JACKSON AND CALVERT. — METAPHENYLENE DIAMINE. 141 



Bromine 



Nitrogen 



These analyses prove that the substance is tribromphenylene diamine, 

 and therefore our experimental result does not agree with that of 

 Hollemaun,* who stated that he obtained a dibromphenylene diamine 

 by the action of bromine water on a solution of the chloride of pheny- 

 lene diamine. As it was possible that this difference in the results ot 

 the action might be due to the fact that Hollemann used a salt of 

 phenylene diamine, whereas we used in our first experiments the free 

 base dissolved and suspended in water, we repeated our experiment 

 with a solution of the chloride of phenylene diamine, and obtained pre- 

 cisely the same result as with the free base, that is, the tribromphenylene 

 diamine melting at 158°. We are therefore forced to the conclusion 

 that Hollemann's statement is due to an error in observation. 



Properties. Tribromphenylene diamine crystallized from alcohol 

 appears in long slender needles united longitudinally into ribbons 

 with the ends serrated so strongly that they look like combs. It is 

 white, with marked silky lustre, and melts at 158°. It is not very solu- 

 ble in cold but freely in hot alcohol ; somewhat more soluble in methyl 

 than ethyl alcohol ; freely soluble in acetone ; soluble in ether, ben- 

 zol, chloroform, glacial acetic acid, or carbonic disulphide ; very slightly 

 soluble in ligroine, but good crystals may be obtained from its solution 

 iu hot ligroine ; essentially insoluble in water. Strong hydrochloric 

 acid dissolves it easily in the cold, depositing after long standing white 

 transparent crystals which soon turn brown; on heating the solution 

 in hydrochloric acid it turned dark brown, almost black, showing de- 

 composition of the substance ; the formation of a similar nearly black 

 decomposition product was brought about at once by cold strong nitric 

 acid. Cold strong sulphuric acid dissolved the tribromphenylene dia- 

 mine at once, the solution having a purplish tint, which turned to dark 

 brown if it was allowed to stand for some time, or if it was stirred in a 

 current of air for a short time. Nevertheless on one occasion a white 

 solid was obtained, but before it could be collected a black spot ap- 

 peared in one part of it which sped rapidly through the whole mass. 

 Dilute sulphuric acid had no apparent effect on it in the cold, but de- 

 composed it when hot. These observations show that the presence of 

 the three atoms of bromine has destroyed in great measure the basic 



* Zeitsch. fur Chem. 1865, p. 555. 



