Experiments in the Methyle- and in the Methylene- Series. 391 



The sparingly soluble iodide is present in proportionally small quan- 

 tity only among the products of the action of di-iodide of methylene 

 on triethylphosphine. I have in*vain endeavoured to detect among 

 these products anything of the nature of a diphosphonium-com- 

 pound. On treating the mother-liquor of the sparingly soluble 

 iodide with chloride of silver, and the dilute filtered solution with 

 dichloride of platinum, a few needles of the iodated platinum-salt 

 are still deposited; but after considerable evaporation the solution 

 yields crystals, all of which exhibit an octahedral habitus. I was 

 equally unsuccessful in a particular experiment, in which I subjected 

 di-iodide of methylene to the action of a large excess of triethyl 

 phosphine ; and a similar report must be made of the attempt to 

 produce the desired body by treating the ready prepared iodide with 

 triethylphosphine, according to the equation 



[(C H 2 1)<C 3 H 5 ) 3 P]T + (C 2 H 5 ) 3 P= [(C H 2 )" (C, H 5 ) 6 PJ" I 2 . 



The examination of the mother-liquor of the sparingly soluble 

 iodide is a difficult and thankless proceeding ; nevertheless, by a suffi- 

 cient number of iodine- and platinum-determinations, it may be shown 

 to be a mixture of four different compounds. The mother-liquor is 

 thus found to contain, together with the hydriodate of the phos- 

 phorus-base, two crystallizable iodides differing in solubility, and to be 

 separated from one another only by a great number of crystallizations. 



The more soluble salt is the iodide of oxymethylated triethyl- 

 phosphonium, corresponding to the iodomethylated compound ; 

 the less soluble salt is the iodide of methyl- triethylphosphonium. 

 The last mother-liquors contain considerable quantities of oxide of 

 triethylphosphine. 



Iodide of Oxymethyl-triethylphosphonium. 

 This salt is extremely soluble both in water and in alcohol, even 

 in absolute alcohol, and crystallizes only after the alcohol has been 

 completely evaporated. The crystals, resembling the frosty efflores- 

 cences on a window-pane, contain 



C 7 H 18 OPI=[(CH 3 0)(C 2 H 6 ) 3 P]I. 

 The iodide, treated with oxide of silver, is converted into the corre- 

 sponding caustic oxide, which, when mixed with hydrochloric acid 

 and dichloride of platinum, yields a rather easily soluble platinum- 

 salt of an octahedral habitus. 



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. 



