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CHAPTER V

GENERAL INFORMATION ON NITRO COMPOUNDS

NITRO compounds are substances in which the nitro group is directly attached

to a carbon atom:

-C-NO 2

The evidence for the fact that the nitro group is actually linked with carbon is

that reduction of nitro compounds leads to the formation of primary amines

-C-NO 2 -> -C-NH 2 (1)

Depending on whether or not and how many hydrogen atoms are linked with

a carbon atom, they are known as primary, secondary and tertiary nitro compounds :

-CH 2 -NO 2 Primary

secondary

tertiary

All aromatic nitro compounds are tertiary derivatives. Aliphatic or aryl-aliphatic nitro

compounds can be primary, secondary and tertiary.

CONSTITUTION OF THE NITRO GROUP

The constitution of the nitro group has been the subject of numerous dis-

cussions. Three types of formulae can be found in the literature:

I II IIIa IIIb

The first of these was abandoned long ago, since the existence of an unstable

three-membered ring in such a stable group as the nitro group can hardly be postu-

lated. Besides, the formula does not explain the tautomerism, that exists in primary

nitro compounds, analogous to the tautomerism of the CH 2 CO system:

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