2-Cyanoanilinium perchlorate

In the title compound, C7H7N2 +·ClO4 −, the cation is almost planar (r.m.s. deviation = 0.042 Å). In the crystal structure, the cations and anions are linked into a two-dimensional network parallel to (100) by N—H⋯O hydrogen bonds.

In the title compound, C 7 H 7 N 2 + ÁClO 4 À , the cation is almost planar (r.m.s. deviation = 0.042 Å ). In the crystal structure, the cations and anions are linked into a two-dimensional network parallel to (100) by N-HÁ Á ÁO hydrogen bonds.
with various acids has been studied and we have obtained a series of new materials with this organic molecule. In this paper, we describe the crystal structure of the title compound, 2-cyanoanilinium perchlorate.
In the crystal structure, all the amine group H atoms are involved in N-H···O hydrogen bonds (Table 1). The N-H···O hydrogen bonds link the ionic units into a two-dimensional network parallel to the ac plane (Fig. 2).

Experimental
The commercial 2-aminobenzonitrile (3 mmol, 324 mg) was dissolved in a water-HClO 4 (50:1 v/v) solution. The solvent was slowly evaporated in air affording colourless crystals of the title compound suitable for X-ray analysis.
While the permittivity measurement shows that there is no phase transition within the temperature range (from 100 K to 400 K), and the permittivity is 7.8 at 1 MHz at room temperature.

Refinement
All H atoms were initially located in a difference Fourier map. They were then constrained to an ideal geometry, with C-H = 0.93 Å, N-H = 0.89 Å and U iso (H) = 1.2U eq (C) and 1.5U eq (N). A rotating-group model was used for the -NH 3 group. Fig. 1. The asymmetric unit of the title compound with the atomic numbering scheme. Displacement ellipsoids were drawn at the 30% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 Rfactors(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.