Tris(1,10-phenanthroline)nickel(II) dichromate tetrahydrate

The asymmetric unit of the title compound, [Ni(C(12)H(8)N(2))(3)][Cr(2)O(7)]center dot 4H(2)O, contains one cation, one anion and four water molecules, three of which are disordered over two sites with equal occupancies. In the cation, the metal centre is coordinated by six N atoms from three 1,10-phenanthroline ligands in a distorted octahedral geometry. The [Cr(2)O(7)](2-) anion exhibits a staggered conformation. The crystal packing is stabilized by intermolecular O-H center dot center dot center dot O hydrogen bonds and pi-pi interactions, evidenced by short distances of 3.531 (5) angstrom between the centroids of aromatic rings.