ON THE QUENCHING OF SINGLET OXYGEN BY α‐TOCOPHEROL

Abstract

Abstract —D‐α‐tocopherol was found to be an effective quencher of 1 O 2 molecules ( k = 2.5 times 10 8 →mol ‐1 s ‐1 in pyridine) by measuring its effect on the autosensitized photooxidation of rubrene. The quenching process was shown to be almost entirely ‘physical’, that is, α‐tocopherol deactivated about 120 1 O 2 molecules before being destroyed. The results suggest that this process may be a mechanism for the protective effect of α ‐ tocopherol in photodynamic action.