3058-35-3Relevant academic research and scientific papers
Effect of Organic Solvents on the Rate of Oxidation of Sulfoxides with Peroxy Acids
Dutka, V. S.,Dutka, Yu. V.,Midyana, G. G.,Pal’chikova, E. Ya.
, p. 329 - 334 (2020/04/27)
Abstract: The reaction of sulfoxides with peroxy acids in various organic media was studied. The reaction mechanism involves the rapid formation of a sulfoxide-–peroxy acid intermediate which decomposes in the second stage to form carboxylic acid and the corresponding sulfone. The second stage is the rate-limiting step. The reaction medium significantly affects the rate of oxidation. The calculated activation parameters of the oxidation process indicate a compensation effect in the investigated reaction. Correlations between the main physicochemical parameters of solvents and the effective rate constants (k) of dimethyl sulfoxide oxidation with peroxy acids were found. Depending on the reaction conditions, the main factors affecting the k values are specific and nonspecific solvation of the reactants and structural factors.
Mass spectrometry characterization of peroxycarboxylic acids as proxies for reactive oxygen species and highly oxygenated molecules in atmospheric aerosols
Steimer, Sarah S.,Kourtchev, Ivan,Kalberer, Markus
, p. 2873 - 2879 (2017/04/13)
A significant fraction of atmospheric aerosol particles is composed of organic material with a highly complex but poorly characterized composition. For a better understanding of aerosol effects and processes in the atmosphere, a more detailed knowledge of aerosol components at a molecular level is needed. Peroxy acids might play a significant role in particle toxicity, due to their oxidizing properties, and they were recently found to be involved in particle formation. Because of the lack of appropriate standards, the identification and quantification of peroxy acids is often highly uncertain. Mass spectrometry (MS) is a powerful tool to characterize unidentified compounds in complex mixtures. However, so far there is only little information regarding the ionization and fragmentation behavior of peroxy acids in mass spectrometers. To study their fragmentation patterns, we synthesized 12 peroxy acids with C8 to C10 carbon backbones and mono- or diperoxy acid functionality. The peroxy acids were separated using liquid chromatography, detected via negative mode electrospray ionization high-resolution MS, and their fragmentation patterns (MS/MS spectra) were identified. The MS/MS spectra of the peroxy acids showed fragmentation patterns clearly different from the corresponding acid, with a strong similarity between compounds of different chain length but analogous functional groups. Neutral loss of CH2O2 was observed for all investigated linear peroxy acids but not for carboxylic acids and could therefore serve as a diagnostic ion for peroxy acids. The obtained results are a large step toward unambiguous characterization of peroxy acids in the atmosphere. (Graph Presented).
Trapping a Highly Reactive Nonheme Iron Intermediate That Oxygenates Strong C-H Bonds with Stereoretention
Serrano-Plana, Joan,Oloo, Williamson N.,Acosta-Rueda, Laura,Meier, Katlyn K.,Verdejo, Bego?a,García-Espa?a, Enrique,Basallote, Manuel G.,Münck, Eckard,Que, Lawrence,Company, Anna,Costas, Miquel
supporting information, p. 15833 - 15842 (2016/01/09)
An unprecedentedly reactive iron species (2) has been generated by reaction of excess peracetic acid with a mononuclear iron complex [FeII(CF3SO3)2(PyNMe3)] (1) at cryogenic temperatures, and characterized spectroscopically. Compound 2 is kinetically competent for breaking strong C-H bonds of alkanes (BDE ≈ 100 kcal·mol-1) through a hydrogen-atom transfer mechanism, and the transformations proceed with stereoretention and regioselectively, responding to bond strength, as well as to steric and polar effects. Bimolecular reaction rates are at least an order of magnitude faster than those of the most reactive synthetic high-valent nonheme oxoiron species described to date. EPR studies in tandem with kinetic analysis show that the 490 nm chromophore of 2 is associated with two S = 1/2 species in rapid equilibrium. The minor component 2a (～5% iron) has g-values at 2.20, 2.19, and 1.99 characteristic of a low-spin iron(III) center, and it is assigned as [FeIII(OOAc)(PyNMe3)]2+, also by comparison with the EPR parameters of the structurally characterized hydroxamate analogue [FeIII(tBuCON(H)O)(PyNMe3)]2+ (4). The major component 2b (～40% iron, g-values = 2.07, 2.01, 1.95) has unusual EPR parameters, and it is proposed to be [FeV(O)(OAc)(PyNMe3)]2+, where the O-O bond in 2a has been broken. Consistent with this assignment, 2b undergoes exchange of its acetate ligand with CD3CO2D and very rapidly reacts with olefins to produce the corresponding cis-1,2-hydroxoacetate product. Therefore, this work constitutes the first example where a synthetic nonheme iron species responsible for stereospecific and site selective C-H hydroxylation is spectroscopically trapped, and its catalytic reactivity against C-H bonds can be directly interrogated by kinetic methods. The accumulated evidence indicates that 2 consists mainly of an extraordinarily reactive [FeV(O)(OAc)(PyNMe3)]2+ (2b) species capable of hydroxylating unactivated alkyl C-H bonds with stereoretention in a rapid and site-selective manner, and that exists in fast equilibrium with its [FeIII(OOAc)(PyNMe3)]2+ precursor.
Thermal decomposition of aliphatic peroxy acids
Dutka,Zagorskaya,Dutka, Yu. V.,Savitskaya
experimental part, p. 353 - 357 (2011/08/05)
The thermal decomposition reactions of aliphatic peroxy acids containing from 8 to 16 carbon atoms in a molecule were studied. It was found that the carbon radical length had no effect on the thermal stability of peroxide groups. The apparent rate constants of thermolysis of peroxydecanoic acid in various solvents and the activation energies of the test reaction were found. The thermal degradation of peroxy acids involved secondary reactions of induced chain degradation in addition to the primary homolysis of the peroxide group. The rate constants of induced chain degradation were found.
Liquid chromatographic simultaneous determination of peroxycarboxylic acids using postcolumn derivatization
Effkemann,Pinkernell,Neumueller,Schwan,Engelhardt,Karst
, p. 3857 - 3862 (2007/10/03)
The first liquid chromatographic method with postcolumn derivatization for the simultaneous determination of peroxycarboxylic acids is described. Aliphatic peracids with chain lengths from C2 to C12 are separated by HPLC on a reversed-phase C18 column with acetonitrile/water gradient elution. For improved peak shape, tetrahydrofuran and acetic acid are added to the aqueous eluent. After chromatographic separation, the peroxycarboxylic acids react with 2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulfonate, a popular substrate for the enzyme peroxidase. Iodide traces are added as catalyst. The oxidation product, a green radical cation, is determined using a UV/ visible detector in four characteristic regions of the visible and near-infrared spectrum in the range 405-815 nm. The advantages of the new method are detection limits in the low micromolar range, negligible matrix interferences, high reproducibility, and the possibility for simultaneous determination of several peroxycarboxylic acids.
