Names | |||
---|---|---|---|
Preferred IUPAC name [(E)-2-Chloroethen-1-yl]arsonous dichloride | |||
Other names Chlorovinylarsine dichloride 2-Chloroethenyldichloroarsine (E)-2-Chlorovinylarsonous dichloride (E)-2-Chlorovinyldichloroarsine Dichloro((E)-2-chlorovinyl)arsine | |||
Identifiers | |||
3D model (JSmol) | |||
ChemSpider | |||
MeSH | lewisite | ||
PubChem CID | |||
UNII | |||
UN number | 2810 | ||
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Properties | |||
C2H2AsCl3 | |||
Molar mass | 207.32 g/mol | ||
Density | 1.89 g/cm3 | ||
Melting point | −18 °C (0 °F; 255 K) | ||
Boiling point | 190 °C (374 °F; 463 K) | ||
Reacts with water | |||
Solubility | Ethers, hydrocarbons, THF | ||
Vapor pressure | 0.58 mmHg (25 °C) | ||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards | Flammable, highly toxic, corrosive, vesicant | ||
NFPA 704 (fire diamond) | |||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Lewisite (L) (A-243) is an organoarsenic compound. It was once manufactured in the U.S., Japan, Germany [2] and the Soviet Union [3] for use as a chemical weapon, acting as a vesicant (blister agent) and lung irritant. Although the substance is colorless and odorless in its pure form, impure samples of lewisite are a yellow, brown, violet-black, green, or amber oily liquid with a distinctive odor that has been described as similar to geraniums. [4] [5] [6]
Lewisite is named after the US chemist and soldier Winford Lee Lewis (1878–1943). Apart from its use as a weapon of war, the compound is useless; a chemist from the United States Army's chemical warfare laboratories said that "no one has ever found any use for the compound". [7]
The compound is prepared by the addition of arsenic trichloride to acetylene in the presence of a suitable catalyst:
This chemical process can occur a second or third time, giving lewisite 2 and lewisite 3 as byproducts. [8]
Lewisite, like other arsenous chlorides, hydrolyses in water to form hydrochloric acid and chlorovinylarsenous oxide (a less-powerful blister agent): [5]
This reaction is accelerated in alkaline solutions, and forms acetylene and trisodium arsenate. [5]
Lewisite reacts with metals to form hydrogen gas. It is combustible, but difficult to ignite. [5]
Apart from deliberately injuring and killing people, lewisite has no commercial, industrial, or scientific applications. [7] In a 1959 paper regarding the development of a batch process for lewisite synthesis, Gordon Jarman of the United States Army Chemical Warfare Laboratories said:
The manufacture can be one of the easiest and most economical in the metal-organic field, and it is regretted that no one has ever found any use for the compound. It is a pity to waste such a neat process. [7]
While the compound itself has no useful application, a 1993 report from the US Defense Nuclear Agency detailed attempts by Russian chemists in "exploring processes for the conversion of these agents to marketable products", including the extraction of high-purity arsenic for use in semiconductor doping (as gallium arsenide). The report, however, concluded that "the engineering and scale up of the process to a production level may be prohibitively difficult" and that "unless other metallic impurities which are likely to be found in Lewisite are removed, the high purity required for chip application may require additional steps", noting that worldwide demand for arsenic compounds (already declining at the time) was projected to shrink further, and that the proposed economics of the conversion process did not align with then-current prices for gallium arsenide. [9]
Lewisite is a suicide inhibitor of the E3 component of pyruvate dehydrogenase. As an efficient method to produce ATP, pyruvate dehydrogenase is involved in the conversion of pyruvate to acetyl-CoA. The latter subsequently enters the TCA cycle. Peripheral nervous system pathology usually arises from Lewisite exposure as the nervous system essentially relies on glucose as its only catabolic fuel. [10]
It can easily penetrate ordinary clothing and latex rubber gloves. Upon skin contact it causes immediate stinging, burning pain and itching that can last for 24 hours. Within minutes, a rash develops and the agent is absorbed through the skin. Large, fluid-filled blisters (similar to those caused by mustard gas exposure) develop after approximately 12 hours and cause pain for 2–3 days. [4] [5] These are severe chemical burns and begin with small blisters in the red areas of the skin within 2–3 hours and grow worse, encompassing the entire red area, for the ensuing 12–18 hours after initial exposure. Liquid lewisite has faster effects than lewisite vapor. [5] Sufficient absorption can cause deadly liver necrosis.
Those exposed to lewisite can develop refractory hypotension (low blood pressure) known as Lewisite shock, with some features of arsenic toxicity. [11] Lewisite damages capillaries, which then become leaky, reducing blood volume required to maintain blood pressure, a condition called hypovolemia. When the blood pressure is low, the kidneys may not receive enough oxygen and can be damaged. [5]
Inhalation, the most common route of exposure, causes burning pain and irritation throughout the respiratory tract, nosebleed (epistaxis), laryngitis, sneezing, coughing, vomiting, difficult breathing (dyspnea), and in severe cases of exposure, can cause fatal pulmonary edema, pneumonitis, or respiratory failure. Ingestion results in severe pain, nausea, vomiting, and tissue damage. [4] [5] The results of eye exposure can range from stinging, burning pain and strong irritation to blistering and scarring of the cornea, along with blepharospasm, lacrimation, and edema of the eyelids and periorbital area. The eyes can swell shut, which can keep the eyes safe from further exposure. The most severe consequences of eye exposure to lewisite are globe perforation and blindness. [5] Generalised symptoms also include restlessness, weakness, hypothermia and low blood pressure.
It is possible that Lewisite is carcinogenic: arsenic is categorized as a respiratory carcinogen by the International Agency for Research on Cancer, though it has not been confirmed that lewisite is a carcinogen. [12]
Lewisite causes damage to the respiratory tract at levels lower than the odor detection threshold. Early tissue damage causes pain. [5]
Hydrolysis leads to chlorovinylarsonous acid, CVAA.
British anti-lewisite, also called dimercaprol, is the antidote for lewisite. It can be injected to prevent systemic toxicity, but will not prevent injury to the skin, eyes, or mucous membranes. Chemically, dimercaprol binds to the arsenic in lewisite. It is contraindicated in those with peanut allergies. [5]
Other treatment for lewisite exposure is primarily supportive. First aid of lewisite exposure consists of decontamination and irrigation of any areas that have been exposed. Other measures can be used as necessary, such as airway management, assisted ventilation, and monitoring of vital signs. In an advanced care setting, supportive care can include fluid and electrolyte replacement. Because the tube may injure or perforate the esophagus, gastric lavage is contraindicated. [5]
From one acute exposure, someone who has inhaled lewisite can develop chronic respiratory disease; eye exposure to lewisite can cause permanent visual impairment or blindness. [5]
Chronic exposure to lewisite can cause arsenic poisoning (due to its arsenic content) and development of a lewisite allergy. It can also cause long-term illnesses or permanent damage to organs, depending on where the exposure has occurred, including conjunctivitis, aversion to light (photophobia), visual impairment, double vision (diplopia), tearing (lacrimation), dry mucous membranes, garlic breath, burning pain in the nose and mouth, toxic encephalopathy, peripheral neuropathy, seizures, nausea, vomiting, chronic obstructive pulmonary disease (COPD), bronchitis, dermatitis, skin ulcers, basal cell carcinoma, and squamous cell carcinoma. [5]
Lewisite can be a mixture of molecules with a different number of vinylchloride groups on the arsenic chloride: lewisite itself (2-chlorovinylarsonous dichloride), along with bis(2-chlorovinyl)arsinous chloride (lewisite 2) and tris(2-chlorovinyl)arsine (lewisite 3). [13] In addition, there are sometimes isomeric impurities: lewisite itself is mostly trans-2-chlorovinylarsonous dichloride, but the cis stereoisomer and the constitutional isomer (1-chlorovinylarsonous dichloride) may also be present. [14]
Experimental and computational studies both find that the trans-2-chloro isomer is the most stable, and that the carbon–arsenic bond has a conformation in which the lone pair on the arsenic is approximately aligned with the vinyl group. [14]
Lewisite was synthesized in 1904 by Julius Arthur Nieuwland during studies for his PhD. [15] [16] [17] In his thesis, he described a reaction between acetylene and arsenic trichloride, which led to the formation of lewisite. [18] Exposure to the resulting compound made Nieuwland so ill he was hospitalized for several days. [16]
Lewisite is named after the US chemist and soldier Winford Lee Lewis (1878–1943). [19] In 1918, John Griffin, Julius Arthur Nieuwland's thesis advisor, drew Lewis's attention to Nieuwland's thesis at Maloney Hall, a chemical laboratory at The Catholic University of America, Washington D.C. [20] Lewis then attempted to purify the compound through distillation but found that the mixture exploded on heating until it was washed with HCl. [20]
Lewisite was developed into a secret weapon at a facility located in Cleveland, Ohio (The Cleveland Plant) at East 131st Street and Taft Avenue, [19] [21] and given the name "G-34", which had previously been the code for mustard gas, in order to confuse its development with mustard gas. [22] On November 1, 1918, production began at a plant in Willoughby, Ohio. [23] It was not used in World War I, but Britain experimented with it in the 1920s as the "Dew of Death". [24]
After World War I, the US became interested in lewisite because it was not flammable. Up until World War II, it had the military symbol of "M1", after which it was changed to "L". Field trials with lewisite during World War II demonstrated that casualty concentrations were not achievable under high humidity, due to the rate of hydrolysis and the characteristic odor of the chemical, and the formation of tears forced troops to don masks and avoid contaminated areas.[ citation needed ] The United States produced about 20,000 tons of lewisite, keeping it on hand primarily as an antifreeze for mustard gas, or to penetrate protective clothing in special situations.
Lewisite was replaced by the mustard gas variant HT (a 60:40 mixture of sulfur mustard and O-Mustard), and was declared obsolete in the 1950s. Lewisite poisoning can be treated effectively with British anti-lewisite (dimercaprol). Most stockpiles of lewisite were neutralised with bleach and dumped into the Gulf of Mexico. [25] The last remaining U.S. stockpiles at the Deseret Chemical Depot located outside Salt Lake City, Utah were destroyed in January 2012. [26]
Production of quantities greater than 100 grams per year per facility were banned by Schedule 1 of the 1993 Chemical Weapons Convention. When the convention entered force in 1997, the parties declared world-wide stockpiles of 6,747 tonnes. By the end of 2015, 98% of the declared stockpiles had been destroyed. [27]
In 2001, lewisite was found in a World War I weapons dump in Washington, D.C. [28]
In July 2023 a spokesman of the Armed Forces of Ukraine claimed that during the battle of Bakhmut a Russian artillery attack against Ukrainian forces had included lewisite, causing symptoms of nausea, vomiting and in some cases loss of consciousness. [29] However, no information from any sample analysis were published.
In mid-2006, China and Japan were negotiating disposal of lewisite stockpile in northeastern China, left by the Japanese military during World War II. People had died over the preceding twenty years from accidental exposure to these stockpiles. [30]
Mustard gas or sulfur mustard is any of the several chemical compounds that contain the chemical structure S(CH2CH2Cl)2. In the wider sense, compounds with the substituent S(CH2CH2X)2 and N(CH2CH2X)3 are known as sulfur mustards and nitrogen mustards, respectively, where X = Cl or Br. Such compounds are potent alkylating agents, which can interfere with several biological processes. Also known as mustard agents, this family of compounds are infamous cytotoxins and blister agents with a long history of use as chemical weapons. The name mustard gas is technically incorrect: the substances, when dispersed, are often not gases but a fine mist of liquid droplets. Sulfur mustards are viscous liquids at room temperature and have an odor resembling mustard plants, garlic, or horseradish, hence the name. When pure, they are colorless, but when used in impure forms, such as in warfare, they are usually yellow-brown. Mustard gases form blisters on exposed skin and in the lungs, often resulting in prolonged illness ending in death. The typical mustard gas is the organosulfur compound bis(2-chloroethyl) sulfide.
Chemical warfare (CW) involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from nuclear warfare, biological warfare and radiological warfare, which together make up CBRN, the military acronym for chemical, biological, radiological, and nuclear, all of which are considered "weapons of mass destruction" (WMDs), a term that contrasts with conventional weapons.
Sarin is an extremely toxic organophosphorus compound. A colourless, odourless liquid, it is used as a chemical weapon due to its extreme potency as a nerve agent. Exposure can be lethal even at very low concentrations, where death can occur within one to ten minutes after direct inhalation of a lethal dose, due to suffocation from respiratory paralysis, unless antidotes are quickly administered. People who absorb a non-lethal dose and do not receive immediate medical treatment may suffer permanent neurological damage.
Tabun or GA is an extremely toxic synthetic organophosphorus compound. It is a clear, colorless, and tasteless liquid with a faint fruity odor. It is classified as a nerve agent because it can fatally interfere with normal functioning of the mammalian nervous system. Its production is strictly controlled and stockpiling outlawed by the Chemical Weapons Convention of 1993. Tabun is the first of the G-series nerve agents along with GB (sarin), GD (soman) and GF (cyclosarin).
The use of toxic chemicals as weapons dates back thousands of years, but the first large-scale use of chemical weapons was during World War I. They were primarily used to demoralize, injure, and kill entrenched defenders, against whom the indiscriminate and generally very slow-moving or static nature of gas clouds would be most effective. The types of weapons employed ranged from disabling chemicals, such as tear gas, to lethal agents like phosgene, chlorine, and mustard gas. These chemical weapons caused medical problems. This chemical warfare was a major component of the first global war and first total war of the 20th century. The killing capacity of gas was profound, with about 90,000 fatalities from a total of 1.3 million casualties caused by gas attacks. Gas was unlike most other weapons of the period because it was possible to develop countermeasures, such as gas masks. In the later stages of the war, as the use of gas increased, its overall effectiveness diminished. The widespread use of these agents of chemical warfare, and wartime advances in the composition of high explosives, gave rise to an occasionally expressed view of World War I as "the chemist's war" and also the era where weapons of mass destruction were created.
A blister agent, is a chemical compound that causes severe skin, eye and mucosal pain and irritation. They are named for their ability to cause severe chemical burns, resulting in painful water blisters on the bodies of those affected. Although the term is often used in connection with large-scale burns caused by chemical spills or chemical warfare agents, some naturally occurring substances such as cantharidin are also blister-producing agents (vesicants). Furanocoumarin, another naturally occurring substance, causes vesicant-like effects indirectly, for example, by increasing skin photosensitivity greatly. Vesicants have medical uses including wart removal but can be dangerous if even small amounts are ingested.
A chemical burn occurs when living tissue is exposed to a corrosive substance or a cytotoxic agent. Chemical burns follow standard burn classification and may cause extensive tissue damage. The main types of irritant and/or corrosive products are: acids, bases, oxidizers / reducing agents, solvents, and alkylants. Additionally, chemical burns can be caused by biological toxins and by some types of cytotoxic chemical weapons, e.g., vesicants such as mustard gas and Lewisite, or urticants such as phosgene oxime.
Dimercaprol, also called British anti-Lewisite (BAL), is a medication used to treat acute poisoning by arsenic, mercury, gold, and lead. It may also be used for antimony, thallium, or bismuth poisoning, although the evidence for those uses is not very strong. It is given by injection into a muscle.
Chlormethine, also known as mechlorethamine, mustine, HN2, and embikhin (эмбихин), is a nitrogen mustard sold under the brand name Mustargen among others. It is the prototype of alkylating agents, a group of anticancer chemotherapeutic drugs. It works by binding to DNA, crosslinking two strands and preventing cell duplication. It binds to the N7 nitrogen on the DNA base guanine. As the chemical is a blister agent, its use is strongly restricted within the Chemical Weapons Convention where it is classified as a Schedule 1 substance.
Bis(2-chloroethyl)ethylamine is the organic compound with the formula C2H5N(CH2CH2Cl)2. Often abbreviated HN1, it is a powerful vesicant and a nitrogen mustard gas used for chemical warfare. HN1 was developed in the 1920s and 1930s to remove warts and later as a military agent. Because of the latter use, it is a Schedule 1 chemical within the Chemical Weapons Convention and therefore use and production is strongly restricted. It has never been used in warfare.
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.
Phenyldichloroarsine, also known by its wartime name phenyl Dick and its NATO abbreviation PD, is an organic arsenical vesicant and vomiting agent developed by Germany and France for use as a chemical warfare agent during World War I. The agent is known by multiple synonyms and is technically classified as a vesicant, or blister agent.
Operation Geranium was a U.S. Army mission that dumped more than 3,000 tons of the chemical agent lewisite into the ocean off the Florida coast in 1948.
Throughout history, chemical weapons have been used as strategic weaponry to devastate the enemy in times of war. After the mass destruction created by WWI and WWII, chemical weapons have been considered to be inhumane by most nations, and governments and organizations have undertaken to locate and destroy existing chemical weapons. However, not all nations have been willing to cooperate with disclosing or demilitarizing their inventory of chemical weapons. Since the start of the worldwide efforts to destroy all existing chemical weapons, some nations and terrorist organizations have used and threatened the use of chemical weapons to leverage their position. Examples of the use of chemical weapons since World War II are Iraq’s Saddam Hussein on the Kurdish village Halabja in 1988 and their employment against civilian passengers of the Tokyo subway by Aum Shinrikyo in 1995. The efforts made by the United States and other chemical weapon destruction agencies intend to prevent such use, but this is a difficult and ongoing effort. Aside from the difficulties of cooperation and locating chemical weapons, the methods to destroy the weapons and to do this safely are also a challenge.
A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as a weapon "or its precursor that can cause death, injury, temporary incapacitation or sensory irritation through its chemical action. Munitions or other delivery devices designed to deliver chemical weapons, whether filled or unfilled, are also considered weapons themselves."
The United States chemical weapons program began in 1917 during World War I with the creation of the U.S. Army's Gas Service Section and ended 73 years later in 1990 with the country's practical adoption of the Chemical Weapons Convention. Destruction of stockpiled chemical weapons began in 1986 and was completed on July 7, 2023. The U.S. Army Medical Research Institute of Chemical Defense (USAMRICD), at Aberdeen Proving Ground, Maryland, continues to operate.
Chemical weapons have been a part of warfare in most societies for centuries. However, their usage has been extremely controversial since the 20th century.
Lewisite 2(L-2) is an organoarsenic chemical weapon with the formula AsCl(CH=CHCl)2. It is similar to lewisite 1 and lewisite 3 and was first synthesized in 1904 by Julius Arthur Nieuwland. It is usually found as a mixture of 2-chlorovinylarsonous dichloride (lewisite 1) as well as bis(2-chloroethenyl) arsinous chloride (lewisite 2) and tris(2-chlorovinyl)arsine (lewisite 3). Pure lewisite 1 is an oily, colorless liquid, however, the impure mixture can appear amber to black with an odor distinct to geraniums.
Lewisite 3(L-3) is an organoarsenic chemical weapon like lewisite 1 and lewisite 2 first synthesized in 1904 by Julius Arthur Nieuwland. It is usually found as a mixture of 2-chlorovinylarsonous dichloride as well as bis(2-chloroethenyl) arsinous chloride and tris(2-chlorovinyl)arsine. Pure lewisite 1 is an oily, colorless liquid, however, the impure mixture can appear amber to black with an odor distinct to geraniums.