On some new Colouring Matters.

The Chemical Gazette 323, 1.4.1856

Proceedings of Societies. Royal Society.
Feb. 21, 1856.
(The Lord Wrottesley, President, in the Chair.)By Arthur H. Church and William H. Perkin.

Nascent hydrogen, actin upon an alcoholic solution of dinitrobenzole or of nitraniline, produces a crimson coloration, due to the formation of a new substance, to which we have given the name nitrosophenyline.

This new body presents some remarkable properties. It fuses below 100° C.; is uncrystallizable, and not volatile without decomposition; it dissolves in alcohol with an orange-red tint, and an alcoholic solution containing only 2 per cent, although perfectly transparent to transmitted light, presents a flame-coloured luminous opacity in reflected light. Nitrosophenyline dissolves in hydrochloric acid, producing an intense crimson colour, which is changed to a yellowish-brown by alkalies and is restored by acids.

The analysis of nitrosophenyline has led us to the formula
C₁₂H₆N₂O₂,
*Suluissa olevat alkuperäisessä tekstissä ilman sulkuja päällekkäin. // In the original text, characters in brackets are written one below another without brackets.which may be written thus C₁₂(H₆NO₂)N *, and so may be viewed as aniline, in which l equiv. of hydrogen is replaced by 1 equiv. of binoxide of nitrogen: the following equation sufficiently explains the formation of nitrosophenyline:– C₁₂H₄2NO₄+8H=C₁₂H₆N₂O₂+6HO.

We have produced from all the dinitro-compounds we have yet experimented upon, colouring matters similar to nitrosophenyline: the following is a list of such dinitro-compounds: —
1. Dinitrobenzole ... C₁₂H₄2NO₄.
2. Dimitrotoluole ... C₁₄H₆2NO₄.
3. Dimitroxylole ... C₁₆H₈2NO₄.
4. Dinitroxylole ... C₁₈H₁₀2NO₄.
5. Dimitrocymole ... C₂₀H₁₂2NO₄.
6. Dinitronaphthaline ... C₂₀H₆2NO₄.

We have examined minutely the colouring substance produced in the case of dinitronaphthaline. It proves to be perfectly analogous in composition with nitrosophenyline; in properties also it is similar; and from its alcoholic solution it may be obtained in crystals, having a lustre somewhat similar to that of murexide: its formula, as deduced from our analysis, is
C₂₀H₈N₂O₂,
*Suluissa olevat alkuperäisessä tekstissä ilman sulkuja päällekkäin. // In the original text, characters in brackets are written one below another without brackets.which we may arrange thus C₂₀(H₈NO₂)N, and so view it as naphthylamine in which l equiv. of hydrogen has been replaced by 1 equiv. of binoxide of nitrogen. This substance we term nitrosomaphthy line. It may likewise be obtained by the action of nitrous acid on naphthylamine, or of nitrite of potassium upon the hydrochlorate of naphthylamine: the following equations represent the three processes for its formation:
1. C₂₀H₆2NO+8H=C₂₀H₈N₂O₂+6HO.
2. C₂₀H₉N+NO₃=C₂₀H₈N₂O₂+HO.
3. C₂₀H₁₀N,Cl+KNO₄=C₂₀H₈N₂O₂+2HO+KCl.