By using the polycyclic aromatic hydrocarbon dye perylene as a visible-light photocatalyst, chemists at the University of Colorado, Boulder, have developed a metal-free controlled radical polymerization method (Macromolecules 2014, DOI: 10.1021/ma502044f). Decomposing peroxide or azo compounds with ultraviolet light is a classic method for initiating free-radical polymerizations. In an effort to develop more energy efficient approaches, researchers have turned to photoredox systems that use visible light. These efforts usually require a transition-metal complex to activate an alkyl halide to form radicals and initiate the polymerization chain reaction. One problem with this method is that residual metal in the polymer can interfere in biomedical or electronic applications. Garret M. Miyake and Jordan C. Theriot used visible light to stimulate perylene to directly reduce alkyl bromides without an added sacrificial electron donor to generate radicals for the polymerization of acrylates and styrene.