Palladium tetrakis

Other names: Tetrakis(triphenylphosphane)palladium(0), TPP palladium(0), tetrakis

C₇₂H₆₀P₄Pd

8/50 common

Palladium tetrakis (or simply 'tetrakis', as the cool kids call it) is a widely used Pd⁽⁰⁾ complex that serves as a versatile catalyst in cross-coupling reactions such as Suzuki, Heck, and Stille couplings. Its structure consists of a central palladium atom coordinated tetrahedrally to four bulky triphenylphosphine (PPh₃) ligands, which stabilize the metal in its zero oxidation state while allowing it to participate in oxidative addition reactions. First synthesized in the mid-20th century, it has become a cornerstone of modern organometallic chemistry. In its pure form, palladium tetrakis appears as a bright yellow crystalline solid, air-sensitive but soluble in many organic solvents. When used as a catalyst, it must be handled under rigorously inert conditions lest it oxidize in air and crash out an infamous precipitate of "palladium black".