Sulfur-containing organic solvents

Janes, A., J. Eskusson, T. Thomberg, and E. Lust. 2014. Supercapacitors based on propylene carbonate with small addition of different sulfur containing organic solvents. Journal of the Electrochemical Society 16LA1284-A1290. 

Section 2.5 reviews papers on lithium and lithium-ion cells using sulfur-containing organic solvents, including sulfide, sulfoxide, sulfone, sulfite, sulfonate, and sulfate. Particularly, the performance of sulfones such as ethyl methyl sulfone and sulfolane as electrolyte solvents for high-voltage cells is introduced. 

Sulfolane (TMS) is the most smdied sulfur-containing organic solvent for lithium [150] and lithium-ion [151] cells. Since sulfolane is a solid at room temperature, like EC, it is often mixed with low-viscosity solvents to make electrolyte solutions. Dimethyl sulfone has a high melting point of 108 °C, and it is not easy to handle as a solvent, although it was used for lithium cells in high-temperature operation above 150 °C [152, 153]. Unsymmetrical ethyl methyl sulfone has a relatively low melting point of 37 °C, and it was studied extensively as an electrolyte solvent [154],... 

Hydrogenolysis of carbon-sulfur bonds is a widely utilized reaction for removing sulfur from sulfur-containing organic compounds, and is known as desulfurization or hydrodesulfurization. Bougault et al. used Raney Ni for the first time for the desulfurization of aliphatic thioalcohols and disulfides in neutral and alkaline solution.126 Since then the reaction has been widely applied, for example, for organic syntheses, purification of solvents and substrates, structural studies, and determination of sulfur contents.127... 

EXPLOSION and FIRE CONCERNS noncombustible solid liquid formulations containing organic solvents may be flammable characteristics of the dust or the solvent used in the formulation will determine the explosion hazard decomposes in acid or base decomposes on heating above 200°C (392°F), producing toxic and corrosive fumes of nitrogen oxides, phosphorous oxides, and oxides of sulfur use dry powder, alcohol foam or carbon dioxide for firefighting purposes. 

In addition to carbonate solvents, much effort has been made to introduce new solvents in order to improve cell performance. In the following section, heteroatom-containing organic solvents applied to lithium cells in recent years are reviewed by each author. The heteroatom includes fluorine, phosphorous, boron, and sulfur. 

Israel Mining Industries developed a process in which hydrochloric acid, instead of sulfuric acid, was used as the acidulant (37). The acidulate contained dissolved calcium chloride which then was separated from the phosphoric acid by use of solvent extraction using a recyclable organic solvent. The process was operated commercially for a limited time, but the generation of HCl fumes was destmctive to production equipment. 

Stripping is accompHshed by dehydration using sulfuric acid (38), lithium chloride [7447-41-8] (39), and tertiary amines containing from 14—32 carbon atoms in an organic solvent immiscible with water followed by thermal treatment of the HCl—organic complex (40). 

For solvent extraction of a tetravalent vanadium oxyvanadium cation, the leach solution is acidified to ca pH 1.6—2.0 by addition of sulfuric acid, and the redox potential is adjusted to —250 mV by heating and reaction with iron powder. Vanadium is extracted from the blue solution in ca six countercurrent mixer—settler stages by a kerosene solution of 5—6 wt % di-2-ethyIhexyl phosphoric acid (EHPA) and 3 wt % tributyl phosphate (TBP). The organic solvent is stripped by a 15 wt % sulfuric acid solution. The rich strip Hquor containing ca 50—65 g V20 /L is oxidized batchwise initially at pH 0.3 by addition of sodium chlorate then it is heated to 70°C and agitated during the addition of NH to raise the pH to 0.6. Vanadium pentoxide of 98—99% grade precipitates, is removed by filtration, and then is fused and flaked. 

Most organic reactions are done in solution, and it is therefore important to recognize some of the ways in which solvent can affect the course and rates of reactions. Some of the more common solvents can be roughly classified as in Table 4.10 on the basis of their structure and dielectric constant. There are important differences between protic solvents—solvents fliat contain relatively mobile protons such as those bonded to oxygen, nitrogen, or sulfur—and aprotic solvents, in which all hydrogens are bound to carbon. Similarly, polar solvents, those fliat have high dielectric constants, have effects on reaction rates that are different from those of nonpolar solvent media. 

Estrone methyl ether (100 g, 0.35 mole) is mixed with 100 ml of absolute ethanol, 100 ml of benzene and 200 ml of triethyl orthoformate. Concentrated sulfuric acid (1.55 ml) is added and the mixture is stirred at room temperature for 2 hr. The mixture is then made alkaline by the addition of excess tetra-methylguanidine (ca. 4 ml) and the organic solvents are removed. The residue is dissolved in heptane and the solution is filtered through Celite to prevent emulsions in the following extraction. The solution is then washed threetimes with 500 ml of 10 % sodium hydroxide solution in methanol to remove excess triethyl orthoformate, which would interfere with the Birch reduction solvent system. The heptane solution is dried over sodium sulfate and the solvent is removed. The residue is satisfactory for the Birch reduction step. Infrared analysis shows that the material contains 1.3-1.5% of estrone methyl ether. The pure ketal may be obtained by crystallization from anhydrous ethanol, mp 99-100°. Acidification of the methanolic sodium hydroxide washes affords 10-12 g of recovered estrone methyl ether. 

In the thermal production of gold coatings on ceramics and glass, paints are used which comprise Au chloro-complexes and sulfur-containing resins dissolved in an organic solvent. It seems likely that polymeric species are responsible for rendering the gold soluble. 

Mass absorption increases strongly with the atomic number Z. For the 14.4 keV radiation of Fe, the coefficient follows approximately the relation k. 0.003 from oxygen to krypton. Therefore, organic solvents containing sulfur or chlorine are virtually opaque to the Mossbauer radiation. The sulfur component of a 2 mm layer of dimethylsulfoxide (DMSO) absorbs 70% of the Mossbauer radiation (/ = 1.1 g cm ) [35]. Even worse is dichloromethane (CH2CI2), having an absorption coefficient of 16.83 cm g. A layer of 0.1 g cm , which is only 0.75 mm thick (p = 1.33 g cm ), absorbs about 82% of 14.4 keV radiation. For the same reason, chlorinated polymers (PVC) or glass should not be used for... 

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