A Comparative Study on Reactions of Hydrogen Peroxide and Peracetic Acid with Lignin Chromophores. Part 1. The Reaction of Coniferaldehyde Model Compounds

Holzforschung ◽  
2000 ◽  
Vol 54 (2) ◽  
pp. 144-152 ◽  
Author(s):  
George X. Pan ◽  
Liam Spencer ◽  
Gordon J. Leary
Keyword(s):  
Hydrogen Peroxide ◽  
Peracetic Acid ◽  
Oxidation Products ◽  
Reaction Pathways ◽  
Main Reaction ◽  
Side Chain ◽  
Reaction Products ◽  
Efficient Utilization ◽  
Model Compounds ◽  
Rate Of Reaction

Summary The reactions of chromophoric model compounds of the coniferaldehyde type with hydrogen peroxide and peracetic acid have been investigated in relation to lignin-retaining bleaching. Analysis of the main reaction products indicated that the side chain of coniferaldehyde could cleave either between the α, β double bond or between the β, γ bond. Comparison of possible reaction pathways to the formation of oxidation products from hydrogen peroxide and peracetic acid suggested that peracetic acid is more effective than hydrogen peroxide. Advantages of peracetic acid over hydrogen peroxide include a faster rate of reaction, more efficient utilization of the bleaching agent and less likelihood of producing new chromophores.

A Comparative Study on Reactions of Hydrogen Peroxide and Peracetic Acid with Lignin Chromophores. Part 2. The Reaction of Stilbene-Type Model Compounds

Holzforschung ◽  
2000 ◽  
Vol 54 (2) ◽  
pp. 153-158 ◽  
Author(s):  
George X. Pan ◽  
Liam Spencer ◽  
Gordon J. Leary
Keyword(s):  
Hydrogen Peroxide ◽  
Comparative Study ◽  
Peracetic Acid ◽  
Type Model ◽  
Model Compounds ◽  
Ph Dependent

Summary The reactions of three hydroxy- and/or methoxy-substituted stilbenes with hydrogen peroxide and peracetic acid have been investigated. Overall, the reactivity of stilbenes was greater towards peracetic acid than towards hydrogen peroxide. Among the stilbene model compounds studied, 4-hydroxystilbene (I) was virtually unreactive to hydrogen peroxide, but was oxidized by peracetic acid to a varying extent that was highly pH-dependent. 4,4′-Dihydroxy-3,3′-dimethoxystilbene (II) and 3,5-dimethoxy-4-hydroxystilbene (III) showed a greater reactivity to either hydrogen peroxide or peracetic acid than 4-hydroxystilbene (I).

scholarly journals Influence of Side Chain in the Reaction of Lignin Model Compounds with Peracetic Acid

1968 ◽  
Vol 71 (2) ◽  
pp. 247-256
Author(s):  
Hyoe HATAKEYAMA ◽  
Kanemichi SUZUKI ◽  
Junzo NAKANO ◽  
Nobuhiko MIGITA
Keyword(s):  
Peracetic Acid ◽  
Side Chain ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Lignin Model

scholarly journals RuO4-mediated oxidation of secondary amines: Part 1. Are hydroxylamines main intermediates?

2016 ◽  
Vol 81 (5) ◽  
pp. 475-486 ◽  
Author(s):  
Cristina Florea ◽  
Horia Petride
Keyword(s):  
Oxidation Products ◽  
Secondary Amines ◽  
Main Reaction ◽  
Reaction Intermediates ◽  
Reaction Products ◽  
Catalyzed Oxidation ◽  
Mediated Oxidation

The RuO4-catalyzed oxidation of secondary amines Bn-NH-CH2R (1a-b; R=H, Me) gave mainly amides, but minute amounts of nitrones PhCH=N(O)-CH2R (9a-b) and traces of Bn-N(OH)-CH2R (R=H, 4a) were also detected. In the presence of cyanide, up to 22 reaction products were identified, but mainly ?-aminonitriles. Comparison of the oxidation products of 1a-b with those of 4a-b, 9a-b, and Bn-N(O)=CHR (10a-b) showed that 4a-b cannot be main reaction intermediates formed from 1a-b.

scholarly journals The oxidation of 4-bromacetophenone by ozone in acetic acid

2021 ◽  
pp. 37-42
Author(s):  
A. Galstyan ◽  
A. Bushuyev ◽  
A. Krasilnikova ◽  
M. Zhurba
Keyword(s):  
Acetic Acid ◽  
Acetic Acid Solution ◽  
Decisive Role ◽  
Reduced Form ◽  
Main Reaction ◽  
Side Chain ◽  
Reaction Products ◽  
Third Order ◽  
Chain Oxidation ◽  
High Concentrations

The kinetics and mechanism of oxidation of 4-bromoacetophenone by ozone in acetic acid solution have been studied. It was shown that 77% of the starting material is oxidized by the benzene ring; 8% of 4-bromobenzoic acid and small amounts of carbon (IV) oxide were identified among the side chain ozonation products. The main reaction products are aliphatic peroxide compounds, which have in their structure one hydroperoxide group. Manganese (II) acetate was shown to be the most effective catalyst for the side chain reaction of 4-bromoacetophenone in acetic acid. High selectivity for the side chain is achieved only at sufficiently high concentrations of catalyst ([Mn(OAc)2]0:[ArH]0=1:4). The main product of the catalytic oxidation of 4-bromoacetophenone is 4-bromobenzoic acid with a yield of 82.5%. The found dependences of the rate of oxidation of 4-bromoacetophenone by ozone on the concentration of reactants are described by the kinetic equation of the third order, the reaction rate has the first order with respect to each reagent. It was found that the decisive role in the selective oxidation of 4-bromoacetophenone is played by two-stage oxidation, in which ozone predominantly reacts with the reduced form of manganese, and the introduction of the substrate into side chain oxidation is carried out by the reaction with the oxidized form of metal. According to the research results, the mechanism of catalytic ozonation of 4-bromoacetophenone in acetic acid has been proposed, which involves ion-radical non-chain oxidation of the substrate.

The influence of an illuminated mercury surface on the Franck-Cario reactions

1926 ◽  
Vol 23 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Herbert Sim Hirst
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Monoxide ◽  
Catalytic Efficiency ◽  
Mercuric Oxide ◽  
Reaction Products ◽  
Marked Influence ◽  
Mercury Surface ◽  
First Order ◽  
Rate Of Reaction ◽  
Hydrogen Mixtures

It has been found that illumination of a mercury surface by ultraviolet light strong in the line λ=2536·7 Å., exerts a marked influence on the photochemical union of hydrogen andgases such as oxygen, ethylene, and carbon monoxide. The rate of reaction is proportional to the first order to the area of surface exposed.The formation of a mercuric oxide film has been shown to occur only in the presence of a mixture of hydrogen and oxygen, and alternative mechanisms for its formation are suggested.In the case of nitrogen-hydrogen mixtures, hydrazine and ammonia have been identified in the reaction products, and in the case of hydrogen and oxygen, hydrogen peroxide and water have been found, and it is suggested that the reactions proceed in steps.The catalytic efficiency of the surface depends on its cleanness and is cut down by poisons, such as the reaction products in the case of the combination of hydrogen and carbon monoxide.

scholarly journals An experimental study of the reactivity of terpinolene and β-caryophyllene with the nitrate radical

2021 ◽  
Author(s):  
Axel Fouqueau ◽  
Manuela Cirtog ◽  
Mathieu Cazaunau ◽  
Edouard Pangui ◽  
Jean-François Doussin ◽  
...  
Keyword(s):  
Gas Phase ◽  
Reaction Pathways ◽  
Main Reaction ◽  
Organic Nitrates ◽  
Nitrate Radical ◽  
Reaction Products ◽  
Radiative Balance ◽  
Chemical Mechanisms ◽  
Volatile Organic

Abstract. Biogenic volatile organic compounds (BVOCs) are subject to an intense emission by forests and crops into the atmosphere. They can rapidly react with the nitrate radical (NO3) during nighttime to form number of functionalized products. Among them, organic nitrates (ON) have been shown to behave as reservoirs of reactive nitrogen and consequently influence the ozone budget and secondary organic aerosols (SOA) which are known to have a direct and indirect effect on the radiative balance, and thus on climate. Nevertheless, BVOCs + NO3 reactions remain poorly understood. Thus, the primary purpose of the follow-up study is to furnish new kinetic and mechanistic data for one monoterpenes (C10H16), terpinolene, and one sesquiterpene (C15H24), β-caryophyllene, using simulation chamber experiments. These two compounds have been chosen in order to fill the lack of experimental data. Rate constants have been measured using both relative and absolute methods. They have been measured to be (5.5 ± 3.8) × 10−11 and (1.7 ± 1.4) × 10−11 cm3 molecule−1 s−1 for terpinolene and β-caryophyllene respectively. Mechanistic studies have also been conducted in order to identify and quantify the main reaction products. Total organic nitrates and SOA yields have been determined. Both terpenes appear to be major ON precursors both in gas and particle phase with formation yields of 69 % for terpinolene and 79 % for β-caryophyllene respectively. They also are major SOA precursor, with maximum SOA yields of around 60 % for both of the compounds. In order to support these observations, chemical analyses of the gas phase products were performed at the molecular scale using PTR-TOF-MS and FTIR. Detected products allowed proposing chemical mechanisms and providing explanations through peroxy and alkoxy reaction pathways.

scholarly journals Atmospheric fate of two relevant unsaturated ketoethers: kinetics, products and mechanisms for the reaction of hydroxyl radicals with (<i>E</i>)-4-methoxy-3-buten-2-one and (1<i>E</i>)-1-methoxy-2-methyl-1-penten-3-one

2020 ◽  
Vol 20 (14) ◽  
pp. 8939-8951
Author(s):  
Rodrigo Gastón Gibilisco ◽  
Ian Barnes ◽  
Iustinian Gabriel Bejan ◽  
Peter Wiesen
Keyword(s):  
Hydroxyl Radicals ◽  
Relative Rate ◽  
Reaction Chamber ◽  
Oxidation Products ◽  
Rate Coefficients ◽  
Main Reaction ◽  
Reaction Products ◽  
Gas Phase Reactions ◽  
Nitrogen Containing Compounds ◽  
First Time

Abstract. The kinetics of the gas phase reactions of hydroxyl radicals with two unsaturated ketoethers (UKEs) at (298±3) K and 1 atm of synthetic air have been studied for the first time using the relative-rate technique in an environmental reaction chamber by in situ Fourier-transform infrared spectroscopy (FTIR). The rate coefficients obtained using propene and isobutene as reference compounds were (in units of 10−10 cm3 molecule−1 s−1) as follows: kTMBO (OH + (E)-4-methoxy-3-buten-2-one)  =  (1.41±0.11) and kMMPO (OH + (1E)-1-methoxy-2-methyl-1-penten-3-one)  =  (3.34±0.43). In addition, quantification of the main oxidation products in the presence of NOx has been performed, and degradation mechanisms for these reactions were developed. Methyl formate, methyl glyoxal, peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN) were identified as main reaction products and quantified for both reactions. The results of the present study provide new insights regarding the contribution of these multifunctional volatile organic compounds (VOCs) in the generation of secondary organic aerosols (SOAs) and long-lived nitrogen containing compounds in the atmosphere. Atmospheric lifetimes and implications are discussed in light of the obtained results.

scholarly journals Inhibition Properties of Arylsulfatase and β-Glucuronidase by Hydrogen Peroxide, Hypochlorite, and Peracetic Acid

ACS Omega ◽  
2021 ◽  
Author(s):  
Shu-shu Zhong ◽  
Jun Zhang ◽  
Ze-hua Liu ◽  
Zhi Dang ◽  
Yu Liu
Keyword(s):  
Hydrogen Peroxide ◽  
Peracetic Acid

scholarly journals Potential-pH diagrams considering complex oxide solution phases for understanding aqueous corrosion of multi-principal element alloys

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Kang Wang ◽  
Junsoo Han ◽  
Angela Yu Gerard ◽  
John R. Scully ◽  
Bi-Cheng Zhou
Keyword(s):  
Solid Solution ◽  
Free Energy ◽  
Graphical Representation ◽  
Equilibrium Composition ◽  
Complex Oxide ◽  
Oxidation Products ◽  
Reaction Products ◽  
Aqueous Corrosion ◽  
Principal Element ◽  
Diagram Method

AbstractThe potential-pH diagram, a graphical representation of the thermodynamically predominant reaction products in aqueous corrosion, is originally proposed for the corrosion of pure metals. The original approach only leads to stoichiometric oxides and hydroxides as the oxidation products. However, numerous experiments show that non-stoichiometric oxide scales are prevalent in the aqueous corrosion of alloys. In the present study, a room temperature potential-pH diagram considering oxide solid solutions, as a generalization of the traditional potential-pH diagram with stoichiometric oxides, is constructed for an FCC single-phase multi-principal element alloy (MPEA) based on the CALculation of PHAse Diagram method. The predominant reaction products, the ions in aqueous solution, and the cation distribution in oxides are predicted. The oxide solid solution is stabilized by the mixing free energy (or mixing entropy) and the stabilizing effect becomes more significant as the temperature increases. Consequently, solid solution oxides are stable in large regions of the potential-pH diagram and the mixing free energy mostly affects the equilibrium composition of the stable oxides, while the shape of stable regions for oxides is mostly determined by the structure of the stable oxides. Agreements are found for Ni2+, Fe2+, and Mn2+ between the atomic emission spectroelectrochemistry measurements and thermodynamic calculations, while deviations exist for Cr3+ and Co2+ possibly due to surface complexation with species such as Cl− and the oxide dissolution. By incorporating the solution models of oxides, the current work presents a general and more accurate way to analyze the reaction products during aqueous corrosion of MPEAs.

Oxidation of hydrocarbons in the liquid phase: n-dodecane in a borosilicate glass chamber at 200 °C

1969 ◽  
Vol 47 (22) ◽  
pp. 4175-4182 ◽  
Author(s):  
B. D. Boss ◽  
R. N. Hazlett
Keyword(s):  
Liquid Phase ◽  
Borosilicate Glass ◽  
Current Knowledge ◽  
Reaction Chamber ◽  
Cyclic Ethers ◽  
Reaction Products ◽  
Isomer Distribution ◽  
Oxidation Of Hydrocarbons ◽  
Volatile Products ◽  
Rate Of Reaction

The 5-h oxidation of n-dodecane at 200 °C by air at 1 atm is reported for experiments in a borosilicate glass reaction chamber equipped with a gas bubbler. The rate of reaction was limited by the rate of oxygen diffusion from the gas phase due to the rapid reaction of dissolved oxygen. The reaction products were analyzed in aliquots taken periodically from the reaction chamber. Chemical analyses, gas–liquid phase chromatography (g.l.p.c.), tandem g.l.p.c.-mass spectroscopy, infrared, and ultraviolet were used to identify products accounting for 98% of the oxygen reacted. The isomer distribution of the dodecenes, dodecanols, and dodecanones formed, as well as the distribution of carboxylic acids, were determined. Three classes of intramolecular reaction products, cyclic ethers, cyclic hydrocarbons, and lactones, were detected. Many volatile products were detected. A filterable precipitate obtained after 10 h of oxidation was studied using infrared attenuated total reflectance techniques. A reaction mechanism is discussed based on current knowledge of other systems, the products identified, and the stoichiometry of the reaction.

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