Dimethylphosphine

Dimethylphosphine

Names
Other names dimethylphosphane
Identifiers
CAS Number	676-59-5
Properties
Chemical formula	C2H7P
Molar mass	62.05
Appearance	colorless gas
Boiling point	21.1 °C
Hazards
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

Dimethylphosphine is the organophosphorus compound with the formula (CH₃)₂PH, often written Me₂PH. It is a malodorous gas that condenses to a colorless liquid just below room temperature. Although it can be produced by methylation of phosphine, a more practical synthesis involves the reduction of tetramethyldiphosphine disulfide with tributylphosphine:^[1]

[Me₂P(S)]₂ + PBu₃ + H₂O → Me₂PH + SPBu₃ + Me₂P(O)H

Reactions

The compound exhibits the properties characteristic of a secondary phosphine, i.e., a compound of the type R₂PH. It can be oxidized to the phosphinic acid:

Me₂PH + O₂ → Me₂PO₂H

It protonates to give the phosphonium ion:

Me₂PH + H⁺ → Me₂PH₂⁺

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

Me₂PH + LiNH₂ → Me₂PLi + NH₃

References