P. T. Austen — Nilro-derivatives of Diphenylamine. 287 



According to Hofmarm, the mono- and dinitrophenylamines 

 lilar ones. This fact was substantiated by Clemm. 



I find that these colors are caused by the formation of salts 

 of the nitrodiphenylamin.es. The hydrogen atom of the imido- 

 group has become so negative by the introduction of the nitro- 

 groups, that it can easily be substituted by basic atoms. It 

 reacts easily, indeed, with carbonates of the alkalies. 



Of the numerous salts of these compounds which I have 

 prepared, I have as yet had time only to investigate one — the 

 barium salt of the alphabetadipicrylamine. 



Barium-alphapicrylbetapicryldiamine. 

 Preparation.- — The a yS-picrylamine was added to an aqueous 

 pap of barium hydrate (or carbonate). The dipicrylamine dis- 

 solved immediately with a deep intense red color. The solution 

 was boiled for a few minutes and then evaporated on a water- 

 bath. After a sufficient concentration had been obtained, the 

 solution was allowed to stand. A beautiful crystallization of 

 dark-red needles was obtained. They were purified by 

 repeated crystallization from water. 



A?ialysis.—A portion of the needles were dried at 100° and 

 mixed with sodium carbonate and citrate. Some sodium car- 

 bonate was then fused in a platinum crucible, and the mixture 

 added to it in small portions. The resulting solution was kept 

 in fusion about five minutes, and then allowed to cool. After 

 ■ ( im .■-1.1 it w:i.» .1'— hvd m vrr\ dilute cblor- 

 _. and pre- 

 cipitated with sulphuric acid. 



04012 grms. of substance gave O0908 grms. of BaSO 4 . 

 j C6H 2 (NO*) 3 /? 

 TWo™ ulaB aj» tePft=C»Ha*..O..B. 

 ]C 6 H2(N0 2 ) 3 a 

 Ba=13'52 13-30 



. The reaction by which this barium salt is formed is very 

 simple : 

 2(NFI[C'H 3 (NO^) 3 ] 2 )+Ba(OH) 3 =Ba[N(C»H 3 (NO ;i ) 3 ) 3 ] a +H s O 

 Solubility.— tyute easily soluble in boiling water, less so in 

 alcohol. 



Properties.— Small, dark saffron- red glittering needles. It 



seems to have enough basic properties to form saltfl with 



-. Tins mtV.,vs!inir fact I li<>|>e shortly to prove. If 



Jf be brought into a flame it explodes in a remarkable manner, 



- 

 beautiful barium-flame. Thrown on a hot surface it explodes 

 Wlfch great violence. 



