Synthesis, crystal structure and Hirshfeld surface analysis of hexa­aqua­nickel(II) bis­(4-hy­droxy­benzoate) dihydrate

The title compound, [Ni(H(2)O)(6)](PHB)(2)·2H(2)O (1) (PHB = 4-hy­droxy­benzoate, C(7)H(5)O(3)), was obtained by the reaction of NiCl(2), 4-hy­droxy­benzoic acid (PHBA) and mono­ethano­lamine in aqueous ethanol solution. The Ni(II) ion is coordinated by six water mol­ecules and is located on an inversion center. The outer coordination sphere in the asymmetric unit comprises one PHB anion and one water mol­ecule, i.e. the compound is a salt and a hydrate consisting of three components. In the crystal, the components are packed into an inter­molecular network stabilized by O—H⋯O hydrogen bonds. A comprehensive Hirshfeld surface analysis was carried out to investigate the inter­molecular inter­actions in detail.