Scandium(III) sulfide

Scandium(III) sulfide
Names
	Other names scandium sesquisulfide
Identifiers
CAS Number	12166-29-9 ;
3D model (JSmol)	Interactive image;
ChemSpider	145824;
ECHA InfoCard	100.032.097
EC Number	235-320-1;
PubChem CID	166646;
CompTox Dashboard (EPA)	DTXSID10923918 ;
	InChI InChI=1S/3S.2Sc/q3-2;2+3 Key: KAYAWNAUDDJSHN-UHFFFAOYSA-N;
	SMILES [S-2].[S-2].[S-2].[Sc+3].[Sc+3];
Properties
Chemical formula	Sc2S3
Molar mass	186.11 g/mol
Appearance	yellow crystals
Density	2.91 g/cm3, solid
Melting point	1,775 °C (3,227 °F; 2,048 K)
Structure
Crystal structure	orthorhombic
Related compounds
Other anions	Scandium oxide
Other cations	Yttrium(III) sulfide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Scandium(III) sulfide is a chemical compound of scandium and sulfur with the chemical formula Sc₂S₃. It is a yellow solid.

Structure

The crystal structure of Sc₂S₃ is closely related to that of sodium chloride, in that it is based on a cubic close packed array of anions. Whereas NaCl has all the octahedral interstices in the anion lattice occupied by cations, Sc₂S₃ has one third of them vacant. The vacancies are ordered, but in a very complicated pattern, leading to a large, orthorhombic unit cell belonging to the space group Fddd.^[1]

Synthesis

Metal sulfides are usually prepared by heating mixtures of the two elements, but in the case of scandium, this method yields scandium monosulfide, ScS. Sc₂S₃ can be prepared by heating scandium(III) oxide under flowing hydrogen sulfide in a graphite crucible to 1550 °C or above for 2–3 hours. The crude product is then purified by chemical vapor transport at 950 °C using iodine as the transport agent.^[1]

Sc₂O₃ + 3H₂S → Sc₂S₃ + 3H₂O

Scandium(III) sulfide can be prepared by reacting scandium(III) chloride with dry hydrogen sulfide at elevated temperature:^[2]

2 ScCl₃ + 3 H₂S → Sc₂S₃ + 6 HCl

Reactivity

Above 1100 °C, Sc₂S₃ loses sulfur, forming nonstoichiometric compounds such as Sc_1.37S₂.^[1]

References

^ ^a ^b ^c Dismukes, J. P.; White, J. G. (1964). "The Preparation, Properties, and Crystal Structures of Some Scandium Sulfides in the Range Sc₂S₃-ScS". Inorg. Chem. 3 (9): 1220–1228. doi:10.1021/ic50019a004.
^ Klemm, W.; Meisel, K.; v. Vogel, H. U. (1930). "Über die Sulfide der seltenen Erden (Sulfides of the rare earths)". Zeitschrift für Anorganische und Allgemeine Chemie. 190: 123–144. doi:10.1002/zaac.19301900113.

[Dismukes&White-1] Dismukes, J. P.; White, J. G. (1964). "The Preparation, Properties, and Crystal Structures of Some Scandium Sulfides in the Range Sc₂S₃-ScS". Inorg. Chem. 3 (9): 1220–1228. doi:10.1021/ic50019a004.

[2] Klemm, W.; Meisel, K.; v. Vogel, H. U. (1930). "Über die Sulfide der seltenen Erden (Sulfides of the rare earths)". Zeitschrift für Anorganische und Allgemeine Chemie. 190: 123–144. doi:10.1002/zaac.19301900113.

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