2 (2 Eth­oxy­phenyl) 1 ethyl 1H benz­imidazole

organic papers

Acta Cryst.(2004). E60, o1563±o1565 DOI: 10.1107/S1600536804019622 Yi-Ping Tong and Wei Li C₁₇H₁₈N₂O

o1563

Structure Reports Online

ISSN 1600-5368

2-(2-Ethoxyphenyl)-1-ethyl-1

H

-benzimidazole

Yi-Ping Tong* and Wei Li

Department of Chemistry, Hanshan Normal College, Chaozhou 521041, Guangdong, People's Republic of China

Correspondence e-mail: typ2469@163.com

Key indicators Single-crystal X-ray study

T= 293 K

Mean(C±C) = 0.004 AÊ

Rfactor = 0.050

wRfactor = 0.110

Data-to-parameter ratio = 10.5

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2004 International Union of Crystallography Printed in Great Britain ± all rights reserved

The title compound, C17H18N2O, was obtained by reaction of

2-(2-hydroxyphenyl)benzimidazole with bromoethane. The

crystal structure is stabilized by intermolecular CÐH

interactions between the benzimidazole/benzimidazole and between the benzimidazole/phenolate moieties of adjacent

molecules. No other hydrogen-bond interactions or ±

stacking interactions occur in the crystal packing, which is somewhat unusual for an aromatic heterocyclic compound.

Comment

Benzimidazole and its derivatives, such as

2-(2-hydroxy-phenyl)benzimidazole and 2-(2-ethoxyphenyl)-1-ethyl-1H

-benzimidazole, are excellent photoluminescent materials (Svejda et al., 1978; Wu et al., 2003). In recent years, more attention has been paid to their complexes and those of other similarN,O-donor ligands with metal ions and non-metal ions, such as ZnII_{, Be}II_{, Al}III_{, Eu}III _{and B}III_{, because of their}

potential role as electroluminescent materials in organic

light-emitting diodes (Wang, 2001; Huang et al., 2002). These

complexes are considered to be better electroluminescent materials than free ligands, owing to their increased thermal stability on coordination to metal or non-metal ions.

In an attempt to synthesize complexes of the ligand

2-(1-ethyl-1H-benzimidazol-2-yl)phenol with the metal ions

mentioned above in order to obtain a blue-light emitter for further fabrication of electroluminescent diodes, we obtained another highly photoluminescent compound, (I), which emits strong blue light at room temperature. The crystal structure of (I) is reported here.

In the crystal structure of (I) (Fig. 1), the CÐO and CÐN bond lengths are similar to those found in related compounds,

e.g. 2-(1H-benzimidazol-2-yl)-6-methoxyphenol (Elerman & Kabak, 1997), and the complexes of 2-(1H -benzimidazol-2-yl)-6-methylphenol with CoII _{and Co}III _{(Crane et al., 1999).}

However, in (I), the benzimidazole and phenolate moieties are almost perpendicular, owing to the steric hindrance arising from ethylation at the O and N positions with, for example, the

C5ÐC6ÐC7ÐN2 torsion angle being ÿ77.6 (3)_{, which is}

quite different from the coplanarity observed for 2-(1H

benzimidazol-2-yl)-6-methoxyphenol (Elerman & Kabak, 1997). Furthermore, this non-coplanarity, as well as the steric hindrance from the ethyl groups on the O and N positions, should block formation of intermolecular±stacking actions. This is consistent with the observation of no

inter-molecular ± stacking interactions in (I). However, CÐ

H interactions (Srinivaset al., 2004; Rodriguezet al., 2004) occur between the benzimidazole/benzimidazole and between the benzimidazole/phenolate moieties of adjacent molecules (Fig. 2). These edge-to-face CÐH interactions are

some-what different, with H distances of ca 2.82, 2.81 and

2.70 AÊ, and corresponding CÐH angles ofca151, 140 and 144_.

Experimental

The title compound, (I), was synthesized by a two-step reaction based on the method of Anthony & Philip (1981). Salicylic acid (0.138 g,

1 mmol) ando-phenylenediamine (0.108 g, 1 mmol) were mixed and stirred in syrupy phosphoric acid (3 ml) at a temperature ofca520 K for 5 h to give white analytically pure 2-(2-hydroxyphenyl)benz-imidazole after recrystallization of the crude product. The yield was

ca10%. 2-(2-Ethoxyphenyl)-1-ethyl-1H-benzimidazole was prepared by the reaction of 2-(2-hydroxyphenyl)benzimidazole and bromo-ethane under re¯ux conditions with a yield ofca70%. The X-ray quality single crystal used in the structure determination was grown by slow evaporation of an ethanol solution for about one week. Analysis found: C 76.73, H 6.59, N 10.66%; calculated for C17H18N2O:

C 76.66, H 6.81, N 10.52%.

Crystal data C17H18N2O

Mr= 266.33

Orthorhombic,P212121

a= 9.3305 (8) AÊ

b= 12.4070 (10) AÊ

c= 12.7422 (10) AÊ

V= 1475.1 (2) AÊ3

Z= 4

Dx= 1.199 Mg mÿ3

MoKradiation Cell parameters from 1432

re¯ections

= 2.3±20.8

= 0.08 mmÿ1

T= 293 (2) K Block, colorless 0.330.260.22 mm

Data collection

Bruker SMART APEX area-detector diffractometer

'and!scans

Absorption correction: multi-scan (SADABS; Sheldrick, 1996)

Tmin= 0.976,Tmax= 0.984

9232 measured re¯ections

1922 independent re¯ections 1582 re¯ections withI> 2(I)

Rint= 0.036

max= 27.5

h=ÿ11!11

k=ÿ15!16

l=ÿ16!12 Re®nement

Re®nement onF2

R[F2_{> 2(F}2_{)] = 0.050}

wR(F2_{) = 0.110}

S= 1.08 1922 re¯ections 183 parameters

H-atom parameters constrained

w= 1/[2_(F

o2) + (0.0455P)2

+ 0.2012P]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.001

max= 0.15 e AÊÿ3

min=ÿ0.16 e AÊÿ3

Table 1

Selected geometric parameters (AÊ,_).

N1ÐC7 1.365 (3)

N1ÐC13 1.382 (3)

N1ÐC14 1.464 (3)

N2ÐC7 1.312 (3)

N2ÐC8 1.387 (3)

O1ÐC1 1.355 (3)

O1ÐC16 1.431 (4)

C14ÐC15 1.498 (4)

C16ÐC17 1.485 (5)

C7ÐN1ÐC13 106.6 (2)

C7ÐN1ÐC14 127.5 (2)

C13ÐN1ÐC14 125.1 (2)

C7ÐN2ÐC8 104.5 (2)

C1ÐO1ÐC16 118.5 (2)

O1ÐC1ÐC2 124.9 (2)

O1ÐC1ÐC6 115.3 (2)

N1ÐC14ÐC15 111.8 (2) O1ÐC16ÐC17 107.8 (3)

H atoms were placed at calculated positions (CÐH = 0.93 AÊ for all aromatic ring H atoms, 0.96 AÊ for all methyl H atoms and 0.97 AÊ for all methylene H atoms) and re®ned using the riding-model approx-imation, withUiso(H) = 1.2Ueq(C) for aromatic ring and methylene H

atoms, andUiso(H) = 1.5Ueq(C) for all methyl H atoms. In the absence

of signi®cant anomalous dispersion effects, Friedel pair re¯ections were merged before the ®nal re®nement.

Data collection:SMART(Bruker, 2001); cell re®nement:SAINT

(Bruker, 2001); data reduction:SAINT; program(s) used to solve structure:SHELXS97 (Sheldrick, 1997); program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:

SHELXTL(Sheldrick, 2000); software used to prepare material for publication:SHELXL97.

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Figure 2

The CÐH interactions (dashed lines) in the crystal packing of (I). Figure 1

The authors thank Professor Xiao-Ming Chen, School of Chemistry and Chemical Engineering, Sun Yat-Sen Univer-sity, China, for his generous help and support of this work, and also thank Hanshan Normal College, China, for support of this work.

References

Anthony, W. A. & Philip, J. B. (1981).J. Heterocycl. Chem.18, 803±805. Bruker (2001).SAINTandSMART. Bruker AXS Inc., Madison, Wisconsin,

USA.

Crane, D. J., Sinn, E. & Tann, B. (1999).Polyhedron,18, 1527±1532. Elerman, Y. & Kabak, M. (1997).Acta Cryst.C53, 372±374.

Huang, L., Wang, K. Z., Huang, C. H., Gao, D. C. & Jin, L. P. (2002).Synth. Met.128, 241±245.

Rodriguez, A., Arturo, G. V. J. & Sousa-Pedradres, A. (2004).J. Organomet. Chem.689, 557±563.

Sheldrick, G. M. (1996).SADABS.University of GoÈttingen, Germany. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of

GoÈttingen, Germany.

Sheldrick, G. M. (2000).SHELXTL.Version 6.10. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.

Srinivas, O., Muktha, B., Radhika, S., Guru Row, T. N. & Jayaraman, N. (2004).

Carbohydr. Res.339, 1087±1092.

Svejda, P., Anderson, R. R. & Maki, A. H. (1978).J. Am. Chem. Soc.100, 7131±7138.

Wang, S. (2001).Coord. Chem. Rev.215, 79±98.

Wu, T., Li, D., Feng, X. L. & Cai, J. W. (2003).Inorg. Chem. Commun.6, 886± 890.

organic papers

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Acta Cryst. (2004). E60, o1563–o1565

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Acta Cryst. (2004). E60, o1563–o1565 [https://doi.org/10.1107/S1600536804019622]

2-(2-Ethoxyphenyl)-1-ethyl-1

H

-benzimidazole

Yi-Ping Tong and Wei Li

2-(2-Ethoxyphenyl)-1-ethyl-1H-benzimidazole

Crystal data

C17H18N2O Mr = 266.33

Orthorhombic, P212121

Hall symbol: P 2ac 2ab

a = 9.3305 (8) Å

b = 12.407 (1) Å

c = 12.7422 (10) Å

V = 1475.1 (2) Å3 Z = 4

F(000) = 568

Dx = 1.199 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 1432 reflections

θ = 2.3–20.8°

µ = 0.08 mm−1 T = 293 K Block, colorless 0.33 × 0.26 × 0.22 mm

Data collection

Bruker APEX area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

φ and ω scans

Absorption correction: multi-scan (SADABS; Sheldrick, 1996)

Tmin = 0.976, Tmax = 0.984

9232 measured reflections 1922 independent reflections 1582 reflections with I > 2σ(I)

Rint = 0.036

θmax = 27.5°, θmin = 2.3° h = −11→11

k = −15→16

l = −16→12

Refinement

Refinement on F2

Least-squares matrix: full

R[F2 _{> 2σ(F}2_{)] = 0.050} wR(F2_{) = 0.110} S = 1.08 1922 reflections 183 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: inferred from neighbouring sites

H-atom parameters constrained

w = 1/[σ2_(F

o2) + (0.0455P)2 + 0.2012P]

where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001

Δρmax = 0.15 e Å−3

Δρmin = −0.16 e Å−3

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

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Acta Cryst. (2004). E60, o1563–o1565

Refinement. Refinement of F2 _{against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F}2_,

conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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₎

x y z Uiso*/Ueq

N1 0.0603 (2) 0.23129 (16) 0.73990 (17) 0.0405 (5) N2 0.0707 (2) 0.38970 (16) 0.65627 (17) 0.0416 (5) O1 0.1413 (2) 0.38910 (18) 0.92994 (16) 0.0588 (6) C1 0.2718 (3) 0.3787 (2) 0.8844 (2) 0.0438 (6) C2 0.4010 (3) 0.3977 (2) 0.9339 (2) 0.0553 (8)

H2 0.4026 0.4211 1.0033 0.066*

C3 0.5273 (3) 0.3819 (3) 0.8804 (3) 0.0601 (8)

H3 0.6138 0.3934 0.9148 0.072*

C4 0.5283 (3) 0.3494 (3) 0.7773 (3) 0.0591 (8)

H4 0.6144 0.3387 0.7421 0.071*

C5 0.3992 (3) 0.3330 (2) 0.7272 (2) 0.0516 (7)

H5 0.3989 0.3122 0.6571 0.062*

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Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

N1 0.0422 (12) 0.0382 (10) 0.0412 (12) −0.0025 (10) −0.0033 (10) 0.0026 (10) N2 0.0468 (13) 0.0352 (10) 0.0427 (12) 0.0014 (10) 0.0000 (10) 0.0009 (10) O1 0.0508 (12) 0.0767 (14) 0.0490 (12) −0.0036 (11) 0.0069 (10) −0.0170 (11) C1 0.0463 (15) 0.0409 (13) 0.0441 (15) 0.0007 (13) 0.0001 (13) −0.0035 (12) C2 0.0549 (18) 0.0635 (18) 0.0477 (17) −0.0070 (15) −0.0083 (15) −0.0098 (15) C3 0.0483 (18) 0.0622 (18) 0.070 (2) −0.0094 (16) −0.0091 (15) −0.0074 (18) C4 0.0403 (16) 0.066 (2) 0.071 (2) −0.0074 (15) 0.0078 (15) −0.0131 (18) C5 0.0506 (17) 0.0550 (16) 0.0492 (16) −0.0070 (14) 0.0033 (14) −0.0077 (14) C6 0.0427 (14) 0.0346 (12) 0.0448 (15) −0.0035 (11) −0.0010 (12) 0.0014 (12) C7 0.0435 (15) 0.0339 (12) 0.0377 (14) 0.0001 (11) 0.0045 (12) −0.0055 (11) C8 0.0429 (15) 0.0366 (12) 0.0367 (13) 0.0039 (12) 0.0013 (11) −0.0055 (11) C9 0.0561 (17) 0.0463 (15) 0.0445 (17) 0.0068 (14) −0.0057 (13) 0.0000 (13) C10 0.0515 (17) 0.0631 (18) 0.0474 (17) 0.0079 (16) −0.0120 (15) −0.0090 (15) C11 0.0479 (17) 0.0567 (17) 0.0591 (19) −0.0087 (14) −0.0086 (15) −0.0116 (15) C12 0.0521 (16) 0.0409 (14) 0.0558 (18) −0.0044 (13) −0.0037 (14) 0.0017 (14) C13 0.0385 (14) 0.0408 (13) 0.0372 (14) 0.0029 (12) 0.0021 (12) −0.0037 (11) C14 0.0531 (16) 0.0453 (14) 0.0440 (15) −0.0072 (13) −0.0025 (13) 0.0117 (13) C15 0.067 (2) 0.0511 (17) 0.070 (2) 0.0127 (15) 0.0059 (17) 0.0127 (17) C16 0.079 (2) 0.072 (2) 0.053 (2) −0.0078 (18) 0.0163 (18) −0.0139 (17) C17 0.094 (3) 0.095 (3) 0.085 (3) 0.001 (2) 0.041 (2) −0.015 (2)

Geometric parameters (Å, º)

N1—C7 1.365 (3) C9—C10 1.369 (4)

N1—C13 1.382 (3) C9—H9 0.9300

N1—C14 1.464 (3) C10—C11 1.387 (4)

N2—C7 1.312 (3) C10—H10 0.9300

N2—C8 1.387 (3) C11—C12 1.378 (4)

O1—C1 1.355 (3) C11—H11 0.9300

O1—C16 1.431 (4) C12—C13 1.386 (4)

C1—C2 1.381 (4) C12—H12 0.9300

C1—C6 1.401 (4) C14—C15 1.498 (4)

C2—C3 1.375 (4) C14—H14A 0.9700

C2—H2 0.9300 C14—H14B 0.9700

C3—C4 1.374 (4) C15—H15A 0.9600

C3—H3 0.9300 C15—H15B 0.9600

C4—C5 1.379 (4) C15—H15C 0.9600

C4—H4 0.9300 C16—C17 1.485 (5)

C5—C6 1.384 (4) C16—H16A 0.9700

C5—H5 0.9300 C16—H16B 0.9700

C6—C7 1.483 (4) C17—H17A 0.9600

C8—C13 1.394 (3) C17—H17B 0.9600

C8—C9 1.398 (4) C17—H17C 0.9600

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C7—N1—C14 127.5 (2) C12—C11—C10 121.3 (3) C13—N1—C14 125.1 (2) C12—C11—H11 119.4 C7—N2—C8 104.5 (2) C10—C11—H11 119.4 C1—O1—C16 118.5 (2) C11—C12—C13 116.6 (3) O1—C1—C2 124.9 (2) C11—C12—H12 121.7 O1—C1—C6 115.3 (2) C13—C12—H12 121.7 C2—C1—C6 119.7 (3) N1—C13—C12 131.9 (2) C3—C2—C1 119.8 (3) N1—C13—C8 105.1 (2) C3—C2—H2 120.1 C12—C13—C8 123.1 (3) C1—C2—H2 120.1 N1—C14—C15 111.8 (2) C4—C3—C2 121.5 (3) N1—C14—H14A 109.3

C4—C3—H3 119.3 C15—C14—H14A 109.3

C2—C3—H3 119.3 N1—C14—H14B 109.3

C3—C4—C5 118.7 (3) C15—C14—H14B 109.3 C3—C4—H4 120.6 H14A—C14—H14B 107.9

C5—C4—H4 120.6 C14—C15—H15A 109.5

C4—C5—C6 121.4 (3) C14—C15—H15B 109.5 C4—C5—H5 119.3 H15A—C15—H15B 109.5

C6—C5—H5 119.3 C14—C15—H15C 109.5

C5—C6—C1 118.9 (3) H15A—C15—H15C 109.5 C5—C6—C7 120.5 (2) H15B—C15—H15C 109.5 C1—C6—C7 120.6 (2) O1—C16—C17 107.8 (3) N2—C7—N1 113.4 (2) O1—C16—H16A 110.1 N2—C7—C6 125.6 (2) C17—C16—H16A 110.1 N1—C7—C6 121.0 (2) O1—C16—H16B 110.1 N2—C8—C13 110.4 (2) C17—C16—H16B 110.1 N2—C8—C9 130.6 (2) H16A—C16—H16B 108.5 C13—C8—C9 119.0 (2) C16—C17—H17A 109.5 C10—C9—C8 118.2 (3) C16—C17—H17B 109.5 C10—C9—H9 120.9 H17A—C17—H17B 109.5

C8—C9—H9 120.9 C16—C17—H17C 109.5

C9—C10—C11 122.0 (3) H17A—C17—H17C 109.5 C9—C10—H10 119.0 H17B—C17—H17C 109.5

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