Bis(4-aminopyridinium) hexaaquanickel(II) bis(sulfate)

In the title compound, (C 5 H 7 N 2 ) 2 [Ni(H 2 O) 6 ](SO 4 ) 2 , the Ni II cation is located on an inversion centre and is coordinated by six aqua ligands in a slightly distorted octahedral coordination environment. The [Ni(H 2 O) 6 ] 2+ ions are connected through an extensive network of O—H...O hydrogen bonds to sulfate anions, leading to the formation of layers parallel to (001). The 4-aminopyridinium cations are located between these layers and are connected to the anionic framework by N—H...O hydrogen bonds. Weak π–π interactions between the pyridine rings, with a centroid–centroid distance of 3.754 (9) Å, provide additional stability to the crystal packing.