Anilinium hydrogen sulfate

The asymmetric unit of the title compound, C6H8N+·HSO4 −, contains two cations and two anions which are linked to each other through N—H⋯O hydrogen bonds, formed by all H atoms covalently bonded to the N atoms. In addition, strong O—H⋯O anion–anion hydrogen-bond interactions are also observed.

The aim of this paper is to discuss hydrogen patterns assuring the connection between anilinium and hydrogensulfate entities and to establish their different graph-set motifs (Bernstein et al., 1995).

Experimental
Single crystals of the title compound are prepared by slow evaporation at room temperature of an aqueous solution of aniline and sulfuric acid.

Refinement
The title compound crystallizes in the centrosymmetric space group P c a 2 1 . All non-H atoms were refined with anisotropic atomic displacement parameters. H atoms were located from Fourier difference maps and treated as riding with C-H =

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.