Revision of Singlet Quantum Yields in the Catalyzed Decomposition of Cyclic Peroxides

Author(s)

de Oliveira, Marcelo Almeida ^[1] ; Bartoloni, Fernando Heering ^[1] ; Augusto, Felipe Alberto ^[1] ; Monteiro Leite Ciscato, Luiz Francisco ^[1] ; Bastos, Erick Leite ^[1] ; Baader, Wilhelm Josef ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Sao Paulo - Brazil

• Document type: Journal article
• Source: Journal of Organic Chemistry; v. 77, n. 23, p. 10537-10544, DEC 7 2012.
• Web of Science Citations: 38

Abstract

The chemiluminescence of cyclic peroxides activated by oxidizable fluorescent dyes is an example of chemically initiated electron exchange luminescence (CIEEL), which has been used also to explain the efficient bioluminescence of fireflies. Diphenoyl peroxide and dimethyl-1,2-dioxetanone were used as model compounds for the development of this CIEEL mechanism. However, the chemiexcitation efficiency of diphenoyl peroxide was found to be much lower than originally described. In this work, we redetermine the chemiexcitation quantum efficiency of dimethyl-1,2-dioxetanone, a more adequate model for firefly bioluminescence, and found a singlet quantum yield (Phi(s)) of 0.1%, a value at least 2 orders of magnitude lower than previously reported. Furthermore, we synthesized two other 1,2-dioxetanone derivatives and confirm the low chemiexcitation efficiency (Phi(s) < 0.1%) of the intermolecular CIEEL-activated decomposition of this class of cyclic. peroxides. These results are compared with other chemiluminescent reactions, supporting the general trend that intermolecular CIEEL systems are much less efficient in generating singlet excited states than analogous intramolecular processes (Phi(s) approximate to 50%), with the notable exception of the peroxyoxalate reaction (Phi(s) approximate to 60%). (AU)

• FAPESP's process: 07/00684-6 - Synthesis and application of modified flower pigments
• Grantee: Erick Leite Bastos
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 12/02428-5 - Cyclic organic peroxides: synthesis and mechanism of reduction
• Grantee: Luiz Francisco Monteiro Leite Ciscato
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/23036-5 - Floral betalamic pigments: fluorescence and antiradical capacity
• Grantee: Erick Leite Bastos
• Support Opportunities: Regular Research Grants