1-Methyl-6-nitro-1H-benzimidazole.

The title compound, C(8)H(7)N(3)O(2), a potential anti-tumour drug and an anti-oxidant agent, was studied in order to give more insight into structure-function relationships. The 1-methyl-benzimidazole unit of the mol-ecule was found to be exactly planar and the nitro group is inclined at an angle of 10.4 (2)° to the plane of the heterocycle. The bond lengths in the present derivative were analyzed in details and compared with those of the parent unsubstituted analogues in the Cambridge Structural Database. The results have shown that the additional nitro group is not involved in conjugation with the adjacent π-system and hence has no effect on the charge distribution of the heterocyclic ring.

Related literature

For related literature on related crystal structures, see for example: Türktekin et al., (2004 ▶) as retrieved from the Cambridge Structural Database (Version of 2007; Allen, 2002 ▶). For the synthesis, see: Ellis & Jones (1974 ▶). For the length of the pure Csp 2—Nsp 2 single bond, see: Adler et al. (1976 ▶). For related literature on biological aspects of the benzimidazole derivatives in general, see: Alpan et al. (2007 ▶); Kettmann et al. (2004 ▶); Le et al. (2004 ▶); Nguyen et al. (2004 ▶); Statkova-Abeghe et al. (2005 ▶). Anti­oxidant properties of the compound are discussed by Hanus et al. (2004 ▶); Katuščák (2003 ▶).

Experimental

Crystal data

C8H7N3O2

M = 177.17

Orthorhombic,

a = 12.852 (3) Å

b = 7.043 (2) Å

c = 17.690 (4) Å

V = 1601.2 (7) Å3

Z = 8

Mo Kα radiation

μ = 0.11 mm−1

T = 296 (2) K

0.30 × 0.20 × 0.15 mm

Data collection

Siemens P4 diffractometer

Absorption correction: none

3027 measured reflections

2325 independent reflections

1493 reflections with I > 2σ(I)

R int = 0.035

3 standard reflections every 97 reflections intensity decay: none

Refinement

R[F 2 > 2σ(F 2)] = 0.045

wR(F 2) = 0.130

S = 0.96

2325 reflections

119 parameters

H-atom parameters constrained

Δρmax = 0.18 e Å−3

Δρmin = −0.15 e Å−3

Data collection: XSCANS (Siemens, 1991 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808005886/nc2091sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808005886/nc2091Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C8H7N3O2	Dx = 1.470 Mg m−3
Mr = 177.17	Melting point: 455 K
Orthorhombic, Pbca	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 20 reflections
a = 12.852 (3) Å	θ = 7–19º
b = 7.043 (2) Å	µ = 0.11 mm−1
c = 17.690 (4) Å	T = 296 (2) K
V = 1601.2 (7) Å3	Prism, yellow
Z = 8	0.30 × 0.20 × 0.15 mm
F000 = 736

Siemens P4 diffractometer	Rint = 0.035
Radiation source: fine-focus sealed tube	θmax = 30.0º
Monochromator: graphite	θmin = 2.3º
T = 296(2) K	h = −1→18
ω/2θ scans	k = −1→9
Absorption correction: none	l = −24→1
3027 measured reflections	3 standard reflections
2325 independent reflections	every 97 reflections
1493 reflections with I > 2σ(I)	intensity decay: none

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.045	H-atom parameters constrained
wR(F2) = 0.130	w = 1/[σ2(Fo2) + (0.0722P)2] where P = (Fo2 + 2Fc2)/3
S = 0.96	(Δ/σ)max = 0.002
2325 reflections	Δρmax = 0.18 e Å−3
119 parameters	Δρmin = −0.15 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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.

	x	y	z	Uiso*/Ueq
N1	0.42194 (9)	0.26257 (16)	0.47003 (6)	0.0416 (3)
C2	0.52515 (10)	0.2941 (2)	0.45973 (9)	0.0497 (4)
H2	0.5525	0.3360	0.4140	0.060*
N3	0.58338 (9)	0.26080 (19)	0.51910 (7)	0.0532 (3)
C4	0.53023 (11)	0.1419 (2)	0.64798 (8)	0.0553 (4)
H4	0.5968	0.1419	0.6686	0.066*
C5	0.44659 (12)	0.0845 (2)	0.68983 (8)	0.0544 (4)
H5	0.4561	0.0432	0.7393	0.065*
C6	0.34599 (10)	0.08772 (19)	0.65813 (7)	0.0425 (3)
C7	0.32568 (9)	0.14664 (19)	0.58497 (7)	0.0390 (3)
H7	0.2587	0.1496	0.5650	0.047*
C8	0.41167 (10)	0.20061 (17)	0.54376 (7)	0.0374 (3)
C9	0.51357 (10)	0.20067 (19)	0.57335 (8)	0.0444 (3)
C10	0.33948 (11)	0.2912 (3)	0.41540 (9)	0.0555 (4)
H10A	0.3428	0.4185	0.3962	0.083*
H10B	0.2733	0.2711	0.4393	0.083*
H10C	0.3476	0.2029	0.3745	0.083*
N4	0.25815 (11)	0.03037 (18)	0.70486 (7)	0.0499 (3)
O1	0.16986 (9)	0.0586 (2)	0.68211 (6)	0.0653 (3)
O2	0.27589 (11)	−0.0462 (2)	0.76606 (6)	0.0721 (4)

	U11	U22	U33	U12	U13	U23
N1	0.0348 (5)	0.0474 (6)	0.0425 (6)	−0.0030 (4)	−0.0002 (4)	0.0008 (5)
C2	0.0376 (7)	0.0532 (8)	0.0583 (8)	−0.0041 (6)	0.0085 (6)	−0.0036 (7)
N3	0.0334 (6)	0.0599 (8)	0.0663 (8)	−0.0019 (5)	0.0008 (5)	−0.0071 (6)
C4	0.0428 (7)	0.0662 (9)	0.0570 (8)	0.0084 (7)	−0.0178 (6)	−0.0072 (8)
C5	0.0592 (9)	0.0607 (9)	0.0434 (7)	0.0103 (7)	−0.0138 (7)	−0.0029 (7)
C6	0.0460 (7)	0.0436 (7)	0.0379 (6)	0.0027 (6)	−0.0017 (5)	−0.0048 (5)
C7	0.0350 (6)	0.0417 (6)	0.0404 (6)	0.0007 (5)	−0.0039 (5)	−0.0044 (6)
C8	0.0349 (6)	0.0376 (6)	0.0398 (6)	0.0011 (5)	−0.0036 (5)	−0.0046 (5)
C9	0.0348 (6)	0.0450 (7)	0.0535 (8)	0.0029 (5)	−0.0055 (6)	−0.0089 (6)
C10	0.0477 (8)	0.0748 (10)	0.0441 (7)	−0.0036 (7)	−0.0071 (6)	0.0084 (7)
N4	0.0605 (8)	0.0515 (7)	0.0377 (6)	−0.0001 (6)	0.0029 (5)	−0.0052 (5)
O1	0.0503 (6)	0.0928 (9)	0.0527 (6)	−0.0051 (6)	0.0055 (5)	0.0053 (6)
O2	0.0891 (10)	0.0851 (9)	0.0420 (6)	0.0051 (7)	0.0043 (6)	0.0149 (6)

N1—C2	1.3571 (17)	C6—C7	1.3840 (19)
N1—C8	1.3817 (17)	C6—N4	1.4563 (18)
N1—C10	1.4483 (18)	C7—C8	1.3775 (18)
C2—N3	1.3107 (19)	C7—H7	0.9300
C2—H2	0.9300	C8—C9	1.4104 (17)
N3—C9	1.3803 (18)	C10—H10A	0.9600
C4—C5	1.366 (2)	C10—H10B	0.9600
C4—C9	1.4001 (19)	C10—H10C	0.9600
C4—H4	0.9300	N4—O1	1.2202 (16)
C5—C6	1.4095 (19)	N4—O2	1.2308 (16)
C5—H5	0.9300
C2—N1—C8	105.76 (11)	C8—C7—H7	122.4
C2—N1—C10	127.08 (12)	C6—C7—H7	122.4
C8—N1—C10	127.15 (11)	C7—C8—N1	131.56 (12)
N3—C2—N1	114.93 (13)	C7—C8—C9	123.28 (12)
N3—C2—H2	122.5	N1—C8—C9	105.17 (11)
N1—C2—H2	122.5	N3—C9—C4	130.31 (13)
C2—N3—C9	103.93 (12)	N3—C9—C8	110.22 (12)
C5—C4—C9	118.57 (13)	C4—C9—C8	119.46 (13)
C5—C4—H4	120.7	N1—C10—H10A	109.5
C9—C4—H4	120.7	N1—C10—H10B	109.5
C4—C5—C6	120.08 (13)	H10A—C10—H10B	109.5
C4—C5—H5	120.0	N1—C10—H10C	109.5
C6—C5—H5	120.0	H10A—C10—H10C	109.5
C7—C6—C5	123.36 (13)	H10B—C10—H10C	109.5
C7—C6—N4	117.89 (12)	O1—N4—O2	122.26 (14)
C5—C6—N4	118.74 (12)	O1—N4—C6	119.23 (12)
C8—C7—C6	115.24 (11)	O2—N4—C6	118.50 (13)
C8—N1—C2—N3	−0.55 (16)	C10—N1—C8—C9	−178.72 (13)
C10—N1—C2—N3	178.49 (14)	C2—N3—C9—C4	178.82 (15)
N1—C2—N3—C9	0.52 (16)	C2—N3—C9—C8	−0.29 (15)
C9—C4—C5—C6	−0.9 (2)	C5—C4—C9—N3	−178.51 (14)
C4—C5—C6—C7	0.2 (2)	C5—C4—C9—C8	0.5 (2)
C4—C5—C6—N4	−178.40 (14)	C7—C8—C9—N3	179.82 (12)
C5—C6—C7—C8	0.9 (2)	N1—C8—C9—N3	−0.02 (15)
N4—C6—C7—C8	179.47 (11)	C7—C8—C9—C4	0.6 (2)
C6—C7—C8—N1	178.54 (13)	N1—C8—C9—C4	−179.25 (12)
C6—C7—C8—C9	−1.26 (19)	C7—C6—N4—O1	−9.28 (19)
C2—N1—C8—C7	−179.50 (14)	C5—C6—N4—O1	169.38 (13)
C10—N1—C8—C7	1.5 (2)	C7—C6—N4—O2	170.32 (13)
C2—N1—C8—C9	0.32 (14)	C5—C6—N4—O2	−11.02 (19)

Table 1

Selected bond lengths (Å)

N1—C2	1.3571 (17)
N1—C8	1.3817 (17)
C2—N3	1.3107 (19)
N3—C9	1.3803 (18)
C4—C5	1.366 (2)
C4—C9	1.4001 (19)
C5—C6	1.4095 (19)
C6—C7	1.3840 (19)
C6—N4	1.4563 (18)
C7—C8	1.3775 (18)
C8—C9	1.4104 (17)