Crystal structure of hexa-aqua-nickel(II) bis-{5-bromo-7-[(2-hy-droxy-eth-yl)amino]-1-methyl-6-oxido-quinolin-1-ium-3-sulfonate} monohydrate.

The asymmetric unit of the title compound, [Ni(H2O)6](C12H12BrN2O5S)2·H2O, contains a half hexa­aqua­nickel(II) complex cation with the NiII ion lying on an inversion center, one 5-bromo-7-[(2-hy­droxy­eth­yl)amino]-1-methyl-6-oxido­quinolin-1-ium-3-sulfonate (QAO) anion and a half lattice water mol­ecule on a twofold rotation axis. In the crystal, QAO anions are stacked in a column along the c axis by π–π stacking inter­actions [centroid–centroid distances 3.5922 (10)–3.7223 (11) A]. The columns are inter­linked by hexa­aqua­nickel(II) cations through O—H⋯O and N—H⋯O hydrogen bonds.