Triethylphosphine

Triethylphosphine
Names
Preferred IUPAC name
Triethylphosphane
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.008.245 Edit this at Wikidata
EC Number
  • 209-068-8
2485
UNII
  • InChI=1S/C6H15P/c1-4-7(5-2)6-3/h4-6H2,1-3H3
    Key: RXJKFRMDXUJTEX-UHFFFAOYSA-N
  • CCP(CC)CC
Properties
C6H15P
Molar mass 118.160 g·mol−1
Appearance colorless liquid
Density 0.802 g/cm3
Boiling point 127–128 °C (261–262 °F; 400–401 K)
Hazards
GHS labelling:
GHS02: FlammableGHS05: Corrosive
Danger
H224, H225, H250, H314
P210, P222, P233, P240, P241, P242, P243, P260, P264, P280, P301+P330+P331, P302+P334, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P370+P378, P403+P235, P405, P422, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Triethylphosphine is the organophosphorus compound with the formula P(CH2CH3)3, commonly abbreviated as PEt3. It is a colorless liquid with an unpleasant odor characteristic of alkylphosphines. The compound is a common ligand in organometallic chemistry, such as in auranofin.

Structure and simple reactions

It is a pyramidal molecule with approximate C3v symmetry.[1]

PEt3 is usually prepared using Grignard reagents:

3 CH3CH2MgCl + P(OC6H5)3 → P(CH2CH3)3 + 3 C6H5OMgCl

PEt3 reacts with strong acids to give salts [HPEt3]X.[2] This reaction is reversible. Similarly, it is also easily alkylated to give phosphonium derivatives. PEt3 is easily oxidised to the phosphine oxide with oxygen.

Coordination chemistry

Triethylphosphine is a highly basic ligand that forms coordination complexes with many metals. As a ligand, triethylphosphine's Tolman cone angle is 132°.[3] Being a relatively compact phosphine, several can bind to a single transition metal, as illustrated by the existence of Pt(PEt3)4.[4] As a phosphine ligand, triethylphosphine gained acceptance earlier than did the simpler trimethylphosphine, as illustrated by the preparation of the hydride complex trans-PtHCl(PEt3)2.[5]

Structure of Pt(PEt3)4.[6]

Safety

PEt3 is toxic. It converts to a low toxicity phosphine oxide upon treatment with sodium hypochlorite or hydrogen peroxide.

References

  1. ^ Bruckmann, J.; Krüger, C. (1995). "Trimethylphosphine and Triethylphosphine in the Solid State". Acta Crystallogr. C. 51 (6): 1155–1158. Bibcode:1995AcCrC..51.1155B. doi:10.1107/S0108270194014368.
  2. ^ Annette Schier and Hubert Schmidbaur "P-Donor Ligands" in Encyclopedia of Inorganic Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/0470862106.ia177
  3. ^ G. L. Miessler and D. A. Tarr Inorganic Chemistry, 3rd Ed, Pearson/Prentice Hall publisher, ISBN 0-13-035471-6.
  4. ^ Yoshida, T.; Matsuda, T.; Otsuka, S. (1990). "Tetrakis(Triethylphosphine)Platinum(0)". Inorganic Syntheses. Vol. 28. p. 122. doi:10.1002/9780470132593.ch32. ISBN 978-0-470-13259-3.
  5. ^ Joseph Chatt (1968). "Hydride Complexes". Science. 160 (3829): 723–729. Bibcode:1968Sci...160..723C. doi:10.1126/science.160.3829.723. PMID 17784306. S2CID 22350909.
  6. ^ Pospiech, S.; Bolte, M.; Lerner, H.-W.; Wagner, M. (2014). "Insertion Reactions into the Boron–Boron Bonds of Barrelene-Type 1,2-Diaminodiboranes(4)". Organometallics. 33 (23): 6967–6974. doi:10.1021/om501087u.