Leucodyes
Leucodyes, or leuco dyes, are a class of dye precursors that exist in a colorless or faintly colored reduced form. These compounds can be converted to their intensely colored dye counterparts through oxidation, hydrolysis, ring-opening, or other chemical reactions. The latent color makes them useful in applications where a concealed image or mark becomes visible only after activation.
Mechanism: In many systems the leuco form is stabilized by structural features that disrupt conjugation. Activation
Chemical families: Leucodyes are commonly derived from well-known dye skeletons, including triarylmethane and xanthene derivatives. The
Applications: The most notable use is in security printing, where leuco dyes and developers create latent images
Safety and handling: As with many organic dye precursors, leucodyes should be handled using standard chemical