Evidence supporting a 1,2-dioxetanone as an intermediate in the benzofuran-2(3H)-one chemiluminescence

Author(s)

Ciscato, Luiz Francisco M. L. ^[1] ; Bartoloni, Fernando H. ^[1] ; Colavite, Aline S. ^[1] ; Weiss, Dieter ^[2] ; Beckert, Rainer ^[2] ; Schramm, Stefan ^[2]

Affiliation

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

^[2] Univ Jena, Inst Organ Chem & Makromol Chem, D-07743 Jena - Germany

• Document type: Journal article
• Source: PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES; v. 13, n. 1, p. 32-37, 2014.
• Web of Science Citations: 18

Abstract

The mechanism of the chemiluminescent reaction of ethyl (5-fluoro-2-oxo-2,3-dihydrobenzofuran-3-yl) carbamate (a 2-coumaranone derivative) with a base and molecular oxygen was investigated. New evidence from the reaction kinetics and absorption/emission profiles was obtained, supporting the existence of a 1,2-dioxetanone as an intermediate: (i) its characteristic activation parameters (Delta H-not equal = 7.2 +/- 0.1 kcal mol(-1); Delta S-not equal = -45 +/- 5 cal K-1 mol(-1)) indicating a high degree of thermal instability and (ii) its bimolecular decomposition rate constant for the reaction with perylene. The newly developed methodology has been shown to be suitable for determining the reactivity of such thermally unstable peroxides, which are very difficult to prepare and isolate, using this alternative approach of in situ generation of a 1,2-dioxetanone. (AU)

• 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: 12/13807-7 - New tools for the study of electron transfer reactions in PS II model systems
• Grantee: Fernando Heering Bartoloni
• Support Opportunities: Regular Research Grants