(4-Methoxyphenyl)methanaminium chloride

In the crystal structure of the title salt, C8H12NO+·Cl−, the methoxy group of the cation is co-planar with the phenylene moiety with an r.m.s. deviation from the mean plane of only 0.005 Å. The ammonium N atom deviates from this plane by 1.403 (1) Å. In the crystal, the (4-methoxyphenyl)methanaminium cations and chloride anions are linked by N—H⋯Cl and C—H⋯O hydrogen bonds, resulting in an open framework architecture with hydrogen-bonded ammonium groups and chloride anions located in layers parallel to (011), separated by more hydrophobic layers with interdigitating anisole groups.

In the crystal structure of the title salt, C 8 H 12 NO + ÁCl À , the methoxy group of the cation is co-planar with the phenylene moiety with an r.m.s. deviation from the mean plane of only 0.005 Å . The ammonium N atom deviates from this plane by 1.403 (1) Å . In the crystal, the (4-methoxyphenyl)methanaminium cations and chloride anions are linked by N-HÁ Á ÁCl and C-HÁ Á ÁO hydrogen bonds, resulting in an open framework architecture with hydrogen-bonded ammonium groups and chloride anions located in layers parallel to (011), separated by more hydrophobic layers with interdigitating anisole groups.
The crystal structure consists of a network of the constituent ammonium and chloride ions connected by N-H···Cl hydrogen bonds (Fig. 2), with a chloride anion acting as a threefold acceptor as similarly observed in related compounds (Oueslati et al., 2005b). The N···Cl distances vary between 3.1475 (9) and 3.1680 (8) Å, indicating strong interactions between the ammonium and halogenide ions (Zaouali et al., 2009). Multiple hydrogen bonds connect the different entities of the compound to form inorganic layers, built from the chloride anions and the ammonium groups, parallel to the bc plane ( Fig.   2). Within the layers, various graph-set motifs (Bernstein et al., 1995) are apparent, including R 2 4 (8) and R 2 8 (16) motifs.
The organic fragments are located between successive inorganic layers (Fig. 3). No π-π stacking interactions between the phenylene rings or C-H···π interactions towards them are observed. A weak intermolecular C-H···O hydrogen interaction involving an aromatic hydrogen atom is present (Table 1). The organic molecule exhibits a regular spatial configuration with usual distances and angles. The distance C1-O1 [1.3637 (11) Å] is slightly shorter than that of C8-O1 [1.4362 (12) Å], which can be attributed to the donor mesomeric effect of the methoxy group. All the geometrical features of the title compound agree with those found in related compounds (e.g. Kefi et al., 2006;El Glaoui et al., 2009).
Experimental 4-Methoxybenzylamine (2 mmol, 0.274 g) was dissolved in aqueous HCl (10 ml, 1M). Colourless crystals suitable for single-crystal X-ray analysis were grown by slow evaporation at room temperature over a period of three weeks (yield 63%).

Refinement
All H atoms were located in a difference Fourier map, but were repositioned geometrically and refined as riding, with C-H distances of 0.95 (aromatic), 0.99 (methylene) or 0.98 Å (methyl), and N-H distances of 0.91 Å. The torsion angles of the methyl and ammonium H atoms were allowed to refine to best fit the experimental electron density map, and the U iso (H) values of the these groups were constrained to 1.5 times that of their carrier atom. For the other hydrogen atoms U iso was set to 1.2 times U eq of the carrier atom.    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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )