Russia's advance westward raised indirectly the Eastern Question, because it threatened two of France's traditional allies, Sweden and Poland, and Choiseul considered that the best means of checkmating Catherine's 7l aryl, aggressive schemes was to incite France's third traditional ally, Turkey, to attack her.
On the chromophoreauxochrome theory (the nitro group being the chromophore, and the hydroxyl the auxochrome) it is necessary in order to explain the high colour of the metallic salts and the colourless alkyl and aryl derivatives to assume that the auxochromic action of the hydroxyl group is only brought strongly into evidence by salt formation.
The replacement of one hydrogen atom by one alkyl or aryl group gives rise to primary amines; of two hydrogen atoms by two groups, to secondary amines; of three hydrogen atoms by three groups, to tertiary amines.
When heated with alkyl or aryl iodides, they are converted into secondary and tertiary amines.
This reaction shows that the alkyl or aryl group is attached to the carbon atom in the nitrile.