Methylphosphonyl difluoride

Methylphosphonyl difluoride
Names
	Preferred IUPAC name Methylphosphonic difluoride
	Other names Methylphosphonyl difluoride; Methylphosphonoyl difluoride, EA-1251
Identifiers
CAS Number	676-99-3;
3D model (JSmol)	Interactive image;
Beilstein Reference	4-04-00-03508
ChemSpider	62813;
MeSH	difluoride Methylphosphonic difluoride
PubChem CID	69610;
CompTox Dashboard (EPA)	DTXSID5060980 ;
	InChI InChI=1S/CH3F2OP/c1-5(2,3)4/h1H3 Key: PQIOSYKVBBWRRI-UHFFFAOYSA-N;
	SMILES CP(F)(F)=O;
Properties
Chemical formula	CH3POF2
Molar mass	100.00
Appearance	Colorless liquid
Odor	Pungent, acid-like
Density	1.359 g/mL (77°F)
Melting point	−37 °C; −35 °F; 236 K
Boiling point	100 °C; 212 °F; 373 K
Solubility in water	Decomposes
Vapor pressure	36 mmHg (77°F)
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). Infobox references

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 in the sense of 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.

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. It has a boiling point of only 55.4 °C at normal atmospheric pressure, and thus a fairly high vapor pressure at room temperature.

References

^ ^a ^b ^c ^d ^e ^f Handbook of chemical and biological warfare agents (2nd ed.). CRC Press. ISBN 9780849314346.
^ "Physical properties of standard agents, candidate agents, and related compounds at several temperatures" (PDF).
^ 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.

[book-1] ^ ^a ^b ^c ^d ^e ^f 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).

[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.

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