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

Abstract

The title compound, [Ni(H2O)6](PHB)2·2H2O (1) (PHB = 4-hydroxybenzoate, C7H5O3), was obtained by the reaction of NiCl2, 4-hydroxybenzoic acid (PHBA) and monoethanolamine in aqueous ethanol solution. The NiII 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.