Solvent viscosity influence on the chemiexcitation efficiency of inter and intramolecular chemiluminescence systems

Author(s)

Khalid, Muhammad ^[1] ; Souza, Jr., Sergio P. ^[1] ; Ciscato, Luiz F. M. L. ^[2] ; Bartoloni, Fernando H. ^[2] ; Baader, Wilhelm J. ^[1]

Affiliation

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

^[2] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Santo Andre, SP - Brazil

• Document type: Journal article
• Source: PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES; v. 14, n. 7, p. 1296-1305, 2015.
• Web of Science Citations: 10

Abstract

The effects of the medium viscosity on the chemiexcitation quantum yields of the induced decomposition of 1,2-dioxetanes (highly efficient intramolecular CIEEL system) and the catalyzed decomposition of diphenoyl peroxide and a 1,2-dioxetanone derivative (model systems for the intermolecular CIEEL mechanism, despite their low efficiency) are compared in this work. Quantum yields of the rubrene catalyzed decomposition of diphenoyl peroxide and spiro-adamantyl-1,2-dioxetanone as well as the fluoride induced decomposition of a phenoxy-substituted 1,2-dioxetane derivative are shown to depend on the composition of the binary solvent mixture toluene/diphenyl ether, which possess similar polarity parameters but different viscosities. Correlations of the quantum yield data with the medium viscosity using the diffusional and the frictional (free-volume) models indicate that the induced 1,2-dioxetane decomposition indeed occurs by an entirely intramolecular process and the low efficiency of the intermolecular chemiluminescence systems (catalyzed decomposition of diphenoyl peroxide and 1,2-dioxetanone derivative) is not primarily due to the cage escape of radical ion species. (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