Aluminum sulfide

Crystal structure
__ Al 3+      __ S 2−
General
Surname	Aluminum sulfide
Ratio formula	Al 2 S 3
Brief description	Yellowish powder or small crystals
External identifiers / databases
CAS number 1302-81-4 EC number 215-109-0 ECHA InfoCard 100.013.736 PubChem 16684788 Wikidata Q412874
properties
Molar mass	150.158 g mol −1
Physical state	firmly
density	2.02 g cm −3
Melting point	1100 ° C
boiling point	1500 ° C (sublimed)
solubility	violent reaction with water liberating hydrogen sulphide
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 260-315-319-335 EUH: 031 P: 261-305 + 351 + 338
Thermodynamic properties
ΔH f 0	−724.0 kJ / mol
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Aluminum sulfide

Aluminum sulfide is a chemical compound from the group of sulfides with the formula Al ₂ S ₃ .

Manufacturing

Aluminum sulfide can be easily made from the elements :

${\displaystyle \mathrm {2\ Al+3\ S\longrightarrow Al_{2}S_{3}} }$

The reaction is extremely exothermic and can reach temperatures over 1100 ° C, so that the product is molten. This must be taken into account when choosing the reaction vessel. The cooled product is in the form of small crystals and is very hard.

It can also be produced by reacting aluminum with hydrogen sulfide .

${\displaystyle \mathrm {2\ Al+3\ H_{2}S\longrightarrow Al_{2}S_{3}+3\ H_{2}} }$

properties

Aluminum sulphide is a yellowish crystalline powder that can be colored gray by excess elemental aluminum. It is trimorphic, so it occurs in three different crystal structures . These are a structure of the aluminum oxide type ( space group R 3 c (space group no.161) ; lattice parameters a = 647, c = 1227 pm), a hexagonal type (space group P 6 ₁ (no.169) , a = 642, 3, c = 1783 pm) and a wurtzite- like type (space group P 6 ₃ / mcm (No. 193) ; a = 620.0, c = 582.9 pm).

The compound is sensitive to moisture, contact with water leads to hydrolysis and the formation of hydrogen sulfide and aluminum hydroxide . This reaction can already be triggered by the humidity in the air. Under oxidizing conditions, the substance can also decompose with the release of sulfur dioxide gas.

Individual evidence

1. ↑ ^{a b c d e} Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 833.
2. ↑ Data sheet Aluminum sulfide from Sigma-Aldrich , accessed on March 30, 2011 ( PDF ).
3. ↑ ^{a b} Brockhaus ABC Chemie, FA Brockhausverlag Leipzig 1971, p. 59.
4. ↑ Safety data sheet at ESPI Metals , accessed on January 5, 2012.
5. ↑ There is not yet a harmonized classification for this substance . A labeling of Dialuminium trisulphide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), which was accessed on January 17, 2020, is reproduced from a self-classification by the distributor .
6. ↑ Data sheet aluminum sulfide from Sigma-Aldrich , accessed on February 16, 2020 ( PDF ).
7. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-5.
8. ^ AF Holleman, E. Wiberg: Inorganic Chemistry. Academic Press, San Diego 2001, ISBN 0-12-352651-5 .