Diaqua­bis­(propane-1,3-diamine)­nickel(II) bis­(propane-1,3-diamine)­disulfato­nickelate(II)

The ionic Ni(II) title complex, [Ni(C(3)H(10)N(2))(2)(H(2)O)(2)][Ni(SO(4))(2)(C(3)H(10)N(2))(2)], is built up of [Ni(dipr)(2)(H(2)O)(2)](2+) complex cations and [Ni(dipr)(2)(SO(4))(2)](2−) complex anions (dipr is propane-1,3-diamine). Both Ni(II) atoms display a slightly distorted octa­hedral coordination and are located on inversion centers. There are several types of hydrogen-bonding inter­actions, which connect complex cations and anions into a two-dimensional network parallel to (010). Hydrogen bonds formed by the axially coordinated water mol­ecule of the complex cation and one of the O atoms of the sulfate groups of the complex anion (first type) link them into chains along the c axis. These chains are linked to each other through hydrogen bonds formed by an O atom (second type) of the SO(4) groups and NH(2) groups of the ligand of the complex cations from neighboring chains, forming a two-dimensional hydrogen-bonded net perpendicular to the b axis. The third type of O atoms of the sulfate groups of the complex anion are also linked into chains by a combination of both previously described types of H-atom connections.