Compounds containing sulfur

Sulfur-containing compounds (thiols and sulfides) are easily recognized from the M -h 2 isotopic peak each sulfur contributes 4.4% to the abundance of the M -I- 2 ion. The fragmentation patterns of thiols (mercaptans) and sulfides (thioethers) parallel the corresponding alcohols and ethers. For example, similar to the alcohol series at m/z 31,45, 59. the a-cleavage in thiols produces a series of ions at m/z 47, 61, 75, 89. and each ion has a satellite peak 2 u higher, due to In addition, thiols exhibit a characteristic loss of H2S, followed by the elimination of alkene moieties to produce peaks at (M — 34)+, (M — 34 — 2114)+, and so on. In contrast, secondary thiols show a characteristic peak at (M — SH)+. Aromatic thiols also behave similarly to phenols under El conditions. In addition, they show ions at (M — S)+, (M — SH)+, and (M — 2114)+.  

The activation rates for the sulfur compounds measured ranged from 15 to 33 Kcal/mole. 2-Acetylthiophene had the highest Ea ranging from 22 to 33 Kcal/mole while methional and dimethyl disulfide Eas ranged from 15 to 27 Kcal/mole. The values for the latter compounds are consistent with the Eas for the Maillard reaction in general. 

L Abbe, G., Destexhe, R., yC.S C/zeni. Comm., 1614(1985). Sulfur Containing Compounds 

Blaschette, A., Dalluhn, J., Proehl, H.H., Jones, P.G., Bubenitschek, P., Phosphorus, Sulfur, silicon related Elements, 70, 91 (1992). 

The most important corrosive contaminant foimd in industrial atmospheres is sulfur dioxide (SO2), which results from the combustion of sulfur-containing coal and oil, and emission from metal, petrochemical, and pulp and paper industries. Once in the atmosphere, SO2 imdergoes physical and chemical state changes. Depending on the environment, the sulfur dioxide is capable of being oxidized in one or more of the following ways  

On moist particles or in droplets of water, the SO2 may be oxidized to sulfuric acid  

Sulfur dioxide has a lifetime in the atmosphere of 0.5-2 days. This limits the distance that the SO2 may be transported to a few hundred kilometers. During this period, the sulfuric add may be partly neutralized, particularly with ammonia that results from the biological decomposition of organic matter. When this occurs, partides containing ammonium sulfate (NH4)2S04 and different forms of acid ammonium sulfate, such as NH4HSO4 and (NH4)3H(S04)2, are formed. 

Fundamentals of Metallic Corrosion Atmospheric and Media Corrosion of Metals 

Atmospheric corrosion results from the deposition of these various materials on metal surfaces. Deposition of the sulfur compounds can be accomplished by  

In 1996, Sony Corporation found that 1,4-butane sultone (24) (5-50 wt%) can be substituted for EC as a solvent [60] in 1997, Ube Industries, Ltd. discovered that the addition of small quantities of cyclic monosulfonic acid esters (sultones), such as 1,3-propane sultone (PS) (25), suppresses PC decomposition [61]. Furthermore, in 1999, researchers at Ube Industries, Ltd. found that 3-hydroxypropanesulfonic add (26), which is present as an impurity in PS, decomposes at the electrode before PS decomposition and thus adversely affects battery performance by inhibiting the formation of SEI of PS [62] and consequently developed highly pure PS containing little 3-hydroxypropanesulfonic acid (26) [62]. In the same year, Ube Industries found that the combination of small amount of PS (25) and VC (1) can be used as additives [54], 

Since then, there has been intensive research on combinations of VC (1) and PS (25). 

In 2001, Mitsui Chemicals discovered that cyclic monosulfonic acid esters containing unsaturated bonds, such as 1,3-propene sultone (PRS) (27) [63], can be used as additives in small quantities however, in 2010, the same company mentioned, PRS which is a comparative unsaturated sultone compound was added, an increase in the initial resistance was confirmed [64]. 

In 2002, NEC Corporation discovered that cyclic alkylenedisulfonic acid esters, such as methylene methanedisulfonate (28), ethylene methanedisulfonate (29), and 

In 1996, Mitsubishi Chemical Corporation discovered that chain sulfonates, such as ethyl methanesulfonate (31), can be used as additives in small quantities [66], Furthermore, Ube Industries, Ltd. discovered the applicability of chain diol disulfonates, such as 1,4-butanediol dimethanesulfonate (32) [67], in 1998, as well as chain diol sulfonates with a branched structure, such as 1,3-butanediol dimethanesulfonate (33) in 20(X) [68], 

Thiols, also called aliphatic mercaptans, with the formula RSH, are the sulfur analogs of alcohols. Thiols generally show stronger molecular ion peaks than the equivalent alcohols. Looking back at Table 10.4, sulfur has a significant isotope. This gives rise to an enhanced (M + 2) peak in the mass spectrum of sulfur-containing compounds. 

Corroborative evidence is often necessary from IR, which identifies the presence of many functional groups, and NMR, which confirms functional groups and, by spin-spin splitting patterns, the placement of these groups. Elemental analysis to determine the C, H, N, O, and heteroatom content is usually performed on pure compounds to assist in the assignment of an empirical formula. Optical activity measurements may be needed for chiral compounds. When used in conjunction with other analytical methods, such as elemental analysis, IR, and NMR, MS makes it possible to identify unknown compounds. Combined with a separation method like chromatography, as in GC-MS or LC-MS, even impure samples and mixtures can be analyzed and components identified. GC-MS and LC-MS are described in Chapters 12 and 13, respectively. 

Other sulfide photoreactions result when appropriate nucleoside derivatives are photolyzed. Upon irradiation in acetonitrile, 9-[5-deoxy-2,3-0-isopropylidene-5-(phenylthio)-/3-D-ribofuranosyl]-adenine (53) is converted into the anhydronucleoside 8,5 -anhydro-(5 -deoxy-2, 3 -0-isopropylidene-adenosine) (55) in 66% yield.111 Similar reactions were observed when other sulfur-containing nucleosides were irradiated (see Table XIII). The reaction of the sulfide 53 

Photochemical, carbon-sulfur bond cleavage is also observed in compounds containing sulfur in oxidation states higher than that which exists in sulfides and in dialkyl dithioacetals. For example, the irradiation of the sulfoxide 47 in methanol produces109 a 58% yield of galacti-tol (52). Even though homolysis of the carbon-sulfur bond does occur in 47, it is unlikely that 52 results from a simple, carbon-sulfur bond-cleavage, as such a reaction predicts products that were not observed 

Photochemical Reactions of Sulfur-Containing, Nucleoside Derivatives 

Several, oxidatively coupled xanthates (64-66), compounds (also called xanthides) containing the photochemically reactive, sulfur-sulfur bond, have been studied.130 Homolytic cleavage of this reactive bond is the primary reaction for these compounds, although this process is normally masked by recombination of the radicals produced. This primary, light-initiated process becomes apparent when a mixture of the xanthide 64 and ethyl xanthide (67) is irradiated in cyclohexane, because an equilibrium between 64, 67, and the mixed xanthide 68 is rapidly established. 

Usui and Paquette have reported the photochemical transformation of the sulfide (251) into the isomeric product (252). This 1,3-phenylthio migration can be brought about using sunlamp irradiation in carbon tetrachloride solution and the isomerised compound is used as a key intermediate in a new synthetic strategy for diquinanes. 

Gravel and co-workers have demonstrated that the cyclohexanediol (253) can be converted into the deoxysugar (254) by irradiation in the presence of benzophenone, acetonitrile and thiophenol. The conversion of (253) into (254) involves the formation of the aldehyde (255) which is transformed into the acetal, i.e. the deoxysugar. An extension of this reaction has demonstrated that deoxyazasugars can also be formed using the same condi-tions. Thus irradiation of (256) gave the aldehyde (257) which can then cyclise by the same path as for the formation of (258). The conditions utilised were irradiation at 350 nm in acetonitrile solution with xanthene and thiophenol. 

The involvement of a-and 7C-type dimeric radical-cations in one electron transfer to the aromatic sulfides (259) has been assessed. A laser-flash study of the behaviour of p-nitrobenzenethiol has shown that S-H fission is the dominant reaction with the formation of the corresponding thiyl radical. This occurs particularly when the irradiations are carried out in nonpolar solvents. The reactions encountered in polar solvents are different. Under these conditions the triplet state of p-nitrobenzenethiol is involved and this undergoes ready deprotonation. The amino acid derivatives (260) can be desulfurised by irradiation using triethylboron and triethylphosphite.  

The influence of the sulfur substituent on the addition of radicals to the enones (265) has been assessed. The radicals are produced by hydrogen abstraction from the alcohols using photoexcited benzophenone and the products formed were identified as (266) and (267). 

Aromatic thioketones are recommended as useful compounds to measure 

Achiral thioamide (412) crystallises in a chiral space group and irradiation of the powdered crystals leads to exclusive formation of optically active p-thio-lactam (413) with high enantiomeric excess by a mechanism involving intramolecular transfer of the appropriately-oriented benzylic hydrogen and cyclisation with minimal molecular motion within the crystal. S-(o-Tolyl)-o-benzoylbenzo-thioate also crystallises in a chiral space group. Irradiation of a solid sample of a single enantiomorphic modification yields optically active 3-phenyl-3-(o-tolyl- 

Photocyclisation of 2-arylthiocyclohexenones (414) yields racemic dihydrobenzo-thiophenes (416) via a thiocarbonyl ylide (415). Theprochiral compounds (414) also form 1 1 inclusion complexes with the homochiral host (63) and irradiation of crystals of these complexes yields the dihydrobenzothiophenes (416) in 32-83% enantiomeric excess, optically pure samples being easily accessible by further recrystallisation. The decay kinetics for ylides (415), produced by laser flash photolysis of the aryl vinyl sulfldes (414), indicate the presence of more than one ylide species in each case.  

The sulfur-sulfur interatomic distance in 9-phenyl-4,8,10-trithiadibenzo[cd,ij]a-zulene-8-oxide (417) is significantly shorter than the sum of their van der Waals radii and photolysis of (417) and (418) yields (420) and aldehydes or ketones (421) quantitatively. The unstable primary photoproduct (419) may be isolated and photolyses to (420) and (421). A similarly short sulfur-sulfur interatomic distance is found in a series of naphtho[l,8-ef][l,4]dithiepins and direct irradiation yields naphtho[l,8-cd][l,2]dithioles quantitatively with analogous S-S bond formation and alkene elimination. Photolysis of compounds (422), (424) and (426) gives the dimerised disulfides (423), (425) and (427) in 45%, 17% and 1% yields respectively. Irradiation of the tetraalkyl-2H-thietes (428) at 254 nm leads to a photostationary mixture containing the purple enethiones (429) (25%). Exposure of the mixture to 300 nm radiation induces almost complete reversion to (428).  

Electron transport across organised bilayers is an integral part of biological energy storage systems such as photosynthesis and provides a means of controlling back electron transfer and of separation of the products of redox reactions. Esters of 2,l,3-benzothiadiazole-4,7-dicarboxylic acid (481) have been used to study the transfer of electrons from 2-(morpholino)ethanesulfonic acid (MES) to 1,5-anthraquinone disulfonate in micelles or across vesicle bilayers. The esters absorb the light, accept an electron from MES and transfer it to the 

If the concentration of the species is not changing, then a steady state may be presumed in which 

To use (2.16) the individual first-order rate constants for removal must be estimated, whereas in (2.17), estimates for the total number of moles in the troposphere, which can be derived from a concentration measurement, and for the source strength terms are needed. If the kt values are difficult to specify, mean residence times are often estimated from (2.17). 

Sulfur is present in the Garth s crust at a mixing ratio of less than 500 parts per million by mass and in the Earth s atmosphere at a total volume mixing ratio of less than 1 ppm. Yet, sulfur-containing compounds exert a profound influence on the chemistry of the atmosphere and on climate. 

Oxidation Stale Compound Name Formula Chemical Structure Usual Atmospheric State 

6 Bisulfite ion Sulfite ion Sulfuric acid so2 h2o HSOj SO h2so4 0 HO-S-OH Aqueous Aqueous Aqueous Gas aqueous/aerosol 

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An analogous fragmentation process occurs m the mass spectra of sulfides As with other sulfur containing compounds the presence of sulfur can be inferred by a peak at m/z of M-l-2... 

The physical properties of the principal constituents of natural gas are Hsted in Table 5. These gases are odorless, but for safety reasons, natural gas is odorized before distribution to provide a distinct odor to warn users of possible gas leaks in equipment. Sulfur-containing compounds such as organic mercaptans, aUphatic sulfides, and cycHc sulfur compounds are effective odorants at low concentrations and are added to natural gas at levels ranging from 4 to 24mg/m. ... 

Detoxifica.tlon. Detoxification systems in the human body often involve reactions that utilize sulfur-containing compounds. For example, reactions in which sulfate esters of potentially toxic compounds are formed, rendering these less toxic or nontoxic, are common as are acetylation reactions involving acetyl—SCoA (45). Another important compound is. Vadenosylmethionine [29908-03-0] (SAM), the active form of methionine. SAM acts as a methylating agent, eg, in detoxification reactions such as the methylation of pyridine derivatives, and in the formation of choline (qv), creatine [60-27-5] carnitine [461-06-3] and epinephrine [329-65-7] (50). 

Sulfur (qv) is among the most widely used chemicals and often considered to be one of the four basic raw materials of the chemical iadustry. In 1993, worldwide production of sulfur reached 55 million metric tons (1). Production of sulfuric acid consumes the vast majority (- 90%) of sulfur (2) (see Sulfuric acid and sulfur trioxide). This acid is a steppiag stone ia the production of other sulfur-containing compounds, most notably ammonium sulfate fertilizer which accounts for 60% of the total worldwide sulfur consumption (2) (see Ammonium compounds Fertilizers). 

The catalysts are prepared by impregnating the support with aqueous salts of molybdenum and the promoter. In acidic solutions, molybdate ions are present largely in the form of heptamers, [Mo2024] , and the resulting surface species are beHeved to be present in islands, perhaps containing only seven Mo ions (100). Before use, the catalyst is treated with H2 and some sulfur-containing compounds, and the surface oxides are converted into the sulfides that are the catalyticaHy active species. 

Thiobacillus thiooxidans is an aerobic organism that oxidizes various sulfur-containing compounds to form sulfuric acid. These bacteria are sometimes found near the tops of tubercles (see Chap. 3, Tubercu-lation ). There is a symbiotic relationship between Thiobacillus and sulfate reducers Thiobacillus oxidizes sulfide to sulfate, whereas the sulfate reducers convert sulfide to sulfate. It is unclear to what extent Thiobacillus directly influences corrosion processes inside tubercles. It is more likely that they indirectly increase corrosion by accelerating sulfate-reducer activity deep in the tubercles. 

Some cracks were clustered into small areas along one side of the tube, but close examination revealed numerous cracks scattered over the tube surface. Chemical spot tests revealed the presence of sulfur-containing compounds on the external surface. 

There are quite a number of crown compounds known which contain a thiophene or other sulfur-containing subunit. The reader is directed to the tables at the end of each chapter in order to locate these species. Because of the expense of including each structure under each possible category, some sulfur-containing compounds may not be listed in this chapter. It is hoped that the tables are well enough organized that the desired compound can be located if it is known by considering other structural features. 

General Incineration (oxidation) is the best-known method for the removal of gaseous industrial waste. Combustible compounds containing carbon, hydrogen, and oxygen are converted to carbon dioxide and water by the overall exothermic reactions [Eq. (13.72)]. When chlorinated or sulfur-containing compounds are present in the effluent, the products of combustion include HCl/CE or S02/S03. ... 

J. Beens and R. Tijssen, The characterization and quantitation of sulfur-containing compounds in (heavy) middle distillates by FC-GC-FID-SCD , J. High Resolut. Chromatogr. 20 131-137 (1997). 

Homogeneous catalysts may also be effective in the hydrogenation of sulfur-containing compounds. (Z)-2-Benzamide(acetamido)-3-(2-thienyl)-2-propenoic acid was reduced in 100% yield and 78% enantiomeric excesses over Rh(I)-DlOP catalysts (25),... 

Sulfur Compounds. All crude oils contain sulfur in one of several forms including elemental sulfur, hydrogen sulfide, carbonyl sulfide (COS), and in aliphatic and aromatic compounds. The amount of sulfur-containing compounds increases progressively with an increase in the boiling point of the fraction. A majority of these compounds have one sulfur atom per molecule, but certain aromatic and polynuclear aromatic molecules found in low concentrations in crude oil contain two and even three sulfur atoms. Identification of the individual sulfur compounds in the heavy fractions poses a considerable challenge to the analytical chemist. 

When high temperatures above 300°F are expected, do not use sulfur-containing compounds as drilling fluid additives. In general, avoid using chemical additives that can at operating temperatures. 

Thiols (m/z 61 and 89 also suggest sulfur-containing compounds)... 

Other major sources of data on the thermochemistry of sulfur-containing compounds are the review by Benson19, which is of particular value in evaluating data on radicals and other labile species, and the review of the present author on the thermochemistry of the inorganic S—O—F compounds20. 

For a review of the use of phase-transfer catalysis to prepare sulfur-Containing compounds, see Weber, W.P. Gokel, G.W. Phase Transfer Catalysis in Organic Synthesis, Ref. 437, p. 221. 

For a discussion of conversions of organomercury compounds to sulfur-containing compounds, see Larock, R.C. Ref. 300, p. 210. 

Before 1980, force field and semiempircal methods (such as CNDO, MNDO, AMI, etc.) [1] were used exclusively to study sulfur-containing compounds due to the lack of computer resources and due to inefficient quantum-chemical programs. Unfortunately, these computational methods are rather hmit-ed in their reliability. The majority of the theoretical studies under this review utilized ab initio MO methods [2]. Not only ab initio MO theory is more reliable, but also it has the desirable feature of not relying on experimental parameters. As a consequence, ab initio MO methods are apphcable to any systems of interest, particularly for novel species and transition states. 

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