A Manual of the Chemistry of the Carbon Compounds

THE CARBON COMPOUNDS. 311
These diazo-compounds are very unstable bodies, and the different
transformations which they undergo are of great interest, as by
means of them a very great number of derivatives can be obtained.
Thus, on boiling a diazo-compound with water, a phenol is formed:—.
C6H6Nj,NOs + H2O = C8H6.OH + NB + HNO3
By using absolute alcohol instead of water, the group N, is replaced
by hydrogen, the alcohol being oxidized to aldehyde-; thus, on
treating the acid sulphate of diazobenzene in this way, we obtain
benzene:—
C0H6NySO4H + C2H6O = C0H6 + SO4H8 + C,H4O
By acting on a diazo-compound with strong acids, the latter take
park in the reaction; Ly treating diazobenzene nitrate with nitric
acid, different nitrophenols are formed, whilst hydriodio acid converts
it into iodobenzene:—
OjHj.Ng.NOs + HI s CflH5I + N2 + HNO8
The diazo-compounds contain the dyad group Ng, the two nitrogenatoms
being liuked together by two combining units of each; diazobenzene
is therefore a monad radical, having the following constitution
:—
By the action of oxidizing agents on amido-compounds, or by that
of weak reducing agents upon Ditto-compounds, a class of bodies is
obtained called coo-compounds, in which two aromatic nuclei are
linked together by nitrogen:—•
Araidobeuzonu, Azoboazeno,
C0H6,tfHa C6H5.N
+ 0,= || +2H.0
O6H6,NH8 O^N
The aromatic compounds, containing more than six atoms of carbon,
are formed by replacing hydrogen iu benzene or its substitutionproducts
by organic radicals. Thus the most simple homologue of
benzene is Methyl-benme or Tolww C6H6,CHj, a hydrocarbon which
in its chemical properties exhibits a close analogy to benzene, yielding
readily substitution.producte with chlorine, nitric acid, sulphuric
acid, &c. These compounds have the greatest analogy with the
benzene derivatives when the substitutions have taken place in the
aromatic nucleus. But the hydrogen of the methyl can also be
replaced by other elements ana radicals; and thus compounds Me
formed, which have the closest resemblance in their chemical properties
with, the derivatives of marsh-gas. By replacing one atom of hydrogen
in the methyl of toluene, a series of compounds is obtained containing
the alcohol-radical Bmyl:—