Constitution of the Diazoamido- Compounds. 525 



In the next place the group — N=N — NH — assumed to 

 be present, according to the prevailing view, has always 

 seemed to me to be a most improbable arrangement of N- 

 atoms, and without any analogy among chemical compounds. 

 Those compounds in which three combined N-atoms are pre- 

 sent are only stable when the N-atoms form a closed chain, 

 as in Griess's benzeneimide : — 



C 6 H 5 .N<|, 

 or in the azimidobenzene of this same author*: — 



c 6 H 4 <g)*r. 



H 



From these considerations I am led to conclude that an 

 open chain of three nitrogen atoms does not exist in any of 

 the diazoamido-compounds, and the remarkable stability of 

 the dinitrodiazoamido-compounds in the presence of alkalis f 

 certainly supports this view. 



The formula which I now venture to suggest for the normal 

 compounds is, as far as I can see, at any rate as equally 

 capable as Kekule's of representing the characters of these 

 compounds, and at the same time indicates the analogy of 

 these to the normal compounds. It has moreover the advan- 

 tage of doing away with the assumption of the open chain of 

 N-atoms : — 



N:N 



NH.X 



According to this formula the preceding compounds would 

 be written : — 



* I have accepted this formula rather than the alternative one 

 C 6 H 4 I NH ; because, according to Boessneck (Ber. xix. 1886, p. 1757), 



acetorthotoluylene-diamine yields acetazimidotoluene by the action of 

 nitrous acid. The N . C 2 H 3 0-group must, therefore, be attached to the 

 aromatic nucleus, and this acetyl compound gives azimidotoluene by 

 hydrolysis, so that the NH-group must also be attached to the aromatic 

 nucleus. 



t These compounds can be boiled with strong potash solution for days 

 "without undergoing any alteration (Journ. Chem. Soc, Trans. 1886, 

 p. 627). Even the simpler compounds like diazoamidobenzene are much 

 more stable in neutral or alkaline solutions than is generally supposed. 



