Activation of hydrogen by palladium(0): Formation of the mononuclear dihydride complex trans-[Pd(H)2(IPr)(PCy3)]

In sharp contrast with the general behavior of Pd⁰ complexes, [Pd(IPr)(PCy₃)] is able to activate the H-H bond. The resulting trans-[Pd(H)₂(IPr)(PCy₃)] is the first isolated mononuclear dihydride palladium compound. Its formation is supported by multinuclear NMR spectroscopy, density functional calculations, and X-ray diffraction studies. The stability and reactivity of this new species are examined.