Bis(3-methylanilinium) hexachloridostannate(IV) dihydrate

In the title compound, (C7H10N)2[SnCl6]·2H2O, the SnIV atom lies on a site with symmetry 2/m. One of the Cl atoms lies on a mirror plane and the 3-methylanilinium cation is also situated on a mirror plane. The water molecule is located on a twofold rotation axis. The H atoms of the methyl and ammonium groups and the solvent water molecule are disordered by symmetry. In the crystal, N—H⋯Cl, O—H⋯Cl and N—H⋯O hydrogen bonds connect the organic cations, the inorganic octahedrally shaped anions and the water molecules.

In the title compound, (C 7 H 10 N) 2 [SnCl 6 ]Á2H 2 O, the Sn IV atom lies on a site with symmetry 2/m. One of the Cl atoms lies on a mirror plane and the 3-methylanilinium cation is also situated on a mirror plane. The water molecule is located on a twofold rotation axis. The H atoms of the methyl and ammonium groups and the solvent water molecule are disordered by symmetry. In the crystal, N-HÁ Á ÁCl, O-HÁ Á ÁCl and N-HÁ Á ÁO hydrogen bonds connect the organic cations, the inorganic octahedrally shaped anions and the water molecules.

Comment
Recently much attention has been devoted to metal-organic compounds due to the tunability of their special structural features and their interesting physical properties (Zhang et al., 2009(Zhang et al., , 2010. As a continuation of our researches (Liu, 2011a,b,c), the title compound has been synthesized and its crystal structure is herein reported.
In the title compound, the Sn IV atom lies on a 2/m symmetry site, and is coordinated by six Cl atoms ( Fig. 1). One of the Cl atoms lies on a mirror plane and the 3-methylanilinium cation is also situated on a mirror plane. The water molecule is located on a twofold rotation axis. The H atoms of the methyl and amidogen groups and the water molecule are disordered induced by symmetry. N-H···Cl, O-H···Cl and N-H···O hydrogen-bonding interactions connect the [SnCl 6 ] 2anions, the 3-methylanilinium cations and the water molecules (Table 1). The non-H atoms of the 3-methylanilinium cation are coplanar. The average Sn-Cl bond distances range from 2.4260 (13) to 2.4384 (9) Å and the cis Cl -Sn-Cl angles range from 88.78 (5) to 91.22 (5)°.
Experimental 3-Methylbenzenamine (3.21 g, 0.03 mol) was dissolved in 30 ml ethanol, to which hydrochloric acid (1.1 g, 0.03 mol) was then added. Stannous chloride (2.25 g, 0.01 mol) was dissolved in 20 ml ethanol, to which was added hydrochloric acid, then mixed with the above solution without any precipitation under stirring at ambient temperature. Single crystals suitable for X-ray structure analysis were obtained by slow evaporation after 4 days in air.
The dielectric constant of the compound as a function of temperature indicates that the permittivity is basically temperature-independent [ε = C/(T-T 0 )], suggesting that this compound is not ferroelectric or there may be no distinct phase transition occurring within the measured temperature (below the melting point).

Refinement
H atoms on C atoms were positioned geometrically and refined as riding atoms, with C-H = 0.93 (aromatic), 0.96 (methyl) and N-H = 0.89 Å and with U iso (H) = 1.2U eq (C, N). Water H atoms were located from a difference Fourier map and refined as riding atoms, with O-H = 0.85 Å and U iso (H) = 1.5U eq (O).    (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.