title: Tricyclohexylphosphine
text: # Tricyclohexylphosphine
  
  Tricyclohexylphosphine is the tertiary phosphine with the formula $P(C_6H_{11})_3.$ Commonly used as a ligand in organometallic chemistry, it is often abbreviated to $PCy_3,$ where Cy stands for cyclohexyl. It is characterized by both high basicity $(pK_a$ = 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.
  
  * Grubbs' catalyst (first generation)
  * Crabtree's catalyst
  