Selenium oxide chloride

Selenium oxide chloride a-Halogenoketones from ketones... 

Selenium oxide chloride added slowly with ice-cooling to acetophenone in benzene, and allowed to stand ca. 1 hr. at room temp. a-chloroacetophenone. Y 54%. F. e. s. J. P. Schaefer and F. Sonnenberg, J. Org. Ghem. 28, 1128 (1963). 

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). 

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... 

The chemistry of the oxide chlorides, bromides, and iodides of tetra-valent tellurium is in marked contrast to the more variable chemistry of corresponding more acidic sulfur and selenium compounds. One of the reasons seems to be the reluctance of Te(lV) to form stable Te=0 double bonds in condensed systems. In contrast to the numerous oxo-haloselenatesdV) with strong Se=0 bonding, or to compounds such as SOCI2, SO2CI2, SOaCl and their homologues, no comparable Te ana-... 

Cl 64.24%. SeCI4. Prepd by the action of an excess of chlorine on selenium Berzelius, cited in Meltor s vol X, 898 (1930) by the action of thionyl chloride or phosphorus trichloride on selenium oxychloride and by the action of phosphorus pentachloride on selenium oxide Michael is. Z Chem. [2) 6, 460 (1870) by the action of anhydr selenic acid on acetyl chloride at 0 Lamb, Am, Chem. J. 30,209 (1903). Crystal structure Shoemaker, Abrahams, Acta Cryst. 18,... 

Cray, hexagonal, microscopic needles, mp 880. d<5 8.216. Two forms exist transition temp at 133. Forms metallic silver and selenium oxide when heated in oxygen transformed by chlorine into silver and selenium chlorides oxidized to silver selenite by fuming nitric acid. So] in mol ten silver or bismuth without chemical change. Practically insol in water. 

Selenium(IV) oxychloride was syntheazed first by Weber in 1859 by heating together the vapors of selenium(IV) oxide and selenium (IV) chloride. It was later prepared by Michaelis by the interaction of selenium(IV) oxide and phosphorus(V) chloride. Cameron and Macallam allowed a mixture of selenium(IV) oxide and sodium chloride to interact and obtained sodium selenite and selenium(IV) oxychloride. 

The classical researches of Victor Lenher on selenium(IV) oxychloride (reviewed by Smith ) were begun about 1919 at the University of Wisconsin. Lenher suggested the following practical laboratory methods for the preparation of selenium(IV) oxychloride (1) union of selenium(IV) oxide and selenium(IV) chloride (2) partial hydrolysis of sele-nium(IV) chloride, and (3) dehydration of Se02 2HCl (dichloroselenious acid, H2Se02Cl2). ... 

Tellurium(IV) chloride is most conveniently prepared by the direct union of the elements, but is also obtainable by the reaction of elemental tellurium or tellurium(IV) oxide with various anhydrous chlorides such as sulfur chloride, iron(III) chloride, and selenium(IV) chloride. " Tellurium of 99.96 per cent purity and chlorine of similar purity are easily obtainable. The absence of other reaction products in the direct union simplifies the purification problem. 

The electrodeposition of copper indium selenide and telluride was discussed by Bhattacharya and Rajeshwar (66). The deposition solutions were made in a multistep process. A 0.5 M solution (A) of indium chloride was prepared. The copper solution (B) was prepared from cuprous chloride dissolved in 30 ml of triethanolamine, 40 ml of 30% ammonia and 150 ml of water. The copper concentration was 0.5 M. Solutions A and B were mixed in equal amounts, diluted 10 times and adjusted to pH 1 with HCI. This solution (C) was aged for 24 hrs. The actual deposition bath was made from 20 ml of either 0.1 M selenium oxide or 0.1 M tellurium oxide and 60 ml of solution C. The triethanolamine was added to the copper solution as a complexing agent to shift the deposition potential. Depositions were carried out at -1.0 volt versus a saturated calomel electrode. The initial current density was 12 mA/cm . 

Alkyl Isoquinolines. Coal tar contains small amounts of l-methylisoquinoline [1721-93-3] 3-methylisoquinoline [1125-80-0] and 1,3-dimetliylisoquinoline [1721-94-4J. The 1- and 3-methyl groups are more reactive than others in the isoquinoline nucleus and readily oxidize with selenium dioxide to form the corresponding isoquinoline aldehydes (174). These compounds can also be obtained by the hydrolysis of the dihalomethyl group. The 1- and 3-methyhsoquinolines condense with benzaldehyde in the presence of zinc chloride or acetic anhydride to produce 1- and 3-styryhsoquinolines. Radicals formed by decarboxylation of carboxyUc acids react to produce 1-aIkyhsoquinolines. 

Production and Economic Aspects. Thallium is obtained commercially as a by-product in the roasting of zinc, copper, and lead ores. The thallium is collected in the flue dust in the form of oxide or sulfate with other by-product metals, eg, cadmium, indium, germanium, selenium, and tellurium. The thallium content of the flue dust is low and further enrichment steps are required. If the thallium compounds present are soluble, ie, as oxides or sulfates, direct leaching with water or dilute acid separates them from the other insoluble metals. Otherwise, the thallium compound is solubilized with oxidizing roasts, by sulfatization, or by treatment with alkaU. The thallium precipitates from these solutions as thaUium(I) chloride [7791 -12-0]. Electrolysis of the thaUium(I) sulfate [7446-18-6] solution affords thallium metal in high purity (5,6). The sulfate solution must be acidified with sulfuric acid to avoid cathodic separation of zinc and anodic deposition of thaUium(III) oxide [1314-32-5]. The metal deposited on the cathode is removed, kneaded into lumps, and dried. It is then compressed into blocks, melted under hydrogen, and cast into sticks. 

In 1956, the alkaloid Methylpseudolycorine (101) isolated from the King Alfred daffodil (Narcissus pseudonarcissus L.) was oxidized to the pale yellow chloride with selenium dioxide (Scheme 36). Conversion into the betaine was accomplished by aqueous ammonia to give yellow prisms of the trihydrate of Criasbetaine (100) (56JA4145, 56JA4151). The UV absorption... 

The solution should be free from the following, which either interfere or lead to an unsatisfactory deposit silver, mercury, bismuth, selenium, tellurium, arsenic, antimony, tin, molybdenum, gold and the platinum metals, thiocyanate, chloride, oxidising agents such as oxides of nitrogen, or excessive amounts of iron(III), nitrate or nitric acid. Chloride ion is avoided because Cu( I) is stabilised as a chloro-complex and remains in solution to be re-oxidised at the anode unless hydrazinium chloride is added as depolariser. 

Diphenyl diselenide has been prepared by disproportionation of phenyl selenocyanate in the presence of potassium hydroxide" or ammonia/ and by air oxidation of benzeneselenol. The preparation of benzeneselenol is described in an earlier volume in this series/ In the present procedure phenylselenomagnesium bromide formed from phenylmagnesium bromide and selenium is oxidized directly to diphenyl diselenide with bromine/ Thus the liberation of the malodorous and toxic hydrogen selenide and benzeneselenol is avoided. Benzeneselenenyl chloride has been prepared by thermal elimination of ethyl chloride from ethyl phenyl selenide di-chloride/ by thermal elimination of chlorine from phenylselenium trichloride," and by chlorinolysis of diphenyl diselenide with either sulfuryl chloride " or chlorine. " ... 

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