Арсенид сурьмы: свойства, применение и опасность

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| verifiedrevid = 441606058
| ImageFile = Orpiment mineral. jpg
| ImageSize = 244
| ImageName = Sample of arsenic trisulfide as orpiment mineral
| ImageFile1 = Orpiment unit cell 3D. png
| ImageSize1 = 244
| ImageName1 = Ball and stick unit cell model of polymeric arsenic trisulfide
| ImageFile2 = Arsenic trisulfide horiz. png
| ImageName2 = Arsenic trisulfide
| PIN = Arsenic trisulfide
| OtherNames = Arsenic(III) sulfide, Orpiment, Sulphuret of arsenic
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|Section7=Chembox Hazards
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| NFPA H = 3
| NFPA F = 0
| NFPA R = 0
| IDLH = Ca [5 mg/m3 (as As)]
| REL = Ca C 0.002 mg/m3 [15 minute] The bonding between the sheets consists of van der Waals forces. The crystalline form is usually found in geological samples. Amorphous |As2S3 does not possess a layered structure but is more highly cross linked. Like other glasses, there is no medium or long range order, but the first co ordination sphere is well defined. |As2S3 is a good glass former and exhibits a wide glass forming region in its phase diagram.

It is a semiconductor, with a direct band gap of 2.7 eV. The wide band gap makes it transparent to infrared light between 620 nm and 11 μm.

|As2S3 forms when aqueous solutions containing As(III) are treated with |H2S. Arsenic was in the past analyzed and assayed by this reaction, which results in the precipitation of |As2S3, which is then weighed. |As2S3 can even be precipitated in 6 M HCl. |As2S3 is so insoluble that it is not toxic.

Due to its high refractive index of 2.45 and its large Knoop hardness compared to organic photoresists, |As2S3 has been investigated for the fabrication of photonic crystals with a full photonic band gap. Advances in laser patterning techniques such as three dimensional direct laser writing (3 D DLW) and chemical wet etching chemistry, has allowed this material to be used as a photoresist to fabricate 3 D nanostructures. |As2S3 has been investigated for use as a high resolution photoresist material since the early 1970s, using aqueous etchants. Although these aqueous etchants allowed for low aspect ratio 2 D structures to be fabricated, they do not allow for the etching of high aspect ratio structures with 3 D periodicity. Certain organic reagents, used in organic solvents, permit the high etch selectivity required to produce high aspect ratio structures with 3 D periodicity.

|As2S3 and |As4S4 have been investigated as treatments for acute promyelocytic leukemia (APL).

Arsenic trisulfide manufactured into amorphous form is used as a chalcogenide glass for infrared optics. It is transparent for light between wavelengths of 620 nm and 11 μm. The arsenic trisulfide glass is more resistant to oxidation than crystalline arsenic trisulfide, which minimizes toxicity concerns. It can be also used as an acousto optic material. Arsenic trisulfide was used for the distinctive eight sided conical nose over the infra red seeker of the de Havilland Firestreak missile.

The ancient Egyptians reportedly used orpiment, natural or synthetic, as a pigment in artistry and cosmetics.

Arsenic trisulfide is also used as a tanning agent. It was formerly used with indigo dye for the production of pencil blue, which allowed dark blue hues to be added to fabric via pencil or brush. Precipitation of arsenic trisulfide is used as an analytical test for presence of dissimilatory arsenic reducing bacteria (DARB).

|As2S3 is so insoluble that its toxicity is low. Aged samples can contain substantial amounts of arsenic oxides, which are soluble and therefore highly toxic.

Orpiment is found in volcanic environments, often together with other arsenic sulfides, mainly realgar. It is sometimes found in low temperature hydrothermal veins, together with some other sulfide and sulfosalt minerals.