diazotized

At this stage, the amino groups of the gel matrix should be diazotized.

Archive 2004-12-01 2004

By itself diazotized primuline is slowly influenced by light, but quickly acted on in presence of organic substances.

Photographic Reproduction Processes Peter C. Duchochois

As said above, primuline is transformed by nitrous oxide into a diazotized compound, and consequently the material is now susceptible of being acted on by light.

Photographic Reproduction Processes Peter C. Duchochois

When the material to print upon is thick and wholly impregnated with diazotized primuline, it is advisable, since the insulation could not be prolonged to effect the change through, to expose the back of the material for a certain but short period in order to _clear_ it.

Photographic Reproduction Processes Peter C. Duchochois

The sensitiveness of diazotized primuline to light, when united to organic substances and the different colors which can be obtained with the unaltered compound, have given rise to an interesting printing method, the invention of Messrs.A. G.

Photographic Reproduction Processes Peter C. Duchochois

The chemical change light effects in the diazotized primuline is not well known.

Photographic Reproduction Processes Peter C. Duchochois

They may be prepared by the reduction of nitro compounds in alkaline solution (using zinc dust and alkali, or a solution of an alkaline stannite as a reducing agent); by oxidation of hydrazo compounds; or by the coupling of a diazotized amine and any compound of a phenolic or aminic type, provided that there is a free para position in the amine or phenol.

Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon" Various

If the material so dyed be placed in an acidified solution of nitrous oxide, the primuline is diazotized, forming a derivative compound of a deeper color, which fades in the light, and which in presence of amines and phenols gives rise to a variety of dyes whose color depends on the reagent employed, while, when acted on by light, the resulting compound is entirely deprived of this property.

Photographic Reproduction Processes Peter C. Duchochois

Para-oxyazobenzene (benzene-azo-phenol), C_6H_5N: N (1) ·C_6H_4·OH (4), is prepared by coupling diazotized aniline with phenol in alkaline solution.

Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 1 "Austria, Lower" to "Bacon" Various

In other words, the diazotized primuline acts as a mordant only when not altered by the luminous action.

Photographic Reproduction Processes Peter C. Duchochois