Selenium dioxide oxychloride

Seiko Chemical Co., Ltd, 188 Selenium and Selenium Compounds, 115 Selenium dioxide, 116 Selenium hexafluoride, 116 Selenium oxychloride, 116 Selenium sulfides, 116... 

Diamino-2,l,3-benzothiadiazole 82 affords [l,2,5]selenodiazolo[3,4-i ]-2,l,3-benzothiadiazole 83 quantitatively on treatment with selenium oxychloride in refluxing chloroform-pyridine <2004JHC955>. This was an improvement of the previous method using selenium dioxide (62% yield) <1984ZNB485>. 6-Isoprenyl-477-imidazo[4,5-< ]-benzothiadiazolone 84 was obtained when 4,5-diaminobenzothiadiazole was reacted with methyl acetoacetate in xylene at reflux (Scheme 10) <1997H(45)19>. 

SELENIUM TETRACHLORIDE SELENIUM HEXAFLUORIDE SELENIUM OXYCHLORIDE SELENIUM DIOXIDE SILICON... 

Compounds Selenium dioxide selenium trioxide selenium oxychloride sodium selenite sodium selenate hydrogen selenide selenic acid selenium sulfide selenium disulfide... 

Elemental selenium is not particularly irritating, but various compounds such as selenium oxychloride and selenium dioxide are strong vesicants. Skin contact with the fume of heated selenium dioxide caused an acute, weeping dermatitis, with the development of hypersensitivity in some cases. Selenium dioxide forms selenious acid when in contact with water if allowed to penetrate beneath the fingernails, it causes an especially painful inflammatory reaction. ... 

Selenium oxychloride may be prepared by several methods (1) by passing chlorine gas into a suspension of selenium dioxide in carbon tetrachloride, (2) by heating thionyl chloride, SOCE, with selenium dioxide, (3) by dehydration of dichloroselenious acid, H2Se(CE)02, and (4) by fusion of selenium dioxide, selenium, and calcium chloride. 

By various methods from selenium dioxide for example, by the action of hydrogen chloride, thionyl chloride or phosphorus pentachloride. The last-named is perhaps the most convenient chlorinating agent. A mixture of the pentachloride and the dioxide is heated until chemical change causes it to solidify. Phosphorus oxychloride can be distilled off with the aid of a current of carbon dioxide and the residual selenium tetrachloride purified by sublimation.8... 

By adding the calculated amount of dry selenium dioxide to selenium tetrachloride suspended in carbon tetrachloride. The oxychloride formed in the cold dissolves in the carbon tetrachloride, from which it may be obtained by distillation. Carbon tetrachloride distils at 76° to 77° C., while the selenium oxychloride distils over at 176-4° C.1... 

This reaction may also be effected by mixing together the selenium dioxide and the dehydrating agent, passing in hydrogen chloride in the cold and then distilling off the oxychloride.4... 

When a mixture of selenium dioxide and selenium tetrachloride is heated in a sealed tube, selenium oxychloride is formed 5... 

Selenium oxychloride is also formed when selenium dioxide is heated with sodium chloride 6... 

Carbon monoxide has no action on selenium oxychloride.2 Water causes decomposition of the liquid into selenium dioxide and hydrogen chloride. Anhydrous ammonia reacts according to the equation. -... 

Phosphorus pentaehloride acts on selenium dioxide with the formation of the tetrachloride, whilst phosphorus trichloride yields brown amorphous selenium in these reactions phosphorus oxychloride is also formed. 

A repetition of the foregoing work by Meyer and Pawletta,4 however, failed to confirm the production of selenium trioxide. According to these investigators, the dissolution of selenium in selenium oxychloride results in the formation of selenious chloride, and the precipitate obtained by the action of ozone is a mixture of this salt with selenium dioxide. Furthermore, substitution of carbon tetrachloride or glacial acetic acid for selenium oxychloride did not lead to the separation of the tri oxide. 

Hydroxymethylpyridazines are easily oxidized with selenium dioxide to the corresponding aldehydes. Oxidation of the corresponding secondary alcohols with chromic acid in aqueous sulfuric acid gives ketones, while oxidation of a hydroxymethyl group with permanganate leads to the pyridazinecarboxylic acids. Hydroxymethyl groups are converted into chloromethyl groups with thionyl chloride or phosphorus oxychloride. 

In this section, ring synthesis of 1,2,5-selenadiazoles and their fused systems such as 2,1,3-benzoselenadiazoles are described. Most synthetic methods involve the reaction of 1,2-diamines with selenium dioxide or selenium oxychloride. The methodology has been described <2004HOU777, 1996CHEC-II(4)743, 1984CHEC(6)513>. A related investigation toward 2,1,3-benzotelluradiazoles is also described here. 

Toxicity and health effects Selenium causes hair and nail loss, discoloration and decay of the teeth, and CNS disturbances, including pain and anesthesia of the extremities. Inhalation of hydrogen selenide causes pulmonary edema. The dusts of selenium produce respiratory tract irritation, while the fumes of selenium dioxide produce metal fume fever. Dermal exposure and ingestion of selenium oxychloride cause skin burns, corrosive injury to the gastrointestinal tract, stupor, respiratory depression, and refractory hypotension. Ingestion of selenious acid causes corrosive injury to the gastrointestinal tract, stupor, respiratory depression, and refractory hypotension... 

Selenious add, xe Selenium dioxide Selenium, 532, 759, 996-992 Selenium dioxide, 477-478,532,992-1666 Selenium oxychloride, 1666 Selenophenol, 423, 992 i8-Selinene, 570 S-Selinene, 570... 

The selenium compounds that are most likely to be encountered in air in occupational settings are dusts of elemental selenium, hydrogen selenide, and selenium dioxide. Other volatile selenium compounds (e.g., dimethyl selenide, dimethyl diselenide) might be encountered in some naturally occurring situations. Because selenium is converted from one form to another, as in plant biosynthesis of selenoamino acids, it is not clear which specific forms may be encountered at hazardous waste sites. If a hazardous waste site specifically contains deposits of compounds of selenium, those compounds could be released off-site in dust or air. Toxicity data for exposures via inhalation are available for elemental selenium, selenium dioxide, selenium oxychloride, hydrogen selenide, and dimethyl selenide. Because there are few studies of inhalation of selenium of any single form, all available studies of inhalation exposures to selenium compounds will be included in this discussion. 

Massachusetts Oil and hazardous material Selenious acid Selenium and compounds Selenium dioxide Selenium disulfide Selenium oxide Selenium oxychloride Selenium sulfide Selenourea BNA 2001... 

Selenium dioxide-Hydrogen peroxide [1, 1000, before Selenium oxychloride],... 

Perchloric acid Phosphomolybdic acid Phosphorus oxychloride Phosphorus pentachloride Phosphorus trichloride y-Picoline Polyphosphoric acid Potassium silicate Rhodium Selenium Selenium dioxide Silica gel Silver oxide (ous) Sodium borohydride Sodium silicate Strontium carbonate Sulfur dioxide Tantalum Tellurium Tetraisopropyl di (dioctylphosphito) titanate Titanocene dichloride Trichloromethylphosphonic acid Tristriphenylphosphine rhodium carbonyl hydride Tungsten carbide Vermiculite Ytterbium oxide Zinc chloride Zinc dust Zinc 2-ethylhexanoate Zirconium potassium hexafluoride... 

Selenium oxychloride, selenium dioxide and tellurium dioxide are extensively ionized owing to protonation. From titanium(IV) chloride TiCl3(S03Cl) is obtained ... 

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