Arsine

::Na3As + 3 HBr → AsH3 + 3 NaBr ## Reactions The understanding of the chemical properties of AsH3 is well developed and can be anticipated based on an average of the behavior of pnictogen counterparts, such as PH3 and SbH3. ### Thermal decomposition Typical for a heavy hydride (e.g., [](stibine), , ), is unstable with respect to its elements. In other words, it is stable kinetically but not thermodynamically. :: This decomposition reaction is the basis of the Marsh test, which detects elemental As. ### Oxidation Continuing the analogy to SbH3, AsH3 is readily oxidized by concentrated O2 or the dilute O2 concentration in air: ::2 AsH3 + 3 O2 → As2O3 + 3 H2O Arsine will react violently in presence of strong oxidizing agents, such as potassium permanganate, sodium hypochlorite, or nitric acid. ### Precursor to metallic derivatives AsH3 is used as a precursor to metal complexes of "naked" (or "nearly naked") arsenic. An example is the dimanganese species [(C5H5)Mn(CO)2]2AsH, wherein the Mn2AsH core is planar. ### Gutzeit test A characteristic test for arsenic involves the reaction of AsH3 with Ag+, called the Gutzeit test for arsenic. Although this test has become obsolete in analytical chemistry, the underlying reactions further illustrate the affinity of AsH3 for "soft" metal cations. In the Gutzeit test, AsH3 is generated by reduction of aqueous arsenic compounds, typically arsenites, with Zn in the presence of H2SO4. The evolved gaseous AsH3 is then exposed to AgNO3 either as powder or as a solution. With solid AgNO3, AsH3 reacts to produce yellow Ag4AsNO3, whereas AsH3 reacts with a solution of AgNO3 to give black Ag3As. ### Acid-base reactions The acidic properties of the As–H bond are often exploited. Thus, AsH3 can be deprotonated: ::AsH3 + NaNH2 → NaAsH2 + NH3 Upon reaction with the aluminium trialkyls, AsH3 gives the trimeric [R2AlAsH2]3, where R = (CH3)3C. This reaction is relevant to the mechanism by which GaAs forms from AsH3 (see below). AsH3 is generally considered non-basic, but it can be protonated by superacids to give isolable salts of the tetrahedral species [AsH4]+. ### Reaction with halogen compounds Reactions of arsine with the halogens (fluorine and chlorine) or some of their compounds, such as nitrogen trichloride, are extremely dangerous and can result in explosions. ### Catenation In contrast to the behavior of PH3, AsH3 does not form stable chains, although diarsine (or diarsane) H2As–AsH2, and even triarsane H2As–As(H)–AsH2 have been detected. The diarsine is unstable above −100 °C. ## Applications ### Microelectronics applications AsH3 is used in the synthesis of semiconducting materials related to microelectronics and solid-state lasers. Related to phosphorus, arsenic is an n-dopant for silicon and germanium. More importantly, AsH3 is used to make the semiconductor GaAs by chemical vapor deposition (CVD) at 700–900 °C: ::Ga(CH3)3 + AsH3 → GaAs + 3 CH4 For microelectronic applications, arsine can be provided by a sub-atmospheric gas source (a source that supplies less than atmospheric pressure). In this type of gas package, the arsine is adsorbed on a solid microporous adsorbent inside a gas cylinder. This method allows the gas to be stored without pressure, significantly reducing the risk of an arsine gas leak from the cylinder. With this apparatus, arsine is obtained by applying vacuum to the gas cylinder valve outlet. For semiconductor manufacturing, this method is feasible, as processes such as ion implantation operate under high vacuum. ### Chemical warfare Since before WWII AsH3 was proposed as a possible chemical warfare weapon. The gas is colorless, almost odorless, and 2.5 times denser than air, as required for a blanketing effect sought in chemical warfare. It is also lethal in concentrations far lower than those required to smell its garlic-like scent. In spite of these characteristics, arsine was never officially used as a weapon, because of its high flammability and its lower efficacy when compared to the non-flammable alternative phosgene. On the other hand, several organic compounds based on arsine, such as lewisite (β-chlorovinyldichloroarsine), adamsite (diphenylaminechloroarsine), Clark 1 (diphenylchloroarsine) and Clark 2 (diphenylcyanoarsine) have been effectively developed for use in chemical warfare. ## Forensic science and the Marsh test *Main article: Marsh test* AsH3 is well known in forensic science because it is a chemical intermediate in the detection of arsenic poisoning. The old (but extremely sensitive) Marsh test generates AsH3 in the presence of arsenic. This procedure, published in 1836 by James Marsh,{{cite journal The Marsh test was widely used by the end of the 19th century and the start of the 20th; nowadays more sophisticated techniques such as atomic spectroscopy, inductively coupled plasma, and x-ray fluorescence analysis are employed in the forensic field. Though neutron activation analysis was used to detect trace levels of arsenic in the mid 20th century, it has since fallen out of use in modern forensics. ## Toxicology The toxicity of arsine is distinct from that of other arsenic compounds. The main route of exposure is by inhalation, although poisoning after skin contact has also been described. Arsine attacks hemoglobin in the red blood cells, causing them to be destroyed by the body.{{cite journal The first signs of exposure, which can take several hours to become apparent, are headaches, vertigo, and nausea, followed by the symptoms of haemolytic anaemia (high levels of unconjugated bilirubin), haemoglobinuria and nephropathy. In severe cases, the damage to the kidneys can be long-lasting. Exposure to arsine concentrations of 250 ppm is rapidly fatal: concentrations of 25–30 ppm are fatal for 30 min exposure, and concentrations of 10 ppm can be fatal at longer exposure times. Symptoms of poisoning appear after exposure to concentrations of 0.5 ppm. There is little information on the chronic toxicity of arsine, although it is reasonable to assume that, in common with other arsenic compounds, a long-term exposure could lead to arsenicosis. Arsine is a potent hemolytic agent, which is in line with its pathophysiological course of action. However, inhaling high concentrations of this agent is highly capable of inducing severe and direct pulmonary trauma. From a strictly clinical perspective, this typically manifests as chemical pneumonitis as well as non-cardiogenic pulmonary edema. Generally, pathological examinations of the acute fatal cases of arsine poisoning have positively identified two primary mechanisms of pulmonary injury: 1. **Diffuse Alveolar Damage:** This is characterized by extensive pulmonary edema, where the alveoli become diffusely infiltrated with leukocytes and fluid. This results in a cellular exudate that fills the air spaces, and therefore severely compromising and constraining the process of physiological gaseous exchange. 1. **Necrotizing Bronchitis:** This involves direct damage to the primary pulmonary conducting airways. In such instances, the smaller bronchi and bronchioles could potentially become surrounded by inflammatory cells and necrotic tissue. This damage to the epithelium can lead to focal lesions resembling bronchopneumonia. Both manifestations are capable of leading to respiratory failure and death, often occurring at the same time as acute renal failure caused by hemolytic injury. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/0/08/Pneumonia_forming_around_bronchioles.png" caption="Pneumonia forming"] :: 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. ### Occupational exposure limits ::data[format=table] | Country | Limit | |---|---| | Argentina | TLV-TWA | | Australia | TWA () | | Austria | {{ubl | | Belgium | TWA () | | Bulgaria | TLV-TWA | | British Columbia, Canada | TLV-TWA | | Colombia | TLV-TWA | | Denmark | TWA () | | Egypt | TWA () | | Finland | TWA | | France | {{ubl | | Hungary | {{ubl | | Japan | {{ubl | | Jordan | TLV-TWA | | Mexico | TWA () | | Netherlands | MAC-TCG | | New Zealand | {{ubl | | Norway | TWA () | | Peru | TWA () | | Philippines | () | | Poland | {{ubl | | Russia | STEL () | | Singapore | TLV-TWA | | South Korea | TWA | | Sweden | TWA () | | Switzerland | MAK-week () | | Thailand | TWA () | | Turkey | TWA () | | United Kingdom | TWA () | | United States | {{ubl | | Vietnam | TLV-TWA | :: ## References ## References 1. Levvy, G.A.. (1946). "The Toxicity of Arsine Administered by Intraperitoneal Injection". *British Journal of Pharmacology and Chemotherapy*. 2. {{PGCH. 0040 3. ["Arsine"](https://pubchem.ncbi.nlm.nih.gov/compound/23969). *[[PubChem]]*. 4. (2010). "Responding to Terrorism. A Medical Handbook". *Elsevier*. 5. ["Medical Management Guidelines for Arsine (AsH₃)"](http://www.atsdr.cdc.gov/MMG/MMG.asp?id=1199&tid=278). *Agency for Toxic Substances & Disease Registry*. 6. Hartman, Robert James. (1947). "Colloid Chemistry". *Houghton Mifflin Company*. 7. Institut National de Recherche et de Sécurité. (2000). ["Fiche toxicologique nº 53: Trihydrure d'arsenic"](http://www.inrs.fr/inrs-pub/inrs01.nsf/IntranetObject-accesParReference/FT%2053/$File/ft53.pdf). 8. (1968). "Synthesis of the Hydrides of Germanium, Phosphorus, Arsenic, and Antimony by the Solid-Phase Reaction of the Corresponding Oxide with Lithium Aluminum Hydride". *Inorganic Chemistry*. 9. [link](https://web.archive.org/web/20160105084518/http://babel.hathitrust.org/cgi/pt?id=mdp.39015039452928;view=1up;seq=293). (2016-01-05 (On arsenic and its acid), ''Kongliga Vetenskaps Academiens Handlingar'' (Proceedings of the Royal Scientific Academy [of Sweden]), '''36''': 263-294. From p. 290: ''"Med Zinck. 30. (a) Denna år den endaste af alla så hela som halfva Metaller, som i digestion met Arsenik-syra effervescerar."'' (With zinc. 30. (a) This is the only [metal] of all whole- as well as semi-metals that effervesces on digestion with arsenic acid.) Scheele collected the arsine and put a mixture of arsine and air into a cylinder. From p. 291: ''"3:0, Då et tåndt ljus kom når o̊pningen, tåndes luften i kolfven med en småll, lågan for mot handen, denna blef o̊fvedragen med brun fårg, ... "'' (3:0, Then as [the] lit candle came near the opening [of the cylinder], the gases in [the] cylinder ignited with a bang; [the] flame [rushed] towards my hand, which became coated with [a] brown color, ... )) 10. "Arsine" in ''Handbook of Preparative Inorganic Chemistry'', 2nd ed., G. Brauer (ed.), Academic Press, 1963, NY, Vol. 1. p. 493. 11. (1985). "Generation and Complex Stabilization of Arsinidene and Diarsine Fragments by Metal-Induced Degradation of Monoarsine". *Chemische Berichte*. 12. King, E. J. (1959) ''Qualitative Analysis and Electrolytic Solutions'' Harcourt, Brace, and World; New York 13. (1993). "Cyclic Trimeric Hydroxy, Amido, Phosphido, and Arsenido Derivatives of aluminum and gallium. X-ray Structures of [tert-Bu₂Ga(m-OH)]₃ and [tert-Bu₂Ga(m-NH₂)]₃". *Organometallics*. 14. (1994). "Über die Darstellung der Pnikogenoniumsalze AsH₄⁺SbF₆⁻, AsH₄⁺AsF₆⁻, SbH₄⁺SbF₆⁻". *Zeitschrift für Anorganische und Allgemeine Chemie*. 15. Suchard, Jeffrey R.. (March 2006). ["CBRNE — Arsenicals, Arsine"](http://www.emedicine.com/EMERG/topic920.htm). *EMedicine*. 16. Holleman, A. F.; Wiberg, E. (2001) ''Inorganic Chemistry'' Academic Press: San Diego, {{ISBN. 0-12-352651-5. 17. {{IDLH. 7784421. Arsine 18. National Research Council (US) Committee on Acute Exposure Guideline Levels. (2000). ["Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 1"](https://www.ncbi.nlm.nih.gov/books/NBK222396/). *National Academies Press*. 19. [[Agency for Toxic Substances and Disease Registry]] (ATSDR). (August 2007). ["Toxicological Profile for Arsenic"](https://www.atsdr.cdc.gov/toxprofiles/tp2.pdf). *U.S. Department of Health and Human Services*. 20. (2011-05-12). ["Arsine: Systemic Agent"](https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750010.html). *[[Centers for Disease Control and Prevention]]*. 21. ["40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities"](http://edocket.access.gpo.gov/cfr_2008/julqtr/pdf/40cfr355AppA.pdf). *[[United States Government Publishing Office*. 22. ["Arsine"](https://www.cdc.gov/niosh-rtecs/CG62CCF8.html). *National Institute for Occupational Safety and Health (NIOSH)*. ::callout[type=info title="Wikipedia Source"] This article was imported from [Wikipedia](https://en.wikipedia.org/wiki/Arsine) and is available under the [Creative Commons Attribution-ShareAlike 4.0 License](https://creativecommons.org/licenses/by-sa/4.0/). Content has been adapted to SurfDoc format. Original contributors can be found on the [article history page](https://en.wikipedia.org/wiki/Arsine?action=history). ::