Based on the UV-vis absorption spectra that we collected, benzoyl peroxide does not display substantial absorption in the visible spectrum. The lack of visible-light-absorption is consistent with the lack of polymerization chemistry that is observed when a sample of styrene is photolyzed in the presence of benzoyl peroxide. The residue left behind following evaporation of the photoreaction described in step 2 contains only benzoyl peroxide; no styrene-derived products have been generated.

In this video, we have seen the impact of structure on the reactivity of radical initiators for olefin polymerization chemistry. We have examined photochemical conditions that: 1) did not contain appropriate absorbers, 2) contained appropriate absorbers but not appropriate initiators, and 3) contained both initiator and absorber molecules. These systems highlight the role of photon absorption and the importance of quantum efficiency on photochemical reactions.

Radical initiators are important