2-Chloroanilinium perchlorate

In the crystal of the title compound, C6H7ClN+·ClO4 −, a layer-like structure parallel to the bc plane is formed through N—H⋯O hydrogen bonds between the cations and anions. These layers are connected by weak C—H⋯O interactions, forming a three-dimensional network.

In the crystal of the title compound, C 6 H 7 ClN + ÁClO 4 À , a layerlike structure parallel to the bc plane is formed through N-HÁ Á ÁO hydrogen bonds between the cations and anions. These layers are connected by weak C-HÁ Á ÁO interactions, forming a three-dimensional network.

Experimental
Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL97. The study of ferroelectric materials has received much attention and some materials 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 materials, we report herein the crystal structure of title compound. Unluckily, the title compound exhibited no dielectric anomalies in the temperature range 93 -453 K, suggesting that it might be only a paraelectric material.
The title compound, C 6 H 7 ClN + .ClO 4 -, exhibits a two-dimensional layer-like structure parallel to the bc plane through intermolecular N-H···O hydrogen bonds between cations and anions ( Fig. 1 & 2). Furthermore, the crystal structure is stabilized by weak C-H···O interactions which connect the two-dimensional layers.

Experimental
For the preparation of the title compound, a water solution of perchloric acid (1 g) was added to the ethanol solution of 2chlorobenzenamine. The resulting precipitate was filtered. Colorless crystals suitable for X-ray analysis were formed after several weeks by slow evaporation of the solvent at room temperature.

Refinement
All H atoms were calculated geometrically and allowed to ride on the parent atom with C-H = 0.93 Å and U iso (H) = 1.2U eq (C), and with N-H = 0.89 Å U iso (H) = 1.2U eq (N).  The molecular structure of the title compound, with the atomic numbering scheme and displacement ellipsoids drawn at the 30% probability level. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.31 e Å −3 Δρ min = −0.38 e Å −3 Extinction correction: SHELXL, Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.231 (7) 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.