Quenching of Singlet Oxygen by Sodium Azide in Reversed Micellar Systems

Abstract

The oxidation reaction of singlet oxygen with 1,3-diphenylisobenzofuran was investigated in cyclohexanic reversed micellar solutions of dodecylammonium propionate, using pyrene as photosensitizer. The furan oxidation was effectively inhibited by azide ion-bound reversed micelles. Empty reversed micelles also inhibited the furan oxidation to some extent. The inhibition of the furan oxidation was due to the quenching of singlet oxygen by azide ion-bound and empty reversed micelles. Such singlet oxygen quenching was dependent on the concentration of water added. Results obtained were discussed in connection with the polarity in the interior of reversed micelles, micellar size, the state of water solubilized in reversed micelles and the lifetime of singlet oxygen. The heavy atom effect on the quenching of singlet oxygen was also studied using heavy water. © 1979, Walter de Gruyter. All rights reserved.