What is auxochrome and chromophore?

A chromophore is a part of a molecule responsible for its color, as it absorbs specific wavelengths of light due to its electronic structure. An auxochrome, on the other hand, is a group that, while not itself responsible for color, can modify the color of the chromophore by altering its ability to absorb light, often by shifting the absorption spectrum. Auxochromes typically contain functional groups such as –OH or –NH2 that influence the electronic properties of the chromophore. Together, chromophores and auxochromes are key in determining the color and absorption characteristics of organic compounds.