Tris(4-chlorophenyl)phosphine is primarily used as a ligand in coordination chemistry and catalysis. It is often employed in the synthesis of organometallic compounds, where it facilitates various transition metal-catalyzed reactions, such as cross-coupling reactions, hydrogenation, and hydroformylation. Its electron-withdrawing chlorophenyl groups enhance the stability and reactivity of the metal complexes it forms, making it valuable in creating efficient catalytic systems. Additionally, it finds applications in the development of phosphorescent materials and organic light-emitting diodes (OLEDs), where it contributes to the tuning of electronic properties. In research, it is utilized as a reagent for studying phosphine-based chemistry and designing novel catalysts for organic transformations.