Confusion between dimethyl selenenyl sulfide and dimethyl selenone released by bacteria

Dimethyl selenone [(CH₃)₂SeO₂] has been reported in the literature as a metabolite released by bacteria in contact with selenium metal or selenium salts. In this study, mass spectral, chromatographic, and boiling-point data are presented that show that dimethyl selenone has been confused with dimethyl selenenyl sulfide (CH₃SeSCH₃). In addition, the headspaces above monocultures of selenium-resistant bacteria were examined using gas chromatography followed by fluorine-induced chemiluminescence detection. A number of alkyl sulfur and selenium species were detected, along with dimethyl selenenyl sulfide. A pathway from oxidized selenium salts to reduced methylated selenides and dimethyl selenenyl sulfide is also presented.     

Determination of Sulfur in Trace Amounts

Abstract

An absolute method for the determination of trace amounts of sulfur in water and organic matrices is described. The method involves decomposition of organic samples in an oxygen bomb or oxidation of water samples with hydrogen peroxide. The resultant sulfates are reduced and distilled as hydrogen sulfide by the action of stannous phosphate in anhydrous phosphoric acid. The evolved hydrogen sulfide is absorbed in zinc acetate solution, converted to methylene blue and measured spectrophotometrically at 665 mm. The range is from 2 to 40 μg of sulfur using 1 cm cells.     

DEHYDROCHLORINATION OF α-CHLORO SULFONES WITH KOH-T-BUOH: KINETIC VS EQUILIBRIUM CONTROL OF THE FORMATION OF α, β-UNSATURATED SULFONES AND THE β-T-BUTOXY AND β-HYDROXY MICHAEL ADDUCTS

Abstract

Inorganic sulfur compounds are used by microorganisms (bacteria, fungi, algae) and plants for assimilation, i.e. biosynthesis of sulfur-containing cell constituents.

Quantitatively, within the biogeochemical cycle of sulfur the utilization of inorganic sulfur compounds in bacterial energy metabolism, i.e. dissimilatory sulfur utilization, is of far higher importance. Reduced sulfur compounds serve as electron donors for photosynthesis and respiration, whereas inorganic sulfur compounds of oxidation levels above sulfide serve as electron donors in anaerobic respiration as well as in fermentation. In still other bacteria reduced sulfur compounds act as protective agents against hydrogen peroxide.     

Changes in Reduced Gaseous Sulfur Compounds Collected in Glass Gas Sampling Bulbs

Abstract

Changes which volatile reduced sulfur species (hydrogen sulfide, carbonyl sulfide, methanethiol, dimethyl sulfide and carbon disulfide) undergo in glass gas sampling bulbs were determined as influenced by the balance gas matrix and moisture. Results have shown that differences in reduced sulfur gas concentrations compared with the initial values were less than 5% in each sulfur compounds within 24 hours if the balance gas was dry nitrogen. There was no change in composition if dry air sample was measured within 3 hours. Significant decrease in hydrogen sulfide and methanethiol concentrations was observed with a short period of time following sampling if moisture was present within the bulb atmosphere.     

A multidimensional gas chromatography method for the analysis of hydrogen sulfide in crude oil and crude oil headspace

Two‐dimensional heart‐cutting gas chromatography is used to analyze dissolved hydrogen sulfide in crude samples. Liquid samples are separated first on an HP‐PONA column, and the light sulfur gases are heart‐cut to a GasPro column, where hydrogen sulfide is separated from other light sulfur gases and detected with a sulfur chemiluminescence detector. Heart‐cutting is accomplished with the use of a Deans switch. Backflushing the columns after hydrogen sulfide detection eliminates any problems caused by high‐boiling hydrocarbons in the samples. Dissolved hydrogen sulfide is quantified in 14 crude oil samples, and the results are shown in this work. The method is also applicable to the analysis of headspace hydrogen sulfide over crude oil samples. Gas hydrogen sulfide measurements are compared to liquid hydrogen sulfide measurements for the same sample set. The chromatographic system design is discussed, and chromatograms of representative gas and liquid measurements are shown.     

ORGANOPHOSPHORUS COMPOUNDS,XXVIII. THE REACTION OF TRIPHENYLPHOSPHINE SULFIDE WITH TETRACHLOROBENZOQUINONES

Abstract

The reaction of triphenylphosphine sulfide with tetrachloro-o-benzoquinone gives a complex of the corresponding hydroquinone and triphenylphosphine oxide. Elemental sulfur is the other product. The tetrachloro-p benzoquinone does not react to any noticeable extent under similar conditions. Several mechanisms are proposed to explain the results.     

REACTIONS BETWEEN SULFUR DIOXIDE AND PHOSPHINES

Abstract

Reaction between sulfur dioxide and trimethyl phosphine yields both phosphine oxide and sulfide. Reactions between sulfur dioxide and phosphines containing P-H bonds generally give rise to the most fully oxidized acid containing phosphorus that can be formed without cleaving P-C bonds. Thus, diphenylphosphine gives diphenylphosphinic acid (and some tetraphenyldiphosphine disulfide) and phenylphosphine gives phenylphosphonic acid.     

Synthesis of Novel 2-Aminothiophene-3-carboxylates by Variations of the Gewald Reaction

Summary.  The synthesis of the title compounds through variations of the Gewald reaction is presented. Knoevenagel condensation of methylketone derivatives with methyl cyanoacetate and subsequent treatment of the α,β-unsaturated nitriles with sulfur and amine resulted in the corresponding 2-aminothiophenes 5 or isomers 9 and 10. Reaction of methylketone derivatives bearing a leaving group at the methyl group under modified Gewald conditions selectively led to the formation of 4-substituted 2-aminothiophenes 9a and 12. The introduction of the sulfur atom occurs through nucleophilic displacement with sodium sulfide. Received July 5, 2000. Accepted (revised) August 23, 2000     

Electroanalytical Chemistry of Sulfur Compounds For the New Coal Conversion Technologies

Abstract

Polarographic methods are described “tailor-made” for the speciation and determination of sulfur contaminants in synfuels and coal gasification/liquefaction process streams. In samples containing the anions, S^2? _x, sulfidic sulfur was quantitated by anodic depolarization of the dropping mercury electrode, while polysulfidic sulfur was determined with the aid of an electroreduction process implicating 2(x-1) electrons. Polythionates were electroreduced to thiosulfate, sulfite, sulfide and/or mixtures thereof, under judiciously controlled experimental conditions. Thiosulfate and sulfite were quantitated by differential pulse polarography at dropping mercury anodes via reactions involving formation of thiosulfato- and sulfitomercurates.     

Determination of Nitrogen,Sulfur, Phosphorus,and Carbon in Solid Ecological Materials Via Hydrogenation and Element-Selective Detection

Abstract

Element-selective detectors for carbon, sulfur, phosphorus, and nitrogen are used to determine methane, hydrogen sulfide, phosphine and ammonia in the effluent from a pyrolytic hydrogenator. Solid ecological field samples, e.g., forest floor litter, plant stream particulate, and insects, require no chemical pretreatment. These are pyrolyzed and the pyrolyzates pass through a catalyst bed which reduces the elements to the corresponding hydrides. Data are given for sulfur, carbon, and nitrogen.     

Analysis of Total Non-Volatile Non-Sulfide Reduced Sulfur in Potable and Untreated Surface and Groundwaters

Abstract

An analytical method was developed to measure the total concentration of non-volatile non-sulfide reduced sulfur in treated and untreated surface and groundwater. The method was based on the alkaline reduction by Raney nickel (prepared in situ from Raney alloy) of organic and inorganic sulfur compounds (in oxidation states below +6) to sulfide. Sulfide was swept out of the reflux apparatus under nitrogen into a trap of zinc acetate and determined colorimetrically as ethylene blue. The recoveries obtained from solutions of elemental sulfur, sulfide, sulfite, thiosulfate, tetrathionate, cysteine, cystine, methionine, glutathione, allylthiourea, sulfanilamide and thiocyanate ranged from 84–102% with typical recoveries of approximately 90%. Sulfate was not detectable by the procedure. Chlorine present in potable water samples interfered in the procedure and was removed with sodium borohydride. The relative standard deviation of the method varied from 0.25 to 5.6% and averaged 3%. The detection limit based on a 500 mL sample was 3 mg m^?3.     

Fluxional rearrangement in congested ruthenium(II) complexes containing pyrimidine- and/or pyridine-based dithioether ligands

The solvento species obtained by the treatment of cis-RuCl₂(N,N-L)₂ [L = di-2-pyridyl sulfide (dps), di-2-pyrimidyl sulfide (dprs)] with AgPF₆, reacted with dithioethers L′ [L′ = 2,6-bis(2-pyridylthiomethyl)pyridine (pytmp), 2,6-bis(2-pyrimidylthiomethyl)pyridine (prtmp) and 2,6-bis{2-(4-methyl)pyrimidylthiomethyl} pyridine (mprtmp)] to afford the compounds [Ru(N,N-L)₂(N,S-L′)][PF₆]₂. The ¹H NMR spectra indicate that L′ is chelated through S and N atoms with the formation of a four-membered ring. As a consequence, the ruthenium and sulfur atoms are stereogenic centers with ∆ and Λ and (R) and (S) configurations, respectively. NMR spectra, at low temperatures, show that two invertomers, of similar abundance, as enantiomeric couples ∆S, ΛR and ∆R, ΛS are present. In the methylene region, four AB systems are observed that in both the species contain two non-equivalent methylene groups. Variable-temperature NMR spectra and EXSY experiments show that the sulfur inversion produces an exchange between the invertomers. The one-dimensional band-shape analysis of the exchanging methylene signals showed that the energy barriers for the process are in the 43–52 kJ mol⁻¹ range. The possible mechanisms of the sulfur inversion are discussed.     

Die Sulfid-Braunstein-Batterie und elektrochemische Energiequellen in der Wächtershäuserschen Hypothese zur Entstehung des Lebens

Zusammenfassung.  In einer kürzlich erschienenen Ver?ffentlichung [1] konnten wir zeigen, dass elementarer Schwefel bei Raumtemperatur als ausgezeichnetes Kathodenmaterial in Zink-Schwefel-Batterien dienen kann, weil er an Eisen(II)sulfidelektroden mit gro?er Geschwindigkeit reduziert wird. In diesem Zusammenhang wurde der elektrochemische Umsatz von elementarem Schwefel an Eisen(II)sulfid in Meerwasser diskutiert, welcher eine der Energiequellen gewesen sein k?nnte, die bei der Entstehung des Lebens eine Rolle gespielt haben. In der W?chtersh?userschen Theorie stehen die exergonische Pyritbildungsreaktion aus Eisensulfid und Schwefelwasserstoff und die folgende Reduktion von Kohlendioxid am Anfang der Entwicklung des Lebens. Wir konnten nun zeigen, dass Sulfidionen an Eisensulfid mit gro?er Schnelligkeit zu Disulfidionen oxidiert werden, was zur Konstruktion einer Sulfid-Braunstein-Batterie führte, deren Ruheklemmenspannung bei 0.8 V liegt und deren Kapazit?ten und spezifische Energiedichten denen der k?uflichen Zink-Braunstein-Zellen vergleichbar sind. Eine elektrochemische Zelle, an der kathodisch an Eisen(II)sulfid Schwefel reduziert wird und anodisch ebenfalls an Eisen(II)sulfid Sulfidionen zu Disulfidionen oxidiert werden, liefert bei 95°C eine Spannung von etwa 0.4 V. Eine solche Energiequelle k?nnte in einer Eisen-Schwefel-Welt von einem sich entwickelnden Leben genutzt worden sein.

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The Sulfide-Manganese Dioxide Battery and the Electrochemical Energy Sources in the Hypothesis of W?chtersh?user Concerning the Origin of Life

Summary.  Recently we could show that elementary sulfur is an excellent cathode material at room temperature in zinc-sulfur batteries as it is reduced rapidly in aqueous solutions on the surface of iron sulfide electrodes [1]. In this context, the electrochemical reaction of solid elementary sulfur on iron sulfide surfaces in sea water was discussed which could have been one of the energy sources playing a role in the development of life. In the theory of W?chtersh?user, the first energy source of life is the formation of pyrite from iron sulfide and hydrogen sulfide, and the first step is the reduction of carbon dioxide on iron sulfide surfaces. We could show that sulfide ions are oxidized rapidly to disulfide ions on the surface of iron sulfide. The capacity and the specific energy of a sulfide-manganese dioxide battery with an open cell voltage of about 0.8 V are comparable to those of commercially available zinc-manganese dioxide batteries. An electrochemical cell where sulfur is reduced on the surface of an iron sulfide cathode and sulfide ions are oxidized on the surface of an iron sulfide anode affords an open-cell voltage of about 0.4 V at 95°C.

Received May 10, 2000. Accepted (revised) September 12, 2000     

HIGH TEMPERATURE REACTIONS OF HYDROGEN SULFIDE AND THIOLS WITH ORGANIC COMPOUNDS

Abstract

The high temperature reaction of hydrogen sulfide with chloro- and bromosubstituted aromatic and heteroaromatic compounds is a convenient method for synthesis of the corresponding thiols and sulfides. The reaction of hydrogen sulfide with ortho-dihalosubstituted aromatic compounds may be directed toward the formation of thianthrene or dibenzo thiophene and their derivatives. The high temperature reaction of thiophenol with chloro- and bromoderivatives of aromatic and heteroaromatic compounds affords the corresponding mixed sulfides. The reaction with ortho-substituted halogen derivatives leads to formation of the sulfur heterocycles of the thianthrene, thioxanthene and dibenzothiophenene series.

The high temperature reaction of hydrogen sulfide with vinyl chloride gives vinylthiol and thiophene. Hydrogen sulfide initiates pyrolytic transformations of thiophene, aniline and benzaldehyde into dithienyls, 5.10-dihydrophenazine and stilbene, respectively. The reaction mechanism has been discussed.     

Hydrogen sulfide as a source of hydrogen production

Potentialities and perspectives of using the known processes of hydrogen sulfide decomposition (thermal, plasmochemical, electrochemical, and photochemical) to produce hydrogen are examined. The results of theoretical and experimental studies of hydrogen sulfide dissociation on the surface of single crystals are presented. The data on the low-temperature decomposition of H₂S on the sulfide and metal catalysts are discussed. The electronic structure of diatomic sulfur and thermodynamics of its formation in the processes of H₂S decomposition are considered. The decomposition of hydrogen sulfide on the heterogeneous catalysts placed under the solvent layer is shown to be promising. The mechanism of assimilation of hydrogen sulfide by colorless sulfur bacteria is proposed.     

STUDIES ON THE EXTRACTION OF SELENIUM AND TELLURIUM FROM COPPER ELECTROLYTIC SLIMES BY SUBLIMATION IN VACUUM

Abstract

Anode slimes obtained from the electrolytic refining of copper contain selenium and tellurium in the form of selenides and tellurides of metals, e.g., copper and silver. The slimes were treated with sulfur under vacuum; selenides and tellurides decomposed to give selenium and tellurium in metallic form which condensed on a cooler zone. Various parameters studied were temperature, time, sulfur addition, briquetting pressure, and fineness of sulfur added. The X-ray diffraction studies carried out on treated and then on untreated slime proved the reaction of sulfur with selenide and telluride of copper to give copper sulfide, selenium, and tellurium. Sulfurization at around 475°C for 60 min gives optimum recoveries.     

Low-temperature catalytic decomposition of hydrogen sulfide into hydrogen and diatomic gaseous sulfur

The thermodynamics of three pathways of the hydrogen sulfide decomposition reaction is considered. In the thermal process, the gas-phase dissociation of hydrogen sulfide yields hydrogen and diatomic singlet sulfur. Over sulfide catalysts, the reaction proceeds via the formation of disulfane (H₂S₂) as the key surface intermediate. This intermediate then decomposes to release hydrogen into the gas phase, and adsorbed singlet sulfur recombines into cyclooctasulfur. Over metal catalysts, H₂S decomposes via dissociation into surface atoms followed by the formation of gaseous hydrogen and gaseous triplet disulfur. The last two pathways are thermodynamically forbidden in the gas phase and can take place at room temperature only on the surface of a catalyst. An alternative mechanism is suggested for hydrogen sulfide assimilation in the chemosynthesis process involving sulfur bacteria. To shift the hydrogen sulfide decomposition equilibrium toward the target product (hydrogen), it is suggested that the reaction should be conducted at room temperature as a three-phase process over a solid catalyst under a layer of a solvent that can dissolve hydrogen sulfide and sulfur. In this case, it is possible to attain an H₂S conversion close to 100%. Therefore, hydrogen sulfide can be considered as an inexhaustible source of hydrogen, a valuable chemical and an environmentally friendly energetic product.     

Determination of the sulfur components of gasoline streams by capillary column gas chromatography with sulfur chemiluminescence detection

A method using a sulfur chemiluminescence detector (SCD) has been developed for the qualitative and quantitative determination of sulfur components in stabilized gasoline-range process streams, including blended gasolines containing between 1 and > 4000 ppm total sulfur. The detection limit per sulfur component was approximately 50 ppb. On-column injection was employed for optimum precision and accuracy. A new probe material was found which did not soften under FID operating conditions. A new method, using a hydrogen sulfide permeation tube, was developed for rapid alignment of the probe in the FID.     

Chemical and electrochemical processes in low-temperature superionic hydrogen sulfide sensors

Effect the morphology of the surface of the working electrode (PbS) exerts on the sensitivity of a low-temperature potentiometric hydrogen sulfide sensor is studied. The sensor, which is based on electrochemical cell Na _x WO₃/NASICON/PbS, may be used for fast selective detection of hydrogen sulfide in air in natural conditions. It is demonstrated that the sensors with PbS that are deposited out of solution have a faster response than the pressed-to ones. The dependence of EMF on the hydrogen sulfide concentration for the former is linear in semilogarithmic coordinates. Thus difference is explained by the microstructure of the lead sulfide layer. It is shown that the lead sulfide interaction with hydrogen sulfide involves a reversible partial reduction of sulfur and lead at the surface. The species that form in so doing contain sulfur atoms in lower oxidation degrees (poly-and oligo sulfides, sulfite). A mechanism of the sensor operation is proposed on the basis of data yielded by experiment and quantum-chemical simulation. The mechanism includes reversible transport of hydrogen from sulfur atoms to oxygen atoms.     

Sulfurization of γ-oxo esters; study of the resulting sulfur compounds

Abstract

Treatment of aliphatic γ-oxo esters with hydrogen chloride/hydrogen sulfide gives three sulfur compounds: an alkyl-5-mercaptothiolan-2-one, an alkyl-4-thiolen-2-one and an alkyl-3-thiolen-2-one. Chemical properties of these products are reported. With aromatic γ-oxo esters we obtain a thiophenic compound.