Which of the following is not a chromophore?

Options

A. `-NO_(2)`
B. `-N = N-`
C. `-NO`
D. `-NH_(2)`

Answer

D

Explanation

A dye molecule is made up to two different part (i) Chromophore (ii) Auxochrome. The groups which produce colour in a compound i.e., chromophores are usual unsaturated groups like nitro, azo, azoxy, carbonyl and olefinic bonds Auxochrome are usually acidic/basic functional group like -OH, -COOH, `-SO_(3)H, -NH_(2), -NHR, -NR_(2)`.
A compound containing only a chromophore may be coloured material but not a dye. For example azo benzene is red coloured but not a dye. Where as para amino azobenzene (aniline yellow) is a dye.