3-Chloro-2-methylanilinium chloride monohydrate

In the title hydrated salt, C7H9ClN+·Cl−·H2O, the organic cations, anions and water molecules are connected by N—H⋯Cl, N—H⋯O and O—H⋯Cl hydrogen bonds. These interactions lead to the formation of layers parallel to the ac plane.

In the title hydrated salt, C 7 H 9 ClN + ÁCl À ÁH 2 O, the organic cations, anions and water molecules are connected by N-HÁ Á ÁCl, N-HÁ Á ÁO and O-HÁ Á ÁCl hydrogen bonds. These interactions lead to the formation of layers parallel to the ac plane.
Supporting information for this paper is available from the IUCr electronic archives (Reference: FJ2671).

Comment
Hydrogen bonding is of interest because of their prevalent occurrence in biological systems (Steiner 2002;Jayaraman et al., 2002). Therefore, it is extremely useful to search simple molecules allowing understanding the configuration and the function of some complex macromolecules. The title compound, was prepared as part of our ongoing studies of hydrogen-bonding interactions in the crystal structure of protonated amines (Hamdi et al., 2014). Structures containing the 3-chloro-2-methylanilinium cation have been already reported with dihydrogenphosphate (Khemiri et al., 2008) and cyclohexaphosphate (Bel Haj Salah et al., 2014).
The asymmetric unit of the title compound (I), illustrated in Fig. 1, consists of one organic cation, one Clanion and one water molecule. All bond distances and angles are within the ranges of accepted values. Moreover, they are close to respect the geometrical features observed in the crystal structure of 5-chloro-2-methylanilinium chloride (Oueslati et al., 2005). Components of the asymmetric unit develop different H-bonds, N-H···Cl, N-H···OW and OW-H···Cl (Fig. 2) that keep them in a state where the aromatic rings of organic buildings are oriented in the direction of the bc planes to form centro-symmetric pairs interconnected by hydrogen bonds in the direction of the b axis (Fig. 2). The resulting sequences are alternated to form the crystal packing of the title compound (Fig. 3).

Experimental
An aqueous solution of AlCl 3 (1 mmol) and 3-chloro-2-methylaniline (2 mmol) in hydrochloric acid was stirred for several minutes at room temperature and 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
All H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C-H distances of 0.93 Å for phenyl and 0.96 Å for methyl groups, and N-H = 0.89 Å; U iso (H) = 1.2 U iso (C,N) for phenyl and ammonium H atoms and 1.5 U iso (C) for methyl. In water molecule the O-H distances were restrained to 0.85 (1) Å, and the distance H···H to 1.44 (2) Å.     where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.35 e Å −3 Δρ min = −0.42 e Å −3 Absolute structure: Flack (1983), unique data only Absolute structure parameter: −0.04 (19) 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq