Methylphosphine

Methylphosphine is the simplest organophosphorus compound with the formula CH₃PH₂, often written MePH₂. It is a malodorous gas that condenses to a colorless liquid. It can be produced by methylation of phosphanide salts:^[1]

KPH₂ + MeI → MePH₂ + KI

Methylphosphine

Names
Other names Methylphosphane
Identifiers
CAS Number	593-54-4
3D model (JSmol)	Interactive image
ChEBI	CHEBI:35887
ChemSpider	62195
PubChem CID	68973
CompTox Dashboard (EPA)	DTXSID00208029
InChI InChI=1S/CH5P/c1-2/h2H2,1H3 Key: SAWKFRBJGLMMES-UHFFFAOYSA-N InChI=1/CH5P/c1-2/h2H2,1H3 Key: SAWKFRBJGLMMES-UHFFFAOYAG
SMILES CP
Properties
Chemical formula	CH3PH2
Molar mass	48.02
Appearance	colorless gas
Boiling point	−17.1 °C (1.2 °F; 256.0 K)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	toxic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Reactions

The compound exhibits the properties characteristic of a primary phosphine, i.e., a compound of the type RPH₂. It can be oxidized to methylphosphonous acid:

MePH₂ + O₂ → MeP(H)O₂H

It protonates to give a phosphonium ion:

MePH₂ + H⁺ → MePH₃⁺

With strong bases, it can be deprotonated to give methylphosphanide derivatives:

MePH₂ + KOH → K[MePH] + H₂O