μ-2,2′,6,6′-Tetramethyl-4,4′-bipyridine-κ²N¹:N^1′-bis[(diethylenetriamine-κ³N,N′,N′′)palladium(II)] tetranitrate

The title compound, [Pd₂(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 P2₁/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.