μ-2,2′,6,6′-Tetramethyl-4,4′-bipyridine-κ2N1:N1′-bis[(diethylenetriamine-κ3N,N′,N")palladium(II)] tetranitrate

The title compound, [Pd-2(C4H13N3)(2)(C14H16N2)](NO3)(4), comprises discrete tetracationic dumbbell-type dinuclear complex molecules and noncoordinating nitrate anions. Two Pd(dien)(2+) moieties (dien is diethylenetriamine) are joined by the rigid linear exo-bidentate bridging 2,2',6,6'-tetramethyl-4,4'-bipyridine ligand to form the dinuclear complex, which lies across a centre of inversion in the space group P2(1)/n, so that the rings in the 2,2',6,6'-tetramethyl-4,4'-bipyridine bridging ligand are parallel. In the crystal, the primary and secondary amino groups of the dien ligand act as hydrogen-bond donors towards the nitrate anions to form a three-dimensional hydrogen-bond network.