Free radical/singlet dioxygen system under the conditions of catalytic hydrogen peroxide decomposition

Моисеева, Н. И.; Гехман, А. Е.; Минин, В. В.; Larin, G. M.; Bashtanov, M. E.; Krasnovskiï, A. A.; Моисеев, И. И.

doi:10.1007/bf02771417

Cited by 32 publications

(16 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 NPs are the only ones to present a clear approach to saturation behaviour at 300 K, typical of the ferrimagnetic magnetite Fe 3 O 4 bulk phase. The observed maximum magnetization is 63.5 emu/g, comparable to the bulk value, 92.0 emu/g at 300 K [47,48]. The other NPs present a much lower curvature in this field range, being still visible in cobalt 3 NP, much less in the others.…”

Section: Vsm (Vibrating Sample Magnetometry)supporting

confidence: 53%

Solvent-Free Microwave-Induced Oxidation of Alcohols Catalyzed by Ferrite Magnetic Nanoparticles

Martins

Amorim

et al. 2017

Catalysts

View full text Add to dashboard Cite

Abstract:A series of first-row-transition-metal ferrite magnetic nanoparticles (NPs) MFe 2 O 4 [M = Mn 2+ (1), Fe 2+ (2), Co 2+ (3), Ni 2+ (4), Cu 2+ (5) or Zn 2+ (6)] were prepared by the co-precipitation method and characterized by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscope -energy dispersive X-ray spectrometry (SEM-EDS), vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). Those NPs were used as catalysts for the microwave-assisted oxidation of various alcohols in solvent-free medium. MnFe 2 O 4 (1), CoFe 2 O 4 (3) and CuFe 2 O 4 (5) act as catalysts for the conversion of alcohols to the corresponding ketones or aldehydes with a yield range of 81 to 94% in 2 h at 120 • C using t-BuOOH as an oxidant. These catalysts can be readily isolated by using an external magnet and no significant loss of activity is observed when reused up to 10 consecutive runs. The effects of some parameters, such as temperature, time, type of oxidant and presence of organic radicals, on the oxidation reactions were also investigated. The presented literature overview highlights the advantages of our new 1-6 NPs catalytic systems in terms of efficiency and economy, mainly due the used microwave (MW) heating mode.

show abstract

Section: Vsm (Vibrating Sample Magnetometry)supporting

confidence: 53%

Solvent-Free Microwave-Induced Oxidation of Alcohols Catalyzed by Ferrite Magnetic Nanoparticles

Martins

Amorim

et al. 2017

Catalysts

View full text Add to dashboard Cite

show abstract

“…Attempts to promote the catalytic performance of 1, 3 and 5 MNPs systems by adding the organic radical TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl) (2.5% mol vs. 1-phenylethanol) were unsuccessful since no obvious changes in the obtained yield of acetophenone were recorded. The addition of known C·and O-radical traps, CBrCl 3 and Ph 2 NH (2.5% mol vs. 1-phenylethanol), respectively, resulted in a serious lack of product formation (below 1% of acetophenone), proving the radical nature of the catalytic system using t-BuOOH [42,43]. On the basis of this results the free radical mechanism illustrated in Scheme 2 is proposed.…”

Section: Catalytic Performancementioning

confidence: 84%

First-Row-Transition Ion Metals(II)-EDTA Functionalized Magnetic Nanoparticles as Catalysts for Solvent-Free Microwave-Induced Oxidation of Alcohols

Martins

Amorim

et al. 2017

Catalysts

View full text Add to dashboard Cite

A series of first-row transition-metals combined with ethylenediamine tetraacetic acid (EDTA), as metal-based N,O-chelating ligands, at the surface of ferrite magnetic nanoparticles (MNPs) was prepared by a co-precipitation method. Those EDTA functionalized MNPs with general formula Fe 3 O 4 @EDTA-M 2+ [M = Mn 2+ (1), Fe 2+ (2), Co 2+ (3), Ni 2+ (4), Cu 2+ (5) or Zn 2+ (6)] were characterized by FTIR (Fourier Transform Infrared) spectroscopy, powder XRD (X-ray Diffraction), SEM (Scanning Electron Microscope), EDS (Energy Dispersive Spectrometer), VSM (Vibrating Sample Magnetometer) and TGA (Thermal Gravity Analysis). The application of the magnetic NPs towards the microwave-assisted oxidation of several alcohol substrates in a solvent-free medium was evaluated. The influence of reaction parameters such as temperature, time, type of oxidant, and presence of organic radicals was investigated. This study demonstrates that these MNPs can act as efficient catalysts for the conversion of alcohols to the corresponding ketones or aldehydes with high selectivity and yields up to 99% after 2 h of reaction at 110 • C using t-BuOOH as oxidant. Moreover, they have the advantage of being magnetically recoverable catalysts that can be easily recycled in following runs.

show abstract

“…The formation of singlet dioxygen from several transition metal complexes is also documented. [26] The singlet state of dioxygen is experimentally [27] and theoretically [28,29] measured to be 24.5 kcal/mol higher than the triplet state; such an excitation of dioxygen would not occur thermally under the mild oxidation conditions used in the anthraquinone process. Singlet dioxygen is unlikely to be involved in the oxidation process, and therefore, in the anthraquinone process we can rule out the involvement of the dioxygen complex shown in Scheme 2.…”

Section: Resultsmentioning

confidence: 99%

Mechanistic Study on the Production of Hydrogen Peroxide in the Anthraquinone Process

et al. 2011

View full text Add to dashboard Cite

Hydrogen peroxide is produced from hydrogen gas and air in industry by using the anthraquinone process. The mechanism for the production of hydrogen peroxide in this process is studied by using DFT calculations and reaction rate measurements. A hydrogen atom of anthrahydroquinone (AHQ) is directly abstracted by triplet dioxygen to produce a hydroperoxide radical (HOO·) and a 10‐hydroxy‐9‐anthroxyl radical (AQH·), followed by subsequent hydrogen atom abstraction that leads to the formation of hydrogen peroxide and anthraquinone (AQ). Hydrogen atom abstraction was found to be the rate‐determining step in this process. Tetrahydroanthrahydroquinone (THAHQ) is also used in this process in a similar way to AHQ, but a higher activation energy is required for the rate‐determining step when THAHQ is used, which would lead to a 25‐fold rate deacceleration compared with AHQ at 27 °C. The reactivities of AHQ and THAHQ are not significantly influenced by effects of side alkyl chain that is used in the industrial process for increasing the solubility of AHQ and AQ in working solution. The relative reaction rate of AHQ and THAHQ is measured under laboratory conditions. The computational results are consistent with an observed lower rate of the oxidation process of THAHQ.

show abstract

Free radical/singlet dioxygen system under the conditions of catalytic hydrogen peroxide decomposition

Cited by 32 publications

References 13 publications

Solvent-Free Microwave-Induced Oxidation of Alcohols Catalyzed by Ferrite Magnetic Nanoparticles

Solvent-Free Microwave-Induced Oxidation of Alcohols Catalyzed by Ferrite Magnetic Nanoparticles

First-Row-Transition Ion Metals(II)-EDTA Functionalized Magnetic Nanoparticles as Catalysts for Solvent-Free Microwave-Induced Oxidation of Alcohols

Mechanistic Study on the Production of Hydrogen Peroxide in the Anthraquinone Process

Contact Info

Product

Resources

About