On Bromide of Bromethylated Triethylphosphonium. 387 



progress has been made in this direction ; one of the reactions, how- 

 ever, which I have studied deserves even now to be mentioned. 



The salts of bromethylated and oxethylated triethylphosphonium 

 may be regarded as tetrethyl-phosphonium-salts, in which an equiva- 

 lent of hydrogen in one of the ethyl-molecules is replaced by bromine 

 and by the molecular group HO respectively. 



Bromide of tetrethylphosphonium [(C 2 H 4 H ) (C a H 5 ) 3 P] Br, 



Bromide of _ bromethylated tri- 1 [(C R Br ) ((J R } p] fir 



phosphomum J LV 2 i ' v 2 5/3 J 



B 7osp e h o f n S h7lated . trieth71 " } [« H - H °) <°> H ->. p ] Bt > 



and the question arose, whether the bromethylated compound might 

 not be converted, simply by reduction, into a salt of tetrethyl- 

 phosphonium. This transformation may, indeed, be effected with- 

 out difficulty. On acidulating the solution of the bromethylated 

 bromide with sulphuric acid and digesting the mixture with granu- 

 lated zinc, the latent bromine is eliminated as hydrobromic acid, its 

 place being at the same time filled by 1 equiv. of hydrogen, 

 [(C 2 H 4 Br) (C 2 H 3 ) 3 P] Br + 2H = HBr + [(C 2 H 5 ) 4 P] Br. 



It was chiefly the facility with which a tetrethyl-phosphonium- 

 compound may be obtained from the brominated bromide, that in- 

 duced me to designate the hydrogen-replacing molecules C 2 H 4 Br, 

 and C 2 H 5 O, which we meet with in the compounds above described, 

 as bromethyle and oxethyle. It remained to be ascertained whether 

 these compounds might actually be formed by means of direct sub- 

 stitution-products of ethyle-compounds. It was with the view of 

 deciding this question that I have examined the deportment of tri- 

 ethylphosphine with the monochlorinated chloride and the mono- 

 brominated bromide of ethyle. 



The former of these substances has been long known, having been 

 investigated by Regnault many years ago ; the latter had not been 

 hitherto obtained. I have prepared it by submitting bromide of 

 ethyle to the action of dry bromine under pressure * It is a heavy 

 aromatic liquid boiling at 110°. 



The chlorinated chloride and the brominated bromide of ethyle, 

 although essentially different in their physical properties from 

 dichloride and dibromide of ethylene, with which they are isomeric, 

 nevertheless resemble the ethylene-compounds in their deportment 

 with triethylphosphine. 



In both cases the final product of the reaction is a salt of hexethyl- 

 ated ethylene-diphosphonium. I have identified these salts with those 

 obtained by means of dichloride and dibromide of ethylene, both by 

 a careful examination of their physical properties, and by the analysis 

 of the characteristic iodide and of the platinum-salt. I have not 

 been able to trace in the first of these reactions a salt of chlorethylated 

 triethylphosphonium ; but I have established by experiment that in 

 the reaction between triethylphosphine and brominated bromide of 



* In addition to the monobrominated bromide of ethyle, (C 4 H 4 Br) Br, there is 

 also formed in this reaction the dibrominated bromide, (C 4 H 3 Br 2 ) Br. 



