Silicon disulfide is the inorganic compound with the formula SiS2. Like silicon dioxide, this material is polymeric, but it adopts a 1-dimensional structure quite different from the usual forms of SiO2.

Silicon disulfide
Names
IUPAC name
silicon(IV) sulfide
Other names
silicon disulfide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.935 Edit this at Wikidata
UNII
  • InChI=1S/S2Si/c1-3-2 checkY
    Key: KHDSWONFYIAAPE-UHFFFAOYSA-N checkY
  • InChI=1/S2Si/c1-3-2
    Key: KHDSWONFYIAAPE-UHFFFAOYAO
  • monomer: S=[Si]=S
  • polymer: S=[Si](S0)S[Si]0(S0)S[Si]0(S0)S[Si]0(S0)S[Si]0(S0)S[Si]0(S0)S[Si]0=S
Properties
SiS2
Molar mass 92.218 g/mol
Appearance White (samples are sometimes grey or brown) needles.
Rotten egg smell in moist air.
Density 1.853 g/cm3
Melting point 1,090 °C (1,990 °F; 1,360 K) sublimes
Decomposes
Structure
Orthorhombic, oI12
Ibam, No.72[1]
Tetrahedral
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no code
2
2
3
Related compounds
Other anions
silicon dioxide
Other cations
carbon disulfide
germanium disulfide
tin(IV) sulfide
lead(IV) sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis, structure, and properties

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The material is formed by heating silicon and sulfur or by the exchange reaction between SiO2 and Al2S3. The material consists of chains of edge-shared tetrahedra, Si(μ-S)2Si(μS)2, etc.[2]

Like other silicon sulfur-compounds (e.g., bis(trimethylsilyl)sulfide) SiS2 hydrolyzes readily to release H2S. In liquid ammonia it is reported to form the imide Si(NH)2 and NH4SH,[3] but a recent report has identified crystalline (NH4)2[SiS3(NH3)]·2NH3 as a product which contains the tetrahedral thiosilicate anion, SiS3(NH3)2-.[4]

Reaction with ethanol gives the alkoxide tetraethyl orthosilicate and H2S.[3] With bulky tert-butanol, alcoholysis gives tris(tert-butoxy)silanethiol:[5]

3 (CH3)3COH + SiS2 → [(CH3)3CO]3SiSH + H2S

Reaction with sodium sulfide, magnesium sulfide and aluminum sulfide give thiosilicates.[3]

SiS2 is claimed to occur in certain interstellar objects.[6]

References

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  1. ^ Weiss, A.; Weiss, A. (1954). "Über Siliciumchalkogenide. VI. Zur Kenntnis der faserigen Siliciumdioxyd-Modifikation". Zeitschrift für Anorganische und Allgemeine Chemie. 276 (1–2): 95–112. doi:10.1002/zaac.19542760110.
  2. ^ Holleman, A. F.; Wiberg, E. (2001). Inorganic Chemistry. San Diego: Academic Press. ISBN 0-12-352651-5. A printing error in this book states that rSiSi is 214 picometers, when in fact that distance describes rSiS.
  3. ^ a b c Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. p. 359. ISBN 978-0-08-022057-4.
  4. ^ Meier, Martin; Korber, Nikolaus (2009). "The first thiosilicate from solution: synthesis and crystal structure of (NH4)2[SiS3(NH3)]·2NH3". Dalton Transactions (9): 1506–1508. doi:10.1039/b818856d. ISSN 1477-9226. PMID 19421590.
  5. ^ R. Piękoś, W. Wojnowski (1962). "Untersuchungen über die Alkoholyse des SiS2. II. Darstellung von Trialkoxysilanthiolen und Tetraalkoxycyclodisilthianen aus den tertiären Alkoholen". Z. Anorg. Allg. Chem. 318 (3–4): 212–216. doi:10.1002/zaac.19623180310.
  6. ^ Goebel, J. H. (1993). "SiS2 in Circumstellar Shells" (PDF). Astronomy and Astrophysics. 278 (1): 226–230. Bibcode:1993A&A...278..226G.