3,4-Dimethylanilinium chloride monohydrate

The crystal structure of the title compound, C8H12N+·Cl−·H2O, consists of hydrophobic layers of dimethylanilinium cations parallel to the bc plane alternated by hydrophilic layers of chloride anions and water molecules. The layers are linked by N—H⋯O and N—H⋯Cl hydrogen bonds involving the ammonium groups of the cations. The cohesion of the ionic structure is further stabilized by O—H⋯Cl hydrogen-bonding interactions.

The crystal structure of the title compound, C 8 H 12 N + ÁCl À Á-H 2 O, consists of hydrophobic layers of dimethylanilinium cations parallel to the bc plane alternated by hydrophilic layers of chloride anions and water molecules. The layers are linked by N-HÁ Á ÁO and N-HÁ Á ÁCl hydrogen bonds involving the ammonium groups of the cations. The cohesion of the ionic structure is further stabilized by O-HÁ Á ÁCl hydrogenbonding interactions.
The molecular structure of the title compound is illustrated in Fig. 1. A l l bond distances and angles are within the ranges of accepted values. The amino N atom is protonated as in other aminoacids (Bouacida et al., 2006;Rademeyer 2004a,b).
A diagram of the layered crystal packing of title compound is shown in Fig. 2, in which the cations are arranged to form zigzag layers parallel the ab plane, with the chloride ions and water molecules located between these layers. The structure may be also described as formed by hydrophobic layers parallel to the bc plane of dimethylanilinium cations alternated by hydrophilic layers of chloride anions and water molecules. In this structure, three types of classical hydrogen bonds are observed, viz. cation-anion, cation-water and water-anion (Fig. 3, Table 1). All three ammonium H atoms are involved in hydrogen bonds. These interactions link the molecules within the layers and also link the layers together, forming a three-dimensional network and reinforcing the cohesion of the ionic structure.

Experimental
An aqueous solution of SnCl 2 .2H 2 O (1 mmol) and 3,4-dimethylaniline (2 mmol) in hydrochloric acid was slowly evaporated to dryness for two weeks. White single crystals of the title compound were carefully isolated under polarizing microscope for X-ray diffraction analysis

Refinement
The water H atoms were located in a difference Fourier map and refined isotropically, with U iso (H) =1.25(O). All other H atoms were localized in difference Fourier maps but introduced in calculated positions and treated as riding on their parent atoms, with C-H = 0.93-0.96 Å, N-H = 0.89Å and U iso (H) = 1.2 U eq (C, N) or 1.5 U eq (C) for methyl H atoms.