Aluminium sulfide

Yellowish powder or small crystals

Fixed

2.02 g · cm -3

1100 ° C.

1500 ° C ( sublimed)

Violent reaction with water to release hydrogen sulfide

-724.0 KJ / mol

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Aluminiumsulfide is a chemical compound selected from the group consisting of sulfides having the formula Al2S3.

Representation

Aluminum sulfide can be easily prepared from the elements:

The reaction is extremely exothermic and can reach temperatures in excess of 1100 ° C so that the product is melted. In the choice of the reaction vessel, this is noted. The cooled product is in small crystals and is very hard.

By reaction of aluminum with hydrogen sulfide may be produced.

Properties

Aluminium sulfide is a yellowish crystalline powder that can be colored gray by excess elemental aluminum. It is trimorph, so come in three different crystal structures. These are a structure of alumina - type (space group R3c; lattice parameters a = 6.47, c = 1227 pm ), a hexagonal type (a = 6.423, c = 1783 pm ) and a wurtzite -like type (space group P6/mcm; a = 6.200, c = 582.9 pm ).

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