Complexation of pyrene in aqueous solution with a self-assembled palladium metallocycle.

A bidentate ligand based on N-monoaryl 4,4'-bipyridinium undergoes self-assembly to dinuclear rectangular metallocycles upon coordination to palladium(II) and platinum(II) centers. These metallocycles form a very stable complex with pyrene in aqueous solution and in the solid state. A crystal structure of the pyrene inclusion complex is presented. The association constants between pyrene and metallocycle 3a in organic solvents and water (K(a) = 2.3 x 10(6)) were determined.