614 



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 

 ethyl-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- 

 rate in vessels filled with carbonic acid and subsequently sealed before 

 the blowpipe. After digestion for a short time at 100, the mixture 

 of the two liquids solidifies to a hard, dazzling, white, crystalline mass 

 containing the two bromides, 



C 5 H 13 P Br 2 = [(C 2 H 4 Br) (C H 8 ) 8 P] Br, 



OH P Br 

 CHFBr_ 



one or the other predominating according to the proportions in which 

 the two bodies were allowed to act upon one another. 



It was not difficult to establish the nature of these two compounds 

 by numbers. 



The solution of the saline mass in absolute alcohol, deposits, on 

 cooling, beautiful prismatic crystals, consisting of the bromide of 

 bromethyl-trimethylphosphonium almost chemically pure, while the 

 diphosphonium-bromide remains in solution. The nature of the 

 monophosphonium-compound was fixed by a bromine determination 

 in the bromide, and by the analysis of a platinum-salt beautifully 

 crystallized in needles containing 



