2-Methyl-5-nitro-1H-benzimidazol-6-amine dihydrate.

The title benzimidazole mol-ecule, C(8)H(8)N(4)O(2)·2H(2)O, is planar with a maximum deviation of 0.079 (2) Å (for one of the O atoms in the nitro group). It crystallized as a dihydrate and inter-molecular O-H⋯O and N-H⋯O hydrogen bonds link the uncoordinated water mol-ecules, and the nitro and amine groups, respectively. In the crystal, N-H⋯O, O-H⋯N, O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules to form a three-dimensional network. A π-π contact between the benzene rings, [centroid-centroid distance = 3.588 (1) Å] may further stabilize the crystal structure.

Related literature

For the anti­tumor, antihelmintic, anti­bacterial, virucidal and fungucidal properties of benzimidazole derivatives, see: Refaat (2010 ▶); Laryea et al. (2010 ▶); Horton et al. (2003 ▶); Spasov et al. (1999 ▶); Soula & Luu-Duc (1986 ▶). For the coord­ination and corrosion inhibitor abilities of benzimidazoles, see: Kuznetsov & Kaza­nsky (2008 ▶); Subramanyam & Mayanna (1985 ▶). For the use of benzimidazole derivatives as photographic materials and dyes, see: Hoffmann et al. (2011 ▶); Alamgir et al. (2007 ▶). For related structures, see: Hökelek et al. (2002 ▶); Dinçer et al. (2011 ▶).

Experimental

Crystal data

C8H8N4O2·2H2O

M = 228.22

Triclinic,

a = 7.0475 (3) Å

b = 7.2801 (3) Å

c = 10.9906 (4) Å

α = 76.754 (3)°

β = 71.686 (2)°

γ = 71.809 (2)°

V = 503.18 (4) Å3

Z = 2

Mo Kα radiation

μ = 0.12 mm−1

T = 100 K

0.43 × 0.19 × 0.10 mm

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T min = 0.973, T max = 0.988

8838 measured reflections

2533 independent reflections

1800 reflections with I > 2σ(I)

R int = 0.036

Refinement

R[F 2 > 2σ(F 2)] = 0.043

wR(F 2) = 0.113

S = 1.03

2533 reflections

174 parameters

4 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.32 e Å−3

Δρmin = −0.31 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; 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 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811034647/su2305sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811034647/su2305Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811034647/su2305Isup3.cml

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

C8H8N4O2·2H2O	Z = 2
Mr = 228.22	F(000) = 240
Triclinic, P1	Dx = 1.506 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.0475 (3) Å	Cell parameters from 2308 reflections
b = 7.2801 (3) Å	θ = 3.0–28.1°
c = 10.9906 (4) Å	µ = 0.12 mm−1
α = 76.754 (3)°	T = 100 K
β = 71.686 (2)°	Rod-shaped, red
γ = 71.809 (2)°	0.43 × 0.19 × 0.10 mm
V = 503.18 (4) Å3

Bruker Kappa APEXII CCD area-detector diffractometer	2533 independent reflections
Radiation source: fine-focus sealed tube	1800 reflections with I > 2σ(I)
graphite	Rint = 0.036
φ and ω scans	θmax = 28.7°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −9→8
Tmin = 0.973, Tmax = 0.988	k = −9→9
8838 measured reflections	l = −14→14

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.113	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ2(Fo2) + (0.0524P)2 + 0.1317P] where P = (Fo2 + 2Fc2)/3
2533 reflections	(Δ/σ)max < 0.001
174 parameters	Δρmax = 0.32 e Å−3
4 restraints	Δρmin = −0.31 e Å−3

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 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 > 2sigma(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
O1	0.42086 (18)	0.73704 (16)	0.82496 (11)	0.0228 (3)
O2	0.52698 (19)	0.97324 (17)	0.68889 (11)	0.0249 (3)
O3	0.0077 (2)	0.36444 (17)	0.67272 (12)	0.0217 (3)
H31	0.006 (3)	0.245 (2)	0.697 (2)	0.036 (6)*
H32	−0.104 (4)	0.434 (5)	0.646 (3)	0.099 (11)*
O4	0.3036 (2)	0.39114 (18)	0.43791 (12)	0.0254 (3)
H41	0.218 (5)	0.370 (6)	0.517 (2)	0.148 (17)*
H42	0.339 (4)	0.292 (3)	0.400 (2)	0.051 (7)*
N1	0.4333 (2)	0.90831 (19)	0.79926 (13)	0.0182 (3)
N2	0.4577 (2)	1.3147 (2)	0.76156 (15)	0.0218 (3)
H21	0.466 (3)	1.434 (3)	0.7566 (18)	0.027 (5)*
H22	0.521 (3)	1.251 (3)	0.698 (2)	0.031 (6)*
N3	0.0180 (2)	1.01263 (18)	1.24009 (12)	0.0167 (3)
N4	0.0340 (2)	1.32261 (19)	1.20831 (13)	0.0164 (3)
H4	0.013 (3)	1.445 (3)	1.231 (2)	0.040 (6)*
C1	0.3378 (2)	1.0322 (2)	0.89745 (15)	0.0158 (3)
C2	0.2319 (2)	0.9471 (2)	1.01679 (15)	0.0156 (3)
H2	0.2269	0.8178	1.0293	0.019*
C3	0.1361 (2)	1.0585 (2)	1.11424 (15)	0.0148 (3)
C4	0.1479 (2)	1.2541 (2)	1.09322 (15)	0.0149 (3)
C5	0.2526 (2)	1.3396 (2)	0.97763 (15)	0.0162 (3)
H5	0.2572	1.4686	0.9674	0.019*
C6	0.3532 (2)	1.2294 (2)	0.87459 (15)	0.0163 (3)
C7	−0.0386 (2)	1.1733 (2)	1.29146 (15)	0.0157 (3)
C8	−0.1690 (3)	1.1990 (2)	1.42471 (15)	0.0206 (4)
H8A	−0.2829	1.3129	1.4215	0.031*
H8B	−0.0876	1.2148	1.4752	0.031*
H8C	−0.2210	1.0861	1.4637	0.031*

	U11	U22	U33	U12	U13	U23
O1	0.0276 (7)	0.0150 (6)	0.0264 (6)	−0.0065 (5)	−0.0035 (5)	−0.0080 (5)
O2	0.0287 (7)	0.0235 (6)	0.0194 (6)	−0.0106 (5)	0.0037 (5)	−0.0061 (5)
O3	0.0281 (7)	0.0135 (6)	0.0253 (6)	−0.0070 (5)	−0.0066 (5)	−0.0045 (5)
O4	0.0267 (7)	0.0215 (7)	0.0261 (7)	−0.0046 (5)	−0.0012 (6)	−0.0099 (5)
N1	0.0168 (7)	0.0178 (7)	0.0215 (7)	−0.0041 (5)	−0.0047 (6)	−0.0066 (5)
N2	0.0257 (8)	0.0174 (7)	0.0207 (8)	−0.0083 (6)	−0.0001 (6)	−0.0043 (6)
N3	0.0174 (7)	0.0154 (7)	0.0180 (7)	−0.0042 (5)	−0.0042 (6)	−0.0046 (5)
N4	0.0191 (7)	0.0129 (7)	0.0175 (7)	−0.0041 (5)	−0.0038 (6)	−0.0043 (5)
C1	0.0147 (8)	0.0156 (8)	0.0180 (8)	−0.0023 (6)	−0.0047 (6)	−0.0061 (6)
C2	0.0151 (8)	0.0131 (7)	0.0210 (8)	−0.0038 (6)	−0.0064 (6)	−0.0045 (6)
C3	0.0139 (8)	0.0147 (7)	0.0175 (8)	−0.0043 (6)	−0.0063 (6)	−0.0021 (6)
C4	0.0140 (8)	0.0142 (7)	0.0186 (8)	−0.0027 (6)	−0.0066 (6)	−0.0043 (6)
C5	0.0177 (8)	0.0112 (7)	0.0211 (8)	−0.0039 (6)	−0.0067 (7)	−0.0025 (6)
C6	0.0140 (8)	0.0175 (8)	0.0185 (8)	−0.0038 (6)	−0.0062 (6)	−0.0022 (6)
C7	0.0158 (8)	0.0146 (7)	0.0187 (8)	−0.0044 (6)	−0.0065 (6)	−0.0031 (6)
C8	0.0239 (9)	0.0182 (8)	0.0191 (8)	−0.0051 (7)	−0.0034 (7)	−0.0053 (6)

O1—N1	1.2383 (17)	C2—C1	1.401 (2)
O2—N1	1.2487 (17)	C2—C3	1.364 (2)
O3—H31	0.854 (16)	C2—H2	0.9300
O3—H32	0.890 (18)	C4—N4	1.376 (2)
O4—H41	0.899 (19)	C4—C3	1.414 (2)
O4—H42	0.845 (16)	C4—C5	1.372 (2)
N1—C1	1.429 (2)	C5—C6	1.409 (2)
N2—C6	1.352 (2)	C5—H5	0.9300
N2—H21	0.87 (2)	C6—C1	1.433 (2)
N2—H22	0.85 (2)	C8—C7	1.482 (2)
N3—C3	1.398 (2)	C8—H8A	0.9600
N3—C7	1.310 (2)	C8—H8B	0.9600
N4—C7	1.370 (2)	C8—H8C	0.9600
N4—H4	0.94 (2)
H31—O3—H32	111 (3)	C2—C3—C4	119.69 (14)
H42—O4—H41	110 (3)	N4—C4—C3	104.44 (13)
O1—N1—O2	120.75 (13)	C5—C4—N4	132.73 (14)
O1—N1—C1	119.17 (13)	C5—C4—C3	122.82 (14)
O2—N1—C1	120.08 (13)	C4—C5—C6	119.18 (14)
C6—N2—H21	118.8 (13)	C4—C5—H5	120.4
C6—N2—H22	120.7 (14)	C6—C5—H5	120.4
H21—N2—H22	120.4 (19)	N2—C6—C1	124.24 (15)
C7—N3—C3	104.78 (13)	N2—C6—C5	118.63 (14)
C4—N4—H4	128.3 (13)	C5—C6—C1	117.13 (14)
C7—N4—C4	107.67 (13)	N3—C7—N4	113.09 (14)
C7—N4—H4	123.9 (13)	N3—C7—C8	125.40 (14)
N1—C1—C6	121.60 (14)	N4—C7—C8	121.52 (14)
C2—C1—N1	115.68 (14)	C7—C8—H8A	109.5
C2—C1—C6	122.71 (14)	C7—C8—H8B	109.5
C1—C2—H2	120.8	C7—C8—H8C	109.5
C3—C2—C1	118.45 (14)	H8A—C8—H8B	109.5
C3—C2—H2	120.8	H8A—C8—H8C	109.5
N3—C3—C4	110.02 (13)	H8B—C8—H8C	109.5
C2—C3—N3	130.29 (14)
O1—N1—C1—C2	−1.3 (2)	C3—C4—N4—C7	0.29 (16)
O1—N1—C1—C6	177.83 (14)	C5—C4—N4—C7	179.23 (16)
O2—N1—C1—C2	178.33 (14)	N4—C4—C3—C2	179.06 (13)
O2—N1—C1—C6	−2.6 (2)	N4—C4—C3—N3	−0.32 (17)
C7—N3—C3—C2	−179.07 (16)	C5—C4—C3—N3	−179.40 (14)
C7—N3—C3—C4	0.23 (17)	C5—C4—C3—C2	0.0 (2)
C3—N3—C7—N4	−0.05 (17)	N4—C4—C5—C6	−178.66 (16)
C3—N3—C7—C8	179.45 (15)	C3—C4—C5—C6	0.1 (2)
C4—N4—C7—N3	−0.16 (18)	C4—C5—C6—N2	−179.35 (14)
C4—N4—C7—C8	−179.68 (14)	C4—C5—C6—C1	0.5 (2)
C3—C2—C1—N1	−179.56 (13)	N2—C6—C1—N1	−0.4 (2)
C3—C2—C1—C6	1.3 (2)	N2—C6—C1—C2	178.59 (15)
C1—C2—C3—N3	178.54 (15)	C5—C6—C1—N1	179.73 (14)
C1—C2—C3—C4	−0.7 (2)	C5—C6—C1—C2	−1.2 (2)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4···O3i	0.94 (2)	1.87 (2)	2.7735 (18)	160.4 (19)
N2—H21···O1ii	0.88 (2)	2.39 (2)	3.2212 (18)	158.8 (17)
N2—H21···O4iii	0.88 (2)	2.59 (2)	3.163 (2)	124.1 (15)
N2—H22···O2	0.85 (2)	2.03 (2)	2.6387 (19)	127.3 (19)
O3—H31···N3iv	0.85 (2)	1.89 (2)	2.7354 (18)	176.(2)
O3—H32···O4v	0.89 (3)	1.90 (3)	2.776 (2)	168 (3)
O4—H41···O3	0.90 (2)	1.88 (3)	2.7727 (19)	170 (4)
O4—H42···O1vi	0.85 (2)	2.53 (2)	3.0930 (17)	125.(2)
O4—H42···O2vi	0.85 (2)	2.17 (2)	3.0126 (17)	171 (3)
C5—H5···O1ii	0.93	2.54	3.3556 (19)	146

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4⋯O3i	0.94 (2)	1.87 (2)	2.7735 (18)	160.4 (19)
N2—H21⋯O1ii	0.88 (2)	2.39 (2)	3.2212 (18)	158.8 (17)
N2—H21⋯O4iii	0.88 (2)	2.59 (2)	3.163 (2)	124.1 (15)
N2—H22⋯O2	0.85 (2)	2.03 (2)	2.6387 (19)	127.3 (19)
O3—H31⋯N3iv	0.85 (2)	1.89 (2)	2.7354 (18)	176 (2)
O3—H32⋯O4v	0.89 (3)	1.90 (3)	2.776 (2)	168 (3)
O4—H41⋯O3	0.90 (2)	1.88 (3)	2.7727 (19)	170 (4)
O4—H42⋯O1vi	0.85 (2)	2.53 (2)	3.0930 (17)	125 (2)
O4—H42⋯O2vi	0.85 (2)	2.17 (2)	3.0126 (17)	171 (3)
C5—H5⋯O1ii	0.93	2.54	3.3556 (19)	146

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .