Pairwise Assembly of Organopalladium(II) Units with Cyanurato(3−) and Trithiocyanurato(3−) Ligands: Formation of Chiral Pd12, Pd10, and Pd9 Cage-Molecules

The o-palladated, chloro-bridged dimers [Pd­{2-phenylpyridine­(-H)}-μ-Cl]2 and [Pd­{N,N-dimethylbenzylamine­(-H)}-μ-Cl]2 react with cyanuric acid in the presence of base to afford closed, chiral cage-molecules in which 12 organo-Pd­(II) centers, located in pairs at the vertices of an octahedron, are linked by four tetrahedrally arranged cyanurato(3−) ligands. Incomplete (Pd10) cages, having structures derived from the corresponding Pd12 cages by replacing one pair of organopalladium centers with two protons, have also been isolated. Reaction of [Pd­{2-phenylpyridine­(-H)}-μ-Cl]2 with trithiocyanuric acid gives an entirely different and more open type of cage-complex, comprising only nine organopalladium centers and three thiocyanurato(3−) ligands: cage-closure in this latter system appears to be inhibited by steric crowding of the thiocarbonyl groups.