dimethylphosphine
{{Chembox
| ImageFile = Me2PH.png
| ImageSize = 124px
| ImageAlt =
| PIN = Dimethylphosphane
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 676-59-5
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = DRV85A28TP
| PubChem = 69607
| ChemSpiderID = 62810
| SMILES = CPC
| StdInChI = 1S/C2H7P/c1-3-2/h3H,1-2H3
| StdInChIKey = YOTZYFSGUCFUKA-UHFFFAOYSA-N}}
|Section2={{Chembox Properties
| Formula = {{chem2|(CH3)2PH}}
| C=2|H=7|P=1
| Appearance = Colorless gas or colorless liquid
| Odor = Malodorous
| Density =
| MeltingPt =
| BoilingPt = 21.1 °C
| Solubility = }}
|Section7={{Chembox Hazards
| MainHazards = toxic
| FlashPt =
| AutoignitionPt = }}
}}
Dimethylphosphine is the organophosphorus compound with the formula {{chem2|(CH3)2PH}}, often written {{chem2|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:A. Trenkle, H. Vahrenkamp “Dimethylphosphine” Inorganic Syntheses 1982, volume 21, p. 180. {{doi|10.1002/9780470132524.ch40}}
:{{chem2|(CH3)2P(S)\sP(S)(CH3)2 + P((CH2)3CH3)3 + H2O → (CH3)2PH + SP((CH2)3CH3)3 + (CH3)2P(O)(OH)}}
Reactions
The compound exhibits the properties characteristic of a secondary phosphine, i.e., a compound of the type {{chem2|R2PH}}. It can be oxidized to the phosphinic acid:
:{{chem2|(CH3)2PH + O2 → (CH3)2P(O)(OH)}}
It can be protonated to give the dimethylphosphonium ion:
:{{chem2|(CH3)2PH + H+ → [(CH3)2PH2]+}}
With strong bases (e.g., lithium amide, it can be deprotonated to give dimethyl phosphide derivatives (e.g., lithium dimethyl phosphide):
:{{chem2|(CH3)2PH + LiNH2 → (CH3)2PLi + NH3}}