Journal articles: 'Polysulfides'

1

Goifman, A., D. Ryzkov, J. Gun, A. Kamyshny, A. D. Modestov, and O. Lev. "Inorganic polysulfides’ quantitation by methyl iodide derivatization: dimethylpolysulfide formation potential." Water Science and Technology 49, no. 9 (May 1, 2004): 179–84. http://dx.doi.org/10.2166/wst.2004.0565.

Full text

Abstract:

Inorganic polysulfides are important intermediates in the formation of dimethylpolysulfides and possibly other volatile sulfur compounds of environmental significance. Currently, direct determination of these ions in the concentration range of natural systems is practically impossible, particularly under oxic conditions. Polysulfide quantification by derivatization with methyl iodide or d6-methyl iodide is emerging as a valuable alternative method for studies of polysulfide formation in natural systems. This manuscript presents detailed studies aimed at the evaluation of this method. We determined the conversion of the inorganic polysulfides to dimethylpolysulfides by methylation with methyl iodide. Close to 100 per cent of the molar concentration of polysulfide salts were converted to organic polysulfides for very low concentrations of dissolved polysulfide solutions, but only a small recovery was obtained for high concentrations of polysulfide precursors or when the solubility limit was exceeded. The recovery of polysulfides based on the calculated dissolved polysulfide concentration exceeds 1,000 per cent for very low dissolved concentrations of polysulfides. This unexpected dependence is attributed to continuous inorganic polysulfide formation from hydrogen sulfide and sulfur precipitate concurrent with, and in fact driven by, the methylation process.

APA, Harvard, Vancouver, ISO, and other styles

2

Xu, Jing, Dawei Su, Wenxue Zhang, Weizhai Bao, and Guoxiu Wang. "A nitrogen–sulfur co-doped porous graphene matrix as a sulfur immobilizer for high performance lithium–sulfur batteries." Journal of Materials Chemistry A 4, no. 44 (2016): 17381–93. http://dx.doi.org/10.1039/c6ta05878g.

Full text

Abstract:

The combination of the physical adsorption of lithium polysulfides onto porous graphene and the chemical binding of polysulfides to N and S sites promotes reversible Li₂S/polysulfide/S conversion, realizing high performance Li–S batteries with long cycle life and high-energy density.

APA, Harvard, Vancouver, ISO, and other styles

3

Braunstein, Ilana, Rotem Engelman, Ofer Yitzhaki, Tamar Ziv, Erwan Galardon, and Moran Benhar. "Opposing effects of polysulfides and thioredoxin on apoptosis through caspase persulfidation." Journal of Biological Chemistry 295, no. 11 (February 10, 2020): 3590–600. http://dx.doi.org/10.1074/jbc.ra119.012357.

Full text

Abstract:

Hydrogen sulfide has been implicated in a large number of physiological processes including cell survival and death, encouraging research into its mechanisms of action and therapeutic potential. Results from recent studies suggest that the cellular effects of hydrogen sulfide are mediated in part by sulfane sulfur species, including persulfides and polysulfides. In the present study, we investigated the apoptosis-modulating effects of polysulfides, especially on the caspase cascade, which mediates the intrinsic apoptotic pathway. Biochemical analyses revealed that organic or synthetic polysulfides strongly and rapidly inhibit the enzymatic activity of caspase-3, a major effector protease in apoptosis. We attributed the caspase-3 inhibition to persulfidation of its catalytic cysteine. In apoptotically stimulated HeLa cells, short-term exposure to polysulfides triggered the persulfidation and deactivation of cleaved caspase-3. These effects were antagonized by the thioredoxin/thioredoxin reductase system (Trx/TrxR). Trx/TrxR restored the activity of polysulfide-inactivated caspase-3 in vitro, and TrxR inhibition potentiated polysulfide-mediated suppression of caspase-3 activity in situ. We further found that under conditions of low TrxR activity, early cell exposure to polysulfides leads to enhanced persulfidation of initiator caspase-9 and decreases apoptosis. Notably, we show that the proenzymes procaspase-3 and -9 are basally persulfidated in resting (unstimulated) cells and become depersulfidated during their processing and activation. Inhibition of TrxR attenuated the depersulfidation and activation of caspase-9. Taken together, our results reveal that polysulfides target the caspase-9/3 cascade and thereby suppress cancer cell apoptosis, and highlight the role of Trx/TrxR-mediated depersulfidation in enabling caspase activation.

APA, Harvard, Vancouver, ISO, and other styles

4

Yu, Xingwen, and Arumugam Manthiram. "A class of polysulfide catholytes for lithium–sulfur batteries: energy density, cyclability, and voltage enhancement." Physical Chemistry Chemical Physics 17, no. 3 (2015): 2127–36. http://dx.doi.org/10.1039/c4cp04895d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Chauvin, Jean-Philippe R., Evan A. Haidasz, Markus Griesser, and Derek A. Pratt. "Polysulfide-1-oxides react with peroxyl radicals as quickly as hindered phenolic antioxidants and do so by a surprising concerted homolytic substitution." Chemical Science 7, no. 10 (2016): 6347–56. http://dx.doi.org/10.1039/c6sc01434h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Chang, Caiyun, and Xiong Pu. "Revisiting the positive roles of liquid polysulfides in alkali metal–sulfur electrochemistry: from electrolyte additives to active catholyte." Nanoscale 11, no. 45 (2019): 21595–621. http://dx.doi.org/10.1039/c9nr07416c.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Yin, Shujun, Chenhui Wei, and Dongqiang Zhu. "Surface quinone-induced formation of aqueous reactive sulfur species controls pine wood biochar-mediated reductive dechlorination of hexachloroethane by sulfide." Environmental Science: Processes & Impacts 22, no. 9 (2020): 1898–907. http://dx.doi.org/10.1039/d0em00307g.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Olson, Kenneth R., Yan Gao, and Karl D. Straub. "Oxidation of Hydrogen Sulfide by Quinones: How Polyphenols Initiate Their Cytoprotective Effects." International Journal of Molecular Sciences 22, no. 2 (January 19, 2021): 961. http://dx.doi.org/10.3390/ijms22020961.

Full text

Abstract:

We have shown that autoxidized polyphenolic nutraceuticals oxidize H2S to polysulfides and thiosulfate and this may convey their cytoprotective effects. Polyphenol reactivity is largely attributed to the B ring, which is usually a form of hydroxyquinone (HQ). Here, we examine the effects of HQs on sulfur metabolism using H2S- and polysulfide-specific fluorophores (AzMC and SSP4, respectively) and thiosulfate sensitive silver nanoparticles (AgNP). In buffer, 1,4-dihydroxybenzene (1,4-DB), 1,4-benzoquinone (1,4-BQ), pyrogallol (PG) and gallic acid (GA) oxidized H2S to polysulfides and thiosulfate, whereas 1,2-DB, 1,3-DB, 1,2-dihydroxy,3,4-benzoquinone and shikimic acid did not. In addition, 1,4-DB, 1,4-BQ, PG and GA also increased polysulfide production in HEK293 cells. In buffer, H2S oxidation by 1,4-DB was oxygen-dependent, partially inhibited by tempol and trolox, and absorbance spectra were consistent with redox cycling between HQ autoxidation and H2S-mediated reduction. Neither 1,2-DB, 1,3-DB, 1,4-DB nor 1,4-BQ reduced polysulfides to H2S in either 21% or 0% oxygen. Epinephrine and norepinephrine also oxidized H2S to polysulfides and thiosulfate; dopamine and tyrosine were ineffective. Polyphenones were also examined, but only 2,5-dihydroxy- and 2,3,4-trihydroxybenzophenones oxidized H2S. These results show that H2S is readily oxidized by specific hydroxyquinones and quinones, most likely through the formation of a semiquinone radical intermediate derived from either reaction of oxygen with the reduced quinones, or from direct reaction between H2S and quinones. We propose that polysulfide production by these reactions contributes to the health-promoting benefits of polyphenolic nutraceuticals.

APA, Harvard, Vancouver, ISO, and other styles

9

Xu, Guiyin, Qing-bo Yan, Shitong Wang, Akihiro Kushima, Peng Bai, Kai Liu, Xiaogang Zhang, Zilong Tang, and Ju Li. "A thin multifunctional coating on a separator improves the cyclability and safety of lithium sulfur batteries." Chemical Science 8, no. 9 (2017): 6619–25. http://dx.doi.org/10.1039/c7sc01961k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Trummer, Modesta, Erwan Galardon, Anita Fischer, Stefan Toegel, Bernhard-Michael Mayer, Guenter Steiner, and Burkhard Kloesch. "Characterization of the Inducible and Slow-Releasing Hydrogen Sulfide and Persulfide Donor P*: Insights into Hydrogen Sulfide Signaling." Antioxidants 10, no. 7 (June 29, 2021): 1049. http://dx.doi.org/10.3390/antiox10071049.

Full text

Abstract:

Hydrogen sulfide (H2S) is an important mediator of inflammatory processes. However, controversial findings also exist, and its underlying molecular mechanisms are largely unknown. Recently, the byproducts of H2S, per-/polysulfides, emerged as biological mediators themselves, highlighting the complex chemistry of H2S. In this study, we characterized the biological effects of P*, a slow-releasing H2S and persulfide donor. To differentiate between H2S and polysulfide-derived effects, we decomposed P* into polysulfides. P* was further compared to the commonly used fast-releasing H2S donor sodium hydrogen sulfide (NaHS). The effects on oxidative stress and interleukin-6 (IL-6) expression were assessed in ATDC5 cells using superoxide measurement, qPCR, ELISA, and Western blotting. The findings on IL-6 expression were corroborated in primary chondrocytes from osteoarthritis patients. In ATDC5 cells, P* not only induced the expression of the antioxidant enzyme heme oxygenase-1 via per-/polysulfides, but also induced activation of Akt and p38 MAPK. NaHS and P* significantly impaired menadione-induced superoxide production. P* reduced IL-6 levels in both ATDC5 cells and primary chondrocytes dependent on H2S release. Taken together, P* provides a valuable research tool for the investigation of H2S and per-/polysulfide signaling. These data demonstrate the importance of not only H2S, but also per-/polysulfides as bioactive signaling molecules with potent anti-inflammatory and, in particular, antioxidant properties.

APA, Harvard, Vancouver, ISO, and other styles

11

Choi, Wonmun, and Tomoyuki Matsumura. "Synthesis of Cyclic Polysulfides and their Properties as Curing Agents." Rubber Chemistry and Technology 77, no. 2 (May 1, 2004): 380–90. http://dx.doi.org/10.5254/1.3547830.

Full text

Abstract:

Abstract The reactions of dichloroalkanes and sodium tetra-sulfide (Na2S4) were carried out in a mixture of water and toluene to produce corresponding cyclic polysulfides and polysulfide polymer. The low molecular weights of cyclic sulfides were obtained by the reaction at 90 °C, while the high molecular weight of polysulfide polymer was obtained by the reaction at 50 °C. GPC chromatograms and Mass spectra revealed that the structures of cyclic polysulfide were 1:1, 2:2, and 3:3 adducts of dichloroalkane and sodium tetra-sulfide. The mechanical properties of vulcanized NR at 148 °C with cyclic sulfides were similar to that with sulfur. However, both tensile strength and elongation at break of vulcanized NR at 170 °C with cyclic sulfides are much higher than that with sulfur. The aging properties of vulcanized NR at 148 °C or 170 °C with cyclic polysulfides indicate better stability.

APA, Harvard, Vancouver, ISO, and other styles

12

Dagnell, Markus, Qing Cheng, and Elias S. J. Arnér. "Qualitative Differences in Protection of PTP1B Activity by the Reductive Trx1 or TRP14 Enzyme Systems upon Oxidative Challenges with Polysulfides or H2O2 Together with Bicarbonate." Antioxidants 10, no. 1 (January 14, 2021): 111. http://dx.doi.org/10.3390/antiox10010111.

Full text

Abstract:

Protein tyrosine phosphatases (PTPs) can be regulated by several redox-dependent mechanisms and control growth factor-activated receptor tyrosine kinase phosphorylation cascades. Reversible oxidation of PTPs is counteracted by reductive enzymes, including thioredoxin (Trx) and Trx-related protein of 14 kDa (TRP14), keeping PTPs in their reduced active states. Different modes of oxidative inactivation of PTPs concomitant with assessment of activating reduction have been little studied in direct comparative analyses. Determining PTP1B activities, we here compared the potency of inactivation by bicarbonate-assisted oxidation using H2O2 with that of polysulfide-mediated inactivation. Inactivation of pure PTP1B was about three times more efficient with polysulfides as compared to the combination of bicarbonate and H2O2. Bicarbonate alone had no effect on PTP1B, neither with nor without a combination with polysulfides, thus strengthening the notion that bicarbonate-assisted H2O2-mediated inactivation of PTP1B involves formation of peroxymonocarbonate. Furthermore, PTP1B was potently protected from polysulfide-mediated inactivation by either TRP14 or Trx1, in contrast to the inactivation by bicarbonate and H2O2. Comparing reductive activation of polysulfide-inactivated PTP1B with that of bicarbonate- and H2O2-treated enzyme, we found Trx1 to be more potent in reactivation than TRP14. Altogether we conclude that inactivation of PTP1B by polysulfides displays striking qualitative differences compared to that by H2O2 together with bicarbonate, also with regard to maintenance of PTP1B activity by either Trx1 or TRP14.

APA, Harvard, Vancouver, ISO, and other styles

13

Yan, Min, Yang Zhang, Yu Li, Yongqi Huo, Yong Yu, Chao Wang, Jun Jin, et al. "Manganese dioxide nanosheet functionalized sulfur@PEDOT core–shell nanospheres for advanced lithium–sulfur batteries." Journal of Materials Chemistry A 4, no. 24 (2016): 9403–12. http://dx.doi.org/10.1039/c6ta03211g.

Full text

Abstract:

MnO₂ nanosheet functionalized S@PEDOT core–shell nanospheres demonstrate highly enhanced electrochemical performance for Li–S batteries, benefitting from effectively trapping polysulfides, minimizing polysulfide dissolution, and improving cathode conductivity and wettability.

APA, Harvard, Vancouver, ISO, and other styles

14

Heitz, A., R. I. Kagi, and R. Alexander. "Polysulfide sulfur in pipewall biofilms: its role in the formation of swampy odour in distribution systems." Water Science and Technology 41, no. 4-5 (February 1, 2000): 271–78. http://dx.doi.org/10.2166/wst.2000.0455.

Full text

Abstract:

Biofilms and pipewall sediments in drinking water distribution systems were analysed for dimethylpolysulfides (DMPS) and inorganic polysulfides in an effort to determine the origin of dimethyltrisulfide, which causes unpleasant swampy odours in drinking water. Inorganic polysulfides were determined using the technique of methyl iodide derivatisation, and subsequent analysis as DMPS by gas chromatography-mass spectrometry. The technique was shown to be quantitative from 0.15 μg/L to 370 μg/L, and not subject to interference from other sulfur compounds. The polysulfide-rich biofilms and sediments occurred in pipes constructed from a variety of different materials, and fed by water from several different surface and groundwater sources. The biofilm/sediment matrix appeared to retard oxidation of polysulfides, by preventing their diffusion into the oxic water and by providing a barrier against the oxidative action of chlorine and dissolved oxygen.

APA, Harvard, Vancouver, ISO, and other styles

15

Wręczycki, Jakub, Dariusz M. Bieliński, Marcin Kozanecki, Paulina Maczugowska, and Grzegorz Mlostoń. "Anionic Copolymerization of Styrene Sulfide with Elemental Sulfur (S8)." Materials 13, no. 11 (June 7, 2020): 2597. http://dx.doi.org/10.3390/ma13112597.

Full text

Abstract:

The superior ability of thiiranes (episulfides) to undergo ring-opening polymerization (ROP) in the presence of anionic initiators allows the preparation of chemically stable polysulfide homopolymers. Incorporation of elemental sulfur (S8) by copolymerization below the floor temperature of S8 permits the placement of a large quantity of sulfur atoms in the polysulfide mainchain. The utility of styrene sulfide (2-phenylthiirane; StS) for copolymerization with elemental sulfur is reported here. A few polysulfides differing depending on the initial ratio of S8 to StS and copolymerization time were synthesized. Various spectroscopic methods (1H NMR, 13C NMR, Raman spectroscopy and FTIR spectroscopy) were applied to characterize the chemical structure of the copolymers. Additionally, the phase structure and thermal stability of the synthesized polysulfides were investigated using DSC and TGA, respectively. The successful anionic copolymerization of styrene sulfide and elemental sulfur has been demonstrated.

APA, Harvard, Vancouver, ISO, and other styles

16

Krejsa, M. R., J. L. Koenig, and A. B. Sullivan. "Analysis of the Mechanism of N-t-Butyl-2-Benzothiazole Sulfenamide Accelerated Sulfur Vulcanization of cis-Polyisoprene." Rubber Chemistry and Technology 67, no. 2 (May 1, 1994): 348–58. http://dx.doi.org/10.5254/1.3538680.

Full text

Abstract:

Abstract Results of previously published work involving network analysis and accelerator intermediate analysis of cis-polyisoprene were compared to help correlate and rationalize network/chemistry relationships. Both classical chemical probe network analysis and further NMR measurements (DEPT analysis) were used as necessary to verify NMR peak assignments. Furthermore, samples of the conventional formulation were vulcanized in the absence of zinc oxide and stearic acid to help elucidate the role of zinc in the vulcanization process. Polysulfidic dibenzothiazole accelerator intermediates were proposed to produce allylic substituted cis-polysulfides both with and without double bond migration, while zinc polysulfidic dibenzothiazole accelerator intermediates were proposed to produce allylic cis and trans polysulfides substituted structures with no double bond migration. Polysulfidic substitution on the isoprene methyl carbon was shown to result from exchange reactions during network maturation. The network-chemistry relationships were compared with earlier mechanistic studies and several points of agreement were noted.

APA, Harvard, Vancouver, ISO, and other styles

17

He, Jiarui, Gregory Hartmann, Myungsuk Lee, Gyeong S. Hwang, Yuanfu Chen, and Arumugam Manthiram. "Freestanding 1T MoS2/graphene heterostructures as a highly efficient electrocatalyst for lithium polysulfides in Li–S batteries." Energy & Environmental Science 12, no. 1 (2019): 344–50. http://dx.doi.org/10.1039/c8ee03252a.

Full text

Abstract:

A novel approach to effectively suppress the “polysulfide shuttle” in Li–S batteries is presented by designing a freestanding, three-dimensional graphene/1T MoS₂ (3DG/TM) heterostructure with highly efficient electrocatalysis properties for lithium polysulfides (LiPSs).

APA, Harvard, Vancouver, ISO, and other styles

18

Ahad, Syed Abdul, P. Ragupathy, Soojy Ryu, Hyun-Wook Lee, and Do Kyung Kim. "Unveiling the synergistic effect of polysulfide additive and MnO2 hollow spheres in evolving a stable cyclic performance in Li–S batteries." Chemical Communications 53, no. 62 (2017): 8782–85. http://dx.doi.org/10.1039/c7cc04229a.

Full text

Abstract:

The inbuilt MnO₂ hollow spheres trap polysulfides effectively, while the polysulfide additive provides mass buffering to compensate for the capacity loss and prevent the formation of Li₂S exhibiting excellent rate capability and cycling stability.

APA, Harvard, Vancouver, ISO, and other styles

19

Boyd, Eric S., and Gregory K. Druschel. "Involvement of Intermediate Sulfur Species in Biological Reduction of Elemental Sulfur under Acidic, Hydrothermal Conditions." Applied and Environmental Microbiology 79, no. 6 (January 18, 2013): 2061–68. http://dx.doi.org/10.1128/aem.03160-12.

Full text

Abstract:

ABSTRACTThe thermoacidophile and obligate elemental sulfur (S80)-reducing anaerobeAcidilobus sulfurireducens18D70 does not associate with bulk solid-phase sulfur during S80-dependent batch culture growth. Cyclic voltammetry indicated the production of hydrogen sulfide (H2S) as well as polysulfides after 1 day of batch growth of the organism at pH 3.0 and 81°C. The production of polysulfide is likely due to the abiotic reaction between S80and the biologically produced H2S, as evinced by a rapid cessation of polysulfide formation when the growth temperature was decreased, inhibiting the biological production of sulfide. After an additional 5 days of growth, nanoparticulate S80was detected in the cultivation medium, a result of the hydrolysis of polysulfides in acidic medium. To examine whether soluble polysulfides and/or nanoparticulate S80can serve as terminal electron acceptors (TEA) supporting the growth ofA. sulfurireducens, total sulfide concentration and cell density were monitored in batch cultures with S80provided as a solid phase in the medium or with S80sequestered in dialysis tubing. The rates of sulfide production in 7-day-old cultures with S80sequestered in dialysis tubing with pore sizes of 12 to 14 kDa and 6 to 8 kDa were 55% and 22%, respectively, of that of cultures with S80provided as a solid phase in the medium. These results indicate that the TEA existed in a range of particle sizes that affected its ability to diffuse through dialysis tubing of different pore sizes. Dynamic light scattering revealed that S80particles generated through polysulfide rapidly grew in size, a rate which was influenced by the pH of the medium and the presence of organic carbon. Thus, S80particles formed through abiological hydrolysis of polysulfide under acidic conditions appeared to serve as a growth-promoting TEA forA. sulfurireducens.

APA, Harvard, Vancouver, ISO, and other styles

20

Wang, Maoxu, Lishuang Fan, Xian Wu, Yue Qiu, Bin Guan, Yan Wang, Naiqing Zhang, and Kening Sun. "Metallic NiSe2nanoarrays towards ultralong life and fast Li2S oxidation kinetics of Li–S batteries." Journal of Materials Chemistry A 7, no. 25 (2019): 15302–8. http://dx.doi.org/10.1039/c9ta03361k.

Full text

Abstract:

The complex solid–liquid–solid phase transition in Li–S batteries, the serious shuttle effect of soluble polysulfides, sluggish polysulfide conversion kinetics and the low conductive nature of Li₂S cause a high decomposition barrier, inevitably limiting the development of advanced Li–S batteries.

APA, Harvard, Vancouver, ISO, and other styles

21

Ji, Jiapeng, Ying Sha, Zeheng Li, Xuehui Gao, Teng Zhang, Shiyu Zhou, Tong Qiu, et al. "Selective Adsorption and Electrocatalysis of Polysulfides through Hexatomic Nickel Clusters Embedded in N-Doped Graphene toward High-Performance Li-S Batteries." Research 2020 (June 26, 2020): 1–13. http://dx.doi.org/10.34133/2020/5714349.

Full text

Abstract:

The shuttle effect hinders the practical application of lithium-sulfur (Li-S) batteries due to the poor affinity between a substrate and Li polysulfides (LiPSs) and the sluggish transition of soluble LiPSs to insoluble Li2S or elemental S. Here, we report that Ni hexatomic clusters embedded in a nitrogen-doped three-dimensional (3D) graphene framework (Ni-N/G) possess stronger interaction with soluble polysulfides than that with insoluble polysulfides. The synthetic electrocatalyst deployed in the sulfur cathode plays a multifunctional role: (i) selectively adsorbing the polysulfides dissolved in the electrolyte, (ii) expediting the sluggish liquid-solid phase transformations at the active sites as electrocatalysts, and (iii) accelerating the kinetics of the electrochemical reaction of multielectron sulfur, thereby inhibiting the dissolution of LiPSs. The constructed S@Ni-N/G cathode delivers an areal capacity of 9.43 mAh cm-2 at 0.1 C at S loading of 6.8 mg cm-2, and it exhibits a gravimetric capacity of 1104 mAh g-1 with a capacity fading rate of 0.045% per cycle over 50 cycles at 0.2 C at S loading of 2.0 mg cm-2. This work opens a rational approach to achieve the selective adsorption and expediting of polysulfide transition for the performance enhancement of Li-S batteries.

APA, Harvard, Vancouver, ISO, and other styles

22

Djordjevic, Dragana, Jelena Milovanovic, Milena Jurisevic, Bojana Stojanovic, Olga Cvetkovic, Marija Pergal, Elizabeta Ristanovic, et al. "Antitumour Effect of a Mixture of N-Propyl Polysulfides In Vitro." Serbian Journal of Experimental and Clinical Research 20, no. 4 (December 31, 2019): 295–300. http://dx.doi.org/10.1515/sjecr-2017-0069.

Full text

Abstract:

Abstract Copper serves as a limiting factor for multiple steps of tumour progression, including angiogenesis, growth and metastasis. High levels of copper have been found in a wide spectrum of human cancers. Antitumour activities of copper-chelating drugs have been reported in animal models. Organosulfur compounds (diallyl sulfide, DAS; diallyl disulfide, DADS; S-ethylcysteine, SEC; N-acetylcysteine, NAC) derived from garlic exhibit marked copper-chelating activity. We analysed a mixture of fifteen n-propyl polysulfides (DPPS) for potential antitumour activity against several murine tumour cell lines, including colon carcinoma (CT26), mammary carcinoma (4T1) and melanoma cell lines (B16F10), and compared the effects with the antiproliferative effect in highly proliferative murine mesenchymal stem cells (mMSCs). The effects of the mixture of n-propyl polysulfides (100%) on cell viability were determined using MTT assays. Cell apoptosis was analysed using Annexin V-FITC/PI assays. The results of the MTT assays indicate that this standardized mixture of n-propyl polysulfides has a strong, dose-dependent cytotoxic effect against all three of the tested tumour cell lines (CT26, 4T1, B16F10). The cytotoxic effect of the n-propyl polysulfide mixture against the CT26 and B16F10 cell lines was much stronger than that of cisplatin and was significantly weaker in mMSCs, which are non-cancerous and highly proliferative cells, than in cancer cells. Flow cytometric analysis of CT26 and 4T1 cells revealed that apoptosis was not the dominant mechanism of cell death induced by the n-propyl polysulfide mixture. The n-propyl polysulfide mixture exerted highly cytotoxic activity against murine colon carcinoma and melanoma cell lines, but its antiproliferative activity against mMSCs was significantly lower than that of cisplatin.

APA, Harvard, Vancouver, ISO, and other styles

23

Wang, Suyu, Fan Gao, Ruina Ma, An Du, Taizhe Tan, Miao Du, Xue Zhao, Yongzhe Fan, and Ming Wen. "ZnO Nanoparticles Anchored on a N-Doped Graphene-Coated Separator for High Performance Lithium/Sulfur Batteries." Metals 8, no. 10 (September 25, 2018): 755. http://dx.doi.org/10.3390/met8100755.

Full text

Abstract:

Fabrication of a nanocrystalline zinc oxide (ZnO)/nitrogen-doped graphene (NDG) composite using a novel and facile in situ sol-gel technique is demonstrated in this study. A two-dimensional nanostructured morphology with uniform ZnO nanoparticles (average diameter of 10 ± 4 nm) anchored on NDG nanosheets was observed via electron microscopy. The polar heteroatoms on the graphene sheets provided abundant sites for polysulfide absorption. More importantly, the strong chemical interaction between ZnO and polysulfides efficiently hindered the transport of polysulfides. Consequently, the lithium/sulfur (Li/S) battery with the ZnO/NDG composite-coated separator exhibited enhanced performance in terms of discharge capacity and cycling stability compared to the cell with a conventional separator. With the modified separator, the Li/S battery achieved a discharge capacity of 942 mAh·g−1 after the first cycle and exhibited a capacity retention of 90.02% after the 200th charge/discharge test at 0.1 C. These results indicate that suppression of the shuttling of polysulfides efficiently improves the performance of the Li/S battery.

APA, Harvard, Vancouver, ISO, and other styles

24

Jay, Jenny Ayla, Karen J. Murray, Cynthia C. Gilmour, Robert P. Mason, François M. M. Morel, A. Lynn Roberts, and Harold F. Hemond. "Mercury Methylation by Desulfovibrio desulfuricans ND132 in the Presence of Polysulfides." Applied and Environmental Microbiology 68, no. 11 (November 2002): 5741–45. http://dx.doi.org/10.1128/aem.68.11.5741-5745.2002.

Full text

Abstract:

ABSTRACT The extracellular speciation of mercury may control bacterial uptake and methylation. Mercury-polysulfide complexes have recently been shown to be prevalent in sulfidic waters containing zero-valent sulfur. Despite substantial increases in total dissolved mercury concentration, methylation rates in cultures of Desulfovibrio desulfuricans ND132 equilibrated with cinnabar did not increase in the presence of polysulfides, as expected due to the large size and charged nature of most of the complexes. In natural waters not at saturation with cinnabar, mercury-polysulfide complexes would be expected to shift the speciation of mercury from HgS0 (aq) toward charged complexes, thereby decreasing methylation rates.

APA, Harvard, Vancouver, ISO, and other styles

25

Kariuki, Stephen, Philippe Babady-Bila, and Breanna Duquette. "N,N-Diethyl-p-phenylenediamine effectiveness in analysis of polysulfides and polythionates in water." Environmental Chemistry 5, no. 3 (2008): 226. http://dx.doi.org/10.1071/en08020.

Full text

Abstract:

Environmental context. The importance of hydrogen sulfide as well as some of the reduced sulfur species such as polysulfides as environmental pollutants is a result of their toxicity, unpleasant odour, and their reactivity with metals and metallic ions found in various environmental samples. Although known to be popular, the effectiveness of N,N-diethyl-p-phenylenediamine and other related compounds in the spectrophotometric analysis of such sulfur compounds in water as well as in other environmental samples has not been fully investigated. Our results show that although the quantification of simple sulfides in the environmental samples may be easily accomplished spectrophotometrically by using N,N-diethyl-p-phenylenediamine, the level of difficulty in analysing such compounds may increase with their increasing sulfur chain. Abstract. The analysis of polysulfides, polythionates and other sulfur species likely to be found in poorly aerated environmental samples such as water is presented. In-depth spectrophotometric testing carried out using N,N-diethyl-p-phenylenediamine shows that the well known acidification-and-purge method is not sufficiently suitable for the analysis of polysulfides and other low oxidation-state sulfur compounds that contain a sulfur chain longer than two. Further, this study finds that the use of chromium(II) which acts as a reducing agent to the sulfur-containing compounds improves the spectrophotometric analysis of the polysulfides and polythionates in water, but only slightly. The extent of reduction of polysulfides and polythionates to sulfide by chromium appears dependent upon the oxidation state of sulfur as well as the chain length in the polysulfidic compounds.

APA, Harvard, Vancouver, ISO, and other styles

26

DeLeon, Eric R., Yan Gao, Evelyn Huang, and Kenneth R. Olson. "Garlic oil polysulfides: H2S- and O2-independent prooxidants in buffer and antioxidants in cells." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 310, no. 11 (June 1, 2016): R1212—R1225. http://dx.doi.org/10.1152/ajpregu.00061.2016.

Full text

Abstract:

The health benefits of garlic and other organosulfur-containing foods are well recognized and have been attributed to both prooxidant and antioxidant activities. The effects of garlic are surprisingly similar to those of hydrogen sulfide (H2S), which is also known to be released from garlic under certain conditions. However, recent evidence suggests that polysulfides, not H2S, may be the actual mediator of physiological signaling. In this study, we monitored formation of H2S and polysulfides from garlic oil in buffer and in human embryonic kidney (HEK) 293 cells with fluorescent dyes, 7-azido-4-methylcoumarin and SSP4, respectively and redox activity with two redox indicators redox-sensitive green fluorescent protein (roGFP) and DCF. Our results show that H2S release from garlic oil in buffer requires other low-molecular-weight thiols, such as cysteine (Cys) or glutathione (GSH), whereas polysulfides are readily detected in garlic oil alone. Administration of garlic oil to cells rapidly increases intracellular polysulfide but has minimal effects on H2S unless Cys or GSH are also present in the extracellular medium. We also observed that garlic oil and diallyltrisulfide (DATS) potently oxidized roGFP in buffer but did not affect DCF. This appears to be a direct polysulfide-mediated oxidation that does not require a reactive oxygen species intermediate. Conversely, when applied to cells, garlic oil became a significant intracellular reductant independent of extracellular Cys or GSH. This suggests that intracellular metabolism and further processing of the sulfur moieties are necessary to confer antioxidant properties to garlic oil in vivo.

APA, Harvard, Vancouver, ISO, and other styles

27

Clark, Peter D., Russell S. Mann, and Kevin L. Lesage. "Reactions of dimethyl polysulfides with organomagnesium reagents." Canadian Journal of Chemistry 70, no. 1 (January 1, 1992): 29–33. http://dx.doi.org/10.1139/v92-006.

Full text

Abstract:

Reactions of a mixture of dimethyl polysulfides (DMPS, CH3SxCH3, x = 3 – 8) with methyl- and phenylmagnesium halides are described. The type of product obtained was dependent on the molar ratio of DMPS to Grignard reagent. When a 6:1 methyl-Grignard to DMPS ratio was used, methanethiol and dimethyl sulfide were the major products obtained after acidification of the reaction mixture. Lesser quantities of methyl-Grignard favored the formation of dimethyl sulfide, dimethyl disulfide, and H2S. Experiments with a 6:1 phenylmagnesium bromide to DMPS ratio produced benzenethiol and phenylmethyl sulfide as major products after acidification. No methanethiol was observed in these experiments. Mixtures of phenylmethyl mono-, di-, and trisulfides and H2S were obtained with a 3:1 Grignard/DMPS molar ratio. From a mechanistic viewpoint, product distributions obtained from reaction of Grignard reagents with DMPS can be explained by the formation of magnesium thiolates that are most readily stabilized by adjacent structures. Experiments using phenyl Grignard reagent in limited supply suggested that the internal sulfur atoms of the polysulfide chains were most reactive. Keywords: organic polysulfides, Grignard reagents.

APA, Harvard, Vancouver, ISO, and other styles

28

Wei, Benben, Chaoqun Shang, Xiaoying Pan, Zhihong Chen, Lingling Shui, Xin Wang, and Guofu Zhou. "Lotus Root-Like Nitrogen-Doped Carbon Nanofiber Structure Assembled with VN Catalysts as a Multifunctional Host for Superior Lithium–Sulfur Batteries." Nanomaterials 9, no. 12 (December 3, 2019): 1724. http://dx.doi.org/10.3390/nano9121724.

Full text

Abstract:

Lithium–sulfur batteries (LSBs) are regarded as one of the most promising energy-recycling storage systems due to their high energy density (up to 2600 Wh kg−1), high theoretical specific capacity (as much as 1672 mAh g−1), environmental friendliness, and low cost. Originating from the complicated redox of lithium polysulfide intermediates, Li–S batteries suffer from several problems, restricting their application and commercialization. Such problems include the shuttle effect of polysulfides (Li2Sx (2 < x ≤ 8)), low electronic conductivity of S/Li2S/Li2S2, and large volumetric expansion of S upon lithiation. In this study, a lotus root-like nitrogen-doped carbon nanofiber (NCNF) structure, assembled with vanadium nitride (VN) catalysts, was fabricated as a 3D freestanding current collector for high performance LSBs. The lotus root-like NCNF structure, which had a multichannel porous nanostructure, was able to provide excellent (ionically/electronically) conductive networks, which promoted ion transport and physical confinement of lithium polysulfides. Further, the structure provided good electrolyte penetration, thereby enhancing the interface contact with active S. VN, with its narrow resolved band gap, showed high electrical conductivity, high catalytic effect and polar chemical adsorption of lithium polysulfides, which is ideal for accelerating the reversible redox kinetics of intermediate polysulfides to improve the utilization of S. Tests showed that the VN-decorated multichannel porous carbon nanofiber structure retained a high specific capacity of 1325 mAh g−1 after 100 cycles at 0.1 C, with a low capacity decay of 0.05% per cycle, and demonstrated excellent rate capability.

APA, Harvard, Vancouver, ISO, and other styles

29

Liu, Ning, Lu Wang, Taizhe Tan, Yan Zhao, and Yongguang Zhang. "TiO2/GO-coated functional separator to suppress polysulfide migration in lithium–sulfur batteries." Beilstein Journal of Nanotechnology 10 (August 19, 2019): 1726–36. http://dx.doi.org/10.3762/bjnano.10.168.

Full text

Abstract:

Lithium–sulfur batteries render a high energy density but suffer from poor cyclic performance due to the dissolution of intermediate polysulfides. Herein, a lightweight nanoporous TiO2 and graphene oxide (GO) composite is prepared and utilized as an interlayer between a Li anode and a sulfur cathode to suppress the polysulfide migration and improve the electrochemical performance of Li/S batteries. The interlayer can capture the polysulfides due to the presence of oxygen functional groups and formation of chemical bonds. The hierarchically porous TiO2 nanoparticles are tightly wrapped in GO sheets and facilitate the polysulfide storage and chemical absorption. The excellent adhesion between TiO2 nanoparticles and GO sheets resulted in enhanced conductivity, which is highly desirable for an efficient electron transfer process. The Li/S battery with a TiO2/GO-coated separator exhibited a high initial discharge capacity of 1102.8 mAh g−1 and a 100th cycle capacity of 843.4 mAh g−1, which corresponds to a capacity retention of 76.48% at a current rate of 0.2 C. Moreover, the Li/S battery with the TiO2/GO-coated separator showed superior cyclic performance and excellent rate capability, which shows the promise of the TiO2/GO composite in next-generation Li/S batteries.

APA, Harvard, Vancouver, ISO, and other styles

30

Tolstikov, Genrikh A., Elvira E. Shul'ts, and Alexander G. Tolstikov. "Natural polysulfides." Russian Chemical Reviews 66, no. 9 (September 30, 1997): 813–26. http://dx.doi.org/10.1070/rc1997v066n09abeh000281.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Kurashova, Irina, and Alexey Kamyshny Jr. "Kinetics and mechanism of the reaction between dimethyl trisulfide and cyanide." Environmental Chemistry 18, no. 2 (2021): 81. http://dx.doi.org/10.1071/en20104.

Full text

Abstract:

Environmental contextDimethyl trisulfide (DMTS) is a malodorous compound formed from decomposing algal matter and can severely compromise the quality of drinking water. The reactivity of DMTS toward cyanide was studied in aqueous solutions at environmentally relevant conditions. It was found that the half-lives of DMTS in the presence of free cyanide varied from several months to several thousand years depending on environmental conditions. AbstractOrganically bound sulfur in the form of mono-, di- and polysulfide bridges constitutes a significant fraction of this element in recent and ancient sediments. In water columns of lakes, the concentrations of organo-sulfur compounds are much lower, and they are present in the form of malodorous dimethyl polysulfides. Currently, information regarding reactivity of organic polysulfides towards nucleophiles that are stronger than hydroxyl anions is lacking. In this work, the reaction kinetics of dimethyl trisulfide (DMTS) with the strong nucleophile and important environmental pollutant cyanide as a function of concentrations of reactants, pH and temperature were studied. It was found that the reaction rate constant as well as the activation energy of the reaction strongly depend on pH. The experimental data agree well with the existence of two distinct pathways: slow reaction between protonated cyanide and DMTS under acidic and neutral conditions and fast reaction between cyanide anion and DMTS under highly alkaline conditions. However, reactions of DMTS with the iron cyanide complexes hexacyanoferrate(ii) and hexacyanoferrate(iii) have no environmental significance since they are slower than the rate of DMTS decomposition. Under environmentally relevant conditions, rates of reactions of free cyanide with DMTS will be lower than the reaction with inorganic polysulfides or tetrathionate, but faster than the reaction with thiosulfate. Examples of application of kinetic parameters for calculation of rates of cyanide consumption in industrial and non-polluted natural aquatic systems as well as a protocol for quantification of organic polysulfide sulfur based on reaction with cyanide are provided.

APA, Harvard, Vancouver, ISO, and other styles

32

Nagahara, Noriyuki, and Maria Wróbel. "H2S, Polysulfides, and Enzymes: Physiological and Pathological Aspects." Biomolecules 10, no. 4 (April 21, 2020): 640. http://dx.doi.org/10.3390/biom10040640.

Full text

Abstract:

We have been studying the general aspects of the functions of H2S and polysulfides, and the enzymes involved in their biosynthesis, for more than 20 years. Our aim has been to elucidate novel physiological and pathological functions of H2S and polysulfides, and unravel the regulation of the enzymes involved in their biosynthesis, including cystathionine β-synthase (EC 4.2.1.22), cystathionine γ-lyase (EC 4.4.1.1), thiosulfate sulfurtransferase (rhodanese, EC 2.8.1.1), and 3-mercaptopyruvate sulfurtransferase (EC 2.8.1.2). Physiological and pathological functions, alternative biosynthetic processes, and additional functions of H2S and polysulfides have been reported. Further, the structure and reaction mechanisms of related enzymes have also been reported. We expect this issue to advance scientific knowledge regarding the detailed functions of H2S and polysulfides as well as the general properties and regulation of the enzymes involved in their metabolism. We would like to cover four topics: the physiological and pathological functions of H2S and polysulfides, the mechanisms of the biosynthesis of H2S and polysulfides, the properties of the biosynthetic enzymes, and the regulation of enzymatic activity. The knockout mouse technique is a useful tool to determine new physiological functions, especially those of H2S and polysulfides. In the future, we shall take a closer look at symptoms in the human congenital deficiency of each enzyme. Further studies on the regulation of enzymatic activity by in vivo substances may be the key to finding new functions of H2S and polysulfides.

APA, Harvard, Vancouver, ISO, and other styles

33

Dóka, Éva, Irina Pader, Adrienn Bíró, Katarina Johansson, Qing Cheng, Krisztina Ballagó, Justin R. Prigge, et al. "A novel persulfide detection method reveals protein persulfide- and polysulfide-reducing functions of thioredoxin and glutathione systems." Science Advances 2, no. 1 (January 2016): e1500968. http://dx.doi.org/10.1126/sciadv.1500968.

Full text

Abstract:

Hydrogen sulfide signaling involves persulfide formation at specific protein Cys residues. However, overcoming current methodological challenges in persulfide detection and elucidation of Cys regeneration mechanisms from persulfides are prerequisites for constructing a bona fide signaling model. We here establish a novel, highly specific protein persulfide detection protocol, ProPerDP, with which we quantify 1.52 ± 0.6 and 11.6 ± 6.9 μg/mg protein steady-state protein persulfide concentrations in human embryonic kidney 293 (HEK293) cells and mouse liver, respectively. Upon treatment with polysulfides, HEK293 and A549 cells exhibited increased protein persulfidation. Deletion of the sulfide-producing cystathionine-γ-lyase or cystathionine-β-synthase enzymes in yeast diminished protein persulfide levels, thereby corroborating their involvement in protein persulfidation processes. We here establish that thioredoxin (Trx) and glutathione (GSH) systems can independently catalyze reductions of inorganic polysulfides and protein persulfides. Increased endogenous persulfide levels and protein persulfidation following polysulfide treatment in thioredoxin reductase-1 (TrxR1) or thioredoxin-related protein of 14 kDa (TRP14) knockdown HEK293 cells indicated that these enzymes constitute a potent regeneration system of Cys residues from persulfides in a cellular context. Furthermore, TrxR1-deficient cells were less viable upon treatment with toxic amounts of polysulfides compared to control cells. Emphasizing the dominant role of cytosolic disulfide reduction systems in maintaining sulfane sulfur homeostasis in vivo, protein persulfide levels were markedly elevated in mouse livers where hepatocytes lack both TrxR1 and glutathione reductase (TR/GR-null). The different persulfide patterns observed in wild-type, GR-null, and TR/GR-null livers suggest distinct roles for the Trx and GSH systems in regulating subsets of protein persulfides and thereby fine-tuning sulfide signaling pathways.

APA, Harvard, Vancouver, ISO, and other styles

34

Wang, Hong-En, Kaili Yin, Ning Qin, Xu Zhao, Fan-Jie Xia, Zhi-Yi Hu, Guanlun Guo, Guozhong Cao, and Wenjun Zhang. "Oxygen-deficient titanium dioxide as a functional host for lithium–sulfur batteries." Journal of Materials Chemistry A 7, no. 17 (2019): 10346–53. http://dx.doi.org/10.1039/c9ta01598a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Yang, Wu, Wang Yang, Liubing Dong, Xiaochun Gao, Guoxiu Wang, and Guangjie Shao. "Enabling immobilization and conversion of polysulfides through a nitrogen-doped carbon nanotubes/ultrathin MoS2 nanosheet core–shell architecture for lithium–sulfur batteries." Journal of Materials Chemistry A 7, no. 21 (2019): 13103–12. http://dx.doi.org/10.1039/c9ta03227d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Roman, Pawel, Martijn F. M. Bijmans, and Albert J. H. Janssen. "Quantification of individual polysulfides in lab-scale and full-scale desulfurisation bioreactors." Environmental Chemistry 11, no. 6 (2014): 702. http://dx.doi.org/10.1071/en14128.

Full text

Abstract:

Environmental context Emission into the atmosphere of gaseous streams containing sulfur compounds, such as H2S and SOx, will lead to the unwanted formation of acid rain. In order to prevent this, biological processes can be employed to treat sulfur-containing gas streams. In this study, we describe a way to investigate the speciation of polysulfide anions in biodesulfurisation systems, which might enable further understanding and development of these processes. Abstract Environmental pollution caused by the combustion of fuel sources containing inorganic and organic sulfur compounds such as hydrogen sulfide (H2S) and thiols, is a global issue as it leads to SO2 emissions. To remove H2S from gas streams such as liquefied petroleum gas (LPG), biological processes can be applied. In these processes, polysulfide anions (Sx2–) play a significant role as they enhance the dissolution of H2S and act as intermediates in the biological oxidation of hydrogen sulfide ions to elemental sulfur. Despite their important role, the distribution of the various polysulfide species in full-scale biodesulfurisation systems has not yet been reported. With conventionally applied spectrophotometric analysis it is only possible to determine the total concentration of Sx2–. Moreover, this method is very sensitive to matrix effects. In this paper, we apply a method that relies on the derivatisation of Sx2– to dimethyl polysulfanes. Owing to the instability of higher dimethyl polysulfanes (Me2S4 to Me2S8), standards are not commercially available and had to be prepared by us. We present a simplified quantification method for higher dimethyl polysulfanes by calculating high performance liquid chromatogaphy (HPLC) UV response factors based on the addition of internal standards. The method was subsequently used to assess the distribution of polysulfide anions in both a laboratory-scale and a full-scale biodesulfurisation unit. We found that the average chain length of polysulfides strongly depends on the process conditions and a maximum of 5.33 sulfur atoms per polysulfide molecule was measured. Results of this study are required by mechanistic and kinetic models that attempt to describe product selectivity of sulfide oxidising bioreactors.

APA, Harvard, Vancouver, ISO, and other styles

37

Qiu, Sheng-You, Chuang Wang, Li-Su Zhang, Liang-Liang Gu, Zai-Xing Jiang, Jian Gao, Joshua Sokolowski, Gang Wu, and Xiao-Dong Zhu. "Hollow C@TiO2 array nanospheres as efficient sulfur hosts for lithium–sulfur batteries." Sustainable Energy & Fuels 4, no. 11 (2020): 5493–97. http://dx.doi.org/10.1039/d0se01061h.

Full text

Abstract:

The organized TiO₂ nanosheets nanoarray grown on the hollow carbon nanospheres fundamentally restricts polysulfides dissolution by polar–polar chemisorption capability of trap polysulfides.

APA, Harvard, Vancouver, ISO, and other styles

38

Yuan, Xiqing, Bingchuan Liu, Huijie Hou, Kemal Zeinu, Yuhang He, Xiaorong Yang, Weijun Xue, et al. "Facile synthesis of mesoporous graphene platelets with in situ nitrogen and sulfur doping for lithium–sulfur batteries." RSC Advances 7, no. 36 (2017): 22567–77. http://dx.doi.org/10.1039/c7ra01946g.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Liang, Xinghua, Xi Wu, Shuaibo Zeng, Wei Xu, Xingtao Jiang, and Lingxiao Lan. "Fast conversion of lithium (poly)sulfides in lithium–sulfur batteries using three-dimensional porous carbon." RSC Advances 11, no. 41 (2021): 25266–73. http://dx.doi.org/10.1039/d1ra02704b.

Full text

Abstract:

A three-dimensional porous carbon was prepared as a sulfur host. It effectively restrains dissolution of polysulfides by improving the conversion kinetics between polysulfides, thereby enhancing the electrochemical cycling stability.

APA, Harvard, Vancouver, ISO, and other styles

40

Wajon, J. E., and A. Heitz. "The reactions of some sulfur compounds in water supplies in Perth, Australia." Water Science and Technology 31, no. 11 (June 1, 1995): 87–92. http://dx.doi.org/10.2166/wst.1995.0409.

Full text

Abstract:

Some residents of Perth, Australia, receiving treated groundwater have complained of intermittent swampy, cooked vegetable odours in their drinking water. The compound primarily responsible is dimethyl trisulfide (CH3SSSCH3) which can be formed in the laboratory from the reaction of methyl iodide with thiosulfate (in the presence of iodine or sulfide) or with polysulfide (Sn2−). Addition of chlorine or sulfide to pre-formed S-methylthiosulfate (produced from the reaction of methyl iodide with sodium thiosulfate) at concentrations possibly expected in water supplies did not produce the swampy odour or only formed it slowly. Dimethyl trisulfide was formed upon the addition of methyl iodide to samples from each water supply system examined, even from those not prone to the formation of swampy odour, suggesting each contained polysulfide. Polysulfides and the reducing agents sodium oxalate, sodium borohydride and sodium thiosulfate reacted with dimethyl trisulfide in solution, removing 50-100% of that originally present.

APA, Harvard, Vancouver, ISO, and other styles

41

Mokudai, Hidehisa, Tomonari Takeuchi, Hikari Sakaebe, Hironori Kobayashi, and Eiichiro Matsubara. "Degradation mechanisms of lithium sulfide (Li2S) composite cathode in carbonate electrolyte and improvement by increasing electrolyte concentration." Sustainable Energy & Fuels 5, no. 6 (2021): 1714–26. http://dx.doi.org/10.1039/d0se01112f.

Full text

Abstract:

Lithium polysulfides (Li₂S_n) react with carbonate solvents, forming organic polysulfides (R–S_n–R) and sulfides (R–S–R); the concentrated electrolyte suppresses these reactions.

APA, Harvard, Vancouver, ISO, and other styles

42

Zaper, A. M., and J. L. Koenig. "Solid State Carbon-13 NMR Studies of Vulcanized Elastomers. III, Accelerated Sulfur Vulcanization of Natural Rubber." Rubber Chemistry and Technology 60, no. 2 (May 1, 1987): 278–97. http://dx.doi.org/10.5254/1.3536130.

Full text

Abstract:

Abstract In summary, the solid state C-13 NMR technique has proven to be a significant method for the detection of crosslinks and other structural modifications in accelerated sulfur-vulcanized NR systems. When the amount of accelerator is high in proportion to the amount of sulfur used, the network structure appears to be simpler with less crosslinking, less main chain structural modification, and fewer cyclic sulfide structures as observed in the C-13 NMR spectra. Polysulfidic crosslinks have been detected in addition to polysulfides terminated by accelerator residues. Cis-to-trans chain isomerization is also evident in these vulcanizates.

APA, Harvard, Vancouver, ISO, and other styles

43

Deng, Ziyi, Lei Sun, Yan Sun, Chunhui Luo, Qiang Zhao, and Kangping Yan. "The phase transfer effect of sulfur in lithium–sulfur batteries." RSC Advances 9, no. 56 (2019): 32826–32. http://dx.doi.org/10.1039/c9ra07291h.

Full text

Abstract:

The insulating elemental sulfur in a Li–S battery could be reduced to high-grade polysulfides by low-grade polysulfides from the cathode, after which they could participate in the discharging process of the Li–S battery.

APA, Harvard, Vancouver, ISO, and other styles

44

Stahl, John W., and Joseph Jordan. "Thermometric titration of polysulfides." Analytical Chemistry 59, no. 8 (April 15, 1987): 1222–25. http://dx.doi.org/10.1021/ac00135a032.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Kimura, T., S. Ogawa, and R. Sato. "Benzo-Annelated Cyclic Polysulfides." Mini-Reviews in Organic Chemistry 4, no. 1 (February 1, 2007): 15–29. http://dx.doi.org/10.2174/157019307779815929.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

TOLSTIKOV, G. A., E. E. SHUL'TS, and A. G. TOLSTIKOV. "ChemInform Abstract: Natural Polysulfides." ChemInform 29, no. 16 (June 23, 2010): no. http://dx.doi.org/10.1002/chin.199816293.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Ma, Jianhua, Jiangli Fan, Haidong Li, Qichao Yao, Feng Xu, Jingyun Wang, and Xiaojun Peng. "A NIR fluorescent chemodosimeter for imaging endogenous hydrogen polysulfides via the CSE enzymatic pathway." Journal of Materials Chemistry B 5, no. 14 (2017): 2574–79. http://dx.doi.org/10.1039/c7tb00098g.

Full text

Abstract:

Sodium polysulfides (Na₂S_n, n > 1) as important raw materials in the chemical industry can afford hydrogen polysulfides (H₂S_n, n > 1) under physiological conditions.

APA, Harvard, Vancouver, ISO, and other styles

48

Du, Lingyu, Xueyi Cheng, Fujie Gao, Youbin Li, Yongfeng Bu, Zhiqi Zhang, Qiang Wu, Lijun Yang, Xizhang Wang, and Zheng Hu. "Electrocatalysis of S-doped carbon with weak polysulfide adsorption enhances lithium–sulfur battery performance." Chemical Communications 55, no. 45 (2019): 6365–68. http://dx.doi.org/10.1039/c9cc02134e.

Full text

Abstract:

S-doped carbon boosts the conversion of lithium polysulfides by electrocatalysis as revealed by kinetic analysis and theoretical calculation, which suppresses the serious polarization effect and thus enhances the Li–S battery performance, despite its weak adsorption to polysulfides.

APA, Harvard, Vancouver, ISO, and other styles

49

Krejsa, M. R., and J. L. Koenig. "Solid State Carbon-13 NMR Studies of Elastomers. XL N-t-Butyl Benzothiazole Sulfenimide Accelerated Sulfur Vulcanization of cis-Polyisoprene at 75 MHz." Rubber Chemistry and Technology 66, no. 1 (March 1, 1993): 73–82. http://dx.doi.org/10.5254/1.3538300.

Full text

Abstract:

Abstract The network structure of TBSI-accelerated vulcanization of cis-polyisoprene was studied using C-13 solid-state NMR. The initial crosslink products consisted of A1c (cis) and A2c (cis) polysulfides. As the percent cure is increased, the A1c and A2c structures reduce in rank to monosulfides, and polysulfidic B1c (cis) and B1t (trans) structures are formed. During the maturation period C1c (cis) polysulfidic structures are also formed. The percent of sulfurization was shown to vary directly with sulfur concentration, while the efficiency of sulfurization (crosslink/cyclic-structure ratio) was shown to vary with accelerator content. TBSI-accelerated vulcanization was found to be more inefficient (lower crosslink/cyclic-structure ratio) than TBBS-accelerated vulcanization during the initial cure region. However, this results in shorter sulfur chains, which decreases the reactivity of TBSI vulcanizates as compared to TBBS vulcanizates during the reversion regime.

APA, Harvard, Vancouver, ISO, and other styles

50

Dürichen, Peter, and Wolfgang Bensch. "Reactions in Molten Alkalimetal Polychalcogenides: What Happens in the Melt? A Study of the Reactions in the System K-Nb-S Using Differential Scanning Calorimetry, Infrared Spectroscopy, and X-Ray Powder Diffraction." Zeitschrift für Naturforschung B 57, no. 12 (December 1, 2002): 1382–86. http://dx.doi.org/10.1515/znb-2002-1207.

Full text

Abstract:

The reactions of potassium polysulfides with elemental Nb were investigated with different analytical techniques. The amount of the polysulfide applied has no influence onto product formation, i. e. the ratio K2Sx: Nb is not important. The length of the polsysulfide chain, i. e. the value of x in K2Sx determines what product is formed. In sulfur-poor melts, K3NbS4 is observed. Increasing x to 5 - 6, K4Nb2S11 is formed with a structure containing S22− anions. Finally, applying a melt with x > 6, K6Nb4S25 is found as the product with a crystal structure containing the S52− polysulfide anion. When K2Sx (x < 5) is heated with sulfur in the first step the pentasulfide K2S5 is formed. Immediately after melting of K2S5 a reaction with elemental Nb occurs. The results of FT-IR and X-ray investigations have demonstrated that after oxidation the anion [Nb2S11]4− is formed relatively fast, and after a short time crystalline K4Nb2S11 can be detected. After 24 h the reaction is complete.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Polysulfides'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles