388 Royal Society : — 



ethyle, the formation of bromethyl-triethylphosphonium invariably 

 precedes the production of the diphosphonium-componnd. 



"Researches on the Phosphorus-Bases." — No. XI. Experiments 

 in the Methvle- and in the Methylene-Series. By A. W. Hofmann, 

 LL.D., F.R.S. Received July 24, 18G0. 



In former notes I have repeatedly called attention to the trans- 

 formation of the bromide of bromethylated triethylpbosphonium 

 under the influence of bases. In continuing the study of these reac- 

 tions, I was led to the discovery of a very large number of new com- 

 pounds, the more important ones of which are briefly mentioned in 

 this abstract. 



Hybrids of Ethylene-diphosphonium. 

 Action of Trimethylphosphine upon Bromide of Bromethyl-triethyl- 

 phosphonium. 



These two bodies act upon each other with the greatest energy, 

 and moreover exactly in the manner indicated by theory. The 

 resulting compound was of course examined only so far as was neces- 

 sary to establish the character of the reaction. 



The dibromide of the hybrid diphosphonium is more soluble than 

 the hexethylated compound formerly described, which in other 

 respects it resembles. Oxide of silver eliminates the extremely 

 caustic base 



c u h 10 p 2 o,=K c = h ^"( ch ^ h ' ) ^"}o i . 



which yields with hydrochloric acid and dichloride of platinum a 

 pale-yellow platinum-salt, 



c n h, p, ft, ci,=[(a hj<< gg£ p ] "a. 2R ci a> 



separating in scales from boiling water. 



The salts of the hybrid diphosphonium crystallize like those of the 

 hexethylated diphosphonium, but, so far as they have been examined, 

 are somewhat more soluble. This remark applies especially to the 

 iodide. 



It seemed worth while to try whether the bromide of brom- 

 ethylated triethylphosphonium was capable of fixing a molecule of 

 phosphoretted hydrogen. It was found, however, that the two 

 bodies do not act upon one another. Phosphoretted hydrogen gas, 

 passed through the alcoholic solution of the bromide, either cold or 

 boiling, did not seem to affect it in any way. 



Action of Trimethylphosphine on Dibromide of Ethylene. 

 This reaction exhibits a repetition of all the phenomena observed 

 in that which takes place between the dibromide and triethylphos- 

 phine. The process is completed sooner, if possible, than in the 

 ethyle-series. The lower boiling-point and the overpowering odour 

 of trimethylphosphine render it advisable to mix the materials with 

 considerable quantities of alcohol or ether ; and on account of the 

 extreme oxidability of the phosphorus-compound, it is best to ope- 



