VR (nerve agent)

Last updated
VR
VR nerve agent.svg
VR-3D-balls.png
Names
Preferred IUPAC name
S-[2-(Diethylamino)ethyl] O-(2-methylpropyl) methylphosphonothioate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
PubChem CID
UNII
  • InChI=1S/C11H26NO2PS/c1-6-12(7-2)8-9-16-15(5,13)14-10-11(3)4/h11H,6-10H2,1-5H3 X mark.svgN
    Key: MNLAVFKVRUQAKW-UHFFFAOYSA-N X mark.svgN
  • InChI=1/C11H26NO2PS/c1-6-12(7-2)8-9-16-15(5,13)14-10-11(3)4/h11H,6-10H2,1-5H3
    Key: MNLAVFKVRUQAKW-UHFFFAOYAF
  • CCN(CC)CCSP(=O)(C)OCC(C)C
Properties
C11H26NO2PS
Molar mass 267.368 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

VR (Russian VX, VXr, Soviet V-gas, GOSNIIOKhT substance No. 33, Agent "November") is a "V-series" unitary nerve agent closely related (it is an isomer) to the better-known VX nerve agent. [1] It became a prototype for the series of Novichok agents. According to chemical weapons expert Jonathan Tucker, the first binary formulation developed under the Soviet Foliant program was used to make Substance 33, differing from VX only in the alkyl substituents on its nitrogen and oxygen atoms. "This weapon was given the code name Novichok." [2]

Contents

History

The development of VR started in 1957, after the Soviet Union obtained information about detection of high level of toxicity in phosphorylthiocholines [3] (the same year Lars-Erik Tammelin published his first articles on fluorophosphorylcholines and phosphorylthiocholines in Acta Chemica Scandinavica) by a team from the Soviet Union's Scientific Research Institute No. 42 (NII-42). Sergei Zotovich Ivin, Leonid Soborovsky, and Iya Danilovna Shilakova jointly developed this analogue of VX. They completed their work in 1963 and were later awarded the Lenin Prize for their achievement. [4] A binary weapon comprising two less toxic precursors which mixed during flight to form Substance 33 was later developed by a team led by Nikolai Kuznetsov. [5]

In 1972 the Soviets opened Cheboksary Khimprom, a manufacturing plant for VR in Novocheboksarsk. [6] All facilities in USSR produced 15,557 tons of VR according to their declaration to the Organisation for the Prohibition of Chemical Weapons (OPCW), [7] although most if not all of this has now been destroyed under disarmament treaties. [8]

Comparison to VX

VR has similar lethal dose levels to VX (between 10–50 mg), as well as being similar in appearance. [9] However, due to usage of diethylamino radicals instead of diisopropylamino it is more prone to decomposition. The former are worse at sterically protecting the nitrogen atom from attacking either phosphorus or the α-carbon atom adjacent to sulfur than the latter. According to UK Defence Science and Technology Laboratory Detection Department scientists Robin M. Black and John M. Harrison, chemical stability was an important factor why of all the similarly toxic phosphorylthiocholines, ethyl N-2-diisopropylaminoethyl methylphosphonothiolate in particular (now known as VX), was weaponized in the West. [10]

According to Russian CW developer Vil Mirzayanov, in the late 1980s a group of GosNIIOKhT chemists led by Georgiy Drozd prepared a scientific report that Substance 33 had much lower shelf life than VX. The report, writes Mirzayanov, caused 'panic' in the institute top management and the military representative office, and later was met with administrative resistance. This finding was independently verified by another chemist Igor Revelskiy but his report wasn't approved either. [11]

Following the poisoning of Sergei and Yulia Skripal, former head of the GosNIIOKhT security department Nikolay Volodin said in an interview to Novaya Gazeta that Substance 33 was decomposing too quickly in combat conditions, and implied that this fact may have influenced the decision to continue research on the Novichok program. [12]

Toxicity

Both agents have similar symptoms and method of action to other nerve agents that act on cholinesterase, and treatment remains the same. However, the window for effectively treating second generation V series seizures is shorter, as they rapidly denature the acetylcholinesterase protein in a similar manner to soman, making treatment with the standard nerve gas antidote pralidoxime ineffective unless it is given very soon after exposure.[ citation needed ] Pre-treatment with pyridostigmine prior to exposure, and treatment with other drugs such as atropine and diazepam after exposure, will reduce symptoms of nerve agent toxicity but may not be sufficient to prevent death if a large dose of nerve agent has been absorbed. In addition to the standard seizures, some of the second generation V series agents are known to cause comas.

See also

Related Research Articles

Nerve agents, sometimes also called nerve gases, are a class of organic chemicals that disrupt the mechanisms by which nerves transfer messages to organs. The disruption is caused by the blocking of acetylcholinesterase (AChE), an enzyme that catalyzes the breakdown of acetylcholine, a neurotransmitter. Nerve agents are irreversible acetylcholinesterase inhibitors used as poison.

<span class="mw-page-title-main">Sarin</span> Chemical compound and chemical warfare nerve agent

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<span class="mw-page-title-main">Tabun (nerve agent)</span> Chemical compound

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).

<span class="mw-page-title-main">Soman</span> Chemical compound (nerve agent)

Soman is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the enzyme cholinesterase. It is an inhibitor of both acetylcholinesterase and butyrylcholinesterase. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN Resolution 687. Its production is strictly controlled, and stockpiling is outlawed by the Chemical Weapons Convention of 1993 where it is classified as a Schedule 1 substance. Soman was the third of the so-called G-series nerve agents to be discovered along with GA (tabun), GB (sarin), and GF (cyclosarin).

<span class="mw-page-title-main">VX (nerve agent)</span> Chemical compound and chemical warfare nerve agent

VX is an extremely toxic synthetic chemical compound in the organophosphorus class, specifically, a thiophosphonate. In the class of nerve agents, it was developed for military use in chemical warfare after translation of earlier discoveries of organophosphate toxicity in pesticide research. In its pure form, VX is an oily, relatively non-volatile liquid that is amber-like in colour. Because of its low volatility, VX persists in environments where it is dispersed.

<span class="mw-page-title-main">VG (nerve agent)</span> Chemical compound

VG is a "V-series" nerve agent chemically similar to the better-known VX nerve agent. Tetram is the common Russian name for the substance. Amiton was the trade name for the substance when it was marketed as an insecticide by ICI in the mid-1950s.

Novichok is a family of nerve agents, some of which are binary chemical weapons. The agents were developed at the GosNIIOKhT state chemical research institute by the Soviet Union and Russia between 1971 and 1993. Some Novichok agents are solids at standard temperature and pressure, while others are liquids. Dispersal of solid form agents is thought possible if in ultrafine powder state.

<span class="mw-page-title-main">EA-3148</span> Chemical compound

EA-3148 is a "V-series" nerve agent related to the better-known compounds VX and VR. It was studied by both the US and Soviet chemical weapons programmes during the Cold War, and is notable as the only V-series organophosphate nerve agent specifically identified in public domain sources as having a higher absolute potency as an acetylcholinesterase inhibitor than VX. However, both the US and Soviet investigations of the compound concluded that despite its high potency, the physicochemical properties of the substance made it unsuitable for weaponisation, and further research was not conducted.

Vil Sultanovich Mirzayanov is a Russian chemist of ethnic Tatar origin who now lives in the United States, best known for revealing secret chemical weapons experimentation in Russia.

<span class="mw-page-title-main">A-232</span> Chemical compound

A-232 is an organophosphate nerve agent. It was developed in the Soviet Union under the FOLIANT program and is one of the group of compounds referred to as Novichok agents that were revealed by Vil Mirzayanov. A-232 is reportedly slightly less potent as a nerve agent compared to some of the other compounds in the series such as A-230 and A-234, having similar potency to the older nerve agent VR. However it proved to be the most versatile agent as it was chemically stable and remained a volatile liquid over a wide temperature range, making it able to be used in standard chemical munitions without requiring special delivery mechanisms to be developed.

<span class="mw-page-title-main">A-234 (nerve agent)</span> Chemical compound

A-234 is an organophosphate nerve agent. It was developed in the Soviet Union under the FOLIANT program and is one of the group of compounds referred to as Novichok agents that were revealed by Vil Mirzayanov. In March 2018 the Russian ambassador to the UK, Alexander Yakovenko, claimed to have been informed by British authorities that A-234 had been identified as the agent used in the poisoning of Sergei and Yulia Skripal. Vladimir Uglev, one of the inventors of the Novichok series of compounds, said he was "99 percent sure that it was A-234" in relation to the 2018 Amesbury poisonings, noting its unusually high persistence in the environment.

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

Methylfluorophosphonylcholine (MFPCh) is an extremely toxic chemical compound related to the G-series nerve agents. It is an extremely potent acetylcholinesterase inhibitor which is around 100 times more potent than sarin at inhibiting acetylcholinesterase in vitro, and around 10 times more potent in vivo, depending on route of administration and animal species tested. MFPCh is resistant to oxime reactivators, meaning the acetylcholinesterase inhibited by MFPCh can't be reactivated by cholinesterase reactivators. MFPCh also acts directly on the acetylcholine receptors. However, despite its high toxicity, methylfluorophosphonylcholine is a relatively unstable compound and degrades rapidly in storage, so it was not deemed suitable to be weaponised for military use.

Chemical weapons have been a part of warfare in most societies for centuries. However, their usage has been extremely controversial since the 20th century.

<span class="mw-page-title-main">A-230</span> Chemical compound

A-230 is an organophosphate nerve agent. It was developed in the Soviet Union under the FOLIANT program and is one of the group of compounds referred to as Novichok agents that were revealed by Vil Mirzayanov. A-230 is possibly the most potent nerve agent for which specific toxicity figures have been published, with a human lethal dose estimated to be less than 0.1 mg. However it was felt to be less suitable for weaponisation than other agents such as A-232 and A-234, due to issues with the liquid agent exhibiting low volatility and solidifying at low temperatures, as well as poor stability in the presence of water.

<span class="mw-page-title-main">A-242</span> Chemical compound

A-242 is an organophosphate nerve agent. It was developed in the Soviet Union under the FOLIANT program and is one of the group of compounds referred to as Novichok agents that were revealed by Vil Mirzayanov. Mirzayanov gives little specific information about A-242, stating that it is highly toxic but no figures are given to compare it to other related agents. It is reportedly a solid rather than a volatile liquid as with most nerve agents, and in order to weaponise it successfully, it had to be milled into a fine powder form that could be dispersed as a dust.

<span class="mw-page-title-main">A-262</span> Chemical compound

A-262 is an organophosphate nerve agent. It was developed in the Soviet Union under the FOLIANT program and is one of the group of compounds referred to as Novichok agents that were revealed by Vil Mirzayanov. Mirzayanov gives little specific information about A-262, stating that it is highly toxic, but no figures are given to compare it to other related agents. It is reportedly a solid rather than a volatile liquid as with most nerve agents, and in order to weaponise it successfully, it had to be milled into a fine powder form that could be dispersed as a dust.

Lev Alexandrovich Fyodorov was a Russian chemist.

<span class="mw-page-title-main">GosNIIOKhT</span> Russian research institute

The State Research Institute of Organic Chemistry and Technology (GosNIIOKhT) is a Russian research institute engaged in the development of chemical technologies for use in the national economy and the production of relevant goods and products.

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

Thiosarin, sulfursarin or GBS, is the organophosphorus compound analogous to sarin. It differs structurally in that sulfur replaces the oxygen of the P=O bond. It is an extremely toxic substance related to G-agents.

References

  1. ↑ Fedorov L. A. Undeclared Chemical War in Russia. Moscow, 1995 (Russian)
  2. ↑ Peplow, Mark (19 March 2018). "Nerve agent attack on spy used 'Novichok' poison". Chemical & Engineering News. American Chemical Society. 96 (12): 3. Retrieved 28 March 2018.
  3. ↑ Major General Antonov, Nikolai S. (1994). Khimicheskoe Oruzhiye na Rubezhe Dvukh StoletiiХимическое оружие на рубеже двух столетий [Chemical Weapons at the Turn of the Century](PDF) (in Russian). Moscow: Progress. p. 22. ISBN   5-01-004462-5. LCCN   96160418.
  4. ↑ Tucker, J. B.; War of Nerves; Anchor Books; New York; 2006; pp 181-182.
  5. ↑ Vil S. Mirzayanov. State Secrets. An Insider's Chronicle of the Russian Chemical Weapons Program. (2009) pp166-168. ISBN   978-1-4327-2566-2
  6. ↑ Tucker, J. B.; War of Nerves; Anchor Books; New York; 2006; pp 230–231.
  7. ↑ "Factsheets on Chemical and Biological Warfare Agents".
  8. ↑ "Chemical Weapons – Russian / Soviet Nuclear Forces".
  9. ↑ "VR". American Chemical Society.
  10. ↑ Black R.M., Harrison J.M. The chemistry of organophosphorus chemical warfare agents. Chapter 10 of The chemistry of organophosphorus compounds. Volume 4, Ter- and quinque-valent phosphorus acids and their derivatives. (1996) Black, R. M.; Harrison, J. M. (2009). "The Chemistry of Organophosphorus Chemical Warfare Agents". PATai's Chemistry of Functional Groups. doi:10.1002/9780470682531.pat0070. ISBN   978-0-471-95706-5.
  11. ↑ Mirzayanov, Vil S. (December 2008). State Secrets: An Insider's Chronicle of the Russian Chemical Weapons Program. Outskirts Press, Incorporated. ISBN   978-1-4327-1923-4.
  12. ↑ ""Новичок" — это слишком для одного Скрипаля"". Новая газета - Novayagazeta.ru. March 23, 2018.
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