Mechanism of C60 Photoreactivity in Water: Fate of Triplet State and Radical Anion and Production of Reactive Oxygen Species

• DOI: 10.1021/es702905g
• Publication Date: 2008-04-01T06:01:37Z
• Authors: Jaesang Lee; Yoko Yamakoshi; Joseph B. Hughes; Jae-Hong Kim
• Keywords: Flash photolysis; Hydroxyl radical; Reactive intermediate

The mechanism involved with (1) energy and electron transfer by C60 in the aqueous phase during UV irradiation (2) subsequent production of reactive oxygen species (ROS) such as singlet superoxide radical anion was investigated. Electron paramagnetic resonance (EPR) study showed that embedded micelles nonionic surfactant (Triton X 100) or anionic (sodium dodecylbenzenesulfonate) produced ROS, but aggregated did not, consistent our earlier findings made using indicator chemicals. Nanosecond femtosecond laser flash photolysis aggregation significantly accelerates decay excited triplet state C60, which is a key intermediate for transfer, thus blocking pathway ROS production. This finding suggests clusters will not contribute to oxidative damage redox reactions natural environment biological systems same way molecular organic reportedly does. In contrast, produces evidence presented formation an intermediate.