A second solvatomorph of poly[[μ(4)-N,N′-(1,3,5-oxadiazinane-3,5-di­yl)bis­(carbamoyl­methano­ato)]nickel(II)dipotassium]: crystal structure, Hirshfeld surface analysis and semi-empirical geometry optimization

The title compound, poly[tri­aqua­bis­[μ(4)-N,N′-(1,3,5-oxadiazinane-3,5-di­yl)bis(carbamoyl­methano­ato)]dinickel(II)tetra­potassium], [K(4)Ni(2)(C(7)H(6)N(4)O(7))(2)(H(2)O)(3)]( n ), is a second solvatomorph of poly[(μ(4)-N,N′-(1,3,5-oxadiazinane-3,5-di­yl)bis­(carbamoyl­methano­ato)nickel(II)dipotassium] reported previously [Plutenko et al. (2021 ▸). Acta Cryst. E77, 298–304]. The asymmetric unit of the title compound includes two structurally independent complex anions [Ni(C(7)H(6)N(4)O(7))](2−), which exhibit an L-shaped geometry and consist of two almost flat fragments perpendicular to one another: the 1,3,5-oxadiazinane fragment and the fragment including other atoms of the anion. The central Ni atom is in a square-planar N(2)O(2) coordination arrangement formed by two amide N and two carboxyl­ate O atoms. In the crystal, the title compound forms a layered structure in which layers of negatively charged complex anions and positively charged potassium cations are stacked along the a-axis direction. The polymeric framework is stabilized by a system of hydrogen-bonding inter­actions in which the water mol­ecules act as donors and the carb­oxy­lic, amide and water O atoms act as acceptors.