Dinuclear palladium(0) and platinum(0) complexes with p-benzoquinone and norbornene ligands

Palladium(0) and platinum(0) precursor complexes, Pd-2(dba)(3) and Pt(dba)(2), reacted with p-benzoquinone (bq) and norbornene (nbe) to afford new dinuclear complexes possessing p-benzoquinone as a bridging ligand and norbornene as a monodentate ligand, Pd-2(bq)(2)(nbe)(2) and Pt-2(bq)(2)(nbe)(2), respectively. The solid-state structure of the obtained complexes presented the short metal-metal distances similar to predecessors possessing the significant d(10)-d(10) bonding interaction. The formations of the previously reported mononuclear p-benzoquinone and p-naphthoquinone complexes using 1,5-cyclooctadiene in place of norbornene were also unambiguously confirmed by the single-crystal X-ray diffraction studies. The present dinuclear palladium complex proved to be an efficient catalyst precursor for the linear cotrimerization of 1-octene and dimethyl acetylenedicarboxylate. On the other hand, the platinum analogue catalyzed the hydrosilylation of styrene under mild reaction conditions.