Dimethyl 2,2'-[2,2'-bi(1H-1,3-benzimidazole)-1,1'-di-yl]diacetate.

The whole mol-ecule of the title compound, C(20)H(18)N(4)O(4), 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, mol-ecules are linked via weak C-H⋯O hydrogen bonds and π-π inter-actions [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

C20H18N4O4

M = 378.38

Triclinic,

a = 6.904 (4) Å

b = 8.494 (5) Å

c = 8.643 (5) Å

α = 67.191 (5)°

β = 70.360 (5)°

γ = 87.172 (5)°

V = 438.1 (4) Å3

Z = 1

Mo Kα radiation

μ = 0.10 mm−1

T = 296 K

0.33 × 0.31 × 0.29 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.967, T max = 0.971

3034 measured reflections

1600 independent reflections

1172 reflections with I > 2σ(I)

R int = 0.027

Refinement

R[F 2 > 2σ(F 2)] = 0.048

wR(F 2) = 0.127

S = 1.06

1600 reflections

128 parameters

H-atom parameters constrained

Δρmax = 0.14 e Å−3

Δρmin = −0.25 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: 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.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812032266/su2479sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812032266/su2479Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812032266/su2479Isup3.cml

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

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

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)

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

Table 1

Hydrogen-bond geometry (Å, °)

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) ; (ii) .