Tricyclohexylphosphine

Tricyclohexylphosphine is the tertiary phosphine with the formula P(C₆H₁₁)₃. Commonly used as a ligand in organometallic chemistry, it is often abbreviated to PCy₃, where Cy stands for cyclohexyl. It is characterized by both high basicity (pK_a = 9.7)[1] and a large ligand cone angle (170°).[2][3]

Tricyclohexylphosphine

Names
IUPAC name Tricyclohexylphosphane
Other names P(Cy)3 PCy3
Identifiers
CAS Number	2622-14-2
3D model (JSmol)	Interactive image Interactive image
ChemSpider	68315
ECHA InfoCard	100.018.246
PubChem CID	75806
CompTox Dashboard (EPA)	DTXSID9062562
InChI InChI=1S/C18H33P/c1-4-10-16(11-5-1)19(17-12-6-2-7-13-17)18-14-8-3-9-15-18/h16-18H,1-15H2 Key: WLPUWLXVBWGYMZ-UHFFFAOYSA-N InChI=1/C18H33P/c1-4-10-16(11-5-1)19(17-12-6-2-7-13-17)18-14-8-3-9-15-18/h16-18H,1-15H2 Key: WLPUWLXVBWGYMZ-UHFFFAOYAM
SMILES C1(CCCCC1)P(C2CCCCC2)C3CCCCC3 C1CCC(CC1)P(C2CCCCC2)C3CCCCC3
Properties
Chemical formula	C18H33P
Molar mass	280.43 g mol^−1
Appearance	white solid
Melting point	82 °C (180 °F; 355 K)
Solubility in water	organic solvents
Hazards
Main hazards	toxic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Important complexes containing P(Cy)₃ ligands include the 2005 Nobel Prize-winning Grubbs' catalyst and the homogeneous hydrogenation catalyst Crabtree's catalyst.

• 
  Grubbs' catalyst (first generation)
• 
  Crabtree's catalyst

References

1. Streuli, C. A. (1960). "Determination of Basicity of Substituted Phosphines by Nonaqueous Titrimetry". Anal. Chem. 32: 985–987. doi:10.1021/ac60164a027.
2. Bush, R. C.; Angelici, R. J. (1988). "Phosphine basicities as determined by enthalpies of protonation". Inorg. Chem. 27 (4): 681–686. doi:10.1021/ic00277a022.
3. Immirzi, A.; Musco, A. (1977). "A Method to Measure the Size of Phosphorus Ligands in Coordination Complexes". Inorg. Chim. Acta. 25: L41–42. doi:10.1016/S0020-1693(00)95635-4.