Sulfur monosulfide

Sulfur Donors. MBSS, DPTH, and the thiuram disulfides (see Table 2) ate examples. The morpholine disulfide and caprolactam disulfide examples in Table 4 can also donate one atom of sulfur from their molecular stmcture for cross-linking purposes. Monosulfide cross-links provide better thermal stabiUty than the sulfur—sulfur bonds in di- and polysulfide cross-links, which predominate when elemental sulfur is used. 

Sulfur. Low sulfur stocks and EV sulfur-accelerated systems have better aging resistance. Normally, the oxidation rate increases with the amount of sulfur used in the cure. The increased rate may be due to activation of adjacent C—H groups by high levels of combined sulfur. Saturated sulfides are more inert to oxidation than aHyUc sulfides. Polysulfidic cross-links impart excessive hardening of SBR as compared to more stable monosulfidic cross-links. 

Carbon monosulfide [2944-05-0] CS, is an unstable gas produced by the decomposition of carbon disulfide at low pressure ia a silent electrical discharge or photolyticaHy (1 3) ia the presence or absence of sulfur (3). It decomposes with a half-life of seconds or minutes to a black soHd of uncertain composition (1—3). The monosulfide can be stabilized ia a CS2 matrix at — 196°C, and many stable coordination complexes of CS with metals have been prepared by iadirect means (8). 

Dithioglycerol is prepared in the following manner 1,537 parts of sodium monosulfide nonahydrate and 411 parts of powdered sulfur are dissolved with stirring in 1,345 parts of water. Magnesium hydroxide is precipitated in the stirred sodium trisulfide solution by adding successively 97 parts of sodium hydroxide dissolved in 180 parts of water and then slowly 246 parts of magnesium chloride hexahydrate dissolved in 180 parts of water. The... 

The S-S linkage of disulfides and the C-S linkage of certain sulfides can undergo photoinduced homolysis. The low reactivity of the sulfur-centered radicals in addition or abstraction processes means that primary radical termination can be a complication. The disulfides may also be extremely susceptible to transfer to initiator (Ci for 88 is ca 0.5, Sections 6.2.2.2 and 9.3.2). However, these features are used to advantage when the disulfides are used as initiators in the synthesis of tel ec he lies295 or in living radical polymerizations. 96 The most common initiators in this context are the dithiuram disulfides (88) which are both thermal and photochemical initiators. The corresponding monosulfides [e.g. (89)J are thermally stable but can be used as photoinitiators. The chemistry of these initiators is discussed in more detail in Section 9.3.2. 

Inorganic polysulfides are ionic substances containing chain-like dianions Sn - 8uch ions are formed in numerous reactions, e.g., by oxidation of monosulfide ions H8 in water or other polar solvents as well as by reaction of aqueous monosulfide with sulfur-rich compounds including elemental sulfur ... 

Consequently, sulfur dissolves in polysulfide solutions much faster than in equimolar monosulfide solutions [73]. In this context it is of interest that the analogous decaselenium dianion Scio has been prepared and structurally characterized in solid [PPN]2Seio [74]. This anion is however bi-cyclic. 

CA-isoprene rubber cured with bis(dusopropyl)thiophosphoryl disulfide (DIPDIS) shows results at 160°C, producing a predominantly monosulfidic network structure [14]. Similar work on heat-resistant network structures has been carried out on other synthetic rubbers. For example, a sulfur-less system using 1 phr TBBS, 2.0 phr DTDM, and 0.4 phr TMTD in SBR gives the best aging resistance [15]. 

The monosulfides of the alkaline earth metals crystallize in the rock salt (MgS, CaS, SrS, BaS) and zinc blende (BeS) structures. BaS is insoluble in water, while the other monosulfides are sparingly soluble but hydrolyzed on warming (except MgS that is completely hydrolyzed). The monoselenides are isomorphous to the sulfides. The monotellurides CaTe, SrTe, BaTe adopt the rock salt stmcture, while BeTe has the zinc blende and MgTe the wurtzite structure. Alkaline earth polysulfides may be prepared by boiling a solution or suspension of the metal hydroxide with sulfur, e.g.,... 

Titanium monosulfide, TiS, assumes two forms, both of which are of the NiAs type. In 384, the packing of sulfur is of the ABAC type, with alternate layers of metal sites being fully occupied but the intermediate sites half filled. A series of intermediate phases Ti2+xS4 (0.2 < x < 1) also occurs. The trisulfide TiS3 is best represented as TiS (S2) . The trichalcogenides of Group IVA elements are typified... 

Another way to describe this non-cyclic phosphino methanide derivatives consists of theuse of monodentate complexes with themono-oxide [203] or monosulfide [204] dppm giving the methanide or methanediide derivatives (14) after addition of the appropriate amounts of [Au(acac)PPh3[. A mixed-valence Au(I)-Au(III) can be isolated by coordination of the fragment AuPPh3 to the free sulfur atom in the mono-oxide starting material [204]. 

Synonym(s) Hydrosulfuric acid stink damp sulfur hydride sulfurated hydrogen dihydrogen monosulfide dihydrogen sulfide sewer gas HSDB 1998... 

Synonym(s) Initiating explosive lead styphnate lead trinitroresorcinate styphnate of lead Sulfuric acid lead(2+) salt lead (II) sulfate Lead monosulfide lead(2+) sulfide Lead (II) sulfide plumbous sulfide natural galena Lead tetraethide TEL tetraethyllead tetraethylplumbane... 

Mixtures of potassium nitrate with antimony trisulfide [1], barium sulfide, calcium sulfide, germanium monosulfide or titanium disulfide all explode on heating [2]. The mixture with arsenic disulfide is detonable, and addition of sulfur gives a pyrotechnic composition [2], Mixtures with molybdenum disulfide are also detonable [3], Interaction with sulfides in molten mixtures is violent [4],... 

Two other compounds containing carbon and sulfur should be mentioned. The first of these is carbon monosulfide, CS. This compound has been reported to be produced by the reaction of CS2 with ozone. The second compound is COS or, more correctly, OCS (m.p. -138.2 °C and b.p. -50.2 °C). It is prepared by the reaction... 

Plant. Major plant metabolites are ethylene thiourea, thiram monosulfide, ethylene thiram disulfide, and sulfur (Hartley and Kidd, 1987). 

Decomposes in acids releasing carbon disulfide. In oxygenated waters, mancozeb degraded to ethylene thiuram monosulfide, ethylene diisocyanate, ethylene thiourea, ethylenediamine, and sulfur (Worthing and fiance, 1991). 

CASRN 12427-38-2 molecular formula C4ff6MnN2S4 FW 265.31 Chemical/Physical. When soil containing maneb was subjected to a stream of moist air, carbon disulfide was formed. Carbon disulfide was also formed when maneb was suspended in a O.IM phosphate buffer at pff 7.0 and air was drawn through the system. The rate of carbon disulfide was higher at neutral and acidic solutions but lower under alkaline conditions. When the air was replaced by nitrogen, no carbon disulfide was evolved. Decomposition products in the reaction vessel identified by TLC were ethylene thiourea, ethylene thiuram monosulfide, elemental sulfur, and trace amounts of ethylenediamine (ffylin, 1973). 

Sulfur occurs in a variety of forms in the mantle, the major sulfur phase is monosulfide solid solution between Fe, Ni, and Cu. Recent ion microprobe measurements on sulfide inclusions from megacrysts and pyroxenite xenohths from alkali basalts and kimberlites and in diamonds gave 5 " S-values from — 11 to - - 14%c (Chaussidon et al. 1987, 1989 Eldridge et al. 1991). Sulfur isotope variations within diamonds exhibit the same characteristics as previously described for carbon i.e., eclogitic diamonds are much more variable than peridotitic diamonds. 

Arsenic trioxide dissolves in concentrated H2SO4 forming arsenyl sulfate, (As02)2S04, a hygroscopic crystalline sohd. Reaction with sulfur trioxide, SO3 at 100°C produces arsenic trisulfate, As2(S04)3. It forms arsenic monosulfide, AS4S4 when heated with sulfur. 

When heated with sulfur at 450 to 500°C, palladium dichloride forms palladium disulfide, PdS2, a grey-black crystalline compound, insoluble in strong acids but soluble in aqua regia, and which converts to monosulfide, PdS, on heating at 600°C. 

Fig. 8. Sulfur-based cure system designs where conventional systems are polysulfidic, EV systems are mono-/disulfidic, and semi-EV systems are clean polysulfidic. A shows pendent sulfide groups terminated by accelerator B, monosulfide cross-links C, disulfide cross-links D, polysulfide cross-links...

---