Modern theory of color constitution is like the first theory of color constitution. When Perkin first manufactured the dye of synthetic type, it was then familiar with the name of Chemistry of Dye. But the Perkin theory was not established until many years later when some other theory and constitutions were developed.
Modern Theory of Color Constitution from different methods
Graebe and Libermann Theory
Graebe and Libermann observed in 1868 that all organic dyes become decolorised on reduction. Then they suggested that color is an unsaturated material. This is their contribution in modern theory of color constitution.
In 1876 Witt’s moderate this view. He found that organic dye is associated with some atoms. And therefore that atoms he named as chromohores. Also he found the the only groups of chromophore are colorfull but they do not behave as like dyes for the natural fibers unless substituted with some acidic groups such as -NH2, -NH(CH3), etc. He named them as auxochromes.This modern theory of color constitution is called the Witt’s theory.
Nietzki found that the color of dye becomes deepened by addition of some substituents. And the effect is proportional to the increase of molecular weight.Nietzki is one of the founder of modern theory of color constitutions.
H.E Armstrong Theory
The another Modern theory of color constitution development found by H.E Armstrong in 1888. He found that the most dyes as quinonoyed form. He then suggested that this type of structure make it rise to color but did not suggest why.
Watson and Meek Theory
In 1927 Hewitt and Mitchell found that the depth of color increases with the conjugated chain of single and double bond. After that Watson and Meek described about the color constitution. Watson showed the depth of color affecting by other factors besides the conjugated single and double bond.
The on top of 2 theories were discussing the link between color and constitution area unit found is empirical. Consecutive 2 vital theories, that make a case for probably the relation between color and constitution, need somewhat theoretical background regarding the impact of sunshine on the molecule.