Tetrakis(4-chloroanilinium) hexachloridostannate(IV) dichloride

The asymmetric unit of the title compound, (C6H7ClN)4[SnCl6]Cl2, comprises two 4-chloroanilinium cations, half of an [SnCl6]2− anion and a Cl− anion. The SnIV atom, located on a special position on a twofold rotation axis, exhibits an octahedral environment. In the crystal, molecules are linked by N—H⋯Cl hydrogen bonds between the 4-chloroanilinium cations, [SnCl6]2− anions and Cl− anions.


Benhua Zhou and Hongxia Liu Comment
The study of ferroelectric materials has received much attention; some of them have predominantly dielectricferroelectric performance (Ye et al., 2006;Fu et al., 2007;Zhao et al. 2008;Zhang et al., 2008;Ye et al., 2009). As a part of our work to obtain potential ferroelectric phase-transition material, we report herein on the crystal structure of title compound. Unluckily, the title compound has no dielectric anomalies in the temperature range 93-453 K, suggesting that it might be only a paraelectric.
The asymmetric unit of the title compound is shown in Fig. 1 and Sn-Cl bonds are listed in Table 1. The crystal packing  (Table 2).

Experimental
For the preparation of the title compound, the water solution of the hydrochloric acid (10 mmol) was added to the ethanol solution of the 4-chlorobenzenamine(10 mmol), then the water solution of the SnCl 4 (5 mmol) was added into a reaction mixture. The resulting precipitate was filtered. Colourless crystals suitable for X-ray analysis were formed after several weeks by slow evaporation of the solvent at room temperature.

Refinement
Positional parameters of all the H atoms bonded to C atoms were calculated geometrically and were allowed to ride on the C atoms to which they are bonded, with U iso (H) = 1.2Ueq(C) and U iso (H) = 1.5Ueq(C) for the methyl group. The other H bonded to N atoms were calculated geometrically and were allowed to ride on the N atoms with U iso (H) = 1.5Ueq(O).

Figure 2
Crystal packing of the title compound. Dashed lines indicate hydrogen bonds.

Tetrakis(4-chloroanilinium) hexachloridostannate(IV) dichloride
Crystal data  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.