the Salts of Triethylbenzylphosphonium. 31 



Hydrate of TriethyTbenzylphosphoniiim. 



The hydrate was prepared by two methods : — (1) by the 

 action of silver oxide on the chloride in aqueous solution ; 

 (2) by the action of barium hydrate on the sulphate. 



When freshly precipitated oxide of silver is added to a 

 solution of the chloride in water a strongly alkaline solution 

 is obtained, but at the same time there is slight reduction of 

 the silver oxide. The second method for the preparation of 

 the hydrate is free from this objection ; and it was also tried 

 in order to see whether a decomposition occurred similar to 

 that noticed during the preparation of the hydrate of tetra- 

 benzylphosphonium, viz. decomposition of the hydrate at the 

 moment of production (if hot and concentrated solutions be 

 used) into phosphine oxide and a hydrocarbon, 



(C 7 H 7 ) 4 PHS0 4 + Ba (OH), = (C 7 H 7 ) 3 PO 4- C 7 H 8 + BaS0 4 ; 



while with cold dilute solutions the tetrabenzylphosphonium 

 hydrate and barium sulphate are formed. This does not seem 

 to be the case with the hydrate of triethylbenzylphosphonium ; 

 both boiling and concentrated solutions were used, but not a 

 trace of toluene or of an oxide of a tertiary phosphine could 

 be detected. The hydrate prepared by either of the above 

 methods forms a strongly alkaline and caustic liquid, which 

 will absorb carbon dioxide readily, and precipitate metals 

 from their solutions in the same way as other phosphonium 

 hydrates do. When perfectly dry by long standing over 

 phosphoric anhydride in vacuo, it crystallizes in long and very 

 deliquescent needles. When it was heated above 100° C. it 

 melted, and was almost at once completely decomposed. No 

 gas was evolved, and the distillate consisted of two layers ; 

 the upper one insoluble in water, and, from its general pro- 

 perties and an analysis made, proved to be toluene ; the lower 

 was nearly pure oxide of triethylphosphine. The decomposition 

 which occurs, therefore, when the hydrate of triethylbenzyl- 

 phosphonium is heated is as follows : — 



(C 2 H 5 ) 3 P< | ' 7 =(C 2 H 5 ) 3 PO+C 7 H 8 

 Oi— H 



and, as there was no gas produced, evidently no oxide of a 

 mixed phosphine could have been formed. 



Carbonate of Triethylbenzylphosphonium. 



Several attempts were made to prepare the normal carbo- 

 nate, but without success, and this salt does not seem capable 



