Tantalum (IV) sulfide

Crystal structure
General
Surname	Tantalum (IV) sulfide
other names	Tantalum disulfide
Ratio formula	TaS 2
Brief description	gray solid or black powder
External identifiers / databases
CAS number 12143-72-5 EC number 235-265-3 ECHA InfoCard 100.032.047 PubChem 82945 Wikidata Q4119775
properties
Molar mass	245.08 g mol −1
Physical state	firmly
density	6.86 g cm −3
Melting point	> 1300 ° C
solubility	almost insoluble in water
safety instructions
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Tantalum (IV) sulfide is an inorganic chemical compound of tantalum from the group of sulfides , i.e. the transition metal dichalcogenides. In addition to this, at least four other tantalum sulfides (Ta ₆ S, Ta ₂ S, Ta _{1 + x} S ₂ and TaS ₃ ) are known. Many of them have areas of homogeneity or differ from one another as stacking variants of a basic grid type.

Extraction and presentation

Tantalum (IV) sulfide can be obtained by reacting tantalum with sulfur at 900 ° C.

${\displaystyle \mathrm {Ta+2\ S\longrightarrow TaS_{2}} }$

It can also be obtained by reacting tantalum (V) oxide with hydrogen sulfide or carbon disulfide .

properties

Tantalum (IV) sulfide is a solid that is present at room temperature as a gray metallic or black powder that occurs in several modifications. The form stable at room temperature is referred to as 2H-TaS ₂ . It has metallic properties (specific resistance 120 µΩ cm), has a layer structure and is superconducting at 0.75 K. It has a trigonal crystal structure with the space group P 6 ₃ / mmc (No. 194) isotype to that of niobium (IV ) sulfide . The yellow-looking high-temperature modification 1T-TaS ₂ is available from temperatures of 780 ° C. This modification is a semiconductor and can be obtained metastable even at room temperature by quenching. It has an octahedral crystal structure with the space group P 3 m 1 (No. 164) . There is also at least one 3R-TaS ₂ , 4H-TaS ₂ and one 6R-TaS ₂ form.

use

Tantalum (IV) sulfide is used as a lubricant.

Individual evidence

1. ↑ ^{a b c d} Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . CRC Press, 2011, ISBN 978-1-4398-1462-8 , pp. 410 ( limited preview in Google Book search).
2. ^ ^{A b} Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer-Verlag, 1998, ISBN 978-3-642-58842-6 , p. 754 ( limited preview in Google Book search).
3. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
4. ↑ Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1470.
5. ↑ ^{a b} R.MA Lieth: Preparation and Crystal Growth of Materials with Layered Structures . Springer Science & Business Media, 1977, ISBN 978-90-277-0638-6 , pp. 188 ( limited preview in Google Book search).
6. ↑ NPCs Board of Consultants & Engineers: Handbook on Rare Earth Metals and Alloys (Properties, Extraction, Preparation and Applications) . ASIA PACIFIC BUSINESS PRESS Inc., 2009, ISBN 81-7833-120-9 , pp. 416 ( limited preview in Google Book search).
7. ↑ Anja Schlicht: Normally conducting and superconducting properties of dye intercalation compounds of the host lattice 2H-TaS2 . Herbert Utz Verlag, 1999, ISBN 978-3-89675-473-8 , p. 11 ( limited preview in Google Book search).
8. ↑ Erwin Riedel: Modern inorganic chemistry . Walter de Gruyter, 2003, ISBN 978-3-11-017838-8 , pp. 498 ( limited preview in Google Book search).