Reaction with reduced sulfur species

In traditional Li-ion batteries, liquid electrolytes are based on organic carbonates, such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC) and diethyl carbonate (DEC). Carbonate solvents underwent a variety of reactions with reduced sulfur species. These were recently confirmed by XAS analysis as a result, this class of solvents is no longer considered for use in Li-S... 

Recent work suggests that rates of atrazine reaction with reduced sulfur species present in the sediment porewaters may be sufficiently rapid to provide an important removal mechanism in sulfate-reducing environments (13). The most significant reaction of atrazine with reduced sulfur nucleophiles occurs with polysulfides. This reaction can be modeled as a pseudo first order reaction... 

Lippa, K. A., Reactions of Chloro-s-triazine and Chloroacetanilide Agrochemicals with Reduced Sulfur Species, Ph.D. Thesis, The Johns Hopkins University, Baltimore, MD, 2002. 

These examples convincingly demonstrate that specific OSC are formed during the early stages of diagenesis by reactions of reduced sulfur species with specific biogenic substrates. The reactive substrates are proposed to contain either carbon-carbon double bonds or other reactive functional groups that react with either hydrogen sulfide or polysulfides to form the OSC (88). These views are consistent with evidence from sulfur isotopes that H2S produced by microbial sulfate reduction is the major source of reduced sulfur in sediments... 

Figure 19 Model for the intramolecular and intermolecular reaction of reduced sulfur species with functionalized lipids. Proposed reaction scheme for sulfur incorporation into (17 )-13 8(J7)-malaharica-14(27),17,21-triene (I)...

Miah H. M. and Jans U. (2001) Reactions of phosphorothionate triesters with reduced sulfur species. Abstract presented at the 22nd annual meeting of the Society for Environmental Toxicology and Chemistry (November, 2001 Baltimore, MD). 

In addition to these nuclear reactions, myriads of other gas-phase transformations produce low-vapor pressure species, with the oxidation of SO2 and other reduced sulfur species dominating aerosol formation and growth. Oxidation of SO2 in the gas phase produces H2SO4, a readily condensable species that either combines with other molecules (new particle formation) or condenses on existing aerosols. 

Tyndall, G. S., and A. R. Ravishankara, Atmospheric Oxidation of Reduced Sulfur Species, Int. J. Chem. Kinet., 23, 483-527 (1991). Urbanski, S. P., R. E. Stickel, and P. H. Wine, Mechanistic and Kinetic Study of the Gas-Phase Reaction of the Hydroxyl Radical with Dimethyl Sulfoxide, / Phys. Chem. A, 102, 10522-10529 (1998). 

Pyrite is a major sink for reduced sulfur from the JH S/S0/]- system to the extent that reactive iron is available. In sediments with limited amounts of reactive iron, reduced sulfur species in the H2S/S°/H2SX system are available for reaction with the sedimentary organic matter. 

In other circumstances, the oxidation reactions may not proceed to completion. Partial oxidation may result in only a small proportion of the sulfur being transformed to sulfate, with the remainder accumulating as reduced sulfur species (polysulfides and elemental sulfur) at the mineral surface (Janzen et al., 2000) ... 

Natural vulcanization, or reaction of organic compounds with sulfur compounds, which renders the sulfur-linked materials less available for degradation (e.g. Kohnen et al. 1992). However, this process is not likely to be significant in many marine environments as it is requires low iron availability and abundant reduced-sulfur species. 

The standard dissolution procedure for titanium oxides is the ammonium sulfate-sulfuric acid mixture developed by Rahm [24]. The most commonly used method in industry is based on the use of metallic aluminum as the reductant, and ferric ammonium sulfate as the titrant. The use of ferric ion as the reagent is preferred, since relatively few species will interfere with its reaction with reduced titanium solutions. 

Eq. (10.12), may oxidize the dissolved SO2 to sulfate in the outer layers. The species within rectangular boxes represent the solution constituents and those in ovals represent the corrosion products. Dotted ovals represent reactions or chemical compounds for which there is no evidence by laboratory or field studies. The chemical reactions that have been described and confirmed by laboratory studies are presented as sohd arrows. The dotted arrows represent the mechanisms that are uncertain. TMI in the upper part of Fig. 10.3 stands for transition metal ions and soot catalyzes the S(IV) to S(VI). The ferrous cations react with reduced sulfur to produce several insoluble sulfides. Multistep processes including Fe(II), Fe(III), and OH produce hydroxysulfate mixed salts [5]. 

Universal sulfur-selective detectors for GC or supercritical fluid chromatography (SFC), that incorporate a cool hydrogen-rich flame or closed hydrogen/ air burner have been developed and are now commercially available. Combustion products are transferred via a connecting line to a low-pressure reaction cell, where they are mixed with ozone. Although sulfur monoxide is believed to be the common intermediate that reacts with ozone to form the excited sulfur dioxide emitter, it is not necessarily the product of the first conversion step, which has caused debate between instrument manufacturers. One proposed mechanism proceeds as shown in reaction [VI] and it was suggested that the reduced sulfur species could be H2S ... 

This first example is relevant for environments where reduced sulfur species (e.g., HS") are present (e.g., produced by microbial sulfate reduction). As already mentioned above, in the presence of hydrogen sulfide, dissolved natural organic matter (NOM) constituents may act as electron transfer mediators for NAC reduction (Figure 4). Such NOM constituents most probably include hydroquinone structures (11,60,64), and sulfur derivatives that result from addition reactions of quinone type structures with hydrogen sulfide (54). Dunnivant et al. (11) found that pseudo-first-order reduction rate constants, kobs (Figure 4), determined for a series of substituted nitrobenzenes and nitrophenols were proportional to NOM concentrations. For a given compound and at given conditions (T, pH, [H2S]tot), they calculated a carbon-normalized second-order rate constant, k oM... 

In photosystem I, absorption of a photon leads to an excited state that functions as a reducing agent. The electrons are passed from one species to another with several intermediate species that include ferrodoxin (a protein containing iron and sulfur) before finally reducing C02. In photosystem II, electrons are transferred to a series of intermediates, of which a cytochrome bf complex is one entity. Ultimately, the transfer of electrons leads to the reaction... 

Typically, intense chemiluminescence in the UV/Vis spectral region requires highly exothermic reactions such as atomic or radical recombinations (e.g., S + S + M - S2 + M) or reactions of reduced species such as hydrogen atoms, olefins, and certain sulfur and phosphorus compounds with strong oxidants such as ozone, fluorine, and chlorine dioxide. Here we review the chemistry and applications of some of the most intense chemiluminescent reactions having either demonstrated or anticipated analytical utility. 

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