To investigate this hypothesis, we need an
electron-rich core that can photochemically react with halocarbons
along with a drastic color change as indication. To
fulfill these criteria, the electron-rich core should have a
reasonably low oxidation potential that would allow PET with
halo-carbons and strong π-conjugation properties with triarylamine
moieties so that it can create strong photochromic
change in the visible region.