BENZYL PHOSPHINES AND THEIR DERIVATIVES. 563 



a dense white precipitate formed. This was thrown into a filter, and then washed about 



six times with ether. Then, to remove any sulphur, it was boiled with chloroform (in 



which very little dissolved), thrown into a filter, and washed with chloroform. It was 



then dried and analysed. 



Analysis. 



0-4248 eave i 11443 C0 * = °' 312082 C = 73 " 46 P er cent " 

 4248 gave } . 2514 H2O==0 . 027904 H= 6 . 57 



Obtained. Calculated for (C 7 H 7 ) 3 PS 



Carbon, . . . 7346 7500 



Hydrogen, . . . 6"57 625 



The compound was evidently not pure, but as it was insoluble in alcohol, and only 



sparingly soluble in chloroform, no method of purification suggested itself immediately. 



Eventually it was found that it would be recrystallised from boiling glacial acetic acid, 



in which it is slightly soluble, crystallising as the solution cools in tufts of needles. 



Some of the product was thus recrystallised several times and analysed. 



Analysis. 



017Q2 aav J0-1089H 2 O-00121 H = 675 per cent. 

 g \ 04883 CO, = 01331727 C - 7431 





Obtained. 



Calculated for (C 7 H 7 ) 3 PS 



Carbon, 



74-31 



7500 



Hydrogen, . 



6-75 



6-25 



Sulphide of tribenzyl phosphine fuses at 276° (corr.), and darkens on exposure to 

 light. It is evidently difficult to purify. 



Experiment 4. — The contents of eleven sealed tubes were treated as before, and 

 an ethereal solution obtained of the " solidified oil." This was filtered and distilled to 

 dryness in a current of carbonic anhydride. The residue consisted of about 50 c.c. 

 of a yellow fluorescent liquid which was very viscous. It was mixed with about 500 c.c. 

 of pure dry benzol, in which it easily dissolved on agitation. On leaving this mixture 

 undisturbed (the flask being filled with carbonic anhydride to prevent oxidation) a bulky 

 crystalline precipitate formed after some hours. This we at first took to be oxide of 

 tribenzyl phosphine, but subsequent investigations proved it to be a totally different 

 substance. We shall refer to it later as the " Insoluble crystalline body." 



The benzol solution filtered from it was saturated with dry hydriodic acid, when an 

 abundant white crystalline precipitate of the phosphine hydriodates was formed. This 

 was collected on a cloth filter, and washed two or three times with dry ether. The mass 

 drained as far as possible from adhering ether by pressure between filter paper weighed 

 88 grms. 



It was next boiled in a stream of hydrogen with solution of caustic potash as long as 

 either benzol or ether passed over ; the mixture allowed to cool, and the oily layer (after 

 syphoning off the potash solution) mixed with ether. This latter did not, however, dissolve 

 the whole product, but left a considerable quantity of a white slimy substance. The 



