indophenin

Indophenine【pigment】

3-[5-[5-(1,2-Dihydro-2-oxo-3H-indol-3-ylidene)-2,5-dihydrothiophen-2-ylidene]-2,5-dihydrothiophen-2-ylidene]-1,3-dihydro-2H-indol-2-one