VG (IUPAC name: O,O-diethyl S-[2-(diethylamino)ethyl] phosphorothioate) (also called Amiton or Tetram) 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.

VG
Skeletal formula of VG
Ball-and-stick model of VG
Names
Preferred IUPAC name
S-[2-(Diethylamino)ethyl] O,O-diethyl phosphorothioate
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/C10H24NO3PS/c1-5-11(6-2)9-10-16-15(12,13-7-3)14-8-4/h5-10H2,1-4H3 checkY
    Key: PJISLFCKHOHLLP-UHFFFAOYSA-N checkY
  • InChI=1/C10H24NO3PS/c1-5-11(6-2)9-10-16-15(12,13-7-3)14-8-4/h5-10H2,1-4H3
    Key: PJISLFCKHOHLLP-UHFFFAOYAO
  • O=P(OCC)(OCC)SCCN(CC)CC
Properties
C10H24NO3PS
Molar mass 269.34 g·mol−1
Boiling point 110 °C (230 °F; 383 K) at 0.2 mmHg
Vapor pressure 0.01 mmHg at 80 °C
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
4
2
1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Chemical

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With a toxicity of about 1/10 that of VX, i.e. similar to that of sarin,[1] it is now considered too dangerous for use in agriculture[2] but unlike other nerve agents it is classified under Schedule 2 of the Chemical Weapons Convention rather than the more restrictive Schedule 1. It is thought that North Korea may have military stockpiles of this chemical .[3]

During the early 1950s at least three chemical companies working on organo-phosphorus insecticides independently discovered the severe toxicity of these chemicals.[4] In 1952, Dr. Ranajit Ghosh, a chemist working for ICI at their Plant Protection Laboratories at Jealott's Hill was investigating the potential of organophosphate esters of substituted aminoethanethiols for use as pesticides. Like the earlier German investigators of organophosphates in the late 1930s who had discovered the G-series nerve agents, Dr. Ghosh discovered that their action on cholinesterase made them effective pesticides. One of them, Amiton, was described in a 1955 paper by Ghosh and another chemist, J. F. Newman, as being particularly effective against mites.[4] It was brought to market as an insecticide by the company in 1954 but was subsequently withdrawn as too toxic.[5][6]

The toxicity of these substances had not passed unnoticed by the British Government, as some of the compounds had already been sent to their research facility at Porton Down for evaluation. Some of the chemicals from this class of compounds formed a new group of nerve agents called V Agents. The British Government unilaterally renounced chemical and biological weapons in 1956, although in 1958 traded their research on VG technology with the United States Government in exchange for information on thermonuclear weapons.[citation needed] The US then went into production of large amounts of the chemically similar, but much more toxic VX in 1961.[7]

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.[8]

References

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  1. ^ "Summary of CWC-Schedules and their Relevance to Chemical Warfare" (PDF). Australia's National Authority for the Chemical Weapons Convention. Archived from the original (PDF) on 2013-05-04. Retrieved 2006-10-07.
  2. ^ Theodore Karasik. "Toxic Warfare" (PDF). RAND. Retrieved 2006-10-07.
  3. ^ "North Korea Profile Chemical Agents VG (Amiton, Tetram)". Nuclear Threat Initiative. Retrieved 2006-10-07.
  4. ^ a b "Nerve Agents - Lethal organo-phosphorus compounds inhibiting cholinesterase". Organisation for the Prohibition of Chemical Weapons website. Archived from the original on 2008-09-27. Retrieved 2006-10-07.
  5. ^ "Nerve Agents: General". The site for information about chemical and biological weapons for emergency, safety and security personnel. Archived from the original on 2006-10-12. Retrieved 2006-10-07.
  6. ^ Calderbank, Alan (1978). "Chapter 6: Organophosphorus Insecticides". In Peacock, F.C. (ed.). Jealott's Hill: Fifty years of Agricultural Research 1928-1978. Imperial Chemical Industries Ltd. pp. 49–51. ISBN 0901747017.
  7. ^ "A Short History of the Development of Nerve Gases". Mitrek Systems. Archived from the original on November 12, 2006. Retrieved 2006-10-07.
  8. ^ "40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities" (PDF) (July 1, 2008 ed.). Government Printing Office. Retrieved October 29, 2011. {{cite journal}}: Cite journal requires |journal= (help)