Thorium disilicide

Thorium disilicide

Names
Other names Thorium(IV) silicide
Identifiers
CAS Number	12067-54-8
3D model (JSmol)	Interactive image
ChemSpider	4891947
ECHA InfoCard	100.031.878
EC Number	235-079-2
PubChem CID	6336980
CompTox Dashboard (EPA)	DTXSID201312971
InChI InChI=1S/2Si.Th Key: SMTSTMIEGMUHOG-UHFFFAOYSA-N
SMILES [Si]=[Th]=[Si]
Properties
Chemical formula	Si2Th
Molar mass	288.208 g·mol−1
Appearance	black solid
Density	7.78 g/cm³
Melting point	1,700 °C (3,090 °F; 1,970 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Thorium disilicide is a binary inorganic chemical compound of thorium and silicon. The compound was first described in detail in 1942 by Georg Brauer and A. Mitius. ^[1] In addition to this compound, other thorium silicides are known: trithorium disilicide, thorium monosilicide, trithorium pentasilicide, and Th₆Si₁₁. ^[2]

Synthesis

Thorium disilicide was obtained in 1905 by reacting thorium dioxide with silicon in an electric arc and in 1907 by Otto Hönigschmid from the elements at 1000 °C in the presence of aluminum as a solvent. ^[3]

Physical properties

Thorium disilicide is a black solid. ^[4] It has a hexagonal crystal structure with the space group P6/mmm (space group no. 191) of the aluminium diboride type. There is also a high-temperature form that forms from the low-temperature form above 1300 °C. This has a tetragonal crystal structure with the space group I4₁/amd (space group no. 141). ^[5]

References

1. Brown, A.; Norreys, J. J. (March 1959). "Beta-Polymorphs of Uranium and Thorium Disilicides". Nature . 183 (4662): 673. Bibcode:1959Natur.183..673B. doi:10.1038/183673a0. ISSN   1476-4687 . Retrieved 18 June 2025.
2. Bickel, Michael; Wedemeyer, Horst (17 April 2013). Th Thorium Supplement Volume C 8: Compounds with Si, P, As, Sb, Bi, and Ge. Springer Science & Business Media. p. 21. ISBN   978-3-662-06348-4 . Retrieved 18 June 2025.
3. Brauer, G.; Mittius, A. (1942). "Die Kristallstruktur des Thoriumsilicids ThSi2" . Zeitschrift für anorganische und allgemeine Chemie (in German). 249 (4): 325–339. doi:10.1002/zaac.19422490401. ISSN   1521-3749 . Retrieved 18 June 2025.
4. Perry, Dale L. (19 April 2016). Handbook of Inorganic Compounds. CRC Press. p. 427. ISBN   978-1-4398-1462-8 . Retrieved 18 June 2025.
5. Yagoubi, S.; Heathman, S.; Svane, A.; Vaitheeswaran, G.; Heines, P.; Griveau, J. -C.; Le Bihan, T.; Idiri, M.; Wastin, F.; Caciuffo, R. (5 January 2013). "High pressure studies on uranium and thorium silicide compounds: Experiment and theory" . Journal of Alloys and Compounds . 546: 63–71. doi:10.1016/j.jallcom.2012.07.094. ISSN   0925-8388 . Retrieved 18 June 2025.