Bis(benzonitrile)palladium(II) dihalides: Structures and cocrystallizationof the cubic cluster Pd6Cl12 with (E)-stilbene and with bis(benzonitrile)palladium(II) dichloride

Crystals of the planar, trans complexes, bis(benzonitrile)palladium(II) dic hloride and bis(benzonitrile)palladium(II) dibromide, suitable for single-c rystal X-ray diffraction studies are obtained by growth from solutions in b enzonitrile and their structures determined. While bis(benzonitrile)palladi um(II) dichloride readily loses benzonitrile to form the cubic cluster Pd6C l12, which cocrystallizes with a variety of planar aromatic hydrocarbon mol ecules, the much less soluble complex bis(benzonitrile)palladium(II) dibrom ide does not act as a source of the so far unknown cluster Pd6Br12 Attempts to prepare the hypothetical bis(benzonitrile)palladium(II) diiodide by rea ction of PdI2 with benzonitrile were not successful. A solution of bis(benz onitrile)palladium(II) dichloride in p-xylene on standing produces crystals of Pd6Cl12.(PhCN)(2)PdCl2. p-xylene, which contain columns of alternating Pd6Cl12 and (PhCN)(2)PdCl2 molecules in face-to-face orientations along wit h similar columns in which Pd6Cl12 and p-xylene molecules are interleaved i n face-to-face arrays. A solution of bis(benzonitrile)palladium(II) dichlor ide and (E)stilbene in benzene solution leads, not to coordination of palla dium to the olefin, but to deposition of crystals of the ternary molecular compound, Pd6Cl12. 0.5((E)-stilbene). 2(benzene). In this solid, two Pd6Cl1 2 clusters make face-to-face contact with phenyl rings on opposite sides of the (E)-stilbene molecule, but the olefinic portion is far from the pallad ium cluster. Additionally, one of the two benzene rings abuts the Pd6Cl12 c luster in a face-to-face fashion.