618 



Iodide of Methyl-triethylphosphonium. 



The nature of the less soluble iodide was determined by an iodine- 

 determination, and by the analysis of the platinum-salt. The iodide 

 dissolves in water and in alcohol, but is insoluble in ether. By adding 

 ether to the alcoholic solution, tolerable crystals are obtained. This 

 compound is most conveniently purified by precipitating the alcoholic 

 mother-liquor, after freeing it by crystallization as far as possible 

 from the iodomethylated iodide, with a quantity of ether insufficient 

 to precipitate the whole, so that the greater part of the iodides may 

 remain in solution. 



The iodide thus prepared contains 



C,H, 8 PI=[(CH 3 )(C 2 H 5 ) 3 P]I. 



For further verification of this formula the crystals were deiodized 

 with silver-oxide, and the caustic liquid thus obtained was saturated 

 with hydrochloric acid and precipitated by dichloride of platinum. 

 The platinum -salt, which crystallizes in beautiful octahedra, was 

 found to contain 



C, H 18 1> PtCl 3 = [(C H a ) (C, H.), P]C1, Ptd, 



The two iodides are accompanied by a considerable quantity of 

 oxide of triethylphosphine, which immediately separates in oily drops 

 on treating the last mother-liquor with potash. Its presence was like- 

 wise unmistakeably recognized by the preparation of the platinum - 

 salt. If the last mother- liquor of the iodine-compounds be deiodized 

 and mixed with hydrochloric acid and dichloride of platinum, a quan- 

 tity of octahedral salts separates in the first place, which are removed 

 by sufficient concentration ; the remaining liquid, when mixed with 

 alcohol and ether, yields a crystalline precipitate, which separates 

 from alcohol by spontaneous evaporation in the beautiful large 

 hexagonal tables consisting of the platinum-salt of the oxychloride 

 of triethylphosphine, which has been more fully described in one of 

 the previous notes on these researches. 



The formation of the four compounds contained in the mother- 

 liquor of the sparingly soluble iodide is illustrated by the following 

 equations : 



3 ) 3 P] + CHJ 2 +H 2 0=[(C 2 H 5 ) 3 HP]H-[(CH 3 0)(C 2 H 5 ) 3 P]I 



2 + H 3 0=[(C 2 H S ) 3 HP]I+[(CH 3 )(C 2 H 6 ) 3 P]I + (C 2 H 5 



