2-Methyl­anilinium nitrate

The crystal structure of the title compound, C₇H₁₀N⁺·NO₃⁻, consists of anion–cation layers parallel to the (100) plane, generated by N—H...O hydrogen bonds. 16 of the 22 atoms (the exceptions being two O and four H atoms) lie on a mirror plane.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.050
• wR factor = 0.135
• Data-to-parameter ratio = 18.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT242_ALERT_2_B Check Low       Ueq as Compared to Neighbors for         N2

Alert level C
PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety         N1
PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety         C7

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

O-toluidine is used in the manufacture of rubber vulcanization accelerator, hypnotic and anesthetic pharmaceuticals, and pesticides. 2-Methylaniline is highly toxic to humans when absorbed through the skin,inhaled as vapor or swallowed, hemoglobine is changed to methemoglobinand and caused damage to the cells of the central nervous system.

The crystal structure of o-methylanilinium nitrate, (I), was determined as part of our investigations on the structural characteristics of organic-inorganic layered compounds and an ongoing study on D—H···A hydrogen-bonding in systems of hybrid materials including anilinium derivatives such as 4-Carboxyanilinium hydrogensulfate (Benali-Cherif, Direm et al., 2007), 2-carboxyanilinium dihydrogenphosphate (Benali-Cherif, Allouche et al., 2007) and guaninium phosphite and guaninium phosphate salts (Bendeif et al. 2007).

The asymmetric unit of (I) contains a monoprotonated o-methylanilinium cation and nitrate anion (Figure 1). Intra atomic bond distances and angles in the title compound shows the monprotonation of the organic entity and confirms the presence of the nitrate (NO₃^-) anion. All atoms in the asymetric unit except three are positionned on a mirror plane (x, 1/4, z).

The structure of (C₇H₁₀N⁺. NO₃^-) is composed of cationic (C₇H₁₀N⁺), and anionic (NO₃^-) entities which are linked by N—H···O hydrogen bonds to build up layers developping parallel to the (1 0 0) plane (Table 1, Fig. 2).

Related literature

For related structures see: Benali-Cherif, Direm et al. (2007); Benali-Cherif, Allouche et al. (2007); Bendeif et al. (2007).

S2. Experimental

Single crystals of the title compound are prepared by slow evaporation at room temperature of an aqueous solution of o-methylaniline (C₇H₉N) and nitrate acid (HNO₃) in the stoichiometric ration 1:1.

S3. Refinement

Aromatic H atoms were located in difference Fourier syntheses and were allowed to ride on their parent C atoms with C—H = 0.93 Å and U_iso = 1.2U_eq(C). The methyle and and amonium H-atoms of the cation entity were located in difference Fourier syntheses but were not refined.

Computing details

Data collection: KappaCCD Server Software (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, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. Molecular view of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Hydrogen bonds are shown as dashed lines. H atoms are represented as small spheres of arbitrary radii. [Symmetry code: (i) x, 1/2 - y, z]
	Fig. 2. Partial packing view showing the hydrogen-bonding network. H atoms not involved in H bonds have been omitted for clarity. [Symmetry code: (i) x, 1/2 - y, z; (ii) 1/2 - x, -y, 1/2 + z.]

2-Methylanilinium nitrate

Crystal data

C7H10N^+·NO3^−	F(000) = 360
Mr = 170.17	Dx = 1.321 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 1467 reflections
a = 16.5632 (2) Å	θ = 2.9–30.0°
b = 6.7242 (2) Å	µ = 0.10 mm^−1
c = 7.6849 (3) Å	T = 293 K
V = 855.90 (4) Å^3	Prism, brown
Z = 4	0.15 × 0.1 × 0.05 mm

Data collection

Nonius KappaCCD diffractometer	895 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.075
Graphite monochromator	θmax = 30.0°, θmin = 2.9°
ω–θ scans	h = 0→23
9040 measured reflections	k = 0→9
1331 independent reflections	l = 0→10

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.050	H-atom parameters constrained
wR(F^2) = 0.135	w = 1/[σ^2(Fo^2) + (0.0468P)^2 + 0.1577P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
1331 reflections	Δρmax = 0.14 e Å^−3
71 parameters	Δρmin = −0.16 e Å^−3
4 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.23 (3)

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² 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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.40546 (11)	0.2500	0.7455 (2)	0.0478 (5)
C2	0.44414 (12)	0.2500	0.9045 (2)	0.0566 (5)
C3	0.52755 (15)	0.2500	0.8999 (4)	0.0880 (8)
H3	0.5563	0.2500	1.0039	0.106*
C4	0.56892 (16)	0.2500	0.7448 (5)	0.1032 (11)
H4	0.6251	0.2500	0.7456	0.124*
C5	0.52909 (18)	0.2500	0.5908 (4)	0.0943 (9)
H5	0.5577	0.2500	0.4866	0.113*
C6	0.44633 (15)	0.2500	0.5899 (3)	0.0722 (6)
H6	0.4182	0.2500	0.4852	0.087*
C7	0.39797 (17)	0.2500	1.0725 (3)	0.0797 (7)
H71	0.4314	0.2500	1.1725	0.120*
H72	0.3651	0.1307	1.0813	0.120*
N1	0.31729 (9)	0.2500	0.74140 (19)	0.0532 (4)
H11	0.3021	0.2500	0.6356	0.080*
H12	0.2989	0.1443	0.7967	0.080*
N2	0.22458 (9)	0.2500	0.3407 (2)	0.0527 (4)
O2	0.18148 (12)	0.2500	0.2138 (2)	0.0919 (6)
O3	0.24779 (7)	0.09186 (15)	0.40892 (14)	0.0761 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0494 (10)	0.0416 (8)	0.0525 (9)	0.000	0.0035 (7)	0.000
C2	0.0555 (11)	0.0532 (10)	0.0611 (11)	0.000	−0.0069 (8)	0.000
C3	0.0553 (14)	0.0946 (19)	0.114 (2)	0.000	−0.0189 (14)	0.000
C4	0.0474 (13)	0.0858 (19)	0.176 (4)	0.000	0.0188 (18)	0.000
C5	0.085 (2)	0.0830 (18)	0.115 (2)	0.000	0.0503 (18)	0.000
C6	0.0780 (16)	0.0786 (15)	0.0599 (12)	0.000	0.0207 (10)	0.000
C7	0.0927 (17)	0.0981 (18)	0.0484 (11)	0.000	−0.0069 (11)	0.000
N1	0.0518 (9)	0.0583 (9)	0.0497 (8)	0.000	−0.0026 (7)	0.000
N2	0.0469 (8)	0.0547 (9)	0.0566 (9)	0.000	−0.0044 (7)	0.000
O2	0.0976 (13)	0.0913 (13)	0.0868 (11)	0.000	−0.0493 (10)	0.000
O3	0.0922 (9)	0.0513 (6)	0.0848 (8)	−0.0052 (5)	−0.0271 (6)	0.0099 (5)

Geometric parameters (Å, º)

C1—C6	1.374 (3)	C5—H5	0.9300
C1—C2	1.380 (2)	C6—H6	0.9300
C1—N1	1.461 (2)	C7—H71	0.9467
C2—C3	1.382 (3)	C7—H72	0.9714
C2—C7	1.501 (3)	N1—H11	0.8508
C3—C4	1.375 (4)	N1—H12	0.8826
C3—H3	0.9300	N2—O2	1.209 (2)
C4—C5	1.355 (4)	N2—O3^i	1.2465 (12)
C4—H4	0.9300	N2—O3	1.2465 (12)
C5—C6	1.371 (4)
C6—C1—C2	122.80 (18)	C6—C5—H5	120.3
C6—C1—N1	118.31 (17)	C5—C6—C1	119.3 (2)
C2—C1—N1	118.89 (15)	C5—C6—H6	120.4
C1—C2—C3	116.2 (2)	C1—C6—H6	120.4
C1—C2—C7	121.70 (18)	C2—C7—H71	113.6
C3—C2—C7	122.1 (2)	C2—C7—H72	110.2
C4—C3—C2	121.3 (3)	H71—C7—H72	105.7
C4—C3—H3	119.3	C1—N1—H11	108.4
C2—C3—H3	119.3	C1—N1—H12	109.6
C5—C4—C3	121.0 (2)	H11—N1—H12	111.0
C5—C4—H4	119.5	O2—N2—O3^i	121.45 (8)
C3—C4—H4	119.5	O2—N2—O3	121.45 (8)
C4—C5—C6	119.4 (2)	O3^i—N2—O3	117.10 (15)
C4—C5—H5	120.3

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H11···N2	0.85	2.61	3.441 (2)	168
N1—H11···O3	0.85	2.23	2.9974 (17)	150
N1—H11···O3^i	0.85	2.23	2.9974 (17)	150
N1—H12···O3^ii	0.88	1.97	2.8466 (14)	176

Symmetry codes: (i) x, −y+1/2, z; (ii) −x+1/2, −y, z+1/2.