Tetrethylphosphonium and their Decomposition by Heat. 191 



are thus forced to the conclusion that Hofmann and Cahours 

 were mistaken in their explanation of the change which it 

 suffers when heated. 



Action of Heat on the Acid Carbonate of 

 Tetrethylphosphonium. 



When a solution of the hydrate of tetrethylphosphonium 

 is saturated with carbonic anhydride, the solution is faintly 

 acid, and solidifies when evaporated over sulphuric acid in 

 vacuo to a mass of highly deliquescent needle-shaped crystals. 

 These, on being subjected to the action of heat, decomposed 

 at about 140° C, yielding carbonic anhydride gas, and the 

 salt in the distilling flask turned alkaline in its action on 

 litmus paper ; on further heating, large quantities of gas 

 were evolved between 140° and 150° C. The thermometer then 

 rapidly rose to 240° C, when it was moved up into the neck 

 of the flask; and between this temperature and 250° C. the 

 whole of the contents of the flask distilled. 



5 grms. of salt yielded when thus distilled 560 cub. centims. 

 of gases, and a distillate consisting of a little free triethyl- 

 phosphine, some ketone insoluble in hydrochloric acid, and 

 with a boiling-point about 100° C. ; but the chief product 

 was the oxide of triethylphosphine. As in the case of the 

 normal carbonate, we could not detect any carbonate of ethyl. 

 The gases were composed of equal volumes of carbonic an- 

 hydride, and a hydrocarbon not absorbable by bromine, which 

 burnt with a luminous flame, and was presumably ethane or 

 butane. 



These results show that the decomposition of the acid 

 carbonate occurs in the same manner as that of the normal 

 carbonate, into which it is probably first converted. 



Action of Heat on the Acetate of Tetrethylphosphonium. 



The interesting and unexpected results obtained with the 

 carbonate induced us to study the action of heat on the 

 acetate of tetrethylphosphonium, as we thought it very pro- 

 bable that it would also yield a ketone, as one half of a ketonic 

 group exists ready formed in the acetyl group. 



The acetate was prepared both by acting on the pure 

 iodide of tetrethylphosphonium with acetate of silver, and by 

 neutralizing the hydrate with acetic acid. In both cases the 

 solution of the salt was first evaporated on the water-bath to 

 a small bulk and then placed over sulphuric acid in vacuo, 

 and eventually yielded a highly deliquescent crystalline mass. 



Some of the salt was dried in vacuo over sulphuric acid 

 till constant in weight, and then a combustion was made. 



