1-(4-Chloro­benz­yl)-2-(4-chloro­phen­yl)-1H-benzimidazole

In the title compound, C₂₀H₁₄Cl₂N₂, the dihedral angles formed by the benzimidazole ring with the benzene rings of the 4-chlorobenzyl and the 4-chlorophenyl groups are 88.15 (8) and 33.4 (1)°, respectively. The mol­ecules are linked by C—H...Cl hydrogen bonds, forming a C(12) chain along the [010] direction.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.042
• wR factor = 0.086
• Data-to-parameter ratio = 12.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C12
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.01
           From the CIF: _reflns_number_total               2749
           Count of symmetry unique reflns         1647
           Completeness (_total/calc)            166.91%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1102
           Fraction of Friedel pairs measured     0.669
           Are heavy atom types Z>Si present        yes
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Benzimidazole derivatives display wide-ranging biological activities, such as as inhibitors of hepatitis C virus NS5B polymerase (Ishida et al., 2006) and heparanase (Xu et al., 2006) and antimicrobial activities (Özden et al., 2005). The crystal structures of some benzimidazole derivatives have been previously reported (Yang et al., 2007). Here we report the crystal structure of a new benzimidazole derivative, 2-(4-chlorophenyl)-1-[(4-chlorophenyl)methyl]-1H benzimidazole, (I).

In the molecule of compound (I) (Fig. 1), the benzene ring C9—C14 is approximately perpendicular to the benzimidazole ring. The dihedral angles enclosed by the benzimidazole ring with the benzene rings C9–C14 and benzene ring C15–C20 are 88.15 (8)° and 33.4 (1)°, respectively. The geometrical parameters for (I) are normal.

In the crystal structure of (I), the C11 atom in the molecule at (x, y, z) acts as hydrogen-bond donor, to the Cl1 atom in the molecule at (1 - x, 3/2 + y, 1 - z), the molecules are linked through C—H···Cl hydrogen bonds, forming a C(12) chain (Bernstein et al., 1995) along the [010] direction (Fig. 2 and Table 1).

Related literature

For related literature, see: Bernstein et al. (1995); Ishida et al. (2006); Özden et al. (2005); Xu et al. (2006); Yang et al. (2007).

S2. Experimental

The reaction mixture containing 4-chlorobenzaldehyde (2.80 g, 20 mmol) and o-phenylene diamine (1.08 g, 10 mmol) was refluxed for about 4 h in ethanol (30 ml), then cooled and the product filtered off, washed with ethanol and dried. Yellow crystals of (I) suitable for X-ray structure analysis were obtained by recrystallizing the crude product from ethanol (m.p. 450–452 K).

S3. Refinement

All H atoms were positioned geometrically and refined as riding on their parent atoms, with C—H = 0.93–0.97 Å and U_iso(H) = 1.2U_eq(C) for all H atoms.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. Part of the crystal structure of (I), showing the formation of a C(12) chain along the [010] direction. For clarity, the H atoms not involved in the motif shown have been omitted. [Symmetry codes: (*) 1 - x, 3/2 + y, 1 - z; (&) 1 - x, -3/2 + y, 1 - z]. Dashed lines indicate hydrogen bonds.

1-(4-Chlorobenzyl)-2-(4-chlorophenyl)-1H-benzimidazole

Crystal data

C20H14Cl2N2	F(000) = 364
Mr = 353.23	Dx = 1.399 Mg m^−3
Monoclinic, P21	Melting point: 450 K
Hall symbol: P 2yb	Mo Kα radiation, λ = 0.71073 Å
a = 11.6427 (17) Å	Cell parameters from 1152 reflections
b = 5.4420 (7) Å	θ = 2.3–21.3°
c = 13.2339 (19) Å	µ = 0.39 mm^−1
β = 90.936 (2)°	T = 298 K
V = 838.4 (2) Å^3	Plate, yellow
Z = 2	0.48 × 0.23 × 0.15 mm

Data collection

Siemens SMART 1000 CCD area-detector diffractometer	2749 independent reflections
Radiation source: fine-focus sealed tube	1744 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
φ and ω scans	θmax = 25.0°, θmin = 1.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→13
Tmin = 0.835, Tmax = 0.944	k = −6→6
4248 measured reflections	l = −15→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.042	H-atom parameters constrained
wR(F^2) = 0.086	w = 1/[σ^2(Fo^2) + (0.0295P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max < 0.001
2749 reflections	Δρmax = 0.23 e Å^−3
217 parameters	Δρmin = −0.19 e Å^−3
1 restraint	Absolute structure: Flack (1983), 1102 Freidel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.01 (8)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.33404 (9)	0.0815 (2)	0.63346 (7)	0.0884 (4)
Cl2	0.75909 (8)	1.0489 (3)	0.12846 (9)	0.1146 (5)
N1	0.2015 (2)	0.8712 (5)	0.24471 (19)	0.0480 (7)
N2	0.0955 (2)	1.0188 (6)	0.3711 (2)	0.0587 (8)
C1	0.1724 (3)	0.8546 (7)	0.3452 (2)	0.0481 (9)
C2	0.0722 (3)	1.1501 (6)	0.2833 (3)	0.0549 (10)
C3	0.1370 (2)	1.0590 (7)	0.2042 (2)	0.0499 (8)
C4	0.1289 (3)	1.1528 (7)	0.1067 (3)	0.0618 (10)
H4	0.1722	1.0892	0.0543	0.074*
C5	0.0540 (3)	1.3436 (8)	0.0918 (3)	0.0710 (12)
H5	0.0457	1.4107	0.0274	0.085*
C6	−0.0100 (3)	1.4397 (8)	0.1699 (4)	0.0788 (13)
H6	−0.0592	1.5710	0.1568	0.095*
C7	−0.0027 (3)	1.3453 (8)	0.2671 (3)	0.0698 (11)
H7	−0.0460	1.4099	0.3192	0.084*
C8	0.2738 (3)	0.7104 (6)	0.1855 (2)	0.0545 (9)
H8A	0.2384	0.6883	0.1193	0.065*
H8B	0.2772	0.5507	0.2180	0.065*
C9	0.3948 (3)	0.8033 (6)	0.1723 (2)	0.0439 (8)
C10	0.4364 (3)	1.0114 (7)	0.2183 (2)	0.0596 (10)
H10	0.3889	1.1036	0.2595	0.071*
C11	0.5489 (3)	1.0852 (8)	0.2038 (3)	0.0680 (10)
H11	0.5764	1.2271	0.2350	0.082*
C12	0.6190 (3)	0.9516 (8)	0.1443 (3)	0.0657 (11)
C13	0.5794 (3)	0.7433 (8)	0.0987 (3)	0.0681 (11)
H13	0.6278	0.6500	0.0587	0.082*
C14	0.4680 (3)	0.6721 (6)	0.1120 (2)	0.0579 (10)
H14	0.4410	0.5315	0.0795	0.069*
C15	0.2178 (3)	0.6688 (6)	0.4160 (2)	0.0506 (9)
C16	0.3296 (3)	0.5778 (8)	0.4130 (2)	0.0588 (9)
H16	0.3803	0.6379	0.3653	0.071*
C17	0.3657 (3)	0.3989 (7)	0.4805 (3)	0.0642 (11)
H17	0.4397	0.3357	0.4772	0.077*
C18	0.2917 (3)	0.3150 (7)	0.5521 (2)	0.0579 (10)
C19	0.1828 (3)	0.4092 (7)	0.5594 (3)	0.0609 (10)
H19	0.1339	0.3547	0.6096	0.073*
C20	0.1469 (3)	0.5865 (8)	0.4911 (2)	0.0587 (9)
H20	0.0734	0.6515	0.4959	0.070*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.1053 (8)	0.0830 (8)	0.0764 (6)	0.0009 (8)	−0.0143 (6)	0.0255 (6)
Cl2	0.0583 (6)	0.1482 (13)	0.1377 (9)	−0.0234 (9)	0.0129 (6)	0.0186 (10)
N1	0.0442 (16)	0.049 (2)	0.0513 (17)	−0.0001 (15)	−0.0003 (13)	0.0016 (16)
N2	0.0527 (17)	0.062 (2)	0.0609 (18)	0.0069 (18)	0.0037 (15)	−0.0004 (17)
C1	0.041 (2)	0.052 (2)	0.051 (2)	−0.0077 (19)	0.0021 (17)	0.0018 (19)
C2	0.042 (2)	0.055 (3)	0.067 (2)	−0.0033 (19)	−0.0052 (19)	−0.001 (2)
C3	0.0389 (18)	0.048 (2)	0.063 (2)	−0.006 (2)	−0.0093 (17)	0.002 (2)
C4	0.056 (2)	0.065 (3)	0.064 (2)	−0.012 (2)	−0.0116 (18)	0.007 (2)
C5	0.062 (3)	0.066 (3)	0.084 (3)	−0.012 (2)	−0.022 (2)	0.019 (3)
C6	0.057 (3)	0.061 (3)	0.118 (4)	−0.002 (2)	−0.027 (3)	0.014 (3)
C7	0.054 (2)	0.063 (3)	0.092 (3)	0.006 (2)	−0.002 (2)	−0.005 (2)
C8	0.060 (2)	0.050 (2)	0.053 (2)	−0.006 (2)	−0.0035 (18)	−0.0054 (18)
C9	0.048 (2)	0.043 (2)	0.0409 (18)	−0.0019 (18)	−0.0019 (16)	0.0008 (17)
C10	0.059 (2)	0.052 (3)	0.068 (2)	−0.004 (2)	0.0028 (19)	−0.013 (2)
C11	0.062 (2)	0.055 (3)	0.086 (3)	−0.022 (2)	−0.004 (2)	−0.010 (2)
C12	0.052 (2)	0.080 (3)	0.065 (3)	−0.002 (2)	0.004 (2)	0.013 (2)
C13	0.067 (3)	0.074 (3)	0.063 (2)	0.008 (2)	0.013 (2)	−0.003 (2)
C14	0.069 (2)	0.054 (3)	0.051 (2)	−0.003 (2)	0.0039 (19)	−0.0112 (18)
C15	0.052 (2)	0.054 (3)	0.0457 (19)	−0.0022 (19)	−0.0030 (17)	−0.0044 (18)
C16	0.048 (2)	0.067 (3)	0.061 (2)	0.001 (2)	0.0053 (17)	0.012 (2)
C17	0.054 (2)	0.069 (3)	0.069 (2)	0.009 (2)	−0.002 (2)	0.005 (2)
C18	0.066 (2)	0.058 (3)	0.049 (2)	−0.004 (2)	−0.0115 (19)	0.005 (2)
C19	0.061 (2)	0.069 (3)	0.052 (2)	−0.010 (2)	0.0045 (19)	0.003 (2)
C20	0.050 (2)	0.073 (3)	0.053 (2)	0.003 (2)	0.0017 (17)	0.005 (2)

Geometric parameters (Å, º)

Cl1—C18	1.732 (4)	C9—C10	1.371 (4)
Cl2—C12	1.731 (4)	C9—C14	1.377 (4)
N1—C3	1.373 (4)	C10—C11	1.387 (4)
N1—C1	1.381 (3)	C10—H10	0.9300
N1—C8	1.453 (4)	C11—C12	1.354 (5)
N2—C1	1.314 (4)	C11—H11	0.9300
N2—C2	1.387 (4)	C12—C13	1.361 (5)
C1—C15	1.471 (4)	C13—C14	1.368 (4)
C2—C7	1.388 (5)	C13—H13	0.9300
C2—C3	1.392 (4)	C14—H14	0.9300
C3—C4	1.389 (4)	C15—C20	1.376 (4)
C4—C5	1.369 (5)	C15—C16	1.394 (4)
C4—H4	0.9300	C16—C17	1.382 (5)
C5—C6	1.387 (5)	C16—H16	0.9300
C5—H5	0.9300	C17—C18	1.369 (4)
C6—C7	1.386 (5)	C17—H17	0.9300
C6—H6	0.9300	C18—C19	1.373 (4)
C7—H7	0.9300	C19—C20	1.382 (5)
C8—C9	1.509 (4)	C19—H19	0.9300
C8—H8A	0.9700	C20—H20	0.9300
C8—H8B	0.9700
C3—N1—C1	106.5 (3)	C9—C10—C11	120.4 (3)
C3—N1—C8	123.8 (3)	C9—C10—H10	119.8
C1—N1—C8	129.3 (3)	C11—C10—H10	119.8
C1—N2—C2	104.9 (3)	C12—C11—C10	120.3 (4)
N2—C1—N1	112.7 (3)	C12—C11—H11	119.8
N2—C1—C15	122.8 (3)	C10—C11—H11	119.8
N1—C1—C15	124.5 (3)	C11—C12—C13	120.1 (4)
N2—C2—C7	129.6 (4)	C11—C12—Cl2	119.0 (4)
N2—C2—C3	110.2 (3)	C13—C12—Cl2	120.9 (3)
C7—C2—C3	120.2 (3)	C12—C13—C14	119.6 (4)
N1—C3—C4	131.7 (3)	C12—C13—H13	120.2
N1—C3—C2	105.7 (3)	C14—C13—H13	120.2
C4—C3—C2	122.6 (4)	C13—C14—C9	121.7 (3)
C5—C4—C3	116.5 (4)	C13—C14—H14	119.2
C5—C4—H4	121.8	C9—C14—H14	119.2
C3—C4—H4	121.8	C20—C15—C16	118.4 (3)
C4—C5—C6	121.9 (4)	C20—C15—C1	118.0 (3)
C4—C5—H5	119.1	C16—C15—C1	123.5 (3)
C6—C5—H5	119.1	C17—C16—C15	120.4 (3)
C7—C6—C5	121.7 (4)	C17—C16—H16	119.8
C7—C6—H6	119.1	C15—C16—H16	119.8
C5—C6—H6	119.1	C18—C17—C16	119.6 (3)
C6—C7—C2	117.2 (4)	C18—C17—H17	120.2
C6—C7—H7	121.4	C16—C17—H17	120.2
C2—C7—H7	121.4	C17—C18—C19	121.1 (3)
N1—C8—C9	114.2 (3)	C17—C18—Cl1	119.9 (3)
N1—C8—H8A	108.7	C19—C18—Cl1	118.9 (3)
C9—C8—H8A	108.7	C18—C19—C20	118.9 (3)
N1—C8—H8B	108.7	C18—C19—H19	120.5
C9—C8—H8B	108.7	C20—C19—H19	120.5
H8A—C8—H8B	107.6	C15—C20—C19	121.4 (3)
C10—C9—C14	117.9 (3)	C15—C20—H20	119.3
C10—C9—C8	123.4 (3)	C19—C20—H20	119.3
C14—C9—C8	118.7 (3)
C2—N2—C1—N1	0.3 (4)	N1—C8—C9—C14	−175.9 (3)
C2—N2—C1—C15	−177.5 (3)	C14—C9—C10—C11	0.1 (5)
C3—N1—C1—N2	−0.6 (3)	C8—C9—C10—C11	179.3 (3)
C8—N1—C1—N2	−173.5 (3)	C9—C10—C11—C12	−0.4 (5)
C3—N1—C1—C15	177.1 (3)	C10—C11—C12—C13	−0.2 (5)
C8—N1—C1—C15	4.3 (5)	C10—C11—C12—Cl2	−179.7 (3)
C1—N2—C2—C7	180.0 (3)	C11—C12—C13—C14	1.0 (6)
C1—N2—C2—C3	0.2 (4)	Cl2—C12—C13—C14	−179.5 (3)
C1—N1—C3—C4	−178.3 (3)	C12—C13—C14—C9	−1.3 (5)
C8—N1—C3—C4	−5.0 (5)	C10—C9—C14—C13	0.8 (5)
C1—N1—C3—C2	0.7 (3)	C8—C9—C14—C13	−178.5 (3)
C8—N1—C3—C2	174.0 (3)	N2—C1—C15—C20	30.5 (5)
N2—C2—C3—N1	−0.6 (3)	N1—C1—C15—C20	−147.0 (3)
C7—C2—C3—N1	179.6 (3)	N2—C1—C15—C16	−147.4 (3)
N2—C2—C3—C4	178.5 (3)	N1—C1—C15—C16	35.1 (5)
C7—C2—C3—C4	−1.3 (5)	C20—C15—C16—C17	3.7 (5)
N1—C3—C4—C5	179.5 (3)	C1—C15—C16—C17	−178.4 (3)
C2—C3—C4—C5	0.6 (5)	C15—C16—C17—C18	−1.5 (5)
C3—C4—C5—C6	0.4 (5)	C16—C17—C18—C19	−1.3 (5)
C4—C5—C6—C7	−0.9 (6)	C16—C17—C18—Cl1	177.3 (3)
C5—C6—C7—C2	0.3 (5)	C17—C18—C19—C20	1.9 (5)
N2—C2—C7—C6	−179.0 (3)	Cl1—C18—C19—C20	−176.7 (3)
C3—C2—C7—C6	0.8 (5)	C16—C15—C20—C19	−3.1 (5)
C3—N1—C8—C9	88.7 (3)	C1—C15—C20—C19	178.9 (3)
C1—N1—C8—C9	−99.6 (4)	C18—C19—C20—C15	0.3 (5)
N1—C8—C9—C10	4.8 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11···Cl1^i	0.93	2.79	3.701 (4)	167

Symmetry code: (i) −x+1, y+3/2, −z+1.