Selenium chloride

Selenium analogues RN=SeCl2 are unknown for R = aryl or alkyl and thermally unstable when R = CE3 or C2E5. The perfluoroalkyl derivatives are prepared by the reaction of dichloroamino compounds and Sc2Cl2 in CCI3E (Eq. 8.18), but they decompose at room temperature to the corresponding diazene and a mixture of selenium chlorides. 

Selenium Nitride (Nitrogen Selenide). Se4N4, mw 371.87, N 15,07%, yel-brick red hygr amorph powd, mp (expl 160—200°), bp (decompn). SI sol in hot w (decompn) v si sol in acet, acet ac, bz CS2. Methods of prepn include passing dry ammonia into a dil soln of selenyl chloride in bz, or into a cooled soln of selenium chloride in CS2 (Refs 1-5 7-10)... 

Lee, B., el al. (2002). Prostaglandin D synthase in the prenatal ovine brain and effects of its inhibition with selenium chloride on fetal sleep/wake activity in utero. 

Sulfur and selenium diamides are obtained by the reaction of sulfur or selenium chlorides with an aliphatic secondary amine. Polyselanes Sex(NR2)2 (x = 2-4, NR2=morpholinyl x = 4, NR2=piperidinyl) are formed in the reaction of elemental selenium with the boiling amine in the presence of Pb304.19 The acyclic tellurium(II) diamide [Te(NMe2)2]00 (see Figure 1) is prepared by the reaction of TeCl4 with LiNMe2.20... 

In 1823 Johann Karl Ludwig Zincken (1790—1862) detected selenium in some ores from Zorge and Tilkerode in the eastern part of the Harz, and in 1825 Heinrich Rose analyzed them quantitatively. By heating them in a current of chlorine gas, Rose converted all the metals to chlorides and separated the selenium chloride, which was the only volatile chloride present, from the non-volatile chlorides of the metals (34). He found these minerals to be selenides of lead, copper, cobalt, and mercury. 

Nitrogen selenide, N4Se4, was prepared by Espenschied [117] by the action of ammonia on selenium chloride. It is an orange-red, amorphous, explosive powder. 

Both of the foregoing varieties of amorphous selenium are somewhat soluble in carbon disulphide, but selenium chloride, carbon diselenide and methylene iodide are better solvents.4 On account of its finer state of division the red form appears more soluble. Discordant results are easily obtained with such solutions because of the tendency to change, especially on warming, into the less soluble crystalline variety —generally the monoclinic form. 

Triethyl selenium chloride, (C2Hg)3SeCl, is obtained by adding hydrochloric acid to the hydroxide with platinic chloride it gives a... 

Diphenyl selenium disulphide,10 (C6H5)2SeS2, results from the action of selenium chloride on a solution of thiophenol in carbon disulphide. It melts at 50° to 51° C. 

These derivatives fall into two classes, the first containing an unsubstituted nucleus, and the second having alkoxy-groups in the nucleus. The former may be represented by triphenyl selenium chloride, prepared by adding diphenyl selenium dichloride to a suspension of aluminium chloride in dry benzene. This chloride is crystalline, absorbs atmospheric moisture to yield a dihydrate, and decomposes at its melting-point, forming diphenyl selenide and chlorobenzene. Boiling with ethylene dibromide converts it into triphenyl selenium bromide. The hydroxide has not been isolated in the solid state, but salts have been prepared. The alkoxy-derivatives are represented by... 

Trianisyl selenium chloride, (C6H4.OCH3)3SeCl, is obtained in a similar manner to the phenetyl compound, and yields a hydroxide, iodide and platinichloride. The platinichloride decomposes below 90° C. and is not very stable at the ordinary temperature. A dichromate is also known, an orange-brown powder decomposing at 68° to 70° C. 

Another method of preparation is as follows 1 33 parts of fluorescein are dissolved in 5 parts of ether and treated with 25 parts of selenium chloride in the same solvent. A yellowish-red precipitate separates, and after long stirring at the ordinary temperature the ether is distilled off. The residue is stirred with water, the mixture filtered and the residue now dissolved in sodium hydroxide. After further filtration the filtrate is treated with hydrochloric acid, which precipitates seleno-fluorescei n. Further purification is effected by solution in alkali and reprecipitation. A reddish-brown powder is obtained, soluble with fluorescence in alcohol, but insoluble in water. In concentrated sulphuric acid it dissolves to give an orange solution. Its alkali salts are very soluble in wrater, giving red solutions. This process may also be applied to phthalins, which are obtained by the reduction of phthaleins and their halogen derivatives. If the selenium chloride is replaced by the oxychloride similar products are obtained.2 In place of the phthalins specified in the patents quoted, their O-acetyl compounds or O-acetyl compounds of the phthaleins may be used in indifferent solvents. The products are different from those obtained by the action of selenium on fluoresceins in aqueous alkali solutions.3... 

This occurs when equimolecular quantities of selenium chloride (SeCl2) and phenyl-j8-naphthylamine are condensed in benzene solution. It crystallises as small, yellow, bushy needles, M.pt. 176° C., readily soluble in boiling benzene or boiling alcohol, sparingly soluble in cold acetic acid. 

The hindered silyl chlorides (Ar X)3SiCl (X = S, Se) react with AgCICU to give a range of sulphides and selenides which are thought to result through the intermediacy of the silicenium ion which loses Ar X+ and (Ar X)2Si (X = S) or Ar X (X = Se). With the thio derivative, the products are the disulphide (5), sulphide (6) and arene (equation 13), while for the selenium chloride, diselenides and selenides dominate (equation 14)25. 

Selenium is a steel gray or purplish powder, also fabricated into pellets, sticks, or plates. Selenium dioxide, selenous acid, and the alkali-metal selenites and selenates are colorless powders or crystals. Selenium chloride (reddish yellow), selenyl chloride (colorless or yellow) (bp, 176°C), and selenic acid (colorless) are liquids, whereas selenium tetrachloride is a cream-colored crystalline solid.1... 

Wear nitrile rubber gloves, laboratory coat, and eye protection. Selenium powder may be mixed with sand and treated as normal refuse, as may the disulfide. Soluble selenites and selenates can be dissolved in water and run to waste, diluting with at least 50 times its volume of running water. Soda ash should be applied liberally to spills of selenium dioxide, selenic and selenous acids, and selenyl and selenium chlorides, which may then be mopped up cautiously with plenty of water wash down the drain, diluting greatly with at least 50 times its volume of water.16... 

Bisfpentafluoroethyltelluro] mercury and pentafluoroethyl selenium chloride yielded pentafluoroethyl pentafluoroethylseleno tellurium2. 

Selenium nitride, SeN, is formed by the reaction of selenium or selenium chlorides Se2Cl2 or SeCLi with active nitrogen prodnced by a high freqnency discharge. To date, only the electron band spectra have been investigated. 

SYNS SELENINYL CHLORIDE SELENIUM CHLORIDE OXIDE... 

Tetravalent selenium chlorides, like selenenyl electrophiles, add readily to alkenes affording tetravalent /i-chloro alkylselenium dichlorides. 

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