Methylphosphonyl difluoride

Methylphosphonyl difluoride

Names
Preferred IUPAC name Methylphosphonic difluoride
Other names Methylphosphonyl difluoride Methylphosphonoyl difluoride
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
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 called methyl difluorophosphite, methylphosphonic difluoride, and difluoromethylphosphine oxide, 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.