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

Autor(es)

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]

Afiliação do(s) autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: Journal of Organic Chemistry; v. 77, n. 23, p. 10537-10544, DEC 7 2012.
• Citações Web of Science: 38

Resumo

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)

• Processo FAPESP: 07/00684-6 - Síntese e aplicação de derivados de pigmentos de flores
• Beneficiário: Erick Leite Bastos
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 06/03420-7 - Estudos sobre o mecanismo da decomposicao induzida de 1,2-dioxetanos e da reacao peroxi-oxalato; aplicacoes da quimiluminescencia do luminol.
• Beneficiário: Joséf Wilhelm Baader
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/02428-5 - Peróxidos orgânicos cíclicos: síntese e mecanismo de redução
• Beneficiário: Luiz Francisco Monteiro Leite Ciscato
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/23036-5 - Pigmentos betalâmicos de flores: fluorescência e capacidade antirradicalar
• Beneficiário: Erick Leite Bastos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 05/58320-4 - Efeito da estrutura e do meio de reação sobre a quimiluminescência de dioxetanonas
• Beneficiário: Fernando Heering Bartoloni
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto