Sulfur d'alumini

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Sulfur d'alumini

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General

Altres noms

FÃ³rmula molecular

Al₂S₃

Massa molar

150.158076 g/mol g/mol

Aspecte

Incolor

NÃºmero CAS

[1302-81-4]

Propietats

2.0 g/cm³, sÃ²lid

soluble

1100Â°C

1500Â°C (sublima)

Estructura

Geometria
de coordinaciÃ³

Estructura cristalÂ·lina

Perills

MSDS

MSDS externa

Perills

Punt d'inflamabilitat

No inflamable

Si no s'indica el contrari, les dades sÃ³n pels materials
en condicions estÃ ndard (25 Â°C, 100 kPa)
AvÃs d'exempciÃ³ de responsabilitat

Aluminium sulfide is the name for the chemical compound with the formula Al₂S₃. This colorless species has an interesting structural chemistry, existing in three different forms. The material is sensitive to moisture, hydrolyzing readily to hydrated aluminium oxides/hydroxides.^[1] The hydrolysis reaction also generates the odoriferous and toxic gas hydrogen sulfide (H₂S).

Unlike Al₂O₃, in which the Al(III) centers occupy octahedral holes, the more expanded framework of Al₂S₃ stabilizes the Al(III) centers into one third of the tetrahedral holes of a hexagonally close-packed arrangement of the sulfide anions. At higher temperature, the Al(III) centers become randomized to give a "defect wurtzite" structure. And at still higher temperatures stabilize the Î³-Al₂S₃ forms, with a structure akin to Î³-Al₂O₃.

Molecular derivatives of Al₂S₃ are not known. Mixed Al-S-Cl compounds are however known. Also Al₂Se₃ and Al₂Te₃ are also known.

[edita] PreparaciÃ³

Aluminium sulfide is readily prepared by ignition of the elements:

2Al + 3S â†’ Al₂S₃

This reaction is extremely exothermic and it is not necessary or desirable to heat the whole mass of the sulfur-aluminium mixture; (except possibly for very small preps). The product will be created in a fused form; that is at greater than 1100Â°C and may melt its way through steel. The cooled product is very hard.