Triethyl phosphite

Triethyl phosphite
Names
Preferred IUPAC name
Triethyl phosphite
Other names
Triethoxyphosphine
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.004.139
UNII
  • InChI=1S/C6H15O3P/c1-4-7-10(8-5-2)9-6-3/h4-6H2,1-3H3 Y
    Key: BDZBKCUKTQZUTL-UHFFFAOYSA-N Y
  • InChI=1/C6H15O3P/c1-4-7-10(8-5-2)9-6-3/h4-6H2,1-3H3
    Key: BDZBKCUKTQZUTL-UHFFFAOYAP
  • O(P(OCC)OCC)CC
Properties
C6H15O3P
Molar mass 166.157 g·mol−1
Appearance colorless liquid
Density 0.969 g/mL
Melting point −70 °C (−94 °F; 203 K)
Boiling point 156 °C (313 °F; 429 K) (57 to 58 °C at 16 mm)
Solubility soluble in most organic solvents
-104.8·10−6 cm3/mol
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).
Y verify (what is YN ?)
Infobox references

Triethyl phosphite (TEP) is an organophosphorus compound, specifically a phosphite ester, with the formula P(OCH2CH3)3, often abbreviated P(OEt)3. It is a colorless, malodorous liquid. It is used as a ligand in organometallic chemistry and as a reagent in organic synthesis.

The molecule features a pyramidal phosphorus(III) center bound to three ethoxide groups. Its 31P NMR spectrum features a signal at around +139 ppm vs phosphoric acid standard.

Triethylphosphite is prepared by treating phosphorus trichloride with ethanol in the presence of a base, typically a tertiary amine:

PCl3 + 3 EtOH + 3 R3N → P(OEt)3 + 3 R3NH + 3 Cl

In the absence of the base, the reaction of ethanol and phosphorus trichloride affords diethylphosphite ((EtO)2P(O)H). Of the many related compounds can be prepared similarly, triisopropyl phosphite is an example (b.p. 43.5 °C/1.0 mm; CAS# 116-17-6).