Arsenic trichloride

Last updated
Arsenic trichloride
Arsenic-trichloride-3D-balls.png
Names
Other names
Arsenic(III) chloride, Arsenous trichloride, Arsine trichloride, Butter of arsenic, de Valagin's solution, Trichloroarsine
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.144 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 232-059-5
PubChem CID
RTECS number
  • CG1750000
UNII
UN number 1560
  • InChI=1S/AsCl3/c2-1(3)4 Yes check.svgY
    Key: OEYOHULQRFXULB-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/AsCl3/c2-1(3)4
    Key: OEYOHULQRFXULB-UHFFFAOYAG
  • Cl[As](Cl)Cl
Properties
AsCl3
Molar mass 181.28 g/mol
Appearancecolourless oily liquid
Density 2.163 g/cm3, liquid
Melting point −16.2 °C (2.8 °F; 256.9 K)
Boiling point 130.2 °C (266.4 °F; 403.3 K)
Hydrolyzes
Solubility soluble in alcohol, ether, HCl, HBr, chloroform, CCl4 [1]
-79.9·10−6 cm3/mol
1.6006
Viscosity 9.77 x 10−6 Pa s
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Very toxic, carcinogen, corrosive, decomposes on contact with water releasing HCl
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-skull.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
H301, H310, H314, H331, H350, H410
P201, P202, P260, P261, P262, P264, P270, P271, P273, P280, P281, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P308+P313, P310, P311, P321, P322, P330, P361, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
4
0
1
Lethal dose or concentration (LD, LC):
48 mg/kg
100 mg/m3 (cat, 1 hr)
200 mg/m3 (cat, 20 min)
338 ppm (rat, 10 min) [2]
NIOSH (US health exposure limits):
PEL (Permissible)
[1910.1018] TWA 0.010 mg/m3 [3]
REL (Recommended)
Ca C 0.002 mg/m3 [15-minute] [3]
IDLH (Immediate danger)
Ca [5 mg/m3 (as As)] [3]
Related compounds
Other anions
Arsenic trioxide, Arsenic trifluoride
Other cations
Antimony trichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Arsenic trichloride is an inorganic compound with the formula AsCl3, also known as arsenous chloride or butter of arsenic. This poisonous oil is colourless, although impure samples may appear yellow. It is an intermediate in the manufacture of organoarsenic compounds. [4]

Contents

Structure

AsCl3 is a pyramidal molecule with C3v symmetry. The As-Cl bond is 2.161 Å and the angle Cl-As-Cl is 98° 25'±30. [5] [6] AsCl3 has four normal modes of vibration: ν1(A1) 416, ν2(A1) 192, ν3 393, and ν4(E) 152 cm−1. [7]

Synthesis

This colourless liquid is prepared by treatment of arsenic(III) oxide with hydrogen chloride followed by distillation:

As2O3 + 6 HCl → 2 AsCl3 + 3 H2O

It can also be prepared by chlorination of arsenic at 80–85 °C, but this method requires elemental arsenic. [4]

2 As + 3 Cl2 → 2 AsCl3

Arsenic trichloride can be prepared by the reaction of arsenic oxide and sulfur monochloride. This method requires simple apparatus and proceeds efficiently: [8]

2 As2O3 + 6 S2Cl2 → 4 AsCl3 + 3 SO2 + 9 S

A convenient laboratory method is refluxing arsenic(III) oxide with thionyl chloride: [9]

2 As2O3 + 3 SOCl2 → 2 AsCl3 + 3 SO2

Arsenic trichloride can also be prepared by the reaction of hydrochloric acid and arsenic(III) sulfide.

As2S3 + 6 HCl → 2 AsCl3 + 3 H2S

Reactions

Hydrolysis gives arsenous acid and hydrochloric acid:

AsCl3 + 3 H2O → As(OH)3 + 3 HCl

Although AsCl3 is less moisture sensitive than PCl3, it still fumes in moist air. [10]

AsCl3 undergoes redistribution upon treatment with As2O3 to give the inorganic polymer AsOCl. With chloride sources, AsCl3 also forms salts containing the anion [AsCl4]. Reaction with potassium bromide and potassium iodide give arsenic tribromide and arsenic triiodide, respectively.

AsCl3 is useful in organoarsenic chemistry, for example triphenylarsine is derived from AsCl3: [11]

AsCl3 + 6 Na + C6H5Cl → As(C6H5)3 + 6 NaCl

The chemical weapons called Lewisites are prepared by the addition of arsenic trichloride to acetylene:

AsCl3 + C2H2 → ClCH=CHAsCl2

Safety

Inorganic arsenic compounds are highly toxic, [4] and AsCl3 especially so because of its volatility and solubility (in water).

It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities. [12]

Related Research Articles

<span class="mw-page-title-main">Samarium(III) chloride</span> Chemical compound

Samarium(III) chloride, also known as samarium trichloride, is an inorganic compound of samarium and chloride. It is a pale yellow salt that rapidly absorbs water to form a hexahydrate, SmCl3.6H2O. The compound has few practical applications but is used in laboratories for research on new compounds of samarium.

<span class="mw-page-title-main">Aluminium chloride</span> Chemical compound

Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula AlCl3. It forms a hexahydrate with the formula [Al(H2O)6]Cl3, containing six water molecules of hydration. Both the anhydrous form and the hexahydrate are colourless crystals, but samples are often contaminated with iron(III) chloride, giving them a yellow colour.

<span class="mw-page-title-main">Manganese(II) chloride</span> Chemical compound

Manganese(II) chloride is the dichloride salt of manganese, MnCl2. This inorganic chemical exists in the anhydrous form, as well as the dihydrate (MnCl2·2H2O) and tetrahydrate (MnCl2·4H2O), with the tetrahydrate being the most common form. Like many Mn(II) species, these salts are pink, with the paleness of the color being characteristic of transition metal complexes with high spin d5 configurations.

<span class="mw-page-title-main">Copper(I) chloride</span> Chemical compound

Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride (CuCl2).

<span class="mw-page-title-main">Chromium(III) chloride</span> Chemical compound

Chromium(III) chloride (also called chromic chloride) is an inorganic chemical compound with the chemical formula CrCl3. It forms several hydrates with the formula CrCl3·nH2O, among which are hydrates where n can be 5 (chromium(III) chloride pentahydrate CrCl3·5H2O) or 6 (chromium(III) chloride hexahydrate CrCl3·6H2O). The anhydrous compound with the formula CrCl3 are violet crystals, while the most common form of the chromium(III) chloride are the dark green crystals of hexahydrate, CrCl3·6H2O. Chromium chlorides find use as catalysts and as precursors to dyes for wool.

Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2. It is a paramagnetic solid with a high melting point. The compound is white, but typical samples are often off-white. FeCl2 crystallizes from water as the greenish tetrahydrate, which is the form that is most commonly encountered in commerce and the laboratory. There is also a dihydrate. The compound is highly soluble in water, giving pale green solutions.

<span class="mw-page-title-main">Phosphorus pentachloride</span> Chemical compound

Phosphorus pentachloride is the chemical compound with the formula PCl5. It is one of the most important phosphorus chlorides/oxychlorides, others being PCl3 and POCl3. PCl5 finds use as a chlorinating reagent. It is a colourless, water-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride.

<span class="mw-page-title-main">Phosphorus trichloride</span> Chemical compound

Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic and reacts readily with water to release hydrogen chloride.

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic solids featuring octahedral Rh(III) centres. Depending on the value of n, the material is either a dense brown solid or a soluble reddish salt. The soluble trihydrated (n = 3) salt is widely used to prepare compounds used in homogeneous catalysis, notably for the industrial production of acetic acid and hydroformylation.

<span class="mw-page-title-main">Gold(III) chloride</span> Chemical compound

Gold(III) chloride, traditionally called auric chloride, is an inorganic compound of gold and chlorine with the molecular formula Au2Cl6. The "III" in the name indicates that the gold has an oxidation state of +3, typical for many gold compounds. It has two forms, the monohydrate (AuCl3·H2O) and the anhydrous form, which are both hygroscopic and light-sensitive solids. This compound is a dimer of AuCl3. This compound has a few uses, such as an oxidizing agent and for catalyzing various organic reactions.

<span class="mw-page-title-main">Ruthenium(III) chloride</span> Chemical compound

Ruthenium(III) chloride is the chemical compound with the formula RuCl3. "Ruthenium(III) chloride" more commonly refers to the hydrate RuCl3·xH2O. Both the anhydrous and hydrated species are dark brown or black solids. The hydrate, with a varying proportion of water of crystallization, often approximating to a trihydrate, is a commonly used starting material in ruthenium chemistry.

<span class="mw-page-title-main">Phosphoryl chloride</span> Chemical compound

Phosphoryl chloride is a colourless liquid with the formula POCl3. It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phosphorus trichloride and oxygen or phosphorus pentoxide. It is mainly used to make phosphate esters.

<span class="mw-page-title-main">Vanadium oxytrichloride</span> Chemical compound

Vanadium oxytrichloride is the inorganic compound with the formula VOCl3. This yellow distillable liquid hydrolyzes readily in air. It is an oxidizing agent. It is used as a reagent in organic synthesis. Samples often appear red or orange owing to an impurity of vanadium tetrachloride.

<span class="mw-page-title-main">Antimony trichloride</span> Chemical compound

Antimony trichloride is the chemical compound with the formula SbCl3. It is a soft colorless solid with a pungent odor and was known to alchemists as butter of antimony.

<span class="mw-page-title-main">Gallium(III) chloride</span> Chemical compound

Gallium(III) chloride is an inorganic chemical compound with the formula GaCl3 which forms a monohydrate, GaCl3·H2O. Solid gallium(III) chloride is a deliquescent white solid and exists as a dimer with the formula Ga2Cl6. It is colourless and soluble in virtually all solvents, even alkanes, which is truly unusual for a metal halide. It is the main precursor to most derivatives of gallium and a reagent in organic synthesis.

<span class="mw-page-title-main">Triphenylarsine</span> Chemical compound

Triphenylarsine is the chemical compound with the formula As(C6H5)3. This organoarsenic compound, often abbreviated AsPh3, is a colorless crystalline solid that is used as a ligand and a reagent in coordination chemistry and organic synthesis. The molecule is pyramidal with As-C distances of 1.942–1.956 Å and C-As-C angles of 99.6–100.5°.

<span class="mw-page-title-main">Thiophosphoryl chloride</span> Chemical compound

Thiophosphoryl chloride is an inorganic compound with the chemical formula PSCl3. It is a colorless pungent smelling liquid that fumes in air. It is synthesized from phosphorus chloride and used to thiophosphorylate organic compounds, such as to produce insecticides.

Organoarsenic chemistry is the chemistry of compounds containing a chemical bond between arsenic and carbon. A few organoarsenic compounds, also called "organoarsenicals," are produced industrially with uses as insecticides, herbicides, and fungicides. In general these applications are declining in step with growing concerns about their impact on the environment and human health. The parent compounds are arsane and arsenic acid. Despite their toxicity, organoarsenic biomolecules are well known.

<span class="mw-page-title-main">Methyldichloroarsine</span> Chemical compound

Methyldichloroarsine, sometimes abbreviated "MD" and also known as methyl Dick, is an organoarsenic compound with the formula CH3AsCl2. This colourless volatile liquid is a highly toxic vesicant that has been used in chemical warfare.

Lanthanide trichlorides are a family of inorganic compound with the formula LnCl3, where Ln stands for a lanthanide metal. The trichlorides are standard reagents in applied and academic chemistry of the lanthanides. They exist as anhydrous solids and as hydrates.

References

  1. John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99th ed.). CRC Press. pp. 4–41. ISBN   978-1138561632.
  2. "Arsenic (inorganic compounds, as As)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0038". National Institute for Occupational Safety and Health (NIOSH).
  4. 1 2 3 Sabina C. Grund, Kunibert Hanusch, Hans Uwe Wolf "Arsenic and Arsenic Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, VCH-Wiley, 2008, Weinheim. doi : 10.1002/14356007.a03_113.pub2
  5. P. Kisliuk; C. H. Townes. "The Microwave Spectra and Molecular Structure of Phosphorus and Arsenic Trichloride". J. Chem. Phys. 1950, 18.
  6. Jean Galy; Renee Enjalbertl Pierre Lecante; Andrzej Burian "AsCl3: From the crystalline to the liquid state. XRD (176< T (K) < 250) and WAXS (295K) studies" Inorg. Chem 2002, volume 41, pp. 693–698. doi : 10.1021/ic0102788
  7. Klapoetke, Thomas M. "The vibrational spectrum of arsenic trichloride" Main Group Metal Chemistry 1997, volume 20, pp. 81–83.
  8. R. C. Smith, "Manufacture of Arsenic trichloride" The Journal of Industrial and Engineering Chemistry 1919, volume 11, pp. 109–110. doi : 10.1021/ie50110a009
  9. Pandey, S. K.; Steiner, A.; Roesky, H. W. (1997). "Arsenic(III) chloride". Inorganic Syntheses. 31: 148-150. doi:10.1002/9780470132623.ch24.
  10. Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. ISBN   0-12-352651-5.
  11. Shriner, R. L.; Wolf, C. N. (1963). "Tetraphenylarsonium Chloride Hydrochloride". Organic Syntheses ; Collected Volumes, vol. 4, p. 910.. Describes the preparation of As(C6H5)3.
  12. 40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities (PDF) (Report) (July 1, 2008 ed.). Government Printing Office. Archived from the original (PDF) on February 25, 2012. Retrieved October 29, 2011.