Isolation and Structures of Polyarene Palladium Nanoclusters.

We report that surrounding coordination of neutral six-membered arene rings affords molecularly well-defined organotransition metal nanoclusters. With the use of [2.2]paracyclophane as the face-capping arene ligand, we have isolated two polyarene palladium nanoclusters, one consisting of a hexakis-arene ligand shell and a hexagonal close-packed Pd anticuboctahedron trichloride core, and the other consisting of an octakis-arene ligand shell and a non-close-packed Pd square gyrobicupola dichloride core, both with Pd-Pd direct bonding.