Diphenyl selenide

C6H5NH2 + NaNOs + 2HCI CeHsNaCl + NaCl + 2H2O 2C0H5N2CI + KaSe - (C6H5)2Se + 2KCI + ( - i)Se + 2N2 

In a 500-cc. beaker are placed 360 g. (6.4 moles) of powdered potassium hydroxide and 240 g. (3 gram atoms) of black powdered selenium, which have been previously ground together in a mortar. This mixture is heated (Note 1) in an oil bath at 140-150° until a thick, dark red liquid is formed (Note 2), and then it is added (Note 3) in small portions to 400 cc. of ice water in a 5-I. flask. The solution is kept in an ice bath until used. 

To 375 cc. (4.3 moles) of hydrochloric acid (sp. gr. 1.18) and 200 g. of ice is added 139.6 g. (1.5 moles) of aniline. The resulting solution is diazotized with a solution of 103.5 S (x-5 moles) of c. p. sodium nitrite, ice being added to the reaction mixture, as necessary, in order to keep the temperature below 50. The final volume of the diazotized solution is about 1 1. This solution is added in a slow stream from a dropping funnel to the potassium selenide solution, which is being vigorously stirred with a mechanical stirrer. When all the diazotized solution has been added, the red aqueous solution is decanted from the dark oil which forms and is heated to boiling (Note 4). It is then poured back on the oil, the mixture is well stirred (Note 5), 200 cc. of chloroform is added, and the selenium collected on a filter and washed with a little more chloroform (Note 6). After the chloroform layer is separated, the aqueous layer is again 

If the potassium hydroxide and selenium are absolutely dry, a thick paste is formed. The addition of a few cubic centimeters of water will form the dark red liquid mentioned. 

If the mass is allowed to cool and solidify, it becomes very hard and is difficult to break up and dissolve. 

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The method described here is a modification of that of Schoeller.1 Diphenyl selenide has also been prepared from diazotized aniline and alkali monoselenides 2 by the Friedel-Crafts reaction with benzene and selenium tetrachloride3 or selenium dioxide 4 from diphenyl sulfone and selenium 5 from phenylmagnesium bromide and selenium,6 selenium dichloride,7... 

A) Diphenylselenium Dichloride.—One hundred twenty-five grams (0.53 mole) of diphenyl selenide (p. 27) is added in portions to 250 cc. (4 moles) of nitric acid (sp. gr. 1.42) in a 1.5-I. beaker. Hydrochloric acid (sp. gr. 1.18) is then added until precipitation is complete. About 170 cc. (2 moles) of acid is required. The mixture is then diluted with 500 cc. of water, and the yellow precipitate is separated by filtration and air-dried. The crude product is purified by extracting with 500 cc. of boiling benzene. The crystals which separate on cooling are collected on a filter and the filtrate used for a further extraction. Three such treatments are necessary for a complete crystallization. The yield of yellow needles, decomposing at 187-188°, is 137-141 g. (85-87 per cent of the theoretical amount). 

Diphenylselenium dichloride has been prepared from diphenyl selenide 2,3 by the action of chlorine and by treatment first with nitric acid and then hydrochloric acid. Triphenylselenonium chloride has been prepared by fusing together diphenylmercury... 

The solution should not be cooled below 0°, since impurities, including diphenyl selenide dichloride, may also crystallize. 

Diphenyl selenide dichloride Selenium, dichlorodiphenyl- (8) Selenium, dichlorodiphenyl-, (T-4)- (9) (2217-81-4)... 

Diphenyl selenide, 24, 91 Dr- -PROPYLAMINO ETHYL AMINE, 23, 24 y-Di-ra-propylaminopropylamine, 24, 46 Disproportionation, of an iodoso and an iodoxy compound, 22, 52 of iodosobenzene by steam distillation, 22, 72... 

The residue in the still (or alkali-insoluble material in the ether layer if Note 6 has been employed) contains diphenyl selenide (b.p. 167°/16 mm.) and diphenyl diselenide (m.p. 63°). It can be separated by a combination of distillation and crystallization from alcohol, but the amounts are small, and, unless the residues from several runs are combined, the procedure is not economical. 

Tetraalkylammonium borohydrides react with elemental selenium and tellurium to form the symmetrical dialkyl selenides and tellurides [44]. Diphenyl selenide yields the alkyl phenyl selenides. 

The oxidation potentials of diphenyl selenides ° and diphenyl tellurides have been measured by electrochemical methods, as well as by pulse radiolysis. Pulse electrolysis was used to determine E° values for diphenylsulfide (84), diphenylselenide (85), and diphenyltelluride (23). In each case, equilibrium... 

The absence of dimer radical cation formation by diphenyl selenide under the pulse radiolysis conditions is in contrast to bimolecular reactions believed to occur under electrochemical conditions/ In these experiments, a rotating disk electrode was used in combination with commutative voltammetry under anhydrous conditions. The results led to the conclusion that reversible one-electron oxidation is followed by disproportionation, then reaction of the resulting dication with diphenyl selenide or an external nucleophile, with the likely intermediacy of the dimer dication (Fig. 33). As expected, the dihydroxy selenane is formed when water is present. Based on the kinetics of the electrochemical reaction, the authors believe the diselenide dication, not the radical cation, to be the intermediate that reacts with the nucleophile. 

Tetrachloroselenophene undergoes a ring-opening reaction on treatment with phenyllithium initiated by nucleophilic attack on selenium. Further reaction with phenyl-lithium results in the formation of diphenyl selenide (Scheme 11) (76CS(10)133). 

Phenyl selenide, CeHg.SeH.1—This selenide may be obtained as follows (1) Selenium tetrachloride is allowed to react with benzene in the presence of aluminium chloride. (2) Magnesium phenyl bromide in ether solution is treated with finely divided selenium and the addition product treated with cold hydrochloric acid. The ether layer is then removed, the extracted solution treated with more ether and the extracts combined, then shaken with one equivalent of sodium hydroxide, calculated on the basis of the total amount of selenium used, and dissolved in water to make a 25 per cent, solution. The ether solution is then dried with calcium chloride, the ether removed and the residue distilled, diphenyl diselenide and diphenyl selenide, B.pt. 303° C., being obtained. The sodium hydroxide solution on acidification with a slight excess of concentrated hydrochloric acid, followed by three more extractions with ether, gives on removal of the solvent almost pure phenyl selenide, B.pt. 182° C. The product melts at 60° C., and is insoluble in water, but dissolves in alcohol mercuric chloride gives a white precipitate.2... 

Diphenyl selenide, (CeHs)aSe, may be prepared in several ways ... 

Benzene (3 parts) and one part of selenium tetrachloride are heated together under reflux in the presence of anhydrous aluminium chloride until no further evolution of hydrogen chloride occurs.3 Benzene, aluminium bromide and selenium bromide interact to give bromobenzene and a 22 to 27 per cent, yield of diphenyl selenide.4... 

Phenyl magnesium bromide and selenium bromide react to form diphenyl selenide as one product.5... 

Mercury diphenyl and powdered selenium react at 220° to 230° C. to form the diphenyl selenide.6... 

Diphenyl selenide is a colourless, strongly refractive oil, B.pt. 167° C. at 16-5 mm. insoluble in water but miscible with alcohol or ether in all proportions. It has a faint odour, and a density of 1 3712 at 0° C., 1 3561 at 15 2° C., and 1 350 at 20° C. With cold bromine in ether solution it yields the dibromide. Diphenyl selenide, unlike dimethyl selenide, does not combine with alkyl iodides, and in this respect it resembles diphenyl sulphide.2 When heated nearly to its boiling-point with sulphur it gives diphenyl sulphide, the reaction being practically quantitative at 300° C.3 With palladium chloride it forms the complex PdCl2.2(C6H5)2Se, orange-red needles, M.pt. 181° to 182° C.4... 

Dibromophenyl selenide, (C6H4Br)2Se, occurs when bromine reacts with diphenyl selenide. It crystallises from alcohol in brilliant white, hexagonal prisms, M.pt. 112° C. 

Diphenyl selenium dichloride, (C6H5)aSeCl2, is formed when diphenyl selenoxide is treated with hydrochloric acid. It crystallises in glistening prisms, M.pt. 179° to 180° C.4 A similar product is obtained when diphenyl selenide is dissolved in an excess of concentrated nitric acid and concentrated hydrochloric acid added.5... 

Diphenyl selenoxide, (C6H5)2SeO.—This oxide may be prepared in several ways (1) Diphenyl selenium dichloride is treated with sodium hydroxide.6 (2) Diphenyl selenium dibromide is allowed to react with sodium hydroxide.7 (3) 7 grams of diphenyl selenide are slowly treated with 10 c.c. of 46 perhydrol. 8 (4) Diphenyl selenoxide... 

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... 

Triphenyl selenium bromide, (C6H5)3SeBr, is formed when the foregoing chloride is dissolved in boiling ethylene dibromide. It is crystallised from methyl ethyl ketone and melts with decomposition at 236° C., heating at this temperature causing decomposition with formation of diphenyl selenide and bromobenzene. 

Triphenyl selenium iodide, (C6H5)3SeI, decomposes at 237-5° C., yielding diphenyl selenide and iodobenzene. On exposure to light the white iodide slowly turns yellow,- it may be crystallised from water. 

When diphenyl selenide di-o-carboxylic acid (II) interacts with concentrated sulphuric acid two products are obtained, selenoxanthone-carboxylic acid (I) and a dilactone (III). The latter may be considered... 

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