The Pd(I) dimer [(Pd(mu-PtBu2)(PtBu2H)}2] reacts with dioxygen in toluene giving the hydrogenation catalyst [Pd(O2PtBu2)(OPtBu2) (HOPtBu2)], 2. The X-ray crystal structure of 2 has shown an unprecedented coordination mode of the phosphinato-ligand, both its oxygen atoms being coordinated to the same Pd atom.