Metronidazolium perchlorate

Wang, Y.-T.; Chu, X.-L.; Yan, S.-C.; Tang, G.-M.

doi:10.1107/S1600536810038055

organic compounds

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ISSN: 2056-9890

Volume 66| Part 10| October 2010| Page o2647

doi:10.1107/S1600536810038055

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Metronidazolium perchlorate

Yong-Tao Wang,^a ^* Xiao-Lei Chu,^a Shi-Chen Yan ^a and Gui-Mei Tang ^a

^aShandong Provincial Key Laboratory of Fine Chemicals, Department of Chemical Engineering, Shandong Institute of Light Industry, Jinan, Shandong 250353, People's Republic of China
^*Correspondence e-mail: ceswyt@sohu.com

(Received 10 September 2010; accepted 23 September 2010; online 30 September 2010)

In the crystal structure of the title compound [systematic name: 1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazol-3-ium perchlorate], C₆H₁₀N₃O₃⁺·ClO₄⁻, the cations are linked by intermolecular N—H⋯O hydrogen bonds into zigzag chains along the c axis. The cations and anions are connected by O—H⋯O and C—H⋯O hydrogen bonds. A weak intramolecular C—H⋯O hydrogen bond is also observed.

Related literature

For metronidazole, see: Castelli et al. (2000 ); Contrerasa et al. (2009 ). For a related structure, see: Wang et al. (2006 ).

Experimental

Crystal data

C₆H₁₀N₃O₃⁺·ClO₄⁻
M_r = 271.62
Monoclinic, P 2₁ /c
a = 7.8541 (13) Å
b = 10.6791 (17) Å
c = 13.032 (2) Å
β = 93.904 (2)°
V = 1090.5 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.38 mm⁻¹
T = 296 K
0.40 × 0.20 × 0.20 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.862, T_max = 0.928
9191 measured reflections
2509 independent reflections
2219 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.053
wR(F²) = 0.159
S = 1.04
2509 reflections
155 parameters
H-atom parameters constrained
Δρ_max = 0.60 e Å⁻³
Δρ_min = −0.43 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O5	0.89	2.02	2.860 (4)	157
N2—H2⋯O1ⁱ	0.83	1.98	2.803 (3)	169
C1—H1B⋯O2	0.97	2.52	3.126 (3)	121
C6—H6B⋯O7ⁱ	0.96	2.52	3.441 (4)	161
Symmetry code: (i) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810038055/is2601sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810038055/is2601Isup2.hkl

checkCIF report

Comment top

Metronidazole is usually applied in the area of anaerobic protozoan and bacterial infections (Castelli et al., 2000). Its solubility is low in water, so that its absorption is not easy in human body. To solve this problem and to increase its solubility in water, a kind of new strategy of protonated metronidazole has been studied though other methods have been developed in the area of medicine, for example, metal complexes (Contrerasa et al., 2009) and pharmaceutical co-crystals. However, co-crystals containing metronidazole has rarely been investigated. In this paper, we report the 1:1 salt formed by metronidazole and perchloric acid, (I).

A view of the title structure is shown in Fig. 1. The H atom is transferred from the perchloric acid group to the imidazole N atom forming an 1:1 organic salt, which is similar to other organic salt published previously (Wang et al., 2006). In the crystal structure, one-dimensional chains are formed via intermolecular O—H···O and N—H···O hydrogen bonds (Table 1 and Fig. 2).

Related literature top

For metronidazole, see: Castelli et al. (2000); Contrerasa et al. (2009). For a related structure, see: Wang et al. (2006).

Experimental top

Metronidazole (1.71 g, 10 mmol) and 75% aqueous HClO₄ (2 ml) were mixed and dissolved in 10 ml water. The reaction mixture was stirred slowly to room temperature. The bar colourless crystals suitable for X-ray diffraction were obtained after two weeks. Analysis found: C 26.17, H 3.69, N 15.41%; calcd. : C 26.53, H 3.71, N 15.47%. IR (KBr, cm^-1): 3394, 3078, 1610, 1546, 1527, 1502, 1411, 1373, 1319, 1251, 1193, 1143, 1111, 1085, 1080, 1062, 037, 867, 831, 736, 671, 630, 559, 516.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of (I), with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. One-dimensional chain running along the c axis.

1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazol-3-ium perchlorate top

Crystal data top

C₆H₁₀N₃O₃⁺·ClO₄⁻	F(000) = 560
M_r = 271.62	D_x = 1.654 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5428 reflections
a = 7.8541 (13) Å	θ = 2.5–27.5°
b = 10.6791 (17) Å	µ = 0.38 mm⁻¹
c = 13.032 (2) Å	T = 296 K
β = 93.904 (2)°	Prism, colourless
V = 1090.5 (3) Å³	0.40 × 0.20 × 0.20 mm
Z = 4

Data collection top

Bruker SMART CCD area-detector diffractometer	2509 independent reflections
Radiation source: fine-focus sealed tube	2219 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.030
ϕ and ω scans	θ_max = 27.5°, θ_min = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→10
T_min = 0.862, T_max = 0.928	k = −13→13
9191 measured reflections	l = −16→16

Refinement top

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)] = 0.053	H-atom parameters constrained
wR(F²) = 0.159	w = 1/[σ²(F_o²) + (0.085P)² + 0.8145P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max = 0.001
2509 reflections	Δρ_max = 0.60 e Å⁻³
155 parameters	Δρ_min = −0.43 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.190 (12)

Crystal data top

C₆H₁₀N₃O₃⁺·ClO₄⁻	V = 1090.5 (3) Å³
M_r = 271.62	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.8541 (13) Å	µ = 0.38 mm⁻¹
b = 10.6791 (17) Å	T = 296 K
c = 13.032 (2) Å	0.40 × 0.20 × 0.20 mm
β = 93.904 (2)°

Data collection top

Bruker SMART CCD area-detector diffractometer	2509 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	2219 reflections with I > 2σ(I)
T_min = 0.862, T_max = 0.928	R_int = 0.030
9191 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.053	0 restraints
wR(F²) = 0.159	H-atom parameters constrained
S = 1.04	Δρ_max = 0.60 e Å⁻³
2509 reflections	Δρ_min = −0.43 e Å⁻³
155 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
O1	0.7469 (2)	0.70762 (17)	0.58597 (12)	0.0486 (4)
H1	0.8599	0.7118	0.5945	0.073*
O2	0.4144 (3)	0.4116 (2)	0.66132 (15)	0.0639 (6)
O3	0.2449 (3)	0.4469 (2)	0.78337 (19)	0.0727 (6)
N1	0.6726 (2)	0.55501 (15)	0.76908 (12)	0.0340 (4)
N2	0.6393 (3)	0.64689 (18)	0.91461 (14)	0.0437 (5)
H2	0.6580	0.6952	0.9643	0.066*
N3	0.3813 (3)	0.45742 (19)	0.74353 (16)	0.0487 (5)
C1	0.7048 (3)	0.5773 (2)	0.58035 (16)	0.0451 (5)
H1A	0.7611	0.5397	0.5240	0.054*
H1B	0.5827	0.5686	0.5656	0.054*
C2	0.7567 (3)	0.5070 (2)	0.67880 (16)	0.0404 (5)
H2A	0.7283	0.4191	0.6694	0.048*
H2B	0.8794	0.5131	0.6922	0.048*
C3	0.7495 (3)	0.6272 (2)	0.84260 (15)	0.0384 (5)
C4	0.4896 (3)	0.5882 (2)	0.88970 (17)	0.0441 (5)
H4A	0.3928	0.5879	0.9270	0.053*
C5	0.5098 (3)	0.53022 (19)	0.79949 (16)	0.0379 (5)
C6	0.9254 (3)	0.6762 (3)	0.8466 (2)	0.0550 (6)
H6A	0.9791	0.6507	0.7860	0.083*
H6B	0.9887	0.6439	0.9065	0.083*
H6C	0.9228	0.7660	0.8500	0.083*
Cl1	1.22616 (7)	0.74741 (5)	0.59693 (4)	0.0442 (3)
O4	1.3343 (4)	0.7477 (2)	0.6879 (2)	0.0994 (10)
O5	1.1033 (4)	0.6500 (3)	0.5984 (3)	0.1022 (10)
O6	1.3237 (5)	0.7180 (3)	0.5116 (2)	0.1074 (11)
O7	1.1515 (5)	0.8663 (3)	0.5795 (2)	0.1214 (14)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0558 (10)	0.0482 (10)	0.0408 (8)	−0.0064 (7)	−0.0038 (7)	0.0107 (7)
O2	0.0773 (14)	0.0622 (12)	0.0503 (11)	−0.0159 (10)	−0.0096 (9)	−0.0110 (9)
O3	0.0564 (12)	0.0751 (14)	0.0870 (16)	−0.0189 (10)	0.0074 (11)	0.0038 (12)
N1	0.0444 (9)	0.0313 (8)	0.0258 (8)	0.0031 (7)	−0.0008 (6)	0.0019 (6)
N2	0.0642 (12)	0.0368 (9)	0.0302 (9)	0.0026 (8)	0.0033 (8)	−0.0042 (7)
N3	0.0558 (12)	0.0405 (10)	0.0487 (11)	−0.0059 (9)	−0.0055 (9)	0.0065 (8)
C1	0.0627 (14)	0.0457 (12)	0.0266 (9)	−0.0026 (10)	0.0012 (9)	−0.0006 (8)
C2	0.0534 (12)	0.0381 (11)	0.0297 (9)	0.0067 (9)	0.0044 (8)	−0.0019 (8)
C3	0.0510 (12)	0.0356 (10)	0.0279 (9)	0.0016 (8)	−0.0038 (8)	0.0012 (7)
C4	0.0549 (13)	0.0390 (11)	0.0391 (11)	0.0050 (9)	0.0086 (9)	0.0025 (9)
C5	0.0452 (11)	0.0335 (10)	0.0347 (10)	0.0013 (8)	−0.0006 (8)	0.0037 (8)
C6	0.0545 (14)	0.0615 (16)	0.0476 (13)	−0.0111 (12)	−0.0074 (10)	−0.0048 (11)
Cl1	0.0468 (4)	0.0427 (4)	0.0425 (4)	−0.0003 (2)	−0.0022 (2)	−0.0002 (2)
O4	0.126 (2)	0.0840 (18)	0.0799 (17)	0.0238 (15)	−0.0504 (17)	−0.0069 (13)
O5	0.0761 (16)	0.097 (2)	0.137 (3)	−0.0317 (15)	0.0297 (16)	−0.0074 (18)
O6	0.137 (3)	0.106 (2)	0.0864 (19)	−0.013 (2)	0.0566 (19)	0.0002 (16)
O7	0.157 (3)	0.0654 (16)	0.129 (2)	0.0509 (17)	−0.084 (2)	−0.0367 (15)

Geometric parameters (Å, º) top

O1—C1	1.431 (3)	C1—H1B	0.9700
O1—H1	0.8881	C2—H2A	0.9700
O2—N3	1.222 (3)	C2—H2B	0.9700
O3—N3	1.227 (3)	C3—C6	1.475 (3)
N1—C3	1.341 (3)	C4—C5	1.348 (3)
N1—C5	1.390 (3)	C4—H4A	0.9300
N1—C2	1.479 (3)	C6—H6A	0.9600
N2—C3	1.336 (3)	C6—H6B	0.9600
N2—C4	1.353 (3)	C6—H6C	0.9600
N2—H2	0.8328	Cl1—O4	1.410 (3)
N3—C5	1.434 (3)	Cl1—O7	1.411 (2)
C1—C2	1.518 (3)	Cl1—O5	1.420 (3)
C1—H1A	0.9700	Cl1—O6	1.427 (3)

C1—O1—H1	106.3	N2—C3—N1	108.12 (19)
C3—N1—C5	106.50 (17)	N2—C3—C6	124.7 (2)
C3—N1—C2	124.35 (18)	N1—C3—C6	127.2 (2)
C5—N1—C2	129.02 (18)	C5—C4—N2	105.7 (2)
C3—N2—C4	110.65 (18)	C5—C4—H4A	127.2
C3—N2—H2	123.8	N2—C4—H4A	127.2
C4—N2—H2	125.3	C4—C5—N1	109.1 (2)
O2—N3—O3	125.3 (2)	C4—C5—N3	124.9 (2)
O2—N3—C5	118.6 (2)	N1—C5—N3	126.03 (19)
O3—N3—C5	116.1 (2)	C3—C6—H6A	109.5
O1—C1—C2	112.96 (18)	C3—C6—H6B	109.5
O1—C1—H1A	109.0	H6A—C6—H6B	109.5
C2—C1—H1A	109.0	C3—C6—H6C	109.5
O1—C1—H1B	109.0	H6A—C6—H6C	109.5
C2—C1—H1B	109.0	H6B—C6—H6C	109.5
H1A—C1—H1B	107.8	O4—Cl1—O7	110.68 (15)
N1—C2—C1	113.07 (18)	O4—Cl1—O5	111.2 (2)
N1—C2—H2A	109.0	O7—Cl1—O5	112.8 (2)
C1—C2—H2A	109.0	O4—Cl1—O6	109.3 (2)
N1—C2—H2B	109.0	O7—Cl1—O6	108.2 (2)
C1—C2—H2B	109.0	O5—Cl1—O6	104.49 (19)
H2A—C2—H2B	107.8

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O5	0.89	2.02	2.860 (4)	157
N2—H2···O1ⁱ	0.83	1.98	2.803 (3)	169
C1—H1B···O2	0.97	2.52	3.126 (3)	121
C6—H6B···O7ⁱ	0.96	2.52	3.441 (4)	161

Symmetry code: (i) x, −y+3/2, z+1/2.

Experimental details

Crystal data
Chemical formula	C₆H₁₀N₃O₃⁺·ClO₄⁻
M_r	271.62
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	7.8541 (13), 10.6791 (17), 13.032 (2)
β (°)	93.904 (2)
V (Å³)	1090.5 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.38
Crystal size (mm)	0.40 × 0.20 × 0.20

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.862, 0.928
No. of measured, independent and observed [I > 2σ(I)] reflections	9191, 2509, 2219
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.053, 0.159, 1.04
No. of reflections	2509
No. of parameters	155
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.60, −0.43

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O5	0.89	2.02	2.860 (4)	157
N2—H2···O1ⁱ	0.83	1.98	2.803 (3)	169
C1—H1B···O2	0.97	2.52	3.126 (3)	121
C6—H6B···O7ⁱ	0.96	2.52	3.441 (4)	161

Symmetry code: (i) x, −y+3/2, z+1/2.

Acknowledgements

The authors thank the Project of Shandong Province Higher Educational Science and Technology Program (J09LB03) and the Starting Fund of Shandong Institute of Light Industry for financial support.

References

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