This is a selection of azo-dye compounds. The energy absorbed at the HOMO/LUMO gap corresponds to a wavelength of light, the observed colour of the dye is complementary to this wavelength.
Click on a structure to view the 3D models, HOMO/LUMO representations and corresponding colour information for each dye.
Aniline Yellow
Oil Red O
Disperse Orange 1
Janus Green B