Methylphosphonyl difluoride

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Methylphosphonyl difluoride
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Names
Preferred IUPAC name
Methylphosphonic difluoride
Other names
Methylphosphonyl difluoride
Methylphosphonoyl difluoride, EA-1251
Identifiers
3D model (JSmol)
4-04-00-03508
ChemSpider
MeSH difluoride Methylphosphonic difluoride
PubChem CID
UNII
  • InChI=1S/CH3F2OP/c1-5(2,3)4/h1H3
    Key: PQIOSYKVBBWRRI-UHFFFAOYSA-N
  • CP(F)(F)=O
Properties
CH3POF2
Molar mass 100.00
AppearanceColorless liquid
Odor Pungent, acid-like [1]
Density 1.359 g/mL (77°F) [1]
Melting point −37 °C; −35 °F; 236 K
Boiling point 100 °C; 212 °F; 373 K
Decomposes [1]
Vapor pressure 36 mmHg (77°F) [1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Corrosive, toxic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Methylphosphonyl difluoride (DF), also known as EA-1251 [2] or difluoro, [3] is a chemical weapon precursor. Its chemical formula is CH3POF2. It is a Schedule 1 substance under the Chemical Weapons Convention. It is used for production of sarin and soman as a component of binary chemical weapons; an example is the M687 artillery shell, where it is used together with a mixture of isopropyl alcohol and isopropyl amine, producing sarin.

Contents

Preparation

Methylphosphonyl difluoride can be prepared by reacting methylphosphonyl dichloride with hydrogen fluoride (HF) or sodium fluoride (NaF).

Safety

Methylphosphonyl difluoride is both reactive and corrosive. It is absorbed through skin and causes burns and mild nerve agent symptoms. It reacts with water producing HF fumes and methylphosphonic acid as a result. It is also capable of corroding glass.

Significance in International Relations

In 2013-2014, the stockpile of chemicals covered by the CWC was removed from Syria and destroyed. Of the stockpile, 581 tons (over 96%) of the stockpile was DF. It was destroyed by the U.S. Army on the MV Cape Ray by hydrolysis. [4] [5]

Related Research Articles

Chemical warfare Using poison gas or other toxins in war

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.

Chemical Weapons Convention Multilateral treaty prohibiting the production, stockpiling, and use of chemical weapons

The Chemical Weapons Convention (CWC), officially the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction, is an arms control treaty administered by the Organisation for the Prohibition of Chemical Weapons (OPCW), an intergovernmental organization based in The Hague, The Netherlands. The treaty entered into force on 29 April 1997, and prohibits the large-scale use, development, production, stockpiling and transfer of chemical weapons and their precursors, except for very limited purposes. The main obligation of member states under the convention is to effect this prohibition, as well as the destruction of all current chemical weapons. All destruction activities must take place under OPCW verification.

Sarin Highly toxic chemical compound

Sarin is an extremely toxic synthetic organophosphorus compound. A colourless, odourless liquid, it is used as a chemical weapon due to its extreme potency as a nerve agent. Exposure is 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 (nerve agent) Chemical compound

Tabun or GA is an extremely toxic chemical substance. It is a clear, colorless, and tasteless liquid with a faint fruity odor. It is classified as a nerve agent because it fatally interferes 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).

Soman 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).

VX (nerve agent) 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 recent years, VX was found to be the agent used in the assassination of Kim Jong-nam. 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.

M687 155 mm projectile

The M687 is an American 155 mm binary sarin chemical artillery shell. The design was standardized in 1976 and production began on December 16, 1987 at Pine Bluff Arsenal, Pine Bluff, Arkansas. Production was halted three years later, following the 1990 Chemical Weapons Accord between America and the USSR, and the dismantling of existing stocks began in November 1997 at Hawthorne Army Depot, Nevada. America's remaining stocks were stored at the Deseret Chemical Depot, Utah, and the Umatilla Chemical Depot.

Binary chemical weapons or munitions are chemical weapons which contain the toxic agent in its active state as chemical precursors that are significantly less toxic than the agent. This improves the safety of storing, transporting, and disposing of the weapon. Commonly, firing the munition removes a barrier between two precursors. These react to form the intended agent which is then aerosolized and distributed by a bursting charge.

Cyclosarin or GF is an extremely toxic substance used as a chemical weapon. It is a member of the G-series family of nerve agents, a group of chemical weapons discovered and synthesized by a German team led by Dr. Gerhard Schrader. The major nerve gases are the G agents, sarin (GB), soman (GD), tabun (GA), and the V agents such as VX. The original agent, tabun, was discovered in Germany in 1936 in the process of work on organophosphorus insecticides. Next came sarin, soman and finally, cyclosarin, a product of commercial insecticide laboratories prior to World War II.

Chemical weapon proliferation Prevalence and spread of chemical weapons

Many nations continue to research and/or stockpile chemical weapon agents despite numerous efforts to reduce or eliminate them. Most states have joined the Chemical Weapons Convention (CWC), which required the destruction of all chemical weapons by 2012. Twelve nations have declared chemical weapons production facilities and six nations have declared stockpiles of chemical weapons. All of the declared production facilities have been destroyed or converted to civilian use after the treaty went into force.

Pine Bluff Arsenal United States Army arsenal

The Pine Bluff Arsenal is a United States Army installation in Jefferson County, Arkansas, about eight miles northwest of Pine Bluff and thirty miles southeast of Little Rock.

QL (chemical) Chemical compound

Isopropyl aminoethylmethyl phosphonite, also known as O-(2-diisopropylaminoethyl) O′-ethyl methylphosphonite, is a precursor chemical to the nerve agent VX and VR-56. It is a colorless liquid with a strong fishy odor, and is slightly soluble in water.

Chemical weapon Device that uses chemicals to kill or harm individuals

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."

Methylphosphonyl dichloride Chemical compound

Methylphosphonyl dichloride (DC) or dichloro is an organophosphorus compound. It has a number of commercial uses but is most notable as being a precursor to several chemical weapons agents. It is a white crystalline solid that melts slightly above room temperature.

There have been numerous reports of chemical weapons attacks in the Syrian Civil War, beginning in 2012, and corroborated by national governments, the United Nations (UN), the Organisation for the Prohibition of Chemical Weapons (OPCW), Human Rights Watch (HRW), and media organizations. The attacks occurred in different areas of Syria, including Khan al-Assal, Jobar, Saraqib, Ashrafiyat Sahnaya, Kafr Zita, Talmenes, Sarmin and Douma. The deadliest attacks were the August 2013 sarin attack in Ghouta and the April 2017 sarin attack in Khan Shaykhun. The most common agent used is chlorine, with sarin and sulphur mustard also reported. Almost half of the attacks between 2014 and 2018 were delivered via aircraft and less than a quarter were delivered from the ground, with the remaining attacks having an undetermined method of delivery.

Destruction of Syrias chemical weapons Part of the Syrian peace process

The destruction of Syria's chemical weapons began on 14 September 2013 after Syria entered into several international agreements which called for the elimination of Syria's chemical weapon stockpiles and set a destruction deadline of 30 June 2014. Also on 14 September 2013, Syria acceded to the Chemical Weapons Convention (CWC) and agreed to its provisional application pending its entry into force on 14 October. Having acceded to the CWC, the Organisation for the Prohibition of Chemical Weapons (OPCW) Executive Council on 27 September approved a detailed implementation plan that required Syria to assume responsibility for and follow a timeline for the destruction of Syrian chemical weapons and Syrian chemical weapon production facilities. Following the signing of the Framework Agreement on 14 September 2013 and after the OPCW implementation plan, on 27 September the United Nations Security Council unanimously adopted Resolution 2118 which bound Syria to the timetable set out in the OPCW implementation plan. The joint OPCW-UN mission was established to oversee the implementation of the destruction program.

The OPCW Fact-Finding Mission in Syria is a mission of the Organisation for the Prohibition of Chemical Weapons (OPCW) to investigate some possible cases of the use of toxic chemicals in Syria during the civil war, including chlorine. The 21 August 2013 Ghouta chemical attack used sarin. The OPCW-Director General Ahmet Üzümcü announced the creation of the mission on 29 April 2014. This initial mission was headed by Malik Ellahi. The Syrian Government agreed to the Mission.

OPA is a mixture of isopropyl alcohol and isopropylamine that is used for production of the sarin nerve agent. The mixture reacts with methylphosphonyl difluoride to produce sarin.

References

  1. 1 2 3 4 Handbook of chemical and biological warfare agents (2nd ed.). CRC Press. ISBN   9780849314346.
  2. "Physical properties of standard agents, candidate agents, and related compounds at several temperatures" (PDF). Archived (PDF) from the original on February 26, 2017.
  3. U. S. Army (12 Dec 1990). Potential Military Chemical/Biological Agents and Compounds (PDF). Washington, D.C.: Headquarters, Dept. of the Army. Retrieved 12 May 2020.
  4. Organization for the Prohibition of Chemical Weapons (OPCW). "U.S. Completes Destruction of Sarin Precursors from Syria on the Cape Ray". OPCW News. Retrieved 12 May 2020.
  5. Trapp, Dr. Ralf. "Lessons Learned from the OPCW Mission in Syria" (PDF). OPCW. Retrieved 12 May 2020.