organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Benzoic acid–2,2′-bi­imidazole (2/1)

aDepartment of Chemistry, Taiyuan Normal College, Taiyuan, Shanxi 030031, People's Republic of China, and bInstitute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of the Education Ministry, Shanxi University, Taiyuan, Shanxi 030006, People's Republic of China
*Correspondence e-mail: miaoli@sxu.edu.cn

(Received 13 October 2010; accepted 4 November 2010; online 10 November 2010)

In the title compound, C6H6N4·2C7H6O2, the asymmetric unit contains a half-mol­ecule of biimidazole and one benzoic acid mol­ecule. The unit cell contains two biimidazole mol­ecules and four benzoic acid mol­ecules, giving the reported 2:1 ratio of benzoic acid to biimidazole. The biimidazole mol­ecule is located on an inversion center (passing through the central C—C bond). Strong N—H⋯O and O—H⋯N hydrogen bonds link the benzoic acid mol­ecules with the neutral biimidazole mol­ecules, which lie in planar sheets. In the crystal packing, the parallel sheets are related by a twofold rotation axis and an inversion centre, respectively, forming an inter­woven three-dimensional network via weak C=O⋯π inter­molecular inter­actions between neighboring mol­ecules.

Related literature

For background to the use of 2,2′-biimidazoles in crystal engineering, see: Matthews et al. (1990[Matthews, D. P., McCarthy, J. R., Whitten, J. P., Kastner, P. R., Barney, C. L., Marshall, F. N., Ertel, M. A., Burkhard, T., Shea, P. J. & Kariya, T. (1990). J. Med. Chem. 33, 317-327.]); Tadokoro & Nakasuji (2000[Tadokoro, M. & Nakasuji, K. (2000). Coord. Chem. Rev. 198, 205-218.]). For similar structures, see: Gao et al. (2009[Gao, X.-L., Lu, L.-P. & Zhu, M.-L. (2009). Acta Cryst. C65, o123-o127.]); Li & Yang (2006[Li, Y.-P. & Yang, P. (2006). Acta Cryst. E62, o3223-o3224.]); Mori & Miyoshi (2004[Mori, H. & Miyoshi, E. (2004). Bull. Chem. Soc. Jpn, 77, 687-690.]).

[Scheme 1]

Experimental

Crystal data
  • C6H6N4·2C7H6O2

  • Mr = 378.38

  • Monoclinic, P 21 /n

  • a = 11.232 (5) Å

  • b = 5.082 (2) Å

  • c = 16.342 (7) Å

  • β = 99.832 (6)°

  • V = 919.2 (7) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 298 K

  • 0.40 × 0.20 × 0.10 mm

Data collection
  • Bruker SMART 1K CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2000[Sheldrick, G. M. (2000). SADABS. University of Göttingen, Germany.]) Tmin = 0.962, Tmax = 0.990

  • 3367 measured reflections

  • 1550 independent reflections

  • 1243 reflections with I > 2σ(I)

  • Rint = 0.047

Refinement
  • R[F2 > 2σ(F2)] = 0.098

  • wR(F2) = 0.188

  • S = 1.25

  • 1550 reflections

  • 131 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.20 e Å−3

  • Δρmin = −0.19 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the N1/C1/N2/C3/C2 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1A⋯N2i 0.86 1.77 2.613 (5) 170
N1—H1⋯O2ii 0.88 (5) 1.89 (5) 2.767 (5) 173 (5)
C4—O2⋯Cg1 1.22 (1) 3.67 (1) 4.388 (2) 118 (1)
Symmetry codes: (i) -x+1, -y, -z+1; (ii) x, y+1, z.

Data collection: SMART (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and SHELXTL/PC (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL/PC.

Supporting information


Comment top

Compounds containing the 2,2'-biimidazole moiety have been the focus of several investigations not only due to their biological activity, but also due to their contribution to the field of crystal engineering (Matthews, et al. 1990; Tadokoro & Nakasuji, 2000). In these compunds weak interactions, such as C—H···O and C=O···π, play crucial roles in building the overall three-dimensional structure (Mori & Miyoshi, 2004; Li & Yang, 2006; Gao et al., 2009).

The asymmetric unit of compound (I) contains one benzoic acid and 1/2 neutral biimidazole molecule, in which the imidazole rings are coplanar (Fig. 1). Each biimidazole molecule is linked to two benzoic acids via strong N—H···O and O—H···N hydrogen bonds (Table 1) twithin planar sheets (Figure 2). These sheets further assemble to layers via weak C=O···π (see Table 1, Cg1 for centre of N1/C1/N2/C3/C2) interactions between neighboring molecules and arrange alternatively and across along b and c axis in two-dimensional structure, and the dihedral angle of the planes are 92.7°. In contrast, two groups of these parallel layers on a twofold rotation axis and inversion centre forming a zigzag conformation along c axis in whole three-dimensional network as shown in Fig. 3.

Related literature top

For background to the use of 2,2'-biimidazoles in crystal engineering, see: Matthews et al. (1990); Tadokoro & Nakasuji (2000). For similar structures, see: Gao et al. (2009); Li & Yang (2006); Mori & Miyoshi (2004).

Experimental top

Benzoic acid (0.25 g, 2 mmol) and biimidazole (1 mmol) were dissolved in water(10 ml) by adding 1.4 ml of 2 M HCl while stirring. The solutions were stirred for 1 h, then filtered. Filtrate was left to stand at room temperature. Crystals suitable for data collection appeared after a few weeks by slow evaporation of the aqueous solvent.

Refinement top

H atoms attached to C atoms were placed in geometrically idealized positions, with Csp2 = 0.93 Å, and constrained to ride on their carrier atoms, with Uiso(H) = 1.2Ueq(C). H atoms attached to N1 and O1 atoms were located in difference Fourier maps and refined with Uiso(H for N) = 0.06 Å2 and Uiso(H) = 1.5Ueq(O); N—H distance is 0.88 (5) Å and the O—H distance is 0.856 Å.

Structure description top

Compounds containing the 2,2'-biimidazole moiety have been the focus of several investigations not only due to their biological activity, but also due to their contribution to the field of crystal engineering (Matthews, et al. 1990; Tadokoro & Nakasuji, 2000). In these compunds weak interactions, such as C—H···O and C=O···π, play crucial roles in building the overall three-dimensional structure (Mori & Miyoshi, 2004; Li & Yang, 2006; Gao et al., 2009).

The asymmetric unit of compound (I) contains one benzoic acid and 1/2 neutral biimidazole molecule, in which the imidazole rings are coplanar (Fig. 1). Each biimidazole molecule is linked to two benzoic acids via strong N—H···O and O—H···N hydrogen bonds (Table 1) twithin planar sheets (Figure 2). These sheets further assemble to layers via weak C=O···π (see Table 1, Cg1 for centre of N1/C1/N2/C3/C2) interactions between neighboring molecules and arrange alternatively and across along b and c axis in two-dimensional structure, and the dihedral angle of the planes are 92.7°. In contrast, two groups of these parallel layers on a twofold rotation axis and inversion centre forming a zigzag conformation along c axis in whole three-dimensional network as shown in Fig. 3.

For background to the use of 2,2'-biimidazoles in crystal engineering, see: Matthews et al. (1990); Tadokoro & Nakasuji (2000). For similar structures, see: Gao et al. (2009); Li & Yang (2006); Mori & Miyoshi (2004).

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and SHELXL97 (Sheldrick, 2008); software used to prepare material for publication: SHELXTL/PC (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the structure of compound (I) with displacement ellipsoids drawn at the 50% probability level, the biimidazole sits on a center of symmetry passing through the C1—C1 bond. Symmetry code: (i) 1 - x, 1 - y, 1 - z.
[Figure 2] Fig. 2. H-bonds (dotting line) in (I). Symmetry codes: (ii) x, 1 + y, z; (iv) 1 - x, -y, 1 - z; (v) 1 - x, 1 - y, 1 - z.
[Figure 3] Fig. 3. The packing view in the title compound (I), dotting line for H-bonds.
Benzoic acid–2,2'-biimidazole (2/1) top
Crystal data top
C6H6N4·2C7H6O2F(000) = 396
Mr = 378.38Dx = 1.367 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 698 reflections
a = 11.232 (5) Åθ = 2.5–20.8°
b = 5.082 (2) ŵ = 0.10 mm1
c = 16.342 (7) ÅT = 298 K
β = 99.832 (6)°Block, colorless
V = 919.2 (7) Å30.40 × 0.20 × 0.10 mm
Z = 2
Data collection top
Bruker SMART 1K CCD area-detector
diffractometer
1550 independent reflections
Radiation source: fine-focus sealed tube1243 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
ω scansθmax = 25.0°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2000)
h = 1312
Tmin = 0.962, Tmax = 0.990k = 62
3367 measured reflectionsl = 1919
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.098Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.188H atoms treated by a mixture of independent and constrained refinement
S = 1.25 w = 1/[σ2(Fo2) + (0.0425P)2 + 1.0781P]
where P = (Fo2 + 2Fc2)/3
1550 reflections(Δ/σ)max < 0.001
131 parametersΔρmax = 0.20 e Å3
0 restraintsΔρmin = 0.19 e Å3
Crystal data top
C6H6N4·2C7H6O2V = 919.2 (7) Å3
Mr = 378.38Z = 2
Monoclinic, P21/nMo Kα radiation
a = 11.232 (5) ŵ = 0.10 mm1
b = 5.082 (2) ÅT = 298 K
c = 16.342 (7) Å0.40 × 0.20 × 0.10 mm
β = 99.832 (6)°
Data collection top
Bruker SMART 1K CCD area-detector
diffractometer
1550 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2000)
1243 reflections with I > 2σ(I)
Tmin = 0.962, Tmax = 0.990Rint = 0.047
3367 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0980 restraints
wR(F2) = 0.188H atoms treated by a mixture of independent and constrained refinement
S = 1.25Δρmax = 0.20 e Å3
1550 reflectionsΔρmin = 0.19 e Å3
131 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
xyzUiso*/Ueq
N10.3655 (3)0.6966 (8)0.4607 (2)0.0406 (10)
H10.383 (4)0.809 (10)0.423 (3)0.064 (17)*
N20.3784 (3)0.3740 (7)0.5510 (2)0.0389 (9)
C10.4360 (4)0.5176 (8)0.5031 (2)0.0307 (10)
C20.2533 (4)0.6694 (10)0.4821 (3)0.0436 (12)
H20.18460.76790.46240.052*
C30.2630 (4)0.4717 (10)0.5372 (3)0.0453 (12)
H30.20030.40970.56250.054*
C40.4969 (4)0.1219 (9)0.3172 (3)0.0376 (11)
C50.4964 (4)0.3271 (9)0.2521 (2)0.0347 (10)
C60.5982 (4)0.3745 (10)0.2158 (3)0.0451 (12)
H60.66870.27900.23290.054*
C70.5946 (4)0.5616 (10)0.1549 (3)0.0516 (13)
H70.66250.59160.13080.062*
C80.4913 (4)0.7050 (10)0.1294 (3)0.0491 (13)
H80.48970.83210.08830.059*
C90.3913 (4)0.6618 (10)0.1641 (3)0.0458 (12)
H90.32160.75950.14680.055*
C100.3934 (4)0.4739 (10)0.2247 (3)0.0441 (12)
H100.32440.44470.24780.053*
O10.5977 (3)0.0029 (7)0.3367 (2)0.0532 (10)
H1A0.59710.11860.37470.080*
O20.4086 (3)0.0801 (7)0.3491 (2)0.0517 (9)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.043 (2)0.037 (2)0.042 (2)0.0004 (19)0.0097 (18)0.009 (2)
N20.041 (2)0.035 (2)0.043 (2)0.0011 (18)0.0116 (17)0.0088 (19)
C10.044 (2)0.022 (2)0.027 (2)0.003 (2)0.0077 (19)0.0055 (19)
C20.037 (3)0.048 (3)0.046 (3)0.004 (2)0.007 (2)0.000 (3)
C30.032 (2)0.057 (3)0.048 (3)0.000 (2)0.009 (2)0.011 (3)
C40.041 (3)0.029 (2)0.043 (3)0.004 (2)0.009 (2)0.002 (2)
C50.038 (2)0.032 (3)0.034 (2)0.004 (2)0.0064 (19)0.005 (2)
C60.037 (3)0.046 (3)0.053 (3)0.002 (2)0.012 (2)0.008 (3)
C70.048 (3)0.052 (3)0.060 (3)0.001 (3)0.024 (2)0.013 (3)
C80.051 (3)0.048 (3)0.049 (3)0.003 (3)0.008 (2)0.013 (3)
C90.036 (3)0.046 (3)0.054 (3)0.006 (2)0.004 (2)0.009 (3)
C100.033 (2)0.055 (3)0.046 (3)0.005 (2)0.013 (2)0.002 (3)
O10.0371 (17)0.058 (2)0.065 (2)0.0067 (18)0.0089 (15)0.0244 (19)
O20.0465 (19)0.051 (2)0.063 (2)0.0094 (17)0.0220 (16)0.0155 (18)
Geometric parameters (Å, º) top
N1—C11.322 (5)C5—C101.385 (6)
N1—C21.371 (5)C5—C61.397 (6)
N1—H10.88 (5)C6—C71.371 (6)
N2—C11.319 (5)C6—H60.9300
N2—C31.370 (5)C7—C81.374 (6)
C1—C1i1.469 (8)C7—H70.9300
C2—C31.342 (6)C8—C91.359 (6)
C2—H20.9300C8—H80.9300
C3—H30.9300C9—C101.373 (6)
C4—O21.216 (5)C9—H90.9300
C4—O11.289 (5)C10—H100.9300
C4—C51.489 (6)O1—H1A0.8564
C1—N1—C2106.9 (4)C6—C5—C4121.4 (4)
C1—N1—H1129 (3)C7—C6—C5120.1 (4)
C2—N1—H1124 (3)C7—C6—H6119.9
C1—N2—C3104.4 (4)C5—C6—H6119.9
N2—C1—N1112.4 (4)C6—C7—C8120.5 (4)
N2—C1—C1i124.0 (5)C6—C7—H7119.8
N1—C1—C1i123.6 (5)C8—C7—H7119.8
C3—C2—N1105.9 (4)C9—C8—C7120.2 (5)
C3—C2—H2127.0C9—C8—H8119.9
N1—C2—H2127.0C7—C8—H8119.9
C2—C3—N2110.4 (4)C8—C9—C10120.0 (4)
C2—C3—H3124.8C8—C9—H9120.0
N2—C3—H3124.8C10—C9—H9120.0
O2—C4—O1123.6 (4)C9—C10—C5121.2 (4)
O2—C4—C5121.7 (4)C9—C10—H10119.4
O1—C4—C5114.7 (4)C5—C10—H10119.4
C10—C5—C6118.0 (4)C4—O1—H1A113.7
C10—C5—C4120.6 (4)
C3—N2—C1—N10.0 (5)O1—C4—C5—C60.5 (6)
C3—N2—C1—C1i179.6 (5)C10—C5—C6—C70.0 (7)
C2—N1—C1—N20.0 (5)C4—C5—C6—C7178.9 (4)
C2—N1—C1—C1i179.6 (5)C5—C6—C7—C80.4 (7)
C1—N1—C2—C30.0 (5)C6—C7—C8—C90.3 (8)
N1—C2—C3—N20.0 (5)C7—C8—C9—C100.1 (7)
C1—N2—C3—C20.0 (5)C8—C9—C10—C50.5 (7)
O2—C4—C5—C101.3 (6)C6—C5—C10—C90.4 (7)
O1—C4—C5—C10179.3 (4)C4—C5—C10—C9179.3 (4)
O2—C4—C5—C6179.8 (4)
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the [please define] ring.
D—H···AD—HH···AD···AD—H···A
O1—H1A···N2ii0.861.772.613 (5)170
N1—H1···O2iii0.88 (5)1.89 (5)2.767 (5)173 (5)
C4—O2···Cg11.22 (1)3.67 (1)4.388 (2)118 (1)
Symmetry codes: (ii) x+1, y, z+1; (iii) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC6H6N4·2C7H6O2
Mr378.38
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)11.232 (5), 5.082 (2), 16.342 (7)
β (°) 99.832 (6)
V3)919.2 (7)
Z2
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.40 × 0.20 × 0.10
Data collection
DiffractometerBruker SMART 1K CCD area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2000)
Tmin, Tmax0.962, 0.990
No. of measured, independent and
observed [I > 2σ(I)] reflections
3367, 1550, 1243
Rint0.047
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.098, 0.188, 1.25
No. of reflections1550
No. of parameters131
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.20, 0.19

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and SHELXL97 (Sheldrick, 2008), SHELXTL/PC (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the [please define] ring.
D—H···AD—HH···AD···AD—H···A
O1—H1A···N2i0.861.772.613 (5)169.6
N1—H1···O2ii0.88 (5)1.89 (5)2.767 (5)173 (5)
C4—O2···Cg11.216 (5)3.674 (2)4.388 (2)118.37 (6)
Symmetry codes: (i) x+1, y, z+1; (ii) x, y+1, z.
 

Acknowledgements

This work was supported financially by the Natural Science Foundation of Shanxi Province of China (grant No. 2010011011–2).

References

First citationBruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationGao, X.-L., Lu, L.-P. & Zhu, M.-L. (2009). Acta Cryst. C65, o123–o127.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationLi, Y.-P. & Yang, P. (2006). Acta Cryst. E62, o3223–o3224.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationMatthews, D. P., McCarthy, J. R., Whitten, J. P., Kastner, P. R., Barney, C. L., Marshall, F. N., Ertel, M. A., Burkhard, T., Shea, P. J. & Kariya, T. (1990). J. Med. Chem. 33, 317–327.  CrossRef CAS PubMed Web of Science Google Scholar
First citationMori, H. & Miyoshi, E. (2004). Bull. Chem. Soc. Jpn, 77, 687–690.  Web of Science CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2000). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationTadokoro, M. & Nakasuji, K. (2000). Coord. Chem. Rev. 198, 205–218.  Web of Science CrossRef CAS Google Scholar

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