Synthesis, crystal structure and Hirshfeld surface analysis of bis-{2-[(pyridin-2-yl)amino]-pyridinium} tetra-cyano-nickelate(II).

In the title mol-ecular salt, (C10H10N3)2[Ni(CN)4], the dihedral angle between the pyridine rings in the cation is 1.92 (13)° and the complete anion is generated by a crystallographic centre of symmetry. An intra-molecular N-H⋯N hydrogen bond occurs in the cation, which closes an S(6) ring. In the crystal, the components are linked by N-H⋯N and weak C-H⋯N hydrogen bonds, which generate chains propagating in the [101] direction. Weak aromatic π-π stacking inter-actions are also observed. A Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contact types in the crystal packing are N⋯H/H⋯N, C⋯H/H⋯C and H⋯H with contributions of 37.2, 28.3 and 21.9%, respectively.