Synthesis and characterization of binuclear palladium(I) compounds and the influence of competing arenes

The binuclear palladium(I) compounds, [Pd2(Ga2Cl7)2(C7H8)2] (1), [Pd2(GaCl4)2(C9H12)2]·C9H12 (2) and [Pd2(Ga2Cl7)2(C6H5Cl)2] (3), have been prepared from palladium(II) chloride in gallium(III) chloride-arene reaction media. All isolated crystalline solids (1, 2 and 3) have been structurally characterized by single crystal X-ray diffraction and Raman spectroscopy. The results form quantum chemical calculations on the interaction energies of the arenes and the dipalladium unit of these compounds is also presented.

With the aim of preparing new polynuclear palladium compounds supported by simple arenes or polyaromatic hydrocarbons, such as naphthalene, anthracene or biphenyl, the exceptional reductive ability of halide-arene mixtures was employed in reaction of palladium(II) chloride in gallium(III) chloride-arene reaction media. Three binuclear palladium(I) sandwich clusters were prepared using this reaction route, [Pd2(Ga2Cl7)2(C7H8)2], [Pd2(GaCl4)2(C9H12)2]·C9H12 and [Pd2(Ga2Cl7)2(C6H5Cl)2]. Quantum chemical calculations indicate a small difference in the interaction energies of the soft-base donors toluene, mesitylene and chlorobenzene.Figure optionsDownload as PowerPoint slide