An ortho­rhom­bic polymorph of 1-benzyl-1H-benzimidazole

Zhang, Y.; Zhu, X.; Qian, H.; Yin, Z.; Zhang, C.

doi:10.1107/S1600536810015114

organic compounds

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Volume 66| Part 5| May 2010| Page o1208

https://doi.org/10.1107/S1600536810015114

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An orthorhombic polymorph of 1-benzyl-1H-benzimidazole

Ying-jun Zhang,^a Xue-wen Zhu,^a ^* Heng-yu Qian,^a Zhi-gang Yin ^a and Chun-xia Zhang ^a

^aKey Laboratory of Surface and Interface Science of Henan, School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, People's Republic of China
^*Correspondence e-mail: zhuxuew@126.com

(Received 24 April 2010; accepted 25 April 2010; online 28 April 2010)

The title compound, C₁₄H₁₂N₂, in contrast to the previously reported monoclinic polymorph [Lei et al. (2009 ). Acta Cryst. E65, o2613], crystallizes in the orthorhombic crystal system. The dihedral angle between the imidazole ring system and the phenyl ring is 76.78 (16)°. Weak C—H⋯N and C—H⋯π interactions are observed in the crystal structure.

Related literature

For the synthesis, see: Lionel et al. (1996 ). For the monoclinic polymorph, see: Lei & Zhou (2009).

Experimental

Crystal data

C₁₄H₁₂N₂
M_r = 208.26
Orthorhombic, P 2₁ 2₁ 2₁
a = 6.124 (3) Å
b = 7.443 (4) Å
c = 23.860 (8) Å
V = 1087.6 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 K
0.25 × 0.20 × 0.18 mm

Data collection

Oxford Diffraction Xcalibur Eos Gemini diffractometer
3168 measured reflections
1886 independent reflections
892 reflections with I > 2σ(I)
R_int = 0.069

Refinement

R[F² > 2σ(F²)] = 0.068
wR(F²) = 0.148
S = 0.98
1886 reflections
154 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg2 is the centroid of the C1–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8B⋯N2ⁱ	1.03 (5)	2.55 (5)	3.570 (8)	171 (4)
C12—H12⋯Cg2ⁱⁱ	0.93	2.66	3.559 (5)	162
Symmetry codes: (i) x+1, y, z; (ii) $[-x, y+{\script{5\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: CrysAlis PRO (Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810015114/hb5418sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810015114/hb5418Isup2.hkl

checkCIF report

Comment top

The title compound, 1-benzyl-1H-benzimidazole was first synthesized by Lionel (Lionel et al. 1996) using DMF as solvent.

The structure reported here is an orthorhombic form polymorph of the title compound, (C₁₄H₁₂N₂), which has been characterized previously in a monoclinic form (Lei & Zhou, 2009). The bond lengths and angles are closely similar to those previously described . The dihedral angle between the imidazole ring and the benzyl ring is 76.78 (16)°, indicated that those two rings are not mutually perpendicular. In the crystal structure, molecules are linked via weak intermolecular C—H···N interactions, forming a chain along the b-axis direction. The structure is further stabilized by C—H···π contacts involving both of the aromatic rings. This arrangement is similar to that observed in the monoclinic polymorph.

Related literature top

For the synthesis, see: Lionel et al. (1996). For the monoclinic polymorph, see: Lei & Zhou (2009).

Experimental top

The title compound was obtained by reacting benzimidazole (1.18 g, 0.01 mol) with benzyl chloride (1.25 g, 0.01 mol) and potassium carbonate (1.38 g, 0.01 mol) in acetone (50 ml). The reaction mixture was refluxed for 10 h. After removal of the solvents, the residue was dispersed in water to obtain an oil layer. Then the oil was dissolved in hot ethanol/water (2:1) and colourless blocks of (I) arose.

Structure description top

The title compound, 1-benzyl-1H-benzimidazole was first synthesized by Lionel (Lionel et al. 1996) using DMF as solvent.

For the synthesis, see: Lionel et al. (1996). For the monoclinic polymorph, see: Lei & Zhou (2009).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2008); cell refinement: CrysAlis PRO (Oxford Diffraction, 2008); data reduction: CrysAlis PRO (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The asymmetric unit of (I), showing 50% probability displacement ellipsoids.
	Fig. 2. The crystal packing of (I), showing the hydrogen-bonded (dashed lines) network. H atoms not involved in the hydrogen bond interactions have been omitted for clarity.

1-benzyl-1H-benzimidazole top

Crystal data top

C₁₄H₁₂N₂	D_x = 1.272 Mg m⁻³
M_r = 208.26	Melting point: 387 K
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 500 reflections
a = 6.124 (3) Å	θ = 3.2–26.2°
b = 7.443 (4) Å	µ = 0.08 mm⁻¹
c = 23.860 (8) Å	T = 293 K
V = 1087.6 (8) Å³	Block, colorless
Z = 4	0.25 × 0.20 × 0.18 mm
F(000) = 440

Data collection top

Oxford Diffraction Xcalibur Eos Gemini diffractometer	R_int = 0.069
Radiation source: fine-focus sealed tube	θ_max = 26.2°, θ_min = 3.2°
Graphite monochromator	h = −7→7
φ and ω scans	k = −9→6
3168 measured reflections	l = −22→29
1886 independent reflections	1886 standard reflections every 0 min
892 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.068	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.148	w = 1/[σ²(F_o²) + (0.0605P)²] where P = (F_o² + 2F_c²)/3
S = 0.98	(Δ/σ)_max < 0.001
1886 reflections	Δρ_max = 0.19 e Å⁻³
154 parameters	Δρ_min = −0.20 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: 0.022 (5)

Crystal data top

C₁₄H₁₂N₂	V = 1087.6 (8) Å³
M_r = 208.26	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 6.124 (3) Å	µ = 0.08 mm⁻¹
b = 7.443 (4) Å	T = 293 K
c = 23.860 (8) Å	0.25 × 0.20 × 0.18 mm

Data collection top

Oxford Diffraction Xcalibur Eos Gemini diffractometer	R_int = 0.069
3168 measured reflections	1886 standard reflections every 0 min
1886 independent reflections	intensity decay: none
892 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.068	0 restraints
wR(F²) = 0.148	H atoms treated by a mixture of independent and constrained refinement
S = 0.98	Δρ_max = 0.19 e Å⁻³
1886 reflections	Δρ_min = −0.20 e Å⁻³
154 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
N1	0.9512 (6)	0.9532 (5)	0.13981 (13)	0.0379 (9)
C2	0.9503 (7)	1.1255 (6)	0.16196 (16)	0.0376 (11)
C7	0.7567 (8)	0.8802 (8)	0.15157 (18)	0.0515 (13)
H7	0.7190	0.7639	0.1411	0.062*
N2	0.6248 (7)	0.9861 (7)	0.17888 (16)	0.0614 (13)
C3	1.1077 (8)	1.2581 (7)	0.16401 (18)	0.0524 (14)
H3	1.2438	1.2429	0.1474	0.063*
C10	0.9963 (8)	0.9160 (6)	0.01210 (18)	0.0463 (13)
H10	0.8689	0.8567	0.0224	0.056*
C9	1.1566 (7)	0.9393 (6)	0.05047 (16)	0.0379 (11)
C14	1.3448 (8)	1.0270 (7)	0.03496 (18)	0.0478 (13)
H14	1.4553	1.0447	0.0611	0.057*
C8	1.1293 (10)	0.8674 (8)	0.1093 (2)	0.0502 (13)
C13	1.3702 (9)	1.0881 (7)	−0.0187 (2)	0.0567 (15)
H13	1.4984	1.1465	−0.0290	0.068*
C11	1.0182 (9)	0.9782 (7)	−0.04190 (18)	0.0564 (14)
H11	0.9057	0.9624	−0.0676	0.068*
C1	0.7441 (8)	1.1405 (8)	0.18669 (18)	0.0484 (14)
C5	0.8491 (14)	1.4320 (9)	0.2169 (2)	0.0766 (19)
H5	0.8180	1.5377	0.2362	0.092*
C4	1.0542 (12)	1.4117 (8)	0.1914 (2)	0.0692 (17)
H4	1.1550	1.5049	0.1934	0.083*
C12	1.2063 (9)	1.0635 (6)	−0.05752 (19)	0.0570 (15)
H12	1.2236	1.1045	−0.0941	0.068*
C6	0.6953 (10)	1.3013 (9)	0.21424 (19)	0.0647 (17)
H6	0.5588	1.3184	0.2305	0.078*
H8B	1.274 (8)	0.887 (6)	0.1303 (18)	0.058 (15)*
H8A	1.078 (7)	0.746 (6)	0.1111 (16)	0.046 (13)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.037 (2)	0.043 (2)	0.0343 (18)	−0.002 (2)	0.0042 (18)	0.0001 (19)
C2	0.043 (3)	0.047 (3)	0.023 (2)	0.001 (3)	−0.011 (2)	0.000 (2)
C7	0.045 (3)	0.057 (3)	0.052 (3)	−0.010 (3)	0.000 (3)	0.009 (3)
N2	0.051 (3)	0.081 (3)	0.052 (3)	0.001 (3)	0.008 (2)	−0.001 (3)
C3	0.059 (3)	0.051 (3)	0.048 (3)	−0.005 (3)	−0.017 (3)	0.004 (3)
C10	0.051 (3)	0.046 (3)	0.042 (2)	−0.013 (3)	0.005 (3)	−0.007 (2)
C9	0.039 (3)	0.038 (3)	0.037 (2)	0.003 (3)	−0.001 (3)	−0.011 (2)
C14	0.041 (3)	0.054 (3)	0.049 (3)	−0.003 (3)	−0.002 (3)	−0.007 (3)
C8	0.053 (3)	0.052 (3)	0.045 (3)	0.007 (3)	0.004 (3)	0.005 (3)
C13	0.054 (3)	0.053 (4)	0.063 (3)	−0.007 (3)	0.022 (3)	−0.006 (3)
C11	0.064 (3)	0.061 (3)	0.044 (3)	−0.004 (3)	−0.008 (3)	−0.003 (3)
C1	0.048 (3)	0.072 (4)	0.025 (2)	0.021 (3)	0.007 (3)	0.006 (3)
C5	0.119 (6)	0.069 (4)	0.042 (3)	0.032 (5)	−0.038 (4)	−0.026 (3)
C4	0.095 (5)	0.053 (4)	0.060 (3)	0.003 (3)	−0.025 (4)	−0.006 (3)
C12	0.078 (4)	0.048 (3)	0.045 (3)	0.003 (3)	0.016 (3)	−0.003 (3)
C6	0.072 (4)	0.090 (5)	0.032 (3)	0.029 (4)	0.002 (3)	−0.010 (3)

Geometric parameters (Å, º) top

N1—C7	1.339 (6)	C14—C13	1.367 (6)
N1—C2	1.387 (5)	C14—H14	0.9300
N1—C8	1.459 (6)	C8—H8B	1.03 (5)
C2—C3	1.380 (6)	C8—H8A	0.96 (5)
C2—C1	1.398 (6)	C13—C12	1.379 (6)
C7—N2	1.303 (6)	C13—H13	0.9300
C7—H7	0.9300	C11—C12	1.367 (6)
N2—C1	1.374 (6)	C11—H11	0.9300
C3—C4	1.358 (7)	C1—C6	1.398 (7)
C3—H3	0.9300	C5—C6	1.356 (8)
C10—C9	1.354 (5)	C5—C4	1.404 (8)
C10—C11	1.376 (6)	C5—H5	0.9300
C10—H10	0.9300	C4—H4	0.9300
C9—C14	1.375 (6)	C12—H12	0.9300
C9—C8	1.511 (6)	C6—H6	0.9300

C7—N1—C2	107.0 (4)	N1—C8—H8A	98 (3)
C7—N1—C8	126.3 (4)	C9—C8—H8A	114 (2)
C2—N1—C8	126.7 (4)	H8B—C8—H8A	113 (4)
C3—C2—N1	132.2 (4)	C14—C13—C12	120.1 (5)
C3—C2—C1	124.0 (5)	C14—C13—H13	119.9
N1—C2—C1	103.8 (4)	C12—C13—H13	119.9
N2—C7—N1	114.3 (5)	C12—C11—C10	119.6 (5)
N2—C7—H7	122.9	C12—C11—H11	120.2
N1—C7—H7	122.9	C10—C11—H11	120.2
C7—N2—C1	104.1 (4)	N2—C1—C6	131.7 (5)
C4—C3—C2	116.8 (5)	N2—C1—C2	110.9 (4)
C4—C3—H3	121.6	C6—C1—C2	117.4 (6)
C2—C3—H3	121.6	C6—C5—C4	121.6 (5)
C9—C10—C11	121.3 (5)	C6—C5—H5	119.2
C9—C10—H10	119.4	C4—C5—H5	119.2
C11—C10—H10	119.4	C3—C4—C5	121.1 (6)
C10—C9—C14	119.1 (4)	C3—C4—H4	119.5
C10—C9—C8	120.2 (5)	C5—C4—H4	119.5
C14—C9—C8	120.7 (4)	C11—C12—C13	119.5 (4)
C13—C14—C9	120.4 (5)	C11—C12—H12	120.3
C13—C14—H14	119.8	C13—C12—H12	120.3
C9—C14—H14	119.8	C5—C6—C1	119.2 (6)
N1—C8—C9	113.0 (4)	C5—C6—H6	120.4
N1—C8—H8B	110 (2)	C1—C6—H6	120.4
C9—C8—H8B	108 (2)

C7—N1—C2—C3	177.5 (5)	C14—C9—C8—N1	116.5 (6)
C8—N1—C2—C3	−2.7 (7)	C9—C14—C13—C12	0.5 (8)
C7—N1—C2—C1	0.4 (4)	C9—C10—C11—C12	0.8 (7)
C8—N1—C2—C1	−179.8 (4)	C7—N2—C1—C6	−178.1 (4)
C2—N1—C7—N2	0.5 (5)	C7—N2—C1—C2	1.5 (5)
C8—N1—C7—N2	−179.2 (4)	C3—C2—C1—N2	−178.6 (4)
N1—C7—N2—C1	−1.2 (5)	N1—C2—C1—N2	−1.2 (5)
N1—C2—C3—C4	−177.3 (4)	C3—C2—C1—C6	1.1 (6)
C1—C2—C3—C4	−0.7 (7)	N1—C2—C1—C6	178.5 (4)
C11—C10—C9—C14	0.0 (7)	C2—C3—C4—C5	0.8 (7)
C11—C10—C9—C8	−179.2 (5)	C6—C5—C4—C3	−1.4 (8)
C10—C9—C14—C13	−0.6 (7)	C10—C11—C12—C13	−0.9 (7)
C8—C9—C14—C13	178.5 (5)	C14—C13—C12—C11	0.3 (7)
C7—N1—C8—C9	106.1 (5)	C4—C5—C6—C1	1.8 (8)
C2—N1—C8—C9	−73.7 (6)	N2—C1—C6—C5	178.0 (5)
C10—C9—C8—N1	−64.3 (6)	C2—C1—C6—C5	−1.6 (7)

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid of the C1–C6 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8B···N2ⁱ	1.03 (5)	2.55 (5)	3.570 (8)	171 (4)
C12—H12···Cg2ⁱⁱ	0.93	2.66	3.559 (5)	162

Symmetry codes: (i) x+1, y, z; (ii) −x, y+5/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₂N₂
M_r	208.26
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	293
a, b, c (Å)	6.124 (3), 7.443 (4), 23.860 (8)
V (Å³)	1087.6 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.25 × 0.20 × 0.18

Data collection
Diffractometer	Oxford Diffraction Xcalibur Eos Gemini
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	3168, 1886, 892
R_int	0.069
(sin θ/λ)_max (Å⁻¹)	0.622

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.068, 0.148, 0.98
No. of reflections	1886
No. of parameters	154
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.20

Computer programs: CrysAlis PRO (Oxford Diffraction, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid of the C1–C6 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8B···N2ⁱ	1.03 (5)	2.55 (5)	3.570 (8)	171 (4)
C12—H12···Cg2ⁱⁱ	0.93	2.66	3.559 (5)	162

Symmetry codes: (i) x+1, y, z; (ii) −x, y+5/2, −z+1/2.

Acknowledgements

The authors thank Hu Min of Zhengzhou University of Light Industry for the X-ray analysis.

References

Lei, G. & Zhou, L. (2009). Acta Cryst. E65, o2613. Web of Science CSD CrossRef IUCr Journals Google Scholar
Lionel, R. M., Philip, J. F. D. & Gokhan, Y. (1996). Tetrahedron, 52, 9877–9890 Google Scholar
Oxford Diffraction (2008). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar

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Volume 66| Part 5| May 2010| Page o1208

https://doi.org/10.1107/S1600536810015114

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