Carbon selenide diselenide

Carbon selenide telluride is a thermally very unstable compound that cannot be sublimed in a high vacuum. The compound was claimed to have been obtained in 8% yield from carbon monoselenide, generated from carbon diselenide in a high frequency discharge, and gaseous tellurium. The infrared spectrum of carbon selenide telluride was recorded. No details about the reaction conditions were reported1. 

ScCI3, Scandium chloride, 22 39 ScCl3Cs, Cesium scandium chloride, 22 23 ScC1303C 2Hm, Scandium(lll), trichloro-tris(tetrahydrofuran)-, 21 139 Sc2CI,Cs3, Cesium scandium chloride, 22 25 SeC, Carbon selenide, chromium complex, 21 1, 2 Se2C, Carbon diselenide, 21 6, 7 Se2NC3H,i, Diselenocaibamic acid, N,N-di-ethyl-,... 

According to Hofman-Bang carbon sulfide selenide, CSSe, catalyzes the iodine-azide reaction but is at the same time decomposed with the formation of selenium. Experiments, in both this laboratory and that of Hofman-Bang have shown that carbon diselenide reacts with sodium azide (in aqueous or aqueous-alcoholic solution) with immediate precipitation of red selenium even at — 20° C. //a selena-triazole is formed in this reaction it must be extremely unstable. 

Parkinson, B.A., Heller, A., and Miller, B., Effects of cations on the performance of the photoanode in the n-gallium arsenide/potassium selenide (K2Se)-potassium diselenide (K2Se2)-potassium hydroxide/carbon semiconductor liquid junction solar cell, /. Electrochem. Soc., 126,954,1979. 

Carbon Diselenide, CSe2, has been produced in very small quantity by the action of carbon tetrachloride vapour on the selenide... 

The carbon diselenide and carbon sulfide selenide complexes of platinum(0) can be synthesized from Pt(PPh3)3. Reaction of the compounds with chelating phosphines results in substitution of the triphenylphosphines (equation 541).1866 With COS the C,S-bonded compound Pt(COS)(PPh3)2 is formed from Pt(PPh3)3. The reaction can also be used to prepare the dithiocarbonato complex Pt(S2CO)(PPh3)2.1867... 

Diphenyl diselenide, (CeH5)2Se2, is formed as a by-product in the preparation of phenyl selenide when magnesium phenyl bromide in ether solution reacts with selenium.5 A 2 per cent, yield is obtained when benzene, aluminium and selenium bromides react in dilute carbon disulphide solution. The product melts at 62° C.6 The corresponding oxide is an oil, B.pt. 230° C. at 65 mm.,7 and the sulphide, (C6H5)2Se2S, M.pt. 55° C., is obtained from sulphur chloride and phenyl selenide in carbon disulphide solution.8... 

Carbon diselenide CSe2 Carbonyl selenide COSe. Hydrogen selenide HjSe... 

The synthesis of substituted sclcnolo 2,3-/ ]thiophcncs 208 and selenolo [2,3-b selenophenes 209 via ketene dithioacetals has been published (Scheme 40) [55], The easy access to ketene dithioacetals via carbon disulfide cannot be applied to selenium since the strongly odorous carbon diselenide cannot be readily prepared. The authors [55] overcame this problem using sodium selenide for the synthesis of selenolo[2,3-/ thiophcncs 208, which could be synthesized from methylsulfanylthiophenes 206 and sodium selenide and/or from 5-methylsulfanylselenophenes 207 and thioglycolate. 

The reactions of selenocarbonyl compounds with electrophiles are also well-established procedures. Alkylations or acylations of the selenium atom of selenoamides409 or selenoureas410 are known. Selenonium salts are formed initially they can then be converted into diselenides, selenazoles, or cyclic selenides depending on their structure. Reactions of selenocarbonyls with bromine and iodine have also been widely exploited. Selenocarbonates, sele-nothiocarbonates,411-415 and selenoureas416-418 can be employed, the reaction of 209 with 1 equiv. bromine led to the hypervalent 10-Se-3 complex 210, whereas an excess of bromine gave rise to a cleavage of the carbon-selenium double bond and formation of product 211 (Scheme 64). 

A-allylic amines are conveniently prepared in high yields by the reaction of azides with allylindium reagents in the presence of sodium iodide at ambient temperature (Equation (74)).307 Stannylation with tributylchloro-stannane occurs exclusively at the a-carbon, yielding allyltributylstannanes (E, Z)-isomerization of the allylic double bond depends largely upon the substitution pattern on the allylic moiety (Equation (75)).26 Allyl and propargyl bromides react with diphenyl diselenides in aqueous media to give allyl and propargyl selenides (Equation (76)).308 309... 

An alternative approach is to use the readily available P-hydroxy phenyl selenides as Ritter substrates. Amide formation occurs with retention of configuration, indicating that fission of the carbon-oxygen bond is assisted by the neighboring phenylseleno group (Scheme 61). Diphenyl diselenide and iodine react with 1,5-dienes to give carbocyclic products. Initial formation of the episelenonium ion is followed by intramolecular attack and subsequent Ritter reaction (Scheme 62). ... 

Other Elements - Irradiation ((>300 nm) of the allene (366) in the presence of diphenyl diselenide affords a high yield of the adduct (367) as an El Z mixture (28 72). Diphenyl disulfide affords a complex mixture of products with the same allene while diphenyl ditelluride does not react. The difference between the sulfide and the selenide is due to the lower ability of diphenyl disulfide to react with carbon radicals. When a mixed system is used [(PhS)2 (PhSe)2 as a 1 1 mixture] mixed addition occurs. Thus with the allene (366) an almost quantitative yield of (368) is produced and other allenes (369) are also reactive imder these conditions, affording (370). The use of diphenyl selenide as a catalyst for the photochemical isomerism of some carotenoids has been described. ... 

Diphenyl diselenide can add to allenes very smoothly, providing (8-(phenylsele-no)allylic selenides in high yields, as depicted in Scheme 15.66 [146]. In contrast, the photoinduced reaction of (PhS)2 with allenes affords a complex mixture, because the lower capturing ability of (PhS)2 for carbon free radicals enables oligomerization of the allenes. 

Less interest has been shown, however, in the photoreactions of organoselenium compounds. Radical additions of diphenyl diselenide to 1,1-dimethylallene to give the l-(phenylseleno-methyl)vinyl selenide (193) and of diethyl (2-phenylseleno)-propanedioate to alkenes to give the adducts (194) have been reported. In contrast, carbon-selenium heterolytic bond cleavage is preferred on irradiation in the presence of 1,4-dicyanonaphthal-ene in this way, for example, the phenylselenylcyclohexane (195) is converted into the ether (196) by irradiation in methanol. 

Triselenane is decomposed by the action of chlorine in carbon tetrachloride into bis(chloro-methyl)selenide, chloromethylselenium chloride, and bis(chloromethyl)diselenide <50JCS1351>. 

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