GIG 



METHYLENE GROUP. 



Action of Triethylphosphine on Di-iodide of Methylene. 

 Triethylphosphine and di-iodide of methylene act so powerfully on 

 one another, that it is necessary to moderate the reaction by the pre- 

 sence of a considerable quantity of ether. The reaction is very soon 

 completed, even when the mixture is largely diluted, especially if it 

 be heated to 100 in sealed tubes. The saline residue left after the 

 evaporation of the ether is immediately seen to be a mixture of several 

 compounds, one of which a sparingly soluble iodide crystallizing in 

 long needles at once arrests attention. 



From analogy we might expect to find in the saline mixture the 

 compounds 



[(CH 2 I)(C 2 H S ) 3 P]I, 



[(CH 2 )(C 2 H S ) 6 P 2 ]"I 2 . 



Experiment has, however, established the presence of the first only. 



The difficultly soluble crystals just mentioned are easily purified, 

 being readily soluble in water, sparingly in alcohol, insoluble in 

 ether. Their solution in boiling alcohol yields splendid needles fre- 

 quently an inch long, and possessing extraordinary lustre. Analysis 

 prove this beautiful salt to be the first of the above-mentioned com- 

 pounds. 



The new iodide behaves with nitrate of silver like the bromide of 

 bromethylated triethylphosphonium ; half the iodine is eliminated 

 in the form of iodide of silver. It differs, however, from the 

 bromide in its deportment with oxide of silver which, after removal 

 of the accessible iodine, leaves the latent iodine untouched, even after 

 protracted ebullition. A powerfully alkaline solution is thus obtained 

 containing the base 



c 7 H 18 iPO=K CH ^)^ H '\ r 



The crystals of the iodide were transformed into the chloride by 

 means of chloride of silver, and the solution was precipitated by 

 dichloride of platinum. The precipitate is very sparingly soluble in 

 cold water, but may be recrystallized from a considerable quantity of 

 boiling water. As the liquid cools, splendid needle-shaped crystals 

 are deposited containing 



C 7 H ]7 1 P PtCl 3 = [(C H 2 1)(C a H 5 ) 3 P]C1, PtCl 2 . 



