Investigations of Chemiluminescence and Oxidation Reactions.
Abstract
Cosensitized electron-transfer photooxygenation has been developed as a new method for the photochemical oxidation of various organic substrates. Compounds which are relatively resistant to standard photooxygenation procedures can be oxidized by a process that utilizes a non-light-absorbing aromatic hydrocarbon (biphenyl, BP) as a catalyst or cosensitizer in conjunction with the cyano-substituted sensitizer, 9.,10-dicyanoanthracene (DCA). Irradiation with visible light (400-500 nm) in the presence of oxygen promotes electron transfer from the cosensitizer to singlet excited DCA with subsequent generation of superoxide ion. Attack by this highly reactive species on the organic substrate or its radical cation effects the oxidation of the material. The photochemical conversion of epoxides, aziridines, and cyclopropanes to 1,2,4-trioxolanes (ozonides), 1,2,4-dioxazolidines, and 1,3-dioxolanes, respectively have been investigated. Insight into the mechanisms of the DCA-sensitized photooxygenation of epoxides and aziridines was obtained through a study of the stereochemistry of the reactions. The exclusive formation of the cios ozonide and cis 1,2,4-dioxazolidine from 2,3-diphenyloxirane and 2,3-diphenylaziridine has suggested a mechanism involving the addition of singlet oxygen as a dipolarophile to intermediate carbonyl and azomethine slides. DCA-BP cosensitized photooxygenation has also been utilized to provide a new approach to the synthesis of chemiluminescent 1,2-dioxetanes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 1986
- Accession Number
- ADA175210
Entities
People
- A. P. Schaap
Organizations
- Wayne State University