Diammonium tetra­kis­(iso­thio­cyanato)­zincate–1,4,10,13,16-hexa­oxa­cyclo­octa­deca­ne–water (1/2/1)

The title compound, (NH(4))(2)[Zn(NCS)(4)]·2C(12)H(24)O(6)·H(2)O, the result of the reaction of ammonium thio­cyanate, 18-crown-6 and zinc(II) chloride in aqueous solution, exhibits an unusual supra­molecular structure. The Zn atom, two of the thio­cyanate chains and a water mol­ecule, disordered over two positions, lie on a mirror plane. The macrocycle adopts a conformation with approximate D (3d) symmetry. The ammonium mol­ecules are contained within the bowl of the macrocycle via extensive N—H⋯O hydrogen bonds and the complex mol­ecules are linked via N—H⋯S hydrogen bonds, forming chains along the c-axis direction. The macrocycle is disordered over two positions [refined occupancy ratio = 0.666 (8):0.334 (8)]. The S atoms of two iso­thio­cyanate ligands are disordered within and about the mirror plane.