1-(4-Hydroxyphenyl)piperazine-1,4-diium tetrachloridocobalt(II) monohydrate

The asymmetric unit of the title inorganic–organic hybrid compound, (C10H16N2O)[CoCl4]·H2O, consists of a tetrahedral [CoCl4]2− anion, together with a [C10H18N2O]2+ cation and a water molecule. Crystal cohesion is achieved through N—H⋯Cl, O—H⋯Cl and N—H⋯O hydrogen bonds between organic cations, inorganic anions and the water molecules, building up a three-dimensional network.

The asymmetric unit of the title inorganic-organic hybrid compound, (C 10 2À anion, together with a [C 10 H 18 N 2 O] 2+ cation and a water molecule. Crystal cohesion is achieved through N-HÁ Á ÁCl, O-HÁ Á ÁCl and N-HÁ Á ÁO hydrogen bonds between organic cations, inorganic anions and the water molecules, building up a three-dimensional network.
Supporting information for this paper is available from the IUCr electronic archives (Reference: CQ2009). Recently, the synthesis of organic-inorganic hybrid compounds has attracted increasing interest, not only from a structural point of view, but also because of their diverse optical properties and various applications in catalysis, electrical conductivity and photochemistry (Bu et al., 2001).
Here we report the synthesis and structural characterisation of the organic-inorganic hybrid compound, (1-hydroxyphenyl)piperazine-1,4-diium tetrachloridocobalt(II) monohydrate, [C 10 H 18 The asymmetric unit of this compound is composed of one tetrachlorocobalt(II) anion, one organic cation and one isolated water molecule, as shown in Figure 1. The coordination geometry of the Co(II) ion is tetrahedral with Co-Cl bond lengths ranging from 2.2475 (7) to 2.2868 (7)  The stability and the cohesion between the different components of the structure are assured by the water molecules connected to the organic cations through N-H···O hydrogen bonds and to the tetrahedral vertices of the tetrachlorocobalt (II) anions to build up a three-dimensional network.

Experimental
A mixture of chloride cobalt (II) CoCl 2 ·H 2 O (0.24 g) and 1-acetyl-4-(4-hydroxyphenyl)piperazine (C 12 H 16 N 2 O 2 ) (0.11 g) (molar ratio 1:1) was dissolved in an aqueous solution of hydrochloric acid. The mixture was stirred then kept at room temperature. Blue crystals of the title compound were obtained two weeks later. The (1-hydroxyphenyl) cations are formed by loss of the acetyl group on acid hydrolysis.

Refinement
The hydrogen atoms were located in difference Fourier maps. Those attached to carbon were placed in calculated

1-(4-Hydroxyphenyl)piperazine-1,4-diium tetrachloridocobalt(II) monohydrate
Crystal data (C 10  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.73 e Å −3 Δρ min = −0.45 e Å −3 Extinction correction: SHELXL97 (Sheldrick, 2008), Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.019 (2) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.