Bis(benzonitrile)palladium(II) Dihalides:  Structures and Cocrystallization of the Cubic Cluster Pd₆Cl₁₂ with (E)-Stilbene and with Bis(benzonitrile)palladium(II) Dichloride

Abstract

Crystals of the planar, trans complexes, bis(benzonitrile)palladium(II) dichloride and bis(benzonitrile)palladium(II) dibromide, suitable for single-crystal X-ray diffraction studies are obtained by growth from solutions in benzonitrile and their structures determined. While bis(benzonitrile)palladium(II) dichloride readily loses benzonitrile to form the cubic cluster Pd6Cl12, which cocrystallizes with a variety of planar aromatic hydrocarbon molecules, the much less soluble complex bis(benzonitrile)palladium(II) dibromide does not act as a source of the so far unknown cluster Pd6Br12. Attempts to prepare the hypothetical bis(benzonitrile)palladium(II) diiodide by reaction of PdI2 with benzonitrile were not successful. A solution of bis(benzonitrile)palladium(II) dichloride in p-xylene on standing produces crystals of Pd6Cl12·(PhCN)2PdCl2·p-xylene, which contain columns of alternating Pd6Cl12 and (PhCN)2PdCl2 molecules in face-to-face orientations along with similar columns in which Pd6Cl12 and p-xylene molecules are interleaved in face-to-face arrays. A solution of bis(benzonitrile)palladium(II) dichloride and (E)-stilbene in benzene solution leads, not to coordination of palladium to the olefin, but to deposition of crystals of the ternary molecular compound, Pd6Cl12·0.5((E)-stilbene)·2(benzene). In this solid, two Pd6Cl12 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 palladium cluster. Additionally, one of the two benzene rings abuts the Pd6Cl12 cluster in a face-to-face fashion.

A Supramolecular Palladium Catalyst Displaying Substrate Selectivity by Remote Control

“…[16d,e,n,o] Other methods, such as UV/Vis,I R, and 13 CNMR spectroscopy,w ere, however,i nconclusived ue to the very small spectroscopicc hanges associated with the Pd···NC interaction. [26] On the other hand, the proton signals of the palladium-coordinated acetate ligandsw ere observed as am ajor singlet at d = 2.03 ppm duringt he titration of [Pd(OAc) 2 ]w ith L2 (see FigureS28 in the Supporting Information). With increasinga mount of palladium,v ery minor proton signals began to appear at d % 1.90-2.05 ppm (see Figure S30 in the Supporting Information), which could indicate the presence of acetate ligandsb ridging two palladium ions according to literature precedents.…”

N-heterocyclic carbene complexes of palladium in oxygen atom transfer reactions involving the making and breaking of N-O bonds

“…2) Å. 30 Also the Pd1−N4 distance of 2.050(4) Å to the amide group is close in values to that found in a related cyclopalladium complex, 1.956(2) Å. 31 The cyclic arrangement of atoms with palladium is quite rare and there are only two other reported crystal structures that have that same arrangement of 5 atoms 32 .…”

Fascinating Structures of a Mixed Valence [MnIII]·[MnIIMnIII] Cocrystal and a MnIIINaIComplex: Slow Magnetic Relaxation and Theoretical Investigations

“…Cocrystals or multicomponent molecular crystals, as described by Desiraju et al, , are a type of crystalline single phase material, containing a stoichiometric ratio of two or more molecules bound together in crystal lattices through noncovalent interactions, which have greatly impacted crystal engineering and therefore the pharmaceutical industry, − since organic cocrystals enhance bioavailability of drugs in physiological systems. Similarly, inorganic cocrystals may be very effective in optimizing catalytic outcomes.…”