SECTION VII. 



NITROGEN BASES. 



AMMONIA is said to have basic properties because it can form 

 salts by combining with acids. This salt formation, which 

 may be illustrated by the conversion of ammonia into am- 

 monium chloride, is due to the unsaturated nature of the 

 trivalent nitrogen atom, and its tendency to assume the pen- 

 tavalent condition. 



/ H 



N Ui H 

 \ 



N^ 



'H 

 Ammonia Ammonium chloride 



The replacement of one or more of the hydrogen atoms in 

 ammonia by organic radicles, such as methyl, CH 8 , ethyl, 

 C 2 H 5 , or phenyl, C 6 H 5 , gives rise to compounds known as 

 amines or substituted ammonias, which still retain the property 

 of salt formation possessed by the parent substance ammonia. 



For example : 



/ H 



CH 3 N iH / H 



H 

 Methylamine 



HCl 



(C 2 H 5 ) 2 = NH + HI 



CH 



Methylamine hydrochloride, or 

 Methyl ammonium chloride 



/ H 



(C 2 H 6 ) 2 = N H 



Diethylamine Diethylamine hydriodide 



(CH 3 ) 3 = N + HBr -> (CH 3 ) 3 = N/ 



\Br 

 Trimethylamine Trimethylamine hydrobromide 



These three substances, CH 3 NH 2 , methylamine, (C 2 H 5 ) 2 NH, 

 diethylamine, and (C 2 H 5 ) 3 :N, triethylamine, are types of three 

 different classes of amines, known respectively as primary, 



261 



