Editing Palladium (section)

===Palladium(0)===
Palladium forms a range of zerovalent complexes with the formula PdL<sub>4</sub>, PdL<sub>3</sub> and PdL<sub>2</sub>. For example, reduction of a mixture of PdCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub> and PPh<sub>3</sub> gives [[tetrakis(triphenylphosphine)palladium(0)]]:<ref>{{cite book |volume=13 |pages=121–124 |first1=D. R. |last1=Coulson |doi=10.1002/9780470132449.ch23 |date=1972 |last2=Satek |first2=L. C. |last3=Grim |first3=S. O. |series=[[Inorganic Syntheses]] |title=Tetrakis(triphenylphosphine)palladium(0) |isbn=978-0-470-13244-9}}</ref>

{{block indent|2 PdCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub> + 4 PPh<sub>3</sub> + 5 [[Hydrazine|N<sub>2</sub>H<sub>4</sub>]] → 2 Pd(PPh<sub>3</sub>)<sub>4</sub> + N<sub>2</sub> + 4 N<sub>2</sub>H<sub>5</sub><sup>+</sup>Cl<sup>−</sup>}}

Another major palladium(0) complex, [[tris(dibenzylideneacetone)dipalladium(0)]] (Pd<sub>2</sub>(dba)<sub>3</sub>), is prepared by reducing [[sodium tetrachloropalladate]] in the presence of [[dibenzylideneacetone]].<ref>{{cite journal |doi=10.1039/C29700001065 |title=A novel palladium(0) complex; bis(dibenzylideneacetone)palladium(0) |journal=Journal of the Chemical Society D: Chemical Communications |issue=17 |pages=1065 |year=1970 |last1=Takahashi |first1=Y |last2=Ito |first2=Ts |last3=Sakai |first3=S |last4=Ishii |first4=Y}}</ref>

Palladium(0), as well as palladium(II), are catalysts in [[palladium-catalyzed coupling reactions|coupling reactions]], as has been recognized by the 2010 [[Nobel Prize in Chemistry]] to [[Richard F. Heck]], [[Ei-ichi Negishi]], and [[Akira Suzuki]]. Such reactions are widely practiced for the synthesis of fine chemicals. Prominent coupling reactions include the [[Heck reaction|Heck]], [[Suzuki reaction|Suzuki]], [[Sonogashira coupling]], [[Stille reaction]]s, and the [[Kumada coupling]]. [[Palladium(II) acetate]], [[tetrakis(triphenylphosphine)palladium(0)]] (Pd(PPh<sub>3</sub>)<sub>4</sub>), and [[tris(dibenzylideneacetone)dipalladium(0)]] (Pd<sub>2</sub>(dba)<sub>3</sub>) serve either as catalysts or precatalysts.<ref>{{cite book |chapter-url=https://books.google.com/books?id=WLb962AKlSEC&pg=PA392 |chapter=Application to Organic Synthesis |page=392 |title=The Organometallic Chemistry of the Transition Metals |first=Robert H. |last=Crabtree |publisher=John Wiley and Sons |date=2009 |isbn=978-0-470-25762-3}}</ref>