title: Chemiluminescence efficiency of catalyzed 1,2-dioxetanone decomposition determined by steric effects.
abstract: The chemiluminescent decomposition of 1,2-dioxetanones (α-peroxylactones), catalyzed by an appropriate fluorescent activator, is an important simple model for efficient bioluminescent transformations. In this work, we report experimental data on the catalyzed decomposition of two spiro-substituted 1,2-dioxetanone derivatives, which support the occurrence of an intermolecular electron transfer from the activator to the peroxide. The low efficiency of the studied systems is associated with steric hindrance during the chemiexcitation sequence, rationalized using the concept of supermolecule formation between the peroxide and the catalyst. This approach explains the difference in the chemiexcitation efficiencies in the decomposition of four-membered cyclic peroxide derivatives: 1,2-dioxetanes, 1,2-dioxetanones, and 1,2-dioxetanedione (the intermediate in the peroxyoxalate reaction), which are the most important model compounds for excited-state formation in chemiluminescence and bioluminescence processes.
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000 São Paulo, Brazil.
authors.forename: Fernando Heering
authors.initials: FH
authors.lastname: Bartoloni
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000 São Paulo, Brazil.
authors.forename: Marcelo Almeida
authors.initials: MA
authors.lastname: de Oliveira
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000 São Paulo, Brazil.
authors.forename: Luiz Francisco Monteiro Leite
authors.initials: LF
authors.lastname: Ciscato
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000 São Paulo, Brazil.
authors.forename: Felipe Alberto
authors.initials: FA
authors.lastname: Augusto
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000 São Paulo, Brazil.
authors.forename: Erick Leite
authors.initials: EL
authors.lastname: Bastos
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000 São Paulo, Brazil.
authors.forename: Wilhelm Josef
authors.initials: WJ
authors.lastname: Baader
mesh_terms: D002384:Catalysis; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry*; D049449:Luminescence; D008163:Luminescent Measurements; D055601:Organic Chemistry Phenomena; D010545:Peroxides / Q000737:chemistry*
chemical_list: D006573:Heterocyclic Compounds, 1-Ring; D010545:Peroxides; C541697:dioxetanone