Silicon disulfide

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
CAS Number	13759-10-9 Y
3D model (JSmol)	monomer: Interactive image polymer: Interactive image
ChemSpider	75527 Y
ECHA InfoCard	100.033.935
PubChem CID	83705
UNII	35Y5PHW16K Y
CompTox Dashboard (EPA)	DTXSID4065606
InChI InChI=1S/S2Si/c1-3-2 Y Key: KHDSWONFYIAAPE-UHFFFAOYSA-N Y InChI=1/S2Si/c1-3-2 Key: KHDSWONFYIAAPE-UHFFFAOYAO
SMILES 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
Chemical formula	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
Solubility in water	Decomposes
Structure
Crystal structure	Orthorhombic, oI12
Space group	Ibam, No.72[1]
Coordination geometry	Tetrahedral
Hazards
NFPA 704 (fire diamond)	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). N verify (what is YN ?) Infobox references

Synthesis, structure, and properties

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

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 r_SiSi is 214 picometers, when in fact that distance describes r_SiS.
3. 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.