Reaction Of Sulfur Dioxide Research Articles

Validation of a fast automated photometric method for the analysis of sulfur dioxide in wines

In this work a simple and rapid automated analytical method for the determination of sulfur dioxide in wines by employing a sequential automatic analyser was validated. The methodology is based on the reaction of sulfur dioxide with 5,5′-dithiobis-(2-nitrobenzoic acid) in an alkaline medium followed by photometric detection. The linearity of the calibration curve was excellent (R2 = 1.000) and the LOQ (2.00 mg L−1) was well suited for the monitoring of regulatory limits. The accuracy and precision were evaluated with reference materials, providing highly successful results (RSD% < 3.8 for precision and R2 = 0.99 of correlation between the obtained and declared values). The method was applied to the analysis of commercial samples of wines ensuring compliance with legislation. The results found were compared to those obtained with the spectrophotometric method recommended for beers, implemented in a flow system, showing that there are no statistical differences between them (α ≤ 0.05). When compared with conventional methods, the proposed methodology showed to be fast, with minimum handling of the sample and small sample and reagents volume requirement, which together with a minimum maintenance, involves a considerable reduction in laboratory costs.

Generation of (E)-β-trifluoromethyl vinylsulfonohydrazides under photocatalysis and their anti-bacteria activity

Trifluoromethylation/sulfonylation of alkynes from trifluoromethyl thianthrenium triflate and sulfur dioxide under extremely mild reaction conditions provides a facile access to trifluoromethyl-substituted vinyl sulfonohydrazides in moderate to good yields. This multicomponent reaction of trifluoromethyl thianthrenium triflate, alkynes, sulfur dioxide and hydrazines proceeds efficiently under visible light irradiation in the presence of photocatalyst at room temperature with broad substrate scope and excellent functional group compatibility. This reaction is highly stereoselective, and only (E)-isomers are obtained. Additionally, these trifluoromethyl-substituted vinyl sulfonohydrazides are further evaluated for anti-bacteria activity. In vitro activities of these compounds against Staphylococcus aureus (G+) and Escherichia coli (G−) are examined.

Daytime SO2 chemistry on ubiquitous urban surfaces as a source of organic sulfur compounds in ambient air.

The reactions of sulfur dioxide (SO2) with surface-bound compounds on atmospheric aerosols lead to the formation of organic sulfur (OS) compounds, thereby affecting the air quality and climate. Here, we show that the heterogeneous reaction of SO2 with authentic urban grime under near-ultraviolet sunlight irradiation leads to a large suite of various organic compounds including OS released in the gas phase. Calculations indicate that at the core area of Guangzhou, building surface uptake of SO2 is 15 times larger than uptake of SO2 on aerosol surfaces, yielding ~20 ng m−3 of OS that represents an important fraction of the observed OS compounds (60 to 200 ng m−3) in ambient aerosols of Chinese megacities. This chemical pathway occurring during daytime can contribute to the observed fraction of OS compounds in aerosols and improve the understanding of haze formation and urban air pollution.

Heterogeneous reaction of SO2 on CaCO3 particles: Different impacts of NO2 and acetic acid on the sulfite and sulfate formation

Despite the heterogeneous reaction of sulfur dioxide (SO2) on mineral dust particles significantly affects the atmospheric environment, the effect of acidic gases on the formation of sulfite and sulfate from this reaction is not particularly clear. In this work, using the in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technique, we employed a mineral dust particle model (CaCO3) combined with NO2 and acetic acid to investigate their effects on the heterogeneous reaction of SO2 on CaCO3 particles. It was found that water vapor can promote the formation of sulfite and simulated radiation can facilitate the oxidation of sulfite to sulfate. The addition of NO2 or acetic acid to the reaction system altered the production of sulfate and sulfite accordingly. There was a synergistic effect between NO2 and SO2 that promoted the oxidation of sulfite to sulfate, and a competitive effect between acetic acid and SO2 that inhibited the formation of sulfite. Moreover, light and water vapor can also affect the heterogeneous reaction of SO2 with the coexistence of multiple gases. These findings improve our understanding of the effects of organic and inorganic gases and environmental factors on the formation of sulfite and sulfate in heterogeneous reactions.

Photoredox-catalyzed reaction of thianthrenium salts, sulfur dioxide and hydrazines

A photoredox-catalyzed reaction of thianthrenium salts, hydrazines and DABCO·(SO2)2 is accomplished, providing diverse arenesulfonohydrazides in moderate to good yields under mild reaction conditions.

New DRIFT spectroscopic methodology for acquiring infrared spectra of fiberglass materials

We report a new approach for infrared spectroscopic analysis of fiberglass materials using a mirror substrate, which allowed the specular reflection from the sample surface to be minimized and detect the light passing through the sample. The application of this technique for platinum-containing fiberglass catalysts made it possible for the first time to identify sulfate compounds formed in glass fibers during the oxidation reaction of sulfur dioxide. The developed technique can be applied for a number of research samples that are difficult to analyze by conventional IR spectroscopic methods.

Photoinduced reaction of potassium alkyltrifluoroborates, sulfur dioxide and para-quinone methides via radical 1,6-addition

A photoinduced reaction of potassium alkyltrifluoroborates, sulfur dioxide, and para-quinone methides under visible light irradiation at room temperature is developed, giving rise to diarylmethyl alkylsulfones in moderate to good yields. This reaction works well under photocatalysis with a broad substrate scope by using DABCO·(SO2)2 as the source of sulfur dioxide. Mechanistic study shows that this transformation is initiated by alkyl radicals generated in situ from potassium alkyltrifluoroborates in the presence of photocatalyst. The subsequent insertion of sulfur dioxide and radical 1,6-addition of para-quinone methides with alkylsulfonyl radical intermediates afford the corresponding diarylmethyl alkylsulfones.

Generation of (E)-β-sulfonyl enamines from sulfur dioxide via a radical process

An iron(ii)-catalyzed three-component reaction of O-acyl oximes, sulfur dioxide, and N-vinylacetamides is accomplished. Diverse (E)-β-sulfonyl enamines are obtained in moderate to good yields by using this protocol with excellent stereoselectivity and regioselectivity.

Assembly of 3-sulfonated 2H-pyrrol-2-ones through the insertion of sulfur dioxide with allenoic amides

Generation of 3-sulfonated 2H-pyrrol-2-ones through a three-component reaction of allenoic amides, sulfur dioxide, and aryldiazonium tetrafluoroborates under metal-free conditions is achieved. This transformation proceeds under mild conditions without the addition of catalysts or additives, giving rise to 3-sulfonated 2H-pyrrol-2-ones in moderate to good yields. Good functional group compatibility is observed. A plausible mechanism is proposed, which is initiated by aryl radicals formed in situ from aryldiazonium tetrafluoroborates and DABCO·(SO2)2. Additionally, excellent chemoselectivity and regioselectivity are presented in this transformation.

Nitrosoarenes as Nitrogen Source for Generation of Sulfonamides with the Insertion of Sulfur Dioxide under Metal‐Free Conditions†

Summary of main observation and conclusionA metal‐free reaction of nitrosoarenes, aryldiazonium tetrafluoroborates, and sulfur dioxide under mild conditions is developed, giving rise to sulfonamides in moderate to good yields. This transformation proceeds efficiently at room temperature in the presence of cyclohexa‐1,4‐diene with a broad reaction scope. Good functional group compatibility is observed, including cyano, halo, and ester. A plausible mechanism involving a radical process with the insertion of sulfur dioxide is proposed, and cyclohexa‐1,4‐diene serves as the reductant during the transformation.

Photoinduced synthesis of alkylalkynyl sulfones through a reaction of potassium alkyltrifluoroborates, sulfur dioxide, and alkynyl bromides

A photoinduced reaction of potassium alkyltrifluoroborates, sodium metabisulfite, and alkynyl bromides under visible light irradiation at room temperature is developed.

A metal-free reaction of sulfur dioxide, cyclopropanols and electron-deficient olefins.

The importance of γ-keto sulfones in medicinal chemistry and organic synthesis is known. An efficient route to γ-keto sulfones via a metal-free reaction of cyclopropanols, sulfur dioxide and electron-deficient olefins is achieved. This reaction proceeds smoothly under mild conditions without the need of catalyst, oxidant or additive. A plausible mechanism is proposed, which occurs through a γ-keto sulfinate intermediate generated in situ from the reaction of cyclopropanol with sulfur dioxide. The γ-keto sulfinate intermediate would be trapped by the electron-deficient olefin, resulting in the formation of γ-keto sulfones. Various functional groups in the cyclopropanols and electron-deficient olefins are compatible in this transformation.

Generation of (Z)-β-alkenyl alkylsulfones via a copper-catalyzed decarboxylative alkylsulfonylation

A copper-catalyzed three-component reaction of acrylamides, sulfur dioxide and phenyliodine(iii) dicarboxylates is developed. The conversion using phenyliodine dicarboxylates as alkyl radical precursors provides diverse (Z)-β-alkenyl alkylsulfones.

Hierarchical three-dimensionally ordered macroporous Fe-V binary metal oxide catalyst for low temperature selective catalytic reduction of NOx from marine diesel engine exhaust

A series of hierarchical three-dimensionally ordered macroporous Fe10-xVx binary metal oxides (3DOM-Fe10-xVx) catalysts were designed and synthesized for selective catalytic reduction of NOx from marine diesel engine exhaust. The physical-chemical performance of the 3DOM-Fe10-xVx catalysts were subjected by various techniques and found that the 3DOM-Fe10-xVx with the Fe to V atomic ratio of 9.0/1.0 exhibited a wider active temperature window, better soot resistance performance compared with the conventional Fe9.0V1.0 catalyst due to its special 3DOM structure. Even when simultaneously exposed to the soot and high concentration of sulfur dioxide reaction feeds, the 3DOM-Fe9.0V1.0 catalyst also displayed superior catalytic activity. Interestingly, we found that the soot had a reduction activity for NOx at high reaction temperature, which can effectively extend its active temperature window. The 3DOM-Fe10-xVx catalysts prepared in this work could be potentially a good candidate for the cargo ships deNOx catalysts to satisfy the more stringent exhaust emission rules.

Synthesis of bismuth oxyiodide (BiOI) by means of microwaves in glycerol with high photocatalytic activity for the elimination of NOx and SO2

A facile microwave route was successfully developed to synthesize BiOI in glycerol as a medium of reaction. The temperature and time of synthesis were selected as the critical experimental variables to rule the physicochemical properties of the samples prepared. The products were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy, adsorption–desorption N2 isotherms, diffuse reflectance spectroscopy, scanning electron microscopy, X-ray electron spectroscopy and thermogravimetric/differential scanning calorimetry (TGA/DSC). The photocatalytic activity of BiOI samples was tested in the oxidation reactions of nitric oxide (NO) and sulfur dioxide (SO2) in gaseous phase under visible light radiation. The photocatalysts with the highest activity were the samples prepared by microwave irradiation at 135 °C for 20–34 min and were able to remove 97.8% of NO2 and 85.2% of SO2. The analysis by XRD revealed aspects of the samples that improved its photocatalytic activity, such as the preferential crystalline orientation in (110) BiOI planes, as well as the presence of the secondary crystalline phases Bi, Bi2O2.5 and Bi4O5I2. The use of chemical scavengers revealed that the ion superoxide (O2−) and photogenerated electrons (e−) were the predominant active species in the mechanism of the NO oxidation reaction.

Simultaneous Construction of C-Se And C-S Bonds via the Visible-Light-Mediated Multicomponent Cascade Reaction of Diselenides, Alkynes, and SO2.

A visible-light mediated multicomponent cascade reaction of diselenides, alkynes, and sulfur dioxide was developed, in which multiple C-Se and C-S bonds were constructed, and unexpected β-sulfonylvinylselane compounds were generated with high selectivity for E configuration. β-Sulfonylvinylselane transformation into 1,4-oxathiine-4,4-dioxide and sulfonylethyne derivates was then investigated. A plausible mechanism involving a selenium radical-initiated cascade reaction and sulfur dioxide insertion was proposed.

Uptake and surface chemistry of SO2 on natural volcanic dusts

V-dust (v-dust) is a highly variable source of natural particles in the atmosphere, and during the period of high volcanic activity it can provide a large surface for heterogeneous interactions with other atmospheric compounds. Icelandic v-dust was chosen as a case study due to frequency of volcanic eruptions and high aeolian activity in the area. In this study, we focus on the kinetics and mechanism of the reaction of sulfur dioxide (SO2) with natural v-dust samples under atmospheric conditions using coated wall flow tube reactor and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Steady state uptake coefficients determined are in the range of 10−9 to 10−8 depending on the considered v-dust. Concomitantly with SO2 uptake, both sulfites and sulfates are monitored on the surface of v-dust, with sulfates being the final oxidation product, attesting of SO2 surface reaction. Surface hydroxyl groups play a crucial role in the conversion of SO2 to sulfites as evidenced from both flow tube and DRIFTS experiments. Based on these experimental results, a mechanism for SO2 interaction with different surface sites of v-dust is proposed and discussed. This study provides original insights in the kinetics of SO2 uptake under simulated atmospheric conditions and its mechanism and transformation on volcanic material. To that regards, it brings an accurate perspective on SO2 heterogeneous sinks in the atmosphere.

Sulfur Dioxide Modifies Aerosol Particle Formation and Growth by Ozonolysis of Monoterpenes and Isoprene

AbstractThe effect of sulfur dioxide on particle formation and growth by ozonolysis of three monoterpenes (α‐pinene, β‐pinene, and limonene) and isoprene was investigated in the presence of monodisperse ammonium sulfate seed particles and an OH scavenger in a flow tube under dry conditions. Without sulfur dioxide, new particle formation was not observed, and seed particle growth was consistent with condensation of low‐volatility oxidation products produced from each organic precursor. With sulfur dioxide, new particle formation was observed from every precursor studied, consistent with sulfuric acid formation by reaction of sulfur dioxide with stabilized Criegee Intermediates. The presence of sulfur dioxide did not significantly affect seed particle growth rates from α‐pinene and limonene ozonolysis, although chemical composition measurements revealed the presence of organosulfates in the particles following SO2 exposure. Contrarily, the growth of seeds by β‐pinene and isoprene ozonolysis was considerably enhanced by sulfur dioxide, and chemical composition measurements revealed that the enhanced growth was not due to additional organic material, suggesting that inorganic sulfate was likely responsible. The results suggest that a previously unconsidered particle‐phase pathway to growth activated by sulfur dioxide may alter production of cloud condensation nuclei over regions with significant SO2‐alkene interactions.

Three‐Component Reaction of Potassium Alkyltrifluoroborates, Sulfur Dioxide and Allylic Bromides under Visible‐Light Irradiation

AbstractDiverse allylic sulfones are generated through a three‐component reaction of potassium alkyltrifluoroborates, sulfur dioxide and allylic bromides in the presence of 9‐mesityl‐10‐methyl acridinium perchlorate under visible light irradiation at room temperature. This transformation proceeds efficiently, and a broad reaction scope is demonstrated with good functional groups tolerance. This reaction is initiated by the treatment of potassium alkyltrifluoroborate under visible‐light irradiation in the presence of a photocatalyst, leading to alkyl radical. This alkyl radical intermediate is trapped by sulfur dioxide to provide alkylsulfonyl radical, which then undergoes further transformation to afford the corresponding allylic sulfone.

Synthesis of β-Sulfonyl Amides through a Multicomponent Reaction with the Insertion of Sulfur Dioxide under Visible Light Irradiation.

A multicomponent reaction of styrenes, aryldiazonium tetrafluoroborates, sulfur dioxide, nitriles, and water in the presence of a photocatalyst at room temperature is performed. This vicinal aminosulfonylation of styrenes with the insertion of sulfur dioxide under visible light irradiation proceeds efficiently with excellent chemoselectivity, giving rise to the corresponding β-sulfonyl amides in moderate to good yields.