sulfide

(noun)

Any compound of sulfur and a metal or other electropositive element or group.

Related Terms

Examples of sulfide in the following topics:

  • Nucleophilicity of Sulfur Compounds

    • Sulfur analogs of alcohols are called thiols or mercaptans, and ether analogs are called sulfides.
    • The chemical behavior of thiols and sulfides contrasts with that of alcohols and ethers in some important ways.
    • Since hydrogen sulfide (H2S) is a much stronger acid than water (by more than ten million fold), we expect, and find, thiols to be stronger acids than equivalent alcohols and phenols.
    • Although the basicity of ethers is roughly a hundred times greater than that of equivalent sulfides, the nucleophilicity of sulfur is much greater than that of oxygen, leading to a number of interesting and useful electrophilic substitutions of sulfur that are not normally observed for oxygen.
    • Sulfides, for example, react with alkyl halides to give ternary sulfonium salts (equation # 1) in the same manner that 3º-amines are alkylated to quaternary ammonium salts.

  • Sulfate and Sulfur Reduction

    • Sulfite is then further reduced to sulfide, while AMP is turned into ADP using another molecule of ATP.
    • By contrast, sulfate-reducing bacteria reduce sulfate in large amounts to obtain energy and expel the resulting sulfide as waste; this is known as "dissimilatory sulfate reduction. " Most sulfate-reducing bacteria can also reduce other oxidized inorganic sulfur compounds, such as sulfite, thiosulfate, or elemental sulfur (which is reduced to sulfide as hydrogen sulfide).
    • Much of the hydrogen sulfide will react with metal ions in the water to produce metal sulfides.
    • These metal sulfides, such as ferrous sulfide (FeS), are insoluble and often black or brown, leading to the dark color of sludge.
    • Hydrogen sulfide from sulfate-reducing bacteria also plays a role in the biogenic sulfide corrosion of concrete, and sours crude oil.

  • Oxidation of Reduced Sulfur Compounds

    • Some species may oxidize hydrogen sulfide to elemental sulfur as a supplemental source of energy (facultatively litho-heterotroph).
    • They can usually be found in habitats that have high levels of hydrogen sulfide.
    • Some species may oxidize hydrogen sulfide to elemental sulfur as a supplemental source of energy (facultatively litho-heterotroph).
    • Sulfur is reduced to sulfide at the cost of stored carbon or by added hydrogen gas.
    • Beggiatoa are able to detoxify hydrogen sulfide in soil.

  • Nomenclature

    • Sulfur analogs of ethers (R–S–R') are called sulfides.
    • For example, (CH3)3C–S–CH3 is tert-butyl methyl sulfide.
    • Sulfides are chemically more reactive than ethers, reflecting the greater nucleophilicity of sulfur relative to oxygen.

  • Copper

    • Hydrogen sulfides and sulfides react with copper to form various copper sulfides on the surface.
    • The principal compounds are the oxides, sulfides, and halides.
    • Hydrogen sulfides and sulfides react with copper to form various copper sulfides on the surface.
    • The principal compounds are the oxides, sulfides, and halides.
    • Among the numerous copper sulfides, important examples include copper(I) sulfide and copper(II) sulfide.

  • Cold-Seep Ecosystems

    • A cold seep is an area of the ocean floor where hydrogen sulfide, methane, and other hydrocarbon-rich fluid seepage occurs.
    • Like the mussels, tubeworms rely on chemosynthetic bacteria (in this case, a type that needs hydrogen sulfide instead of methane) for survival.
    • True to any symbiotic relationship, a tubeworm also provides for their bacteria by appropriating hydrogen sulfide from the environment.
    • As long as there is some sulfide in the sediment, the sulfide-mining tubeworms can persist.
    • Beggiatoa are able to detoxify hydrogen sulfide in soil.

  • Sulfur Compounds

    • Treatment of sulfur with hydrogen produces hydrogen sulfide.
    • When dissolved in water, hydrogen sulfide is mildly acidic:
    • Phosphorus sulfides are numerous.
    • The principal ores of copper, zinc, nickel, cobalt, molybdenum, and other metals are sulfides.
    • They are formed by the reaction of hydrogen sulfide with metal salts.

  • Magnetosomes

    • Magnetotactic bacteria usually mineralize either iron oxide magnetosomes , which contain crystals of magnetite (Fe3O4), or iron sulfide magnetosomes, which contain crystals of greigite (Fe3S4).
    • Several other iron sulfide minerals have also been identified in iron sulfide magnetosomes — including mackinawite (tetragonal FeS) and a cubic FeS — which are thought to be precursors of Fe3S4.
    • One type of magnetotactic bacterium present at the oxic-anoxic transition zone (OATZ) of the southern basin of the Pettaquamscutt River Estuary, Narragansett, Rhode Island is known to produce both iron oxide and iron sulfide magnetosomes.

  • Electron Donors and Acceptors in Anaerobic Respiration

    • Sulfate reduction uses sulfate (SO2−4) as the electron acceptor, producing hydrogen sulfide (H2S) as a metabolic end product.
    • Others, such as certain Desulfovibrio species, are capable of sulfur disproportionation (splitting one compound into an electron donor and an electron acceptor) using elemental sulfur (S0), sulfite (SO3−2), and thiosulfate (S2O32-) to produce both hydrogen sulfide (H2S) and sulfate (SO2−).
    • These include the reduction of fumarate to succinate, Trimethylamine N-oxide (TMAO) to trimethylamine (TMA), and Dimethyl sulfoxide (DMSO) to Dimethyl sulfide (DMS).

  • Microbial Ore Leaching

    • The ferric iron produced in reaction (2) oxidized more sulfide as in reaction (1), closing the cycle and given the net reaction:
    • The critical reaction is the oxidation of sulfide by ferric iron.