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| Names | |||
|---|---|---|---|
| Preferred IUPAC name Trimethyl phosphite[1] | |||
| Other names Trimethoxyphosphine Trimethoxyphosphane | |||
| Identifiers | |||
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3D model (JSmol) | |||
| ChEBI | |||
| ChemSpider |
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| ECHA InfoCard | 100.004.065 | ||
| UNII | |||
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| Properties | |||
| C3H9O3P | |||
| Molar mass | 124.08 | ||
| Appearance | colorless liquid | ||
| Odor | distinctive, pungent[2] | ||
| Density | 1.052 | ||
| Melting point | −78 °C (−108 °F; 195 K) | ||
| Boiling point | 111 °C (232 °F; 384 K) | ||
| reacts[2] | |||
| Vapor pressure | 24 mmHg (25°C)[2] | ||
| Hazards | |||
| Flash point | 28 °C; 82 °F; 301 K[2] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) | none[2] | ||
REL (Recommended) | TWA 2 ppm (10 mg/m3)[2] | ||
IDLH (Immediate danger) | N.D.[2] | ||
| Related compounds | |||
Related compounds | Dimethyl methylphosphonate | ||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Trimethyl phosphite is anorganophosphorus compound with theformula P(OCH3)3, often abbreviated P(OMe)3. It is a colorless liquid with a highly pungent odor. It is the simplestphosphite ester and finds used as aligand inorganometallic chemistry and as a reagent inorganic synthesis. The molecule features a pyramidal phosphorus(III) center bound to threemethoxy groups.
Trimethyl phosphite is in principle obtainable by methanolysis ofphosphorus trichloride, say in the presence of a proton accepting base. This method suffers from numerous side reactions however. The use ofsodium methoxide is superior:[3]
Trimethyl phosphite is susceptible to oxidation totrimethyl phosphate:
It reacts with a catalytic amount of methyl iodide in theArbuzov reaction to givedimethyl methylphosphonate:
As a ligand, trimethyl phosphite has a smallercone angle and better acceptor properties relative totrimethylphosphine. A representative derivative is the colorless tetrahedral complex Ni(P(OMe)3)4 (m.p. 108 °C).[4] The tridentate ligand called theKläui ligand is derived from trimethyl phosphite. The formation of this ligand illustrates the susceptibility of trimethyl phosphite (and metal complexes thereof) to the Arbuzov reaction.
Trimethyl phosphite is also used as a mild desulfurization reagent in organic synthesis, for example in the preparation of derivatives oftetrathiafulvalene.[5]
TheLD50 is 1600–2890 mg/kg (oral, rat).[6]
