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 (pKa = 9.7) and a large ligand cone angle (170°).
Important complexes containing P(Cy)3 ligands include the 2005 Nobel Prize-winning Grubbs' catalyst and the homogeneous hydrogenation catalyst Crabtree's catalyst.
References
Streuli, C. A. (1960). "Determination of Basicity of Substituted Phosphines by Nonaqueous Titrimetry". Anal. Chem. 32 (8): 985–987. doi:10.1021/ac60164a027. /wiki/Doi_(identifier) ↩
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. /wiki/Inorg._Chem. ↩
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. /wiki/Doi_(identifier) ↩