Diphenylselenium dichloride

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). 

B) Tripkenylselenonium Chloride.—To 87 g. (100 cc., 1.12 moles) of benzene in a x-1. three-necked flask provided with a mechanical stirrer, is added 30 g. (0.22 mole) of anhydrous aluminum chloride. The suspension is cooled in an ice bath, and to it is added, with stirring, 40 g. (0.13 mole) of diphenylselenium dichloride in portions of approximately 1 g. at a time over a period of twenty-five minutes. Before each addition the... 

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... 

DIPHENYLSELENIUM DICHLORIDE AND TRIPHEN YLSELEN ONIUM CHLORIDE... 

Fig. 18 Halogenation of 1,3,5-trimethoxybenzene di-4-chlorophenyltellurium(IV) dibromide (36), diphenylselenium(IV) dibromide (1), /V./V-dimethyl-2-(aminomethyl)phenyl phenyl bromoselenonium bromide (37), and diphenylselenium(IV) dichloride (38).

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