Antimony trisulfide
| Names | |
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IUPAC name
diantimony trisulfide, antimony(III) sulfide
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| Other names
antimony sulfide, antimonous sufide, antimony sesquisulfide, antimony vermilion, black antimony, sulphuret of antimony
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| Identifiers | |
| 1345-04-6 | |
| ECHA InfoCard | 100.014.285 |
| Properties | |
| Sb2S3 | |
| Molar mass | 339.715 |
| Appearance | grey / black orthorhombic crystal (stibnite) |
| Density | 6.5g cm−3 (stibnite) |
| Melting point | 620 °C (1,148 °F; 893 K) (stibnite) |
| -86.0·10−6 cm3/mol | |
| Hazards | |
| US health exposure limits (NIOSH): | |
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PEL (Permissible)
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TWA 0.5 mg/m3 (as Sb) |
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REL (Recommended)
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TWA 0.5 mg/m3 (as Sb) |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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| Infobox references | |
Antimony trisulfide Sb2S3 is found in nature as the crystalline mineral stibnite and the amorphous red mineral metastibnite. It is manufactured for use in safety matches, military ammunition, explosives and fireworks. It also is used in the production of ruby-colored glass and in plastics as a flame retardant. Historically the stibnite form was used as a grey pigment in paintings produced in the 16th century. It is a semiconductor with a direct band gap of 1.8-2.5 eV. With suitable doping, p and n type materials can be produced.
Sb2S3 can be prepared from the elements at temperature 500-900 °C:
Sb2S3 is precipitated when H2S is passed through an acidified solution of Sb(III). This reaction has been used as a gravimetric method for determining antimony, bubbling H2S through a solution of Sb(III) compound in hot HCl deposits an orange form of Sb2S3 which turns black under the reaction conditions.
Sb2S3 is readily oxidised, reacting vigorously with oxidising agents. It burns in air with a blue flame. It reacts with incandescence with cadmium, magnesium and zinc chlorates. Mixtures of Sb2S3 and chlorates may explode.
In the extraction of antimony from antimony ores the alkaline sulfide process is employed where Sb2S3 reacts to form thioantimonate(III) salts (also called thioantimonite):
A number of salts containing different thioantimonate(III) ions can be prepared from Sb2S3 these include:
"Schlippe's salt", Na3SbS4·9H2O, a thioantimonate(V) salt is formed when Sb2S3 is boiled with sulfur and sodium hydroxide. The reaction can be represented as:
The structure of the black needle like form of Sb2S3, stibnite, consists of linked ribbons in which antimony atoms are in two different coordination environments, trigonal pyramidal and square pyramidal. Similar ribbons occur in Bi2S3 and Sb2Se3. The red form, metastibnite, is amorphous. Recent work suggests that there are a number of closely related temperature dependant structures of stibnite which have been termed stibnite(I) the high temperature form, identified previously, stibnite (II) and stibnite(III). Other paper shows that the actual coordination polyhedra of antimony are in fact SbS7, with (3+4) coordination at the M1 site and (5+2) at the M2 site. These coordinations consider the presence of secondary bonds. Some of the secondary bonds impart cohesion and are connected with packing.
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