organic compounds
Dimethyl 2,2′-[2,2′-bi(1H-1,3-benzimidazole)-1,1′-diyl]diacetate
aKey Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
*Correspondence e-mail: jcliu8@163.com
The whole molecule of the title compound, C20H18N4O4, is generated by an inversion center. The benzimidazole ring mean plane make a dihedral angle of 89.4 (8)° with the plane passing through the acetate group (COO). In the crystal, molecules are linked via weak C—H⋯O hydrogen bonds and π–π interactions [centroid–centroid distance = 3.743 (3) Å] involving inversion-related benzimidazole groups.
Related literature
For related structures, see: Al-Mohammed et al. (2012); Fu & Xu (2009); Xu & Wang (2008). For the synthesis of 2,2′-bibenzimidazole, see: Tang et al. (2007).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2005); cell SAINT (Bruker, 2005); 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
https://doi.org/10.1107/S1600536812032266/su2479sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812032266/su2479Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536812032266/su2479Isup3.cml
The synthesis of 2,2'-bibenzimidazole [systematic name: 1H,1'H-2,2'-bibenzo[d]imidazole] has been reported (Tang et al., 2007). A mixture of 2,2'-bibenzimidazole (11.71 g, 50 mmol) and NaOH (4.00 g, 100 mmol) in DMSO (40 mL) was stirred at 278 K for 2 h, and then methyl chloroacetate (10.85 g, 100 mmol) was added. The mixture was cooled to room temperature after stirring at 353 K for 24 h, and then poured into 200 mL of water. A yellow solid formed immediately, which was isolated by filtration. The crude product was then crystallized from methanol. Single crystals of the title compound, suitable for X-ray analysis, were obtained by slow evaporation of a solution in methanol.
The C-bound H-atoms were included in calculated positions and treated as riding atoms: C-H = 0.93, 0.96 and 0.97 Å for CH, CH3 and CH2 H-atoms, respectively, with Uiso(H) = k × Ueq(parent C-atom), where k = 1.5 for CH3 H-atoms and = 1.2 for other H-atoms.
The whole molecule of the title compound (Fig.1) is generated by an inversion center. The benzimidazole system is essentially planar, with a dihedral angle of 0.8 (5)° between the planes of the benzene and imidazole rings. The benzimidazole ring make a dihedral angle of 89.4 (8)° with the plane passing through the acetate group (C9/O1/O2). This value is comparable to that observed in some similar structures (Al-Mohammed et al., 2012; Fu et al., 2009; Xu et al., 2008).
In the crystal, weak intermolecular C—H···O hydrogen bonds (Table 1 and Fig. 2) and π–π stacking interactions [Cg1···Cg2i = 3.743 (3) Å, where Cg1 is the centroid of ring N1/C1/C6/N2/C7; Cg2 is the centroid of ring C1-C6; symmetry code: (i) -x+1, -y+1, -z+1] stabilize the crystal structure.
For related structures, see: Al-Mohammed et al. (2012); Fu & Xu (2009); Xu & Wang (2008). For the synthesis of 2,2'-bibenzimidazole, see: Tang et al. (2007).
Data collection: APEX2 (Bruker, 2005); cell
SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); 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).C20H18N4O4 | Z = 1 |
Mr = 378.38 | F(000) = 198 |
Triclinic, P1 | Dx = 1.434 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.904 (4) Å | Cell parameters from 853 reflections |
b = 8.494 (5) Å | θ = 2.6–23.8° |
c = 8.643 (5) Å | µ = 0.10 mm−1 |
α = 67.191 (5)° | T = 296 K |
β = 70.360 (5)° | Block, brown |
γ = 87.172 (5)° | 0.33 × 0.31 × 0.29 mm |
V = 438.1 (4) Å3 |
Bruker APEXII CCD diffractometer | 1600 independent reflections |
Radiation source: fine-focus sealed tube | 1172 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.027 |
φ and ω scans | θmax = 25.5°, θmin = 2.6° |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | h = −8→8 |
Tmin = 0.967, Tmax = 0.971 | k = −9→10 |
3034 measured reflections | l = −10→10 |
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)] = 0.048 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.127 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0656P)2 + 0.0023P] where P = (Fo2 + 2Fc2)/3 |
1600 reflections | (Δ/σ)max < 0.001 |
128 parameters | Δρmax = 0.14 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
C20H18N4O4 | γ = 87.172 (5)° |
Mr = 378.38 | V = 438.1 (4) Å3 |
Triclinic, P1 | Z = 1 |
a = 6.904 (4) Å | Mo Kα radiation |
b = 8.494 (5) Å | µ = 0.10 mm−1 |
c = 8.643 (5) Å | T = 296 K |
α = 67.191 (5)° | 0.33 × 0.31 × 0.29 mm |
β = 70.360 (5)° |
Bruker APEXII CCD diffractometer | 1600 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 1172 reflections with I > 2σ(I) |
Tmin = 0.967, Tmax = 0.971 | Rint = 0.027 |
3034 measured reflections |
R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
wR(F2) = 0.127 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.14 e Å−3 |
1600 reflections | Δρmin = −0.25 e Å−3 |
128 parameters |
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 | ||
C1 | 0.3492 (3) | 0.6658 (2) | 0.5117 (2) | 0.0382 (5) | |
C2 | 0.5275 (3) | 0.7663 (3) | 0.4646 (3) | 0.0485 (6) | |
H2 | 0.6033 | 0.8332 | 0.3460 | 0.058* | |
C3 | 0.5865 (4) | 0.7619 (3) | 0.6022 (3) | 0.0539 (6) | |
H3 | 0.7063 | 0.8271 | 0.5762 | 0.065* | |
C4 | 0.4722 (4) | 0.6624 (3) | 0.7808 (3) | 0.0533 (6) | |
H4 | 0.5173 | 0.6635 | 0.8704 | 0.064* | |
C5 | 0.2955 (3) | 0.5636 (3) | 0.8265 (3) | 0.0497 (6) | |
H5 | 0.2197 | 0.4979 | 0.9454 | 0.060* | |
C6 | 0.2327 (3) | 0.5645 (2) | 0.6892 (2) | 0.0397 (5) | |
C7 | 0.0742 (3) | 0.5291 (2) | 0.5281 (2) | 0.0385 (5) | |
C8 | 0.3089 (3) | 0.7314 (2) | 0.2179 (2) | 0.0433 (5) | |
H8A | 0.2674 | 0.6583 | 0.1696 | 0.052* | |
H8B | 0.4585 | 0.7504 | 0.1691 | 0.052* | |
C9 | 0.2220 (3) | 0.9010 (3) | 0.1547 (3) | 0.0435 (5) | |
C10 | 0.0081 (4) | 1.1015 (3) | 0.2334 (4) | 0.0720 (8) | |
H10A | 0.1162 | 1.1933 | 0.1612 | 0.108* | |
H10B | −0.0752 | 1.1195 | 0.3382 | 0.108* | |
H10C | −0.0764 | 1.0989 | 0.1659 | 0.108* | |
N1 | 0.2463 (2) | 0.64117 (18) | 0.41008 (19) | 0.0388 (4) | |
N2 | 0.0622 (3) | 0.4797 (2) | 0.6961 (2) | 0.0435 (5) | |
O1 | 0.2651 (3) | 0.9897 (2) | −0.00051 (19) | 0.0731 (6) | |
O2 | 0.0980 (2) | 0.94015 (17) | 0.28611 (18) | 0.0535 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0432 (12) | 0.0319 (10) | 0.0357 (10) | 0.0078 (9) | −0.0109 (9) | −0.0122 (8) |
C2 | 0.0521 (14) | 0.0445 (12) | 0.0380 (11) | −0.0018 (10) | −0.0083 (10) | −0.0104 (9) |
C3 | 0.0519 (14) | 0.0543 (13) | 0.0493 (13) | −0.0041 (11) | −0.0148 (11) | −0.0153 (11) |
C4 | 0.0571 (15) | 0.0605 (14) | 0.0434 (12) | 0.0081 (12) | −0.0224 (11) | −0.0176 (11) |
C5 | 0.0498 (14) | 0.0542 (13) | 0.0354 (11) | 0.0099 (11) | −0.0134 (10) | −0.0094 (9) |
C6 | 0.0429 (13) | 0.0351 (10) | 0.0329 (10) | 0.0077 (9) | −0.0102 (9) | −0.0079 (8) |
C7 | 0.0420 (12) | 0.0299 (10) | 0.0321 (10) | 0.0035 (9) | −0.0063 (8) | −0.0059 (8) |
C8 | 0.0497 (13) | 0.0421 (11) | 0.0280 (10) | −0.0052 (10) | −0.0030 (9) | −0.0110 (8) |
C9 | 0.0431 (13) | 0.0446 (12) | 0.0335 (10) | −0.0084 (9) | −0.0131 (9) | −0.0044 (9) |
C10 | 0.082 (2) | 0.0443 (13) | 0.0862 (18) | 0.0167 (13) | −0.0383 (16) | −0.0158 (13) |
N1 | 0.0442 (10) | 0.0304 (8) | 0.0302 (8) | 0.0015 (7) | −0.0059 (7) | −0.0058 (7) |
N2 | 0.0454 (11) | 0.0396 (9) | 0.0321 (9) | 0.0036 (8) | −0.0079 (8) | −0.0049 (7) |
O1 | 0.0739 (12) | 0.0779 (12) | 0.0375 (9) | 0.0000 (10) | −0.0172 (8) | 0.0073 (8) |
O2 | 0.0684 (11) | 0.0384 (8) | 0.0470 (9) | 0.0120 (7) | −0.0185 (8) | −0.0119 (7) |
C1—N1 | 1.377 (3) | C7—N1 | 1.379 (2) |
C1—C2 | 1.381 (3) | C7—C7i | 1.449 (4) |
C1—C6 | 1.398 (3) | C8—N1 | 1.448 (2) |
C2—C3 | 1.368 (3) | C8—C9 | 1.503 (3) |
C2—H2 | 0.9300 | C8—H8A | 0.9700 |
C3—C4 | 1.398 (3) | C8—H8B | 0.9700 |
C3—H3 | 0.9300 | C9—O1 | 1.194 (2) |
C4—C5 | 1.367 (3) | C9—O2 | 1.321 (2) |
C4—H4 | 0.9300 | C10—O2 | 1.447 (3) |
C5—C6 | 1.391 (3) | C10—H10A | 0.9600 |
C5—H5 | 0.9300 | C10—H10B | 0.9600 |
C6—N2 | 1.383 (3) | C10—H10C | 0.9600 |
C7—N2 | 1.320 (2) | ||
N1—C1—C2 | 131.59 (18) | N1—C8—C9 | 115.16 (16) |
N1—C1—C6 | 105.60 (18) | N1—C8—H8A | 108.5 |
C2—C1—C6 | 122.81 (19) | C9—C8—H8A | 108.5 |
C3—C2—C1 | 116.29 (19) | N1—C8—H8B | 108.5 |
C3—C2—H2 | 121.9 | C9—C8—H8B | 108.5 |
C1—C2—H2 | 121.9 | H8A—C8—H8B | 107.5 |
C2—C3—C4 | 122.0 (2) | O1—C9—O2 | 124.6 (2) |
C2—C3—H3 | 119.0 | O1—C9—C8 | 121.8 (2) |
C4—C3—H3 | 119.0 | O2—C9—C8 | 113.58 (15) |
C5—C4—C3 | 121.4 (2) | O2—C10—H10A | 109.5 |
C5—C4—H4 | 119.3 | O2—C10—H10B | 109.5 |
C3—C4—H4 | 119.3 | H10A—C10—H10B | 109.5 |
C4—C5—C6 | 117.83 (19) | O2—C10—H10C | 109.5 |
C4—C5—H5 | 121.1 | H10A—C10—H10C | 109.5 |
C6—C5—H5 | 121.1 | H10B—C10—H10C | 109.5 |
N2—C6—C5 | 130.18 (18) | C1—N1—C7 | 106.58 (15) |
N2—C6—C1 | 110.13 (17) | C1—N1—C8 | 123.60 (16) |
C5—C6—C1 | 119.7 (2) | C7—N1—C8 | 129.65 (17) |
N2—C7—N1 | 112.52 (18) | C7—N2—C6 | 105.16 (16) |
N2—C7—C7i | 124.2 (2) | C9—O2—C10 | 116.11 (17) |
N1—C7—C7i | 123.3 (2) | ||
N1—C1—C2—C3 | 179.33 (19) | C2—C1—N1—C8 | −3.2 (3) |
C6—C1—C2—C3 | 0.1 (3) | C6—C1—N1—C8 | 176.12 (16) |
C1—C2—C3—C4 | −0.5 (3) | N2—C7—N1—C1 | −0.7 (2) |
C2—C3—C4—C5 | 0.3 (3) | C7i—C7—N1—C1 | −179.9 (2) |
C3—C4—C5—C6 | 0.2 (3) | N2—C7—N1—C8 | −176.09 (18) |
C4—C5—C6—N2 | −179.3 (2) | C7i—C7—N1—C8 | 4.8 (3) |
C4—C5—C6—C1 | −0.5 (3) | C9—C8—N1—C1 | −87.6 (2) |
N1—C1—C6—N2 | 0.0 (2) | C9—C8—N1—C7 | 87.1 (2) |
C2—C1—C6—N2 | 179.38 (19) | N1—C7—N2—C6 | 0.7 (2) |
N1—C1—C6—C5 | −179.02 (17) | C7i—C7—N2—C6 | 179.9 (2) |
C2—C1—C6—C5 | 0.4 (3) | C5—C6—N2—C7 | 178.5 (2) |
N1—C8—C9—O1 | 178.39 (19) | C1—C6—N2—C7 | −0.4 (2) |
N1—C8—C9—O2 | −1.1 (3) | O1—C9—O2—C10 | 1.1 (3) |
C2—C1—N1—C7 | −178.9 (2) | C8—C9—O2—C10 | −179.49 (17) |
C6—C1—N1—C7 | 0.42 (19) |
Symmetry code: (i) −x, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8B···O1ii | 0.97 | 2.59 | 3.364 (3) | 137 |
C10—H10C···O1iii | 0.96 | 2.55 | 3.481 (4) | 164 |
Symmetry codes: (ii) −x+1, −y+2, −z; (iii) −x, −y+2, −z. |
Experimental details
Crystal data | |
Chemical formula | C20H18N4O4 |
Mr | 378.38 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 296 |
a, b, c (Å) | 6.904 (4), 8.494 (5), 8.643 (5) |
α, β, γ (°) | 67.191 (5), 70.360 (5), 87.172 (5) |
V (Å3) | 438.1 (4) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.33 × 0.31 × 0.29 |
Data collection | |
Diffractometer | Bruker APEXII CCD |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.967, 0.971 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3034, 1600, 1172 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.606 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.127, 1.06 |
No. of reflections | 1600 |
No. of parameters | 128 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.25 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8B···O1i | 0.97 | 2.59 | 3.364 (3) | 137 |
C10—H10C···O1ii | 0.96 | 2.55 | 3.481 (4) | 164 |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x, −y+2, −z. |
Acknowledgements
This work was supported by the Natural Science Foundation of Gansu (No. 0710RJ ZA113).
References
Al-Mohammed, N. N., Alias, Y., Abdullah, Z. & Khaledi, H. (2012). Acta Cryst. E68, o571. CSD CrossRef IUCr Journals Google Scholar
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Fu, X. & Xu, G. (2009). Acta Cryst. E65, o1535. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Tang, H.-J., Zhang, Z.-G., Cong, C.-J. & Zhang, K.-L. (2007). Huaxue Shiji, 29, 733–735. CAS Google Scholar
Xu, G.-H. & Wang, W. (2008). Acta Cryst. E64, o1811. Web of Science CrossRef IUCr Journals Google Scholar
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The whole molecule of the title compound (Fig.1) is generated by an inversion center. The benzimidazole system is essentially planar, with a dihedral angle of 0.8 (5)° between the planes of the benzene and imidazole rings. The benzimidazole ring make a dihedral angle of 89.4 (8)° with the plane passing through the acetate group (C9/O1/O2). This value is comparable to that observed in some similar structures (Al-Mohammed et al., 2012; Fu et al., 2009; Xu et al., 2008).
In the crystal, weak intermolecular C—H···O hydrogen bonds (Table 1 and Fig. 2) and π–π stacking interactions [Cg1···Cg2i = 3.743 (3) Å, where Cg1 is the centroid of ring N1/C1/C6/N2/C7; Cg2 is the centroid of ring C1-C6; symmetry code: (i) -x+1, -y+1, -z+1] stabilize the crystal structure.