Evidence for the Formation of 1,2-Dioxetane as a High-Energy Intermediate and Possible Chemiexcitation Pathways in the Chemiluminescence of Lophine Peroxides

Autor(es)

Boaro, Andreia ^[1] ; Reis, Roberta Albino ^[1] ; Silva, Carolina Santana ^[1] ; Melo, Diego Ulysses ^[1] ; Goncalves Costa Pinto, Alexander Garreta ^[1] ; Bartoloni, Fernando Heering ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Organic Chemistry; v. 86, n. 9, p. 6633-6647, MAY 7 2021.
• Citações Web of Science: 0

Resumo

A kinetic study of the chemiluminescent (CL) reaction mechanism of lophine-derived hydroperoxides and silylperoxides induced by a base and fluoride, respectively, provided evidence for the formation of a 1,2-dioxetane as a high-energy intermediate (HEI) of this CL transformation. This was postulated using a linear Hammett relationship, consistent with the formation of negative charge on the transition state of HEI generation (rho > 1). The decomposition of this HEI leads to chemiexcitation with overall low singlet excited state formation quantum yield (Phi(s) from 1.1 to 14.5 x 10(-5) E mol(-1)); nonetheless, Phi(s) = 1.20 x 10(-3) E mol(-1) was observed with both peroxides substituted with bromine. The use of electron-donating sub-stituents increases chemiexcitation efficiency, while it also reduces the rate for both formation and decomposition of the HEI. Different possible pathways for HEI decomposition and chemiexcitation are discussed in light of literature data from the perspective of the substituent effect. This system could be explored in the future for analytical and labeling purposes or for biological oxidation through chemiexcitation. (AU)

• Processo FAPESP: 12/13807-7 - Novas ferramentas para o estudo de reações de transferência de elétron em sistemas modelo do PS II
• Beneficiário: Fernando Heering Bartoloni
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/15871-3 - Derivados de arginina emissores de luz como marcadores de peptídeos antimicrobianos
• Beneficiário: Andréia Boaro
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 16/10585-4 - Aspectos mecanísticos da decomposição induzida de hidroperóxidos e sililperóxidos derivados de lofina
• Beneficiário: Andréia Boaro
• Modalidade de apoio: Bolsas no Brasil - Doutorado