Sulfur-containing Reagents Research Articles

A Platform for the Synthesis of Diverse Phosphonyl and Thiofunctionalized Sulfoxonium Ylides.

A practical strategy for the construction of diverse phosphonyl and thiofunctionalized sulfoxonium ylides via controllable monofunctionalization of hybrid I(III)/S(VI) ylides is presented. This process allows efficient P-H insertion of I(III)/S(VI) ylides under Cu catalysis, enabling the synthesis of phosphonyl sulfoxonium ylides, whereas reaction with sulfur-containing reagents including AgSCF3, KSC(S)OR, and KSCN under mild conditions resulted in α-trifluoromethylthiolation, dithiocarbanation, and thiocyanation of sulfoxonium ylides accordingly. Of note, wide substrate compatibility (108 examples), excellent efficiency (up to 99% yield), gram-scale experiments, and various product derivatizations highlight the synthetic utility of this protocol.

Green synthesis of non-stoichiometric indium sulfide (In2.77S4) nanoparticles for water splitting and supercapacitance

The synthesis of electroactive multifunctional materials with high performance is an inherently challenging process. Furthermore, finding a green approach to make the process more feasible and convenient is highly desirable. Based on these challenges, herein, a facile and green microwave-assisted approach for the synthesis of phase pure sulfur-deficient indium sulfide (In2.77S4) nanoparticles is demonstrated. Green, economical and readily available reagents, such as castor oil and olive oil, were employed as green dispersants, solvents, and capping agents. Moreover, different sulfur-containing reagents, i.e., sodium sulfide, thioacetamide and thiourea, were employed in the synthesis to elucidate the effect of sulfur source on synthesized nanoparticles. Since electrocatalytic properties are significantly affected by the nature of the ligand on the surface of catalysts, therefore their performance for supercapacitance and water splitting is investigated. High-quality In2.77S4 prepared in castor oil, using thiourea as a sulfur source, showed satisfactory properties for energy storage such as specific capacitance of 540 F/g at 1 A/g current density as well as for both HER and OER with overpotentials of 158 and 346 mV, respectively.

Catalysts for dehydration of isopropyl alcohol based on chlorinated carbon fiber

Gas-phase chlorination of carbon fiber based on polyacrylonitrile was performed and active chlorine-containing precursors were obtained, in which chlorine can be replaced by sulfur-containing functional groups. It is shown that chlorination of carbon fiber samples with carbon tetrachloride at temperatures of 300, 450 and 6000C in an argon stream leads to the introduction of 0.2–1.7 mmol g–1 of chlorine into the surface layer of the fiber. The thermodesorption properties of the modified carbon fiber samples were investigated by thermogravimetry and thermoprogrammed desorption with mass spectrometric registration of products. It was established that the obtained samples exhibit a relatively high thermal stability. The study conducted by means of thermoprogrammed desorption method showed that chlorine is desorbed from the surface in a wide temperature range (up to 8000C). It was found that the treatment of chlorinated samples with sulfur-containing reagents with subsequent oxidation produce the samples of carbon fiber with a concentration of sulfo-groups up to 0.3 mmol g–1, which are catalytically active in the dehydration reaction of isopropyl alcohol in the gas phase. The temperature of 50% conversion of isopropyl alcohol to propylene was used as a measure of catalytic activity. It was found that pre-chlorination leads to an increase in the catalytic activity of the fiber modified with sulfur-containing reagents: the temperature of 50% conversion of isopropyl alcohol to propylene is 215–2900C, depending on the concentration of sulfo-groups.

ИССЛЕДОВАНИЕ ЗАКОНОМЕРНОСТЕЙ ПРОЦЕССА ХИМИЧЕСКОГО ОСАЖДЕНИЯ ДИСУЛЬФИДА МОЛИБДЕНА ИЗ ГАЗОВОЙ ФАЗЫ В СИСТЕМЕ MO(CO)6-C2H6S2

In this article, the influence of the temperature and composition of the gas in the reactor on the morphology, structure, and composition of thin films deposited using the new sulfur-containing reagent C2H6S2 was studied. The existence of horizontal layers and their deformation, confirmed by X-ray diffraction and Raman scattering, suggest that vertical dendrites grow from horizontal layers that bend due to deformation, which is very similar to the growth of vertical nanoleaves. However, the transition from vertical dendritic growth at low temperature and high deposition rates to vertical sheet growth at high temperature or lower deposition rates suggests that the formation mechanism can be described by a diffusion-limited aggregation model. The results of experimental studies have shown that vertical dendrites are the main morphology of films deposited at low pressure in the reactor, while at a relatively high pressure it is possible to grow a monolayer in a reasonable time. The probability of formation of layers consisting of dendrites or flat fragments strongly depends on both the deposition temperature and the composition of the reaction gas mixture in the reactor.

Dehydration of isopropyl alcohol with activated carbon functionalized with Br- and S-containing reagents

Bromination of activated carbon GSGD was performed and active bromine-containing precursors were obtained, in which bromine is capable of being replaced by sulfur-containing functional groups. Bromination with liquid bromine and a solution of bromine in potassium bromide at room temperature leads to the introduction of 0.44–0.45 mmol g–1 of bromine into the surface layer of activated carbon. The treatment of brominated samples with sulfur-containing reagents with subsequent oxidation allows obtaining carbon samples that are catalytically active in the dehydration reaction of isopropyl alcohol in a gas phase. The temperature of complete conversion of isopropyl alcohol to propylene is a measure of catalytic activity. The concentration of sulfogroups in the prepared samples is up to 0.3 mol g–1. Thermogravimetry and thermoprogrammed desorption with mass spectrometric registration of products were used to study the thermal stability of modified activated carbon samples. The influence of the nature of brominating reagents, hydrolysis conditions and oxidation conditions on the structure, surface concentration of grafted S-containing groups and catalytic properties of the obtained materials was studied. Pre-bromination leads to an increase in the catalytic activity of activated carbon modified with sulfur-containing groups and the temperature of complete conversion of isopropyl alcohol to propylene decreases up to 400C depending on the concentration of sulfogroups.

Inhibition of Type IV Secretion Activity and Growth of Helicobacter pylori by Cisplatin and Other Platinum Complexes.

Type IV secretion systems are protein secretion machineries that are frequently used by pathogenic bacteria to inject their virulence factors into target cells of their respective hosts. In the case of the human gastric pathogen Helicobacter pylori, the cytotoxin-associated gene (Cag) type IV secretion system is considered a major cause for severe disease, such as gastric cancer, and thus constitutes an attractive target for specific treatment options against H. pylori infections. Here, we have used a Cag type IV secretion reporter assay for screening a repurposing compound library for inhibitors targeting this system. We found that the antitumor agent cisplatin, a platinum coordination complex that kills target cells by formation of DNA crosslinks, is a potent inhibitor of the Cag type IV secretion system. Strikingly, we found that this inhibitory activity of cisplatin depends on a ligand exchange reaction which incorporates a solvent molecule (dimethylsulfoxide) into the complex, a modification which is known to be deleterious for DNA crosslinking, and for its anticancer activity. We extended our analysis to several analogous platinum complexes containing N-heterocyclic carbene, as well as DMSO or other ligands, and found varying inhibitory activities toward the Cag system which were not congruent with their DNA-binding properties, suggesting that protein interactions may cause the inhibitory effect. Inhibition experiments under varying conditions revealed effects on adherence and bacterial viability as well, and showed that the type IV secretion-inhibitory capacity of platinum complexes can be inactivated by sulfur-containing reagents and in complex bacterial growth media. Taken together, our results demonstrate DNA binding-independent inhibitory effects of cisplatin and other platinum complexes against different H. pylori processes including type IV secretion.

Effects of humus on the mobility of arsenic in tailing soil and the thiol-modification of humus

The ability of thiol-modified humic acids (HAs) to release arsenic in tailings soil after being modified with different sulfur-containing reagents were significantly improved. The structure and physicochemical properties of humic acid (HA) before and after thiol-modification were characterized. The 3-MPTS-HA treated with 3-mercaptopropyltrimethoxysilane (3-MPTS) effectively improved the mobility of arsenic, and its reducing ability was increased from 2 mmol g−1 to 3.54 mmol g−1. The S content of humic acids were also significantly increased after treatment with sulfur-containing reagents, in which the oxygen-containing functional group (e.g., C = O, C–O) on the surface of HA may be the active sites for binding with sulfur-containing reagents. It was found in the XPS spectrum that because the thiol group is easily oxidized, there are many S forms in thiol-modified HA. The –SH content in Na2S·9H2O-HA, l (+)-Cysteine-HA (Cys-HA), thioglycolic acid (TGA-HA) and 3-MPTS-HA was determined by fluorescence method to be 13.9, 78.45, 90.34, and 192.29 μmol g−1, respectively. The study demonstrated that surface thiol modification can increase the abundance of thiol in HA and enhance reactivity, which will further promote the application of HA in the treatment of heavy metal contaminated tailing soil.

Mechanisms for the formation of ester compounds in the liquid-phase oxidation of cyclohexane

The channels of formation of ester compounds in the liquid-phase oxidation of cyclohexane are reviewed. At least 99.8% cyclohexyl esters of mono- and dicarboxylic acids are formed as a result of cyclohexanol acylation with mixed anhydrides including residues of all compounds with carboxyl groups present in the oxidized cyclohexane. The formation of mixed anhydrides is related to the fast reacylation of adipic anhydride with carboxylic acids. Alcoholysis of mixed anhydrides containing the formic acid residue with cyclohexanol leads mainly to cyclohexyl formate. The formation of e-caprolactone during cyclohexane oxidation is the result of the Baeyer–Villiger oxidation of cyclohexanone with peroxy acids through α-hydroxy-α-hydroperoxy ester. A decrease in the yield of e-caprolactone is reached under the conditions of decomposition or reduction of peroxy acids in the presence the compounds of variable valency metals or sulfur-containing reagents, respectively. The cobalt(II) and manganese(II) compounds stimulate the homolytic decomposition of α-hydroxy-α-hydroperoxy ester during which no lactone is formed. The cyclization of 5-hydroxypentanoic acid, which was formed by the oxidative transformations of cyclohexanone, leads to δ-valerolactone. The compounds of variable valency metals slightly affect the yield of δ-valerolactone. The mechanism of ester formation associated with the acylation of oxiranes formed by the radical chain oxidation of carbonyl compounds at the β-CH bonds was proposed.

5-Sulfurofunctionalized (1,3-thiazolidin-2-ylidene)pyrimidine-2,4,6-triones and their antibacterial activity

Aim. Studying of the antimicrobial and antifungal activity of 5-sulfurofunctionalized derivatives (1,3-thiazolidine-2-ylidene)pyrimidine-2,4,6(1H,3H,5H)-triones, obtained by the interaction of [5-(iodomethyl)thiazolidine-2-ylidene]pyrimidine-2,4,6(1H,3H,5H)-triones with a number of S-nucleophilic reagents.Results and discussion. A series of new derivatives containing 5-thiocyanato(acetylthio, butylxanthonato)methyl groups has been synthesized by functionalization of [5-(iodomethyl)thiazolidine-2-ylidene]pyrimidine-2,4,6(1H,3H,5H)-triones with sulfur-containing reagents. Among the synthesized compounds substances with moderate antibacterial and antifungal activity were found.Experimental part. Novel 5-thiofunctionalized derivatives were obtained by reaction of [5-(iodomethyl)thiazolidine-2-ylidene]pyrimidine-2,4,6(1H,3H,5H)-triones with potassium thiocyanate, potassium thioacetate in dimethylformamide or potassium buthylxanthate in ethanol with 72-99% yields. The structure of new compounds was confirmed by complex spectral methods. Screening of the antifungal and antimicrobial effects of the synthesized compounds was carried out using a micro-method of double serial dilutions in a liquid nutrient medium.Conclusions. 5-Sulfurofunctionalized (1,3-thiazolidine-2-ylidene)pyrimidine-2,4,6-triones, obtained by the reaction of corresponding 5-iodomethyl derivatives with a number of S-nucleophilic reagents, have shown moderate antimicrobial and antifungal activity and are promising for further in-depth research.

Green diesel production through simultaneous deoxygenation of palmitic acid and desulfurization of 4,6-Dimethyl-dibenzothiophene over commercial CoMo/Al2O3

This study investigated the deoxygenation of palmitic acid as a model compound of palm fatty acid distillate (PFAD), in the presence of 4,6- di-methyl-di-benzothiophene as a sulfur-containing light gas oil (LGO). Reactions were performed at the pressure of 25 barg, liquid hourly space velocity (LHSV) of 1.7 h-1, and H2/oil of 630 NL/L over CoMo/Al2O3 as catalyst. The effect of temperature was studied in the range of 275-300 oC. Both deoxygenation and desulfurization led to approximately 100% conversions at 300 oC, while at 275 oC, palmitic acid deoxygenation was recorded at a higher conversion rate compared with that of the desulfurization of 4,6- di-methyl-di-benzothiophene. The presence of 4,6- di-methyl-di-benzothiophene during the deoxygenation of palmitic acid resulted in high conversions (>95%). Pressure drop studies showed that the formation of heavy products caused a gradual pressure drop throughout the reactor over time. The catalyst was deactivated during 10 d. Two different sulfur-containing reagents were used for catalyst reactivation including dimethyl-disulfide in n-C18 and LGO containing 484 ppmw of sulfur. Reactivation with 2 wt.% of dimethyl-disulfide in n-C18 at 320 oC for 36 h led to more favrable performance recovery vs. the sulfur-containing LGO.

Layered hydroxyl sulfate: Controlled crystallization, structure analysis, and green derivation of multi-color luminescent (La,RE)2O2SO4 and (La,RE)2O2S phosphors (RE = Pr, Sm, Eu, Tb, and Dy)

The two important groups of Ln2O2SO4 and Ln2O2S compounds are traditionally synthesized with the involvements of environmentally harmful sulfur-containing reagents. We developed in this work a unique green approach for their synthesis, using Ln2(OH)4SO4·2H2O layered hydroxyl sulfate as the precursor (Ln-241 phase). Phase selective crystallization of La-241 under both atmospheric pressure and hydrothermal conditions was firstly optimized, followed by transformation into La2O2S and La2O2SO4 by controlled calcination. Rietveld structure refinement was performed for La-241, La(OH)SO4, La2O2SO4, and La2O2S, and the crystal structure and cell parameters of La-241 were originally reported. The photoluminescence performances of several important activators (Pr3+, Sm3+, Eu3+, Tb3+, and Dy3+) in the two hosts, in terms of excitation, emission, quantum yield, and color coordinates of emission, were thoroughly investigated, and multi-color luminescence including bright red, green, orange red, and yellow was obtained under ultraviolet excitation. Detailed investigations of Tb3+ photoluminescence revealed that the lack of 5D3 emission in La2O2S and the gradual quenching of 5D3 blue emission at a higher Tb3+ content (hence decreasing I488/I545 ratio and changing color coordinates) in La2O2SO4 were suggested to be due to thermal activation of the 5D3 electrons into the conduction band and cross relaxation between adjacent Tb3+, respectively. The synthesis approach developed in this work for La2O2SO4 and La2O2S, with water vapor as the only exhaust gas, is environmentally benign and holds great potential in the facile synthesis of analogous compounds of other lanthanides.

Fluorometric determination of copper(II) using CdTe quantum dots coated with 1-(2-thiazolylazo)-2-naphthol and an ionic liquid

The sulfur-containing reagents dithizone, 2,3-dimercapto-1-propanol, 2-thenoyltrifluoroacetone, 1,3,4-thiadiazole-2,5-dithiol, and 1-(2-thiazolylazo)-2-naphthol (TAN) were first examined with respect to their stabilizing effect on CdTe nanocrystals. The indicator TAN was found to best passivate the surface of CdTe NCs if added during synthesis of the NCs at 100 °C. These NCs (referred to as NC-1) have an emission that peaks at 430 nm, and a quantum yield (QY) of 25 %. If, however, TAN-capped particles are prepared in presence of an ionic liquid at room temperature, the QY of such nanocrystals (referred to as NC-2) is increased by 80 % and the emission peak is shifted to 460 nm. The NC-1 particles bind Ag(I), Pb(II), Hg(II), Fe(III), Cr(III), and Cu(II) in phosphate buffer of pH 6.5 while NC-2 particles bind Cu(II) only. Binding of metal ions is associated with a drop in fluorescence intensity. In case of NC-1, quenching is observed in the 23.3 nM to 23.3 μM Cu(II) concentration range with detection limit of 0.5 nM. In case of NC-2, quenching occurs in the 233 nM to 233 μM Cu(II) concentration range with detection limit of 5.0 nM. The method was applied to the determination of Cu(II) in spiked biosamples, and recoveries of Cu(II) (at a 233 nM level) in BSA and fetal bovine serum using NC-2 are 95 % and 92 %. This is better than the recoveries from the same media with NC-1 (70 % and 32 %). These findings demonstrate that the NC-2 material is superior in terms of selectivity and stability but inferior in terms of detection limit.

Oxidation and Decomposition Kinetics of Thiourea Oxides

In this report the decomposition and oxidation kinetics of thiourea dioxide and thiourea trioxide are investigated with a reversed-phase ion-pair high-performance liquid chromatography (HPLC) method. The HPLC method allows us to simultaneously determine and quantify several sulfur-containing reagents such as (NH2)2CSO2, (NH2)2CSO3, (NH2)2CO, and SO3(2-) (HSO3-). Experiments illustrate that the decomposition of thiourea oxides is a first-order reaction, in which the rate constants increase with the pH of the solution. Oxidations of thiourea oxides by hydrogen peroxide are first order with respect to both reagents within the studied pH range between 4.0 and 8.0. Oxidation rate constants are measured under different pH conditions, which show that increasing the pH of the reaction solution significantly accelerates the oxidation process.

The enantioseparation of amino acids on a teicoplanin chiral stationary phase using non-aqueous mobile phases after pre-column derivatization with sulfur-containing reagents: the considerations of mobile phase composition and analyte structure variation on resolution enhancement

Amino acids were derivatized with sulfur-containing reagents in alkaline medium and enantioresolved by HPLC on a teicoplanin chiral stationary phase. Much better resolution was achieved using methanol-based mobile phase compared with elution with acetonitrile-based solvent mixture. The value of selectivity factor for many derivatives examined in the study can be easily several tenths of 100 or even exceed 100 in some cases. This magnitude of resolution is suitable for the preparative-scale application of isolating alpha-amino acid enantiomers in the derivatized form using a short column. The resolution is believed to be a result of the hydrogen bonding and steric hindrance by the nitrogen and sulfur atoms from the isothiocyanatyl fragment of the reagent, respectively, and is enhanced as the fragment is structurally phenylated (e.g. 2,4-difluorophenyl isothiocyanate and others examined in this study). The enhancement is even more significant if the aromatic moiety of the reagent becomes more acidic through halogenation with chlorine or fluorine for the stronger pi-pi interaction. However, this type of enhancement is offset to some extent and sometimes obscured by a chlorinated reagent that is relatively large in size as compared with the fluorinated one. Judging from the chromatographic data and the elution profile, the mechanisms leading to the resolutions are believed to be different under the elution of polar-organic mobile phases (i.e. methanol- and acetonitrile-based mobile phases).

Photometric and Gas-Chromatographic Determination of Hydrogen Peroxide and Peroxybutanoic Acid in Oxidized Butanoic Acid

Procedures were developed for determining hydrogen peroxide and peroxy acids mixed with peroxide compounds of other classes in the oxidation products of butanoic acid with atmospheric oxygen and hydrogen peroxide. Conditions were found for the selective decomposition of hydrogen peroxide with catalase in the presence of an excess of the carboxylic acid deactivating the enzyme. The errors introduced by the acylation of hydrogen peroxide with the carboxylic acid in the course of sample treatment with the enzyme were eliminated by adding diphenyl sulfide or dimethyl sulfoxide, which selectively reduced the peroxy acids. The concentrations of hydrogen peroxide and the peroxy acid were found from the difference between the total concentration of the peroxide compounds before and after treating a sample with catalase and a sulfur-containing reagent by the photometric method using a reagent containing Fe2+ ions and N, N-dimethyl-p-phenylenediamine. Peroxy acids were determined by GLC from the yields of the oxidation products of diphenyl sulfide with the peroxy acid (diphenyl sulfoxide and diphenyl sulfones).

REACTION OF TRIFLUOROMETHYLSULFENYL CHLORIDE WITH 3-CHLORO- AND 3-HYDROXYPROPYNES

Vinylsulfides are often obtained via the reaction of substituted acetylenes with sulfur-containing reagents. The presence of other functional groups such as the halide or the hydroxyl moieties enhances the usefulness of the vinylsulfide intermediates. To this end, propargyl alcohol and halides have found wide application. With a view to enhance the biological properties of the end products synthesized from the vinylsulfide intermediates, the trifluoromethylthio function has now been incorporated as a part of the vinylic system. This communication presents the free-radical addition of trifluoromethylsulfenyl chloride to 3-chloro- and 3-hydroxypropynes, and the mechanism of the formation of the various products and their spectral characterization.

Supercritical Fluid Extraction of Toxic Heavy Metals from Solid and Aqueous Matrices

The feasibility of using dithiocarbamate chelating agents or sulfur-containing organophosphorus reagents for the supercritical fluid extraction (SFE) of toxic heavy metals from solid and aqueous matrices was investigated. Effective extraction of heavy metal ions from both sand matrix and water samples was demonstrated by using supercritical CO2 containing dithiocarbamate chelating agents. A commercially available sulfur-containing organophosphorus reagent, Cyanex 302, was used for the extraction of toxic heavy metals from wood samples. The extraction profiles were initially rapid followed by a very low level of metal extraction, indicating that the process is limited to extraction of leachable toxic metals.

Trans-Diepoxy Derivative of Limonene. Synthesis, Structure, and Products of Oxirane Ring Opening with Sulfur-Containing Reagents *

Pure trans-diepoxy derivative of limonene was synthesized for the first time. Its reactions with sulfur-containing nucleophiles in basic medium resulted in formation of polyfunctional derivatives of the menthane series, 2,9-bis(R-thio)-trans-p-menthane-1,8-diols.

Production of sulfur-containing reagents from petroleum for use in hydrometallurgy

The author, A. Kh. Sharipov, Candidate of Technical Sciences, was graduated from the Ufa State Petroleum Technical University. Specialty: Oil and gas processing technology. Director, Scientific Group of the Institute of Petroleum Chemistry and Catalysis, Academy of Sciences of the Republic of Bashkortostan. Member of the Scientific Council for the Problem Area “Chemistry and Technology of Organic Sulfur Compounds,” Ministry of General and Professional Education of the Russian Federation. Circle of scientific interests: Development and commercialization of nontraditional methods for treating fuels and gases to remove sulfur compounds; recovery and utilization of these compounds in the national economy. Publications: More than 150 scientific works. Inventions: 58 Inventor’s Certificates.

Ion–molecule reactions of charged thiols with neutral epoxides in the collision cell of a tandem quadrupole mass spectrometer. A model for invivo biomolecule reactions

Gas-phase ion‐molecule chemistry has been used to study the reactions of mutagenic epoxides toward sulfur-containing (SH) organic chemicals. Reactions are selectively observed between mass-selected radical ions of thiols and neutral epoxides in the collision cell (Q2) of a tandem quadrupole mass spectrometer. A daughter-ion scan function is used to produce associative reaction product spectra by scanning the third quadrupole upward from the m/z value of the molecular ion of the sulfur-containing reagent ion. Optimal product yields are obtained by varying the collision cell energy from +1 to ‐5 V. It was observed that gas-phase product formation proceeded in a manner analogous to acidic solution chemistry (e.g. via the protonated epoxide) and that the product spectrum was sensitive to the structure of both the thiol radical-ion and the neutral epoxide. Q2 gas-phase reactions represent, therefore, a potentially new analytical technique to identify selectively chemicals in a gas stream (e.g. gas chromatography effluent) the toxicity of which are defined by their reactivity as electrophiles with nucleophilic sites in biomolecules.