Research Article: trans-Tetra­aqua­bis­(isonicotinamide-κN1)nickel(II) bis­(3-hy­droxy­benzoate) tetra­hydrate

Date Published: February 01, 2012

Publisher: International Union of Crystallography

Author(s): Ibrahim Göker Zaman, Nagihan Çaylak Delibaş, Hacali Necefoğlu, Tuncer Hökelek.


The asymmetric unit of the title compound, [Ni(C6H6N2O)2(H2O)4](C7H5O3)2·4H2O, contains one-half of the complex cation with the NiII ion located on an inversion center, a 3-hy­droxy­benzoate counter-anion and two uncoordinated water mol­ecules. Four water O atoms in the equatorial plane around the NiII ion [Ni—O = 2.052 (2) and 2.079 (2) Å] form a slightly distorted square-planar arrangement, which is completed up to a distorted octa­hedron by the two N atoms [Ni—N = 2.075 (3) Å] from two isonicotinamide ligands. In the anion, the carboxyl­ate group is twisted from the attached benzene ring by 8.8 (3)°. In the crystal, a three-dimensional hydrogen-bonding network, formed by classical O—H⋯O and N—H⋯O hydrogen bonds, consolidates the crystal packing, which also exhibits π–π inter­actions between the benzene and pyridine rings, with centroid–centroid distances of 3.455 (2) and 3.621 (2) Å, respectively.

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For general background, see: Bigoli et al. (1972 ▶); Krishnamachari (1974 ▶). For related structures, see: Hökelek et al. (2009a ▶,b ▶,c ▶,d ▶,e ▶); Sertçelik et al. (2009a ▶,b ▶).