Photoinduced Luminescence and Epr Signals of Polyphenol and Quinone Polymers

Aqueous basic solutions, pH 9.0 of humic acids and melanin‐like, synthetic polymers, obtained with adrenochrome, hydroquinone and purpurogallin, were illuminated with visible light under N2 or O2 atmospheres. It has been found that light enhances a singlet electron‐paramagnetic‐resonance (EPR) signal of polymers both under N2 and O2, and induces ultra‐weak luminescence in the presence of O2. Degradative oxidation of polymers, accelerated by light, leads to a decrease of EPR signal intensity and generates weak chemiluminescence.