Chemiexcitation Efficiency of Intermolecular Electron‐transfer Catalyzed Peroxide Decomposition Shows Low Sensitivity to Solvent‐cavity Effects

Khalid, Muhammad; Souza, Sérgio Pereira de; Bartoloni, Fernando Heering; Augusto, Felipe A.; Baader, W. J.

doi:10.1111/php.12599

Cited by 13 publications

(12 citation statements)

References 55 publications

(107 reference statements)

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“…During the triggered decomposition of electron‐rich aryl‐substituted 1,2‐dioxetanes, however, it is the activator that is formed in situ , resulting in efficient intramolecular singlet chemiexcitation . In both systems, the physicochemical properties of the medium, such as polarity and viscosity, affect the chemiluminescence efficiency …”

Section: The (Bio)chemistry Of Four‐membered Ring Peroxidesmentioning

confidence: 99%

Four‐membered cyclic peroxides: Carriers of chemical energy

Bastos

Farahani

Bechara

et al. 2017

J of Physical Organic Chem

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Four-membered cyclic peroxides are high-energy compounds often associated to cold light emission, but whose chemical and biological roles are still matters of debate. The often-dangerous synthesis of 1,2-dioxetanes, achieved around 50 years ago, has been mastered over the years to a point where some derivatives are commercially available. This fact does not imply that 1,2-dioxetanes can be conveniently prepared in the gram scale or that the synthesis of analogous 1,2-dioxetanones and the elusive 1,2-dioxetanedione are simple. Important questions on the mechanism of chemiluminescence and bioluminescence reactions are under experimental and theoretical scrutiny. The available data have contributed to relate structural and medium effects to the quantum efficiency of these compounds to produce excited states. Consequently, such peroxides have been suggested to produce biologically relevant electronically excited species in vivo in the absence of light. The connection of this hypothesis with melanin-mediated photodamage in the dark has renewed the interest in such cyclic peroxides. This review gives some insight on the synthesis, chemiluminescence mechanism, and biological relevance of 1,2-dioxetanes, 1,2-dioxetanones, and 1,2-dioxetanedione and provides practical protocols for those interested in engaging this field.

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Section: The (Bio)chemistry Of Four‐membered Ring Peroxidesmentioning

confidence: 99%

Four‐membered cyclic peroxides: Carriers of chemical energy

Bastos

Farahani

Bechara

et al. 2017

J of Physical Organic Chem

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“…Thus, it is hypothesized that the observed differences in Φ S values for hydro- and silylperoxides bearing the same substituent are actually related to the influence of a solvent-cage effect on the overall EBT efficiency and not to the starting peroxide structure. Our interpretation could be better supported by additional experimental data, employing different mixtures of benzene/diphenylmethane as reaction media. , This binary solvent system allows for different viscosities without significantly affecting the solvent reorganization energy and has been successfully applied for both intramolecular , and intermolecular CIEEL systems. , …”

Section: Resultsmentioning

confidence: 58%

“…Adam, Matsumoto, and Trofimov proposed that an increase in viscosity prevents C–C bond rotation, frictionally reducing ground-state formation of molecules and increasing chemiexcitation yields . This dependence of Φ S in viscosity has been debated more recently, ,, and it seems that chemiexcitation in the intramolecular system is compromised when conformational changes compete with the concerted EBT and C–C bond cleavage . Thus, it is hypothesized that the observed differences in Φ S values for hydro- and silylperoxides bearing the same substituent are actually related to the influence of a solvent-cage effect on the overall EBT efficiency and not to the starting peroxide structure.…”

Section: Resultsmentioning

confidence: 99%

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

et al. 2021

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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 (ρ > 1). The decomposition of this HEI leads to chemiexcitation with overall low singlet excited state formation quantum yield (ΦS from 1.1 to 14.5 × 10–5 E mol–1); nonetheless, ΦS = 1.20 × 10–3 E mol–1 was observed with both peroxides substituted with bromine. The use of electron-donating substituents 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.

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“…In a recent analytical application, peroxyoxalate nanoparticles have been used in vivo for drug delivery and for imaging of hydrogen peroxide and glucose (18)(19)(20)(21)(22)(23). However, the mechanism leading to light emission in water is not as well characterized as in organic solvents, although the mechanism of the peroxyoxalate reaction has been studied in different media recently (24)(25)(26)(27)(28)(29)(30)(31).…”

Section: Introductionmentioning

confidence: 99%

Mechanistic Study of the Peroxyoxalate System in Completely Aqueous Carbonate Buffer

Augusto

Bartoloni

Pagano

et al. 2020

Photochem & Photobiology

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The peroxyoxalate reaction is one of the most efficient chemiluminescence transformations, with emission quantum yields of up to 50%; additionally, it is widely utilized in analytical and bioanalytical assays. Although the real reason for its extremely high efficiency is still not yet understood, the mechanism of this transformation has been well elucidated in anhydrous medium. Contrarily, only few mechanistic studies have been performed in aqueous media, which would be of great importance for its application in biological systems. We report here our experimental results of the peroxyoxalate reaction in completely aqueous carbonate buffer, using fluorescein as chemiluminescence activator. The kinetics are very fast in the used basic conditions (pH > 9); despite this, reproducible kinetic results were obtained. The reaction proceeds by specific base catalysis, with rate‐limiting attack of hydrogen peroxide anion to the oxalic ester, in competition with ester hydrolysis by hydroxide ion. Emission quantum yields increase with the hydrogen peroxide concentration up to an optimal concentration of 10 mmol L–1. The infinite singlet quantum yield of (5.8 ± 0.2) × 10–7 is much lower than in anhydrous medium; however, it is similar to quantum yields measured before in partially aqueous media.

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Chemiexcitation Efficiency of Intermolecular Electron‐transfer Catalyzed Peroxide Decomposition Shows Low Sensitivity to Solvent‐cavity Effects

Cited by 13 publications

References 55 publications

Four‐membered cyclic peroxides: Carriers of chemical energy

Four‐membered cyclic peroxides: Carriers of chemical energy

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

Mechanistic Study of the Peroxyoxalate System in Completely Aqueous Carbonate Buffer

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