mil] on Neiv Organic Compounds of JVitro//en. 15;> 



tvil»uted iimoiig naturally occurriiijj; substances almost as widely as 

 carbon itself, there is no recorded example of a triazo-compound being 

 obtained from natural sources. Clearly then, the union of atoms in 

 the triazo-group is not among those marriages which are made in 

 Heaven. 



That being the case, it becomes necessary to consider the materials 

 and processes which underly the synthetical production of triazo-com- 

 pounds. Proceeding from ammonia, and replacing one of the hydrogen 

 atoms by an amino-group, diatnide, or hydrazine, is produced, but 

 although discovered by Curtius in 1887, the method by which he 

 prepared it is of historical interest only, it having been left to the 

 ingenuity of Raschig, as recently as 1907, to accomplish the produc- 

 tion of this substance by a simple and inexpensive process. This 

 consists in first replacing an atom of hydrogen in ammonia by an 

 atom of chlorine, and then, by direct action of more ammonia on the 

 resulting chloramine, replacing the halogen by an amino-group : 



NHg + NaOCl = NH.Cl + NaOH. 

 NHg + NH.Cl = NH;-NH2,HC1. 



The new process illustrates in remarkable fashion the effect whicli 

 physical condition may exert on chemical change. Although chlora- 

 mine and ammonia may act together as already shown in a constructive 

 direction, an alternative, destructive course is open to them, which is 

 accelerated if the viscosity of the liquid is diminished : 



2NH3 + oNH.Cl = N, + 3NH,C1. 



Thus Raschig was able to increase the yield of hydrazine by increasing 

 the viscosity of the solution with addition of glue, whilst the unde- 

 sirable effect, namely. Ulceration of nitrogen, was shown to follow the 

 addition of acetone. 



Just as ammonia may be doubled on itself to produce diamide or 

 hydrazine, the latter might be expected to allow one of its hydrogen 

 atoms to be replaced by another amino-group and furnish triamide, 

 or triazane. This, however, has not been accomplished, and there is 

 evidence to suggest that such a substance would be most unstable. 

 Whenever attempts are made to add another nitrogen link to the 

 chain of two atoms in hydrazine, the terminal atoms of tlie three- 

 link chain are found to have combined with one another, forming an 

 enclosed association or ring of atoms. This is the triazo-group, and 

 its simplest known form is the compound with hydrogen called azoi- 

 mide. or hydrazoic acid, HN3. The latter name emphasises the first 

 point of interest in connection with the triazo-group. Whereas the 

 simpler compounds of nitrogen with hydrogen, namely, ammonia and 

 hydrazine, are both strong bases, forming very stable salts with acids, 

 azoimide is a well-detined acid, forming salts with bases including 

 ammonia and hydrazine themselves, the products then having com- 



