Triethylphosphine

Triethylphosphine
Names
	Preferred IUPAC name Triethylphosphane
Identifiers
CAS Number	554-70-1;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:39971;
ChemSpider	25463;
ECHA InfoCard	100.008.245
EC Number	209-068-8;
Gmelin Reference	2485
PubChem CID	27365;
UNII	5W435D16PM;
CompTox Dashboard (EPA)	DTXSID3060293 ;
	InChI InChI=1S/C6H15P/c1-4-7(5-2)6-3/h4-6H2,1-3H3 Key: RXJKFRMDXUJTEX-UHFFFAOYSA-N;
	SMILES CCP(CC)CC;
Properties
Chemical formula	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:
Pictograms
Signal word	Danger
Hazard statements	H224, H225, H250, H314
Precautionary statements	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). Infobox references

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 C_3v 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]

Safety

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

References

^ 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.
^ Annette Schier and Hubert Schmidbaur "P-Donor Ligands" in Encyclopedia of Inorganic Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/0470862106.ia177
^ G. L. Miessler and D. A. Tarr Inorganic Chemistry, 3rd Ed, Pearson/Prentice Hall publisher, ISBN 0-13-035471-6.
^ 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.
^ 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.
^ 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.

[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.

[Schmidbaur-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.

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