Detection of small quantities of photochemically produced oxygen by reaction with alkaline pyrogallol

Duncan, Ian A.; Harriman, A.; Porter, Gerald B.

doi:10.1021/ac50049a034

Cited by 19 publications

(15 citation statements)

References 27 publications

(13 reference statements)

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“…An examination of the yield of sulfoxide in Table 1, entry 2 suggested that even under the best conditions, a significant amount of H 2 O 2 was either unreacted or potentially being consumed by a competing pathway. Exposure of the headspace of the sulfoxidation reaction to an alkaline pyrogallol solution indicated the presence of O 2 ,17 pointing to iron‐catalyzed disproportionation of H 2 O 2 (catalase behavior). The yield of O 2 was quantified, and when both oxidation products are considered, 92 % mass balance for H 2 O 2 is obtained.…”

Section: Methodsmentioning

confidence: 99%

H₂O₂ Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

2007

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Section: Methodsmentioning

confidence: 99%

H₂O₂ Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

2007

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“…When H 2 O 2 was added to a basic solution of the diiron compounds 6 , 7 , or 8 , O 2 formation was observed, as confirmed by a test with an alkaline pyrogallol solution 63,64. The catalase-like activity of the carbonato complex 8 was investigated in more detail and the O 2 formed in the reactions was quantified.…”

Section: Resultsmentioning

confidence: 87%

“…A test with an alkaline pyrogallol-solution confirmed the formation of dioxygen 63,64. The intermediate products from reactions with H 2 O 2 , 6a , 7a , and 8a , in solutions of CH 3 CN/H 2 O were monitored by UV-vis spectroscopy.…”

Section: Resultsmentioning

confidence: 97%

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H₂BPG₂DEV

et al. 2009

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In order to model the syn disposition of histidine residues in carboxylate-bridged non-heme diiron enzymes, we prepared a new dinucleating ligand, H2BPG2DEV, that provides this geometric feature. The ligand incorporates biologically relevant carboxylate functionalities, which have not been explored as extensively as nitrogen-only analogs. Three novel oxo-bridged diiron(III) complexes [Fe2(μ-O)(H2O)2-(BPG2DEV)](ClO4)2 (6), [Fe2(μ-O)(μ-O CAriPrO)(BPG2DEV)](ClO4) (7), and [Fe2(μ-O)(μ-CO3)(BPG2DEV)] (8) were prepared. Single crystal X-ray structural characterization confirms that two pyridines are bound syn with respect to the Fe–Fe vector in these compounds. The carbonato-bridged complex 8 forms quantitatively from 6 in a rapid reaction with gaseous CO2 in organic solvents. A common maroon-colored intermediate (λmax = 490 nm; ε = 1500 M−1 cm−1) forms in reactions of 6, 7, or 8 with H2O2 and NEt3 in CH3CN/H2O solutions. Mass spectrometric analyses of this species, formed using 18O-labeled H2O2, indicate the presence of a peroxide ligand bound to the oxo-bridged diiron(III) center. The Mössbauer spectrum at 90 K of the EPR-silent intermediate exhibits a quadrupole doublet with trueδ. = 0.58 mm/s and ΔEQ = 0.58 mm/s. The isomer shift is typical for a peroxodiiron(III) species, but the quadrupole splitting parameter is unusually small compared to related complexes. These Mössbauer parameters are comparable to those observed for a peroxo intermediate formed in the reaction of reduced toluene/o-xylene monooxygenase hydroxylase (ToMOH) with dioxygen. Resonance Raman studies reveal an unusually low-energy O–O stretching mode in the peroxo intermediate that is consistent with a short diiron distance. Although peroxodiiron(III) intermediates generated from 6, 7, and 8 are poor O-atom transfer catalysts, they display highly efficient catalase activity, with turnover numbers up to 10,000. In contrast to hydrogen peroxide reactions of diiron(III) complexes that lack a dinucleating ligand, the intermediates generated here could be reformed in significant quantities after a second addition of H2O2, as observed spectroscopically and by mass spectrometry.

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“…Experiments with alkaline pyrogallol 66 were performed to confirm that our cells remain anaerobic with flow of deoxygenated electrolyte (Figures S-12−S-14).…”

Section: ■ Results and Discussionmentioning

confidence: 92%

A Terahertz-Transparent Electrochemical Cell for In Situ Terahertz Spectroelectrochemistry

2018

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Terahertz spectroscopy is broadly applicable for the study of a wide variety of materials, but spectroelectrochemistry has not been performed in the THz range because of the lack of a THz-transparent electrochemical cell. While THz-transparent electrodes do exist, they have never been utilized in a complete three-electrode cell, which is the configuration required for accurate potential control in aqueous media. We have designed and constructed a THz-transparent three-electrode electrochemical cell and have performed THz spectroelectrochemistry of a SnO thin film. The cell utilizes a custom-made reference electrode and tubing which allows the composition of electrolyte to be changed during an experiment. THz spectroelectrochemical measurements show a decrease in THz transmission at potentials where SnO conduction band states are potentiostatically filled. We also describe a simple method for measuring the uncompensated resistance and RC time constant.

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Detection of small quantities of photochemically produced oxygen by reaction with alkaline pyrogallol

Cited by 19 publications

References 27 publications

H₂O₂ Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

H₂O₂ Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H₂BPG₂DEV

A Terahertz-Transparent Electrochemical Cell for In Situ Terahertz Spectroelectrochemistry

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Detection of small quantities of photochemically produced oxygen by reaction with alkaline pyrogallol

Cited by 19 publications

References 27 publications

H2O2 Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

H2O2 Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H2BPG2DEV

A Terahertz-Transparent Electrochemical Cell for In Situ Terahertz Spectroelectrochemistry

Contact Info

Product

Resources

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H₂O₂ Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

H₂O₂ Oxidations Catalyzed by an Iron(III) Corrolazine: Avoiding High‐Valent Iron–Oxido Species?

Modeling the Syn Disposition of Nitrogen Donors in Non-Heme Diiron Enzymes. Synthesis, Characterization, and Hydrogen Peroxide Reactivity of Diiron(III) Complexes with the Syn N-Donor Ligand H₂BPG₂DEV