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Selenium dioxide imparts a red colour to glass. It is used in small quantities to counteract the colour due to iron impurities and so to create (apparently) colourless glass. In larger quantities, it gives a deep ruby red colour. Selenium dioxide is the active ingredient in some cold-bluing solutions.
The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of DC power surge protectors and one type of fluorescent quantum dot.
Selenium is a nutrient that is naturally present in many foods, added to others and is also available as a dietary supplement in pill, powder and liquid form, explains Perri Halperin, a ...
Selenium forms two oxides: selenium dioxide (SeO 2) and selenium trioxide (SeO 3). Selenium dioxide is formed by the reaction of elemental selenium with oxygen: [5] + It is a polymeric solid that forms monomeric SeO 2 molecules in the gas phase. It dissolves in water to form selenous acid, H 2 SeO 3.
Selenium is a component of the amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient that functions as cofactor for glutathione peroxidases and certain forms of thioredoxin reductase. [1] Selenium-containing proteins are produced from inorganic selenium via the intermediacy of selenophosphate (PSeO 3 3 ...
Selenium is toxic in high concentrations. As sodium selenite, the chronic toxic dose for human beings was described as about 2.4 to 3 milligrams of selenium per day. [7] In 2000, the US Institute of Medicine set the adult Tolerable upper intake levels (UL) for selenium from all sources - food, drinking water and dietary supplements - at 400 μg/day. [8]
Oxidations involving selenium dioxide are often carried out with catalytic amounts of the selenium compound and in presence of a sacrificial catalyst or co-oxidant such as hydrogen peroxide. SeO 2 -based oxidations sometimes afford carbonyl compounds such as ketones , [ 24 ] β- Pinene [ 25 ] and cyclohexanone oxidation to 1,2-cyclohexanedione ...
The Riley oxidation is a selenium dioxide-mediated oxidation of methylene groups adjacent to carbonyls. It was first reported by Harry Lister Riley and co-workers in 1932. [ 1 ] In the decade that ensued, selenium -mediated oxidation rapidly expanded in use, and in 1939, Andre Guillemonat and co-workers disclosed the selenium dioxide-mediated ...