Question

What is a chromophore?

Answer 1

A chromophore is an atom or group that is responsible for the colour of a compound.

Explanation:

For example, β-carotene is a strongly colored orange-red pigment found in yellow and orange fruits, such as carrots, pumpkins, and yams.

Its structure is

The long, extended series of conjugated double bonds (shown in red) is the chromophore.

The colour arises because the extended π system absorbs a certain wavelength of visible light and excites a π electron from its ground state to a higher-energy orbital.

In β-carotene, the π system absorbs green light, so the transmitted light appears red-orange.