2-Amino-6-nitro-1H-benzoimidazol-3-ium chloride

Chen, Y.-S.; Zhang, K.; Zhao, S.-Q.

doi:10.1107/S1600536809027342

organic compounds

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ISSN: 2056-9890

Volume 65| Part 8| August 2009| Page o1926

doi:10.1107/S1600536809027342

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2-Amino-6-nitro-1H-benzoimidazol-3-ium chloride

You-Sheng Chen,^a Kun Zhang ^a ^* and Su-Qing Zhao ^a

^aFaculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Waihuan Xi Road No. 100, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou, Guangzhou 510006, People's Republic of China
^*Correspondence e-mail: gdut_chen@163.com

(Received 27 June 2009; accepted 12 July 2009; online 18 July 2009)

In the cation of the title compound, C₇H₇N₄O₂⁺·Cl⁻, the benzimidazole ring system is planar with a maximum deviation of −0.019 (3) Å. In the crystal structure, C—H⋯Cl, N—H⋯Cl, and N—H⋯Cl interactions link the molecules into a two-dimensional network. π–π contacts between benzimidazole rings [centroid–centroid distances = 3.928 (1) and 3.587 (1) Å] may further stabilize the structure.

Related literature

For bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₇H₇N₄O₂⁺·Cl⁻
M_r = 214.62
Monoclinic, C 2/c
a = 13.969 (3) Å
b = 7.8064 (19) Å
c = 16.490 (4) Å
β = 91.303 (3)°
V = 1797.7 (7) Å³
Z = 8
Mo Kα radiation
μ = 0.40 mm⁻¹
T = 291 K
0.12 × 0.12 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.953, T_max = 0.961
4345 measured reflections
1580 independent reflections
1242 reflections with I > 2σ(I)
R_int = 0.041
3 standard reflections frequency: 120 min intensity decay: none

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.096
S = 1.02
1580 reflections
127 parameters
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7⋯Cl1	0.93	2.75	3.436 (2)	132
N1—H1A⋯Cl1	0.86	2.61	3.2830 (19)	135
N1—H1A⋯Cl1ⁱ	0.86	2.76	3.4102 (19)	134
N3—H3A⋯Cl1ⁱⁱ	0.86	2.55	3.269 (2)	142
N2—H2A⋯Cl1ⁱⁱ	0.86	2.31	3.0601 (19)	145
Symmetry codes: (i) $[-x+1, y, -z+{\script{3\over 2}}]$ ; (ii) $[x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ .

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97 and PLATON.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809027342/hk2728sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809027342/hk2728Isup2.hkl

checkCIF report

Comment top

Some derivatives of 2-aminobenzimidazolium are important chemical materials. We report herein the crystal structure of the title compound.

In the molecule of the title compound, (Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges. Rings A (N1/N2/C1-C3) and B (C2-C7) are, of course, planar and they are oriented at a dihedral angle of 1.70 (3)°. The benzimidazole ring system is planar with a maximum deviation of -0.019 (3) Å for atom C5. Atoms O1, N3 and N4 are 0.064 (3), -0.044 (3) and -0.094 (3) Å away from the plane of the benzimidazole ring system, respectively.

In the crystal structure, intramolecular C-H···Cl and N-H···Cl and intermolecular N-H···Cl interactions (Table 1) link the molecules into a two dimensional network (Fig. 2), in which they may be effective in the stabilization of the structure. The π–π contacts between the benzimidazole rings, Cg1—Cg2ⁱ and Cg2—Cg2ⁱⁱ [symmetry codes: (i) 1/2 - x, 3/2 - y, -z, (ii) -x, 1 - y, -z, where Cg1 and Cg2 are centroids of the rings A (N1/N2/C1-C3) and B (C2-C7), respectively] may further stabilize the structure, with centroid-centroid distances of 3.928 (1) and 3.587 (1) Å, respectively.

Related literature top

For bond-length data, see: Allen et al. (1987).

Experimental top

For the preparation of the title compound, a suspension of 4-nitro-o-phenylenediamine (1.4 g, 9.1 mmol) in a solution of BrCN (0.97 g, 9.2 mmol) in water (30 ml) was refluxed for 7 h, and then cooled and neutralized with NH₄OH (25%) to pH = 11. The formed precipitate was filtered, washed with water and dried to give the title compound, as a yellow solid (yield; 1.5 g, 92%). Crystals suitable for X-ray analysis were obtained after 3 d by slow evaporation of the mother liquid at room temperature.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A partial packing diagram of the title compound. Hydrogen bonds are shown as dashed lines.

2-Amino-6-nitro-1H-benzoimidazol-3-ium chloride top

Crystal data top

C₇H₇N₄O₂⁺·Cl⁻	F(000) = 880
M_r = 214.62	D_x = 1.586 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 13.969 (3) Å	θ = 2.1–25.3°
b = 7.8064 (19) Å	µ = 0.40 mm⁻¹
c = 16.490 (4) Å	T = 291 K
β = 91.303 (3)°	Block, yellow
V = 1797.7 (7) Å³	0.12 × 0.12 × 0.10 mm
Z = 8

Data collection top

Enraf–Nonius CAD-4 diffractometer	1242 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.041
Graphite monochromator	θ_max = 25.0°, θ_min = 2.5°
ω/2θ scans	h = −16→16
Absorption correction: ψ scan (North et al., 1968)	k = −9→9
T_min = 0.953, T_max = 0.961	l = −19→13
4345 measured reflections	3 standard reflections every 120 min
1580 independent reflections	intensity decay: none

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.096	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.0429P)² + 0.969P] where P = (F_o² + 2F_c²)/3
1580 reflections	(Δ/σ)_max < 0.001
127 parameters	Δρ_max = 0.18 e Å⁻³
0 restraints	Δρ_min = −0.20 e Å⁻³

Crystal data top

C₇H₇N₄O₂⁺·Cl⁻	V = 1797.7 (7) Å³
M_r = 214.62	Z = 8
Monoclinic, C2/c	Mo Kα radiation
a = 13.969 (3) Å	µ = 0.40 mm⁻¹
b = 7.8064 (19) Å	T = 291 K
c = 16.490 (4) Å	0.12 × 0.12 × 0.10 mm
β = 91.303 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1242 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.041
T_min = 0.953, T_max = 0.961	3 standard reflections every 120 min
4345 measured reflections	intensity decay: none
1580 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	0 restraints
wR(F²) = 0.096	H-atom parameters constrained
S = 1.02	Δρ_max = 0.18 e Å⁻³
1580 reflections	Δρ_min = −0.20 e Å⁻³
127 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
Cl1	0.40318 (4)	0.59647 (8)	0.67245 (4)	0.0535 (2)
O1	0.38248 (13)	0.6546 (3)	0.39469 (12)	0.0718 (6)
O2	0.42766 (13)	0.8483 (3)	0.31128 (11)	0.0743 (6)
N1	0.61668 (12)	0.7489 (2)	0.63485 (10)	0.0424 (5)
H1A	0.5835	0.6840	0.6656	0.051*
N2	0.72946 (12)	0.9189 (2)	0.59344 (10)	0.0403 (4)
H2A	0.7805	0.9804	0.5934	0.048*
N3	0.73958 (14)	0.8248 (3)	0.72889 (12)	0.0552 (6)
H3A	0.7916	0.8812	0.7380	0.066*
H3B	0.7150	0.7649	0.7669	0.066*
N4	0.43847 (13)	0.7660 (3)	0.37360 (12)	0.0491 (5)
C1	0.69763 (15)	0.8301 (3)	0.65691 (13)	0.0392 (5)
C2	0.59515 (14)	0.7865 (3)	0.55416 (12)	0.0363 (5)
C3	0.66716 (14)	0.8960 (3)	0.52782 (13)	0.0361 (5)
C4	0.66616 (16)	0.9615 (3)	0.44987 (13)	0.0420 (5)
H4	0.7147	1.0332	0.4323	0.050*
C5	0.59021 (16)	0.9163 (3)	0.39925 (13)	0.0432 (5)
H5	0.5859	0.9590	0.3466	0.052*
C6	0.52047 (15)	0.8067 (3)	0.42752 (13)	0.0392 (5)
C7	0.52051 (15)	0.7385 (3)	0.50434 (13)	0.0401 (5)
H7	0.4728	0.6644	0.5213	0.048*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0422 (4)	0.0708 (4)	0.0475 (4)	−0.0144 (3)	0.0034 (3)	−0.0083 (3)
O1	0.0580 (12)	0.0805 (13)	0.0762 (13)	−0.0252 (10)	−0.0151 (10)	0.0019 (11)
O2	0.0612 (12)	0.1070 (16)	0.0539 (12)	−0.0053 (11)	−0.0168 (9)	0.0130 (11)
N1	0.0447 (11)	0.0431 (11)	0.0393 (11)	−0.0091 (9)	0.0011 (8)	0.0035 (8)
N2	0.0328 (10)	0.0461 (11)	0.0419 (10)	−0.0076 (8)	−0.0012 (8)	0.0000 (8)
N3	0.0523 (13)	0.0663 (14)	0.0466 (12)	−0.0117 (10)	−0.0096 (10)	0.0075 (10)
N4	0.0387 (11)	0.0593 (13)	0.0491 (12)	0.0016 (10)	−0.0039 (9)	−0.0090 (10)
C1	0.0351 (11)	0.0413 (12)	0.0411 (13)	0.0005 (9)	−0.0013 (9)	−0.0016 (10)
C2	0.0357 (11)	0.0366 (11)	0.0367 (12)	0.0003 (9)	0.0019 (9)	−0.0012 (9)
C3	0.0311 (11)	0.0368 (11)	0.0405 (12)	0.0005 (9)	0.0022 (9)	−0.0035 (9)
C4	0.0372 (12)	0.0445 (13)	0.0446 (13)	−0.0050 (10)	0.0064 (10)	0.0019 (10)
C5	0.0430 (13)	0.0479 (13)	0.0387 (12)	0.0007 (10)	0.0026 (10)	0.0006 (10)
C6	0.0364 (12)	0.0420 (12)	0.0391 (12)	0.0023 (9)	−0.0021 (9)	−0.0063 (10)
C7	0.0362 (12)	0.0393 (12)	0.0448 (13)	−0.0059 (9)	0.0039 (10)	−0.0051 (10)

Geometric parameters (Å, º) top

N1—H1A	0.8600	C2—C7	1.365 (3)
N2—H2A	0.8600	C3—N2	1.385 (3)
N3—H3A	0.8600	C3—C4	1.383 (3)
N3—H3B	0.8600	C4—C5	1.381 (3)
N4—O1	1.225 (3)	C4—H4	0.9300
N4—O2	1.219 (2)	C5—C6	1.385 (3)
C1—N1	1.340 (3)	C5—H5	0.9300
C1—N2	1.340 (3)	C6—C7	1.374 (3)
C1—N3	1.312 (3)	C6—N4	1.469 (3)
C2—N1	1.389 (3)	C7—H7	0.9300
C2—C3	1.397 (3)

C1—N1—C2	108.84 (17)	C7—C2—C3	121.8 (2)
C1—N1—H1A	125.6	N2—C3—C2	106.28 (18)
C2—N1—H1A	125.6	C4—C3—N2	132.2 (2)
C1—N2—C3	109.26 (17)	C4—C3—C2	121.6 (2)
C1—N2—H2A	125.4	C3—C4—H4	121.4
C3—N2—H2A	125.4	C5—C4—C3	117.3 (2)
C1—N3—H3A	120.0	C5—C4—H4	121.4
C1—N3—H3B	120.0	C4—C5—C6	119.4 (2)
H3A—N3—H3B	120.0	C4—C5—H5	120.3
O1—N4—C6	118.4 (2)	C6—C5—H5	120.3
O2—N4—O1	123.1 (2)	C5—C6—N4	118.3 (2)
O2—N4—C6	118.5 (2)	C7—C6—N4	117.27 (19)
N2—C1—N1	109.02 (18)	C7—C6—C5	124.3 (2)
N3—C1—N1	126.0 (2)	C2—C7—C6	115.6 (2)
N3—C1—N2	125.0 (2)	C2—C7—H7	122.2
N1—C2—C3	106.60 (18)	C6—C7—H7	122.2
C7—C2—N1	131.6 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···Cl1	0.93	2.75	3.436 (2)	132
N1—H1A···Cl1	0.86	2.61	3.2830 (19)	135
N1—H1A···Cl1ⁱ	0.86	2.76	3.4102 (19)	134
N3—H3A···Cl1ⁱⁱ	0.86	2.55	3.269 (2)	142
N2—H2A···Cl1ⁱⁱ	0.86	2.31	3.0601 (19)	145

Symmetry codes: (i) −x+1, y, −z+3/2; (ii) x+1/2, y+1/2, z.

Experimental details

Crystal data
Chemical formula	C₇H₇N₄O₂⁺·Cl⁻
M_r	214.62
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	291
a, b, c (Å)	13.969 (3), 7.8064 (19), 16.490 (4)
β (°)	91.303 (3)
V (Å³)	1797.7 (7)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.40
Crystal size (mm)	0.12 × 0.12 × 0.10

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.953, 0.961
No. of measured, independent and observed [I > 2σ(I)] reflections	4345, 1580, 1242
R_int	0.041
(sin θ/λ)_max (Å⁻¹)	0.594

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.096, 1.02
No. of reflections	1580
No. of parameters	127
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.20

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···Cl1	0.93	2.75	3.436 (2)	131.6
N1—H1A···Cl1	0.86	2.61	3.2830 (19)	135.4
N1—H1A···Cl1ⁱ	0.86	2.76	3.4102 (19)	133.7
N3—H3A···Cl1ⁱⁱ	0.86	2.55	3.269 (2)	141.8
N2—H2A···Cl1ⁱⁱ	0.86	2.31	3.0601 (19)	145.3

Symmetry codes: (i) −x+1, y, −z+3/2; (ii) x+1/2, y+1/2, z.

Acknowledgements

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
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