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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Experimental Evidence of the Occurrence of Intramolecular Electron Transfer in Catalyzed 1,2-Dioxetane Decomposition

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Author(s):
Ciscato, Luiz Francisco M. L. [1, 2] ; Bartoloni, Fernando H. [1] ; Weiss, Dieter [2] ; Beckert, Rainer [2] ; Baader, Wilhelm J. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, BR-05508000 Sao Paulo - Brazil
[2] Univ Jena, Inst Organ Chem & Makromol Chem, D-07743 Jena - Germany
Total Affiliations: 2
Document type: Journal article
Source: Journal of Organic Chemistry; v. 75, n. 19, p. 6574-6580, OCT 1 2010.
Web of Science Citations: 38
Abstract

The activation parameters for the thermal decomposition of 13 acridinium-substituted 1,2-dioxetanes, bearing an aromatic moiety, were determined and their chemiluminescence emission quantum yields estimated, utilizing in situ photosensitized 1,2-dioxetane generation and observation of its thermal decomposition kinetics, without isolation of these highly unstable cyclic peroxides. Decomposition rate constants show linear free-energy correlation for electron-withdrawing substituents, with a Hammett reaction constant of rho = 1.3 +/- 0.1, indicating the occurrence of an intramolecular electron transfer from the acridinium moiety to the 1,2-dioxetane ring, as postulated by the intramolecular chemically initiated electron exchange luminescence (CIEEL) mechanism. Emission quantum yield behavior can also be rationalized on the basis of the intramolecular CIEEL mechanism, additionally evidencing its occurrence in this transformation. Both relations constitute the first experimental evidence for the occurrence of the postulated intramolecular electron transfer in the catalyzed and induced decomposition of properly substituted 1,2-dioxetanes. (AU)