4-Methylanilinium nitrate

The asymmetric unit of the title compound, C7H10N+·NO3 −, consists of a 4-methylanilinium cation protonated at the amino group and a nitrate anion. In the crystal, anions and cations are linked through N—H⋯O and N—H⋯(O,O) hydrogen bonds, buiding a corrugated layer structure parallel to (001).


Experimental
Data collection: KappaCCD (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and CAMERON (Pearce et al., 2000); software used to prepare material for publication: WinGX (Farrugia, 1999).  p-toluidine is an organic benzene derivative with a methyl substituent and an amino group, the name is derived from toluene and aniline. Its physical appearance is that of white lustrous plates or leaflets with an amine odour. p-toluidine can cause anoxia (due to formation of methemoglobin) and hematuria in man. The substance irritates the eyes and the skin and may cause effects on the blood, bladder and kidneys, resulting in tissue lesions and formation of methamoglobin (Kennedy et al., 1984). The crystal structure of p-methylanilinium nitrate, (I), was determined as part of our investigations on the structural characteristicsof organic-inorganic layered compounds and an ongoing study on D-H···A hydrogen-bonding in systems of hybrid materials including anilinium derivatives such as, 3-hydroxyanilinium hydrogensulfate (Benali-Cherif, , o-methylanilinium nitrate (Benali-Cherif, , 2-carboxyanilinium dihydrogenphosphate (Benali-Cherif, Allouche et al., 2007) and 2-carboxyanilinium nitrate (Bahadur et al., 2007).

Structure Reports Online
The asymmetric unit of (I) contains a monoprotonated p-methylanilinium cation and nitrate anion link trough N-H···O hydrogen bond (Figure 1). Intra atomic bond distances and angles confirm the monprotonation of the organic entity. There are differences in the N-O distances of nitrate anion N2-O2, N2-03 (1.260 (2) Å, 1.276 (2) Å) are longer than N2-O1 (1.232 (2) Å), this is the due that only the O2 and O3 atoms are involved in hydrogen bonds of types N-H ··· O. (Table 1).

Experimental
Single crystals of the title compound are prepared by slow evaporation at room temperature of an aqueous solution of p-methylaniline (C 7 H 9 N) and nitric acid in the stoichiometric ratio 1:1.

Refinement
All H atoms attached to C atoms and N atom were fixed geometrically and treated as riding with C-H = 0.96 Å (methyl) or 0.93 Å (aromatic) and N-H = 0.89 Å with U iso (H) = 1.2U eq (aromatic) or U iso (H) = 1.5U eq (methyl,N).

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.