidation to the hexavalent form is a function of temperature. 

Inorganic Compounds. Inorganic selenium compounds are similar to those of sulfur and tellurium. The most important inorganic compounds are the selenides, haUdes, oxides, and oxyacids. Selenium oxidation states are —2, 0, +1, +2, +4, and +6. Detailed descriptions of the compounds, techniques, and methods of preparation, and references to original work are available (1—3,5,6—10, 51—54). Some important physical properties of inorganic selenium compounds are Hsted in Table 3. 

Chemical Properties. The most significant chemical property of L-ascorbic acid is its reversible oxidation to dehydro-L-ascorbic acid. Dehydro-L-ascorbic acid has been prepared by uv irradiation and by oxidation with air and charcoal, halogens, ferric chloride, hydrogen peroxide, 2,6-dichlorophenolindophenol, neutral potassium permanganate, selenium oxide, and many other compounds. Dehydro-L-ascorbic acid has been reduced to L-ascorbic acid by hydrogen iodide, hydrogen sulfide, 1,4-dithiothreitol (l,4-dimercapto-2,3-butanediol), and the like (33). 

Chemical Designations - Synonyms Selenious anhydride Selenium oxide Chemical Formula SeOj. Observable Characteristics - Physical State (as nomuiUy shipped) Solid Color. White Odor. Pungent sour. 

Selen-oxyd, n. selenium oxide, -quecksilber, n. mercury selenide. -quecksilberblei, n. (Min.) lehrbachite. -salz, n. selenide. 

Selenium oxide (SeO,) [7446-08-4], 25 Silane, tnchloro [ 10025-78-2], 83 Sodium azide [26628-22-8], 109 Sodium hydride [7646-69-7], 20 Stannane, tetrachloro- [7646-78-8], 97 Sulfuric acid, diethyl ester [64-67-5], 48 dimethyl ester [77-78-1], 62 Sulfuryl chloride isocyanate [1189-71-5], 41... 

BVMOs were also reported to facilitate mild and chemoselective conversion of boronic acids to borates, which usually hydrolyze upon biotransformation conditions using isolates protein [217]. Additionally selenium oxidation has been described in analogy to sulfoxidations [218]. 

Bebien M, G Lagniel, J Garin, D Touati, A Vermeglio, J Labarre (2002) Involvement of superoxide dismutases in the response of Escherichia coli to selenium oxides. J Bacterial 184 1556-1564. 

In the U.S.A. a common mixture for delay elements consists of selenium and barium peroxide which reacts to give selenium oxides and barium oxide. Usual proportions are 85% of barium peroxide with 15% of selenium. 

Dining attempted conversion of recovered selenium metal to the dioxide by heating in oxygen, a vigorous explosion occurred. This was attributed to selenium-catalysed oxidation of traces of organic impurities in the selenium. Oxidation of recovered selenium with nitric acid is rendered vigorous by presence of organic impurities, but is a safe procedure [1]. The later reference incorrectly attributed the explosions to the nitric acid procedure [2],... 

Antimony telluride films have been grown from antimony(III) and tellurium(IV) oxides.167 Antimony telluride films were stoichimetric and consisted of nanoscale particles of the size 100 nm. The films had a good crystallinity.167 Indium selenide films were grown from indium sulphate and selenium oxide precursors.168 The films consisted of large particles, 70 to 200 nm in diameter. The band gap was 1.73 eV.168... 

Selenium-containing donors, synthesis and manufacture of, 22 212 Selenium dichloride, 22 75t Selenium diethyldithiocarbamate, 22 73t Selenium dioxide, 22 73t, 75t, 88 toxicify of, 22 95 Selenium disulfide, 22 73t Selenium hexafluoride, 22 75t, 87 toxicify of, 22 96 Selenium hypofluorite, 22 75t Selenium iodides, 22 87 Selenium monobromide, 22 75t, 88 Selenium monochloride, 22 75t, 87 in selenium recovery, 22 85 Selenium monoxide, 22 88 Selenium oxidation, selenium recovery via, 22 81-83... 

Selenium dusts produce respiratory tract irritation manifested by nasal discharge, loss of smell, epistaxis, and cough. A group of workers briefly exposed to unmeasured but high concentrations of selenium fume developed severe irritation of the eyes, nose, and throat, followed by headaches. Transient dyspnea occurred in one case. Workers exposed to an undetermined concentration of selenium oxide developed bronchospasm and dyspnea followed within 12 hours by metal fume fever (chills, fever, headache) and bronchitis, leading to pneumonitis in a few cases all were asymptomatic within a week. ... 

Heating with oxygen at elevated temperatures decomposes hydrogen selenide forming selenium oxides and water ... 

Selenium dioxide (see Selenium and selenium eompounds) Selenium oxide (see Selenium and selenium eompounds) Semiearbazide hydrochloride... 

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