188 Drs. Letts and Collie on the Salts of 



oxide and sulphide of triethylphosphine, gaseous hydrocarbons, 

 and oxidized products. As, however, a strong smell of 

 triethylphosphine became manifest during the concentration 

 of the salt, another reaction probably occurs, though to a very 

 small extent. Its exact nature we had no means of ascer- 

 taining. 



Action of Heat on the Carbonate of Tetrethylphosphonium. 



Hofmann and Cahours had already investigated the action 

 of heat on this salt, and state that it decomposes into triethyl- 

 phosphine and ethyl carbonate. 



(C 2 H 5 ) 3 P< 



(C 2 H 5 ) 3 K 



/0 2 H 5 



>°°3 = 2(C 2 H 6 ) 3 P+(C 2 H 6 ) 2 C0 3 

 X 2 H 6 



This reaction appeared to be of peculiar interest : first 

 because of its analogy with the behaviour of the compounds 

 of triethylsulphine when heated *, and, secondly, because it 

 ought to afford an easy and simple method for preparing 

 triethylphosphine from tetrethylphosphonium salts. Unfor- 

 tunately, however, this decomposition of the carbonate by 

 heat does not occur in the simple manner we anticipated, as 

 the following experiments show. 



A considerable quantity of the rather impure carbonate 

 was submitted to distillation. It yielded a large quantity of 

 the oxide of triethylphosphine, but only a small amount of 

 the phosphine itself. 



In view of this result we determined to investigate the re- 

 action more carefully, and to employ the carbonate in as 

 complete a state of purity as possible. An aqueous solution 

 of 40 grms. of the pure iodide of tetrethylphosphonium was 

 treated with an excess of recently precipitated carbonate of 

 silver. The solution was filtered from the resulting iodide of 

 silver and concentrated on the water-bath, until a slight smell 

 of triethylphosphine became manifest. It was then well 

 shaken with ether to dissolve out any oxide of triethylphos- 

 phine that might be present t, and placed in vacuo over phos- 

 phoric anhydride, where, after some time, it solidified to a 

 mass of highly deliquescent needle-shaped crystals. This 

 was transferred to an ordinary distilling flask, which was 



* Crum Brown and Blaikie, Journal/, prak. Chemie [2] xxiii. p. 395. 

 t Ether readily dissolves this "body, contrary to the statement of another 

 observer. 



