1-(4-Methyl­benz­yl)-2-(4-methyl­phen­yl)-1H-benzimidazole

S Rosepriya; A Thiruvalluvar; K Jayamoorthy; J Jayabharathi; Anthony Linden

doi:10.1107/S160053681105077X

. 2011 Nov 30;67(Pt 12):o3519. doi: 10.1107/S160053681105077X

1-(4-Methylbenzyl)-2-(4-methylphenyl)-1H-benzimidazole

S Rosepriya ^a, A Thiruvalluvar ^a,^*, K Jayamoorthy ^b, J Jayabharathi ^b, Anthony Linden ^c

PMCID: PMC3239139 PMID: 22199987

Abstract

The title compound, C₂₂H₂₀N₂, crystallizes with two independent molecules (A and B) in the asymmetric unit. The benzimidazole units are almost planar [maximum deviations = 0.0161 (8) Å for A and 0.0276 (8) Å for B]. The dihedral angles between the benzimidazole unit and the benzene rings of the 4-methylbenzyl and 4-methylphenyl groups are 76.64 (3) and 46.87 (4)°, respectively, in molecule A. The corresponding values in molecule B are 86.31 (2) and 39.14 (4)°. The dihedral angles between the planes of the two benzene rings are 73.73 (3) and 80.69 (4)° in molecules A and B, respectively. Pairs of weak intermolecular C—H⋯N hydrogen bonds link B molecules, forming centrosymmetric dimers with R ₂ ²(8) ring motifs. There are no significant corresponding interactions involving the A molecules.

Related literature

For biological applications and the synthesis of related benzimidazole compounds, see: Mohammadizadeh & Taghavi (2011 ▶). For background to iridium(III) organic light-emitting devices (OLED’s), see: Li et al. (2009 ▶). For a closely related crystal structure, see: Yang et al. (2007 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₂H₂₀N₂
M _r = 312.40
Triclinic,
a = 9.6610 (2) Å
b = 10.2900 (2) Å
c = 17.7271 (3) Å
α = 84.437 (2)°
β = 81.536 (2)°
γ = 76.165 (2)°
V = 1689.02 (6) Å³
Z = 4
Cu Kα radiation
μ = 0.55 mm⁻¹
T = 160 K
0.40 × 0.40 × 0.30 mm

Data collection

Agilent SuperNova dual radiation CCD diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.334, T _max = 1.000
35399 measured reflections
6985 independent reflections
6452 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.104
S = 1.04
6985 reflections
433 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2002 (Burla et al., 2003 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681105077X/tk5028sup1.cif

e-67-o3519-sup1.cif^{(34.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681105077X/tk5028Isup2.hkl

e-67-o3519-Isup2.hkl^{(334.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S160053681105077X/tk5028Isup3.cdx

Supplementary material file. DOI: 10.1107/S160053681105077X/tk5028Isup4.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4B—H4B⋯N3Bⁱ	0.93	2.57	3.4623 (14)	160

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Symmetry code: (i) Inline graphic .

Acknowledgments

JJ is thankful to the Department of Science and Technology (No. SR/S1/IC-73/2010) and the University Grants Commission [F. No. 36–21/2008 (SR)] for providing funds for this research.

supplementary crystallographic information

Comment

Mohammadizadeh & Taghavi (2011) have reported biological applications and room temperature syntheses of 2-aryl-1-arylmethyl-1H-1,3-benzimidazoles in aqueous media. Yang et al. (2007) have reported the crystal structure of 1-(4-chlorobenzyl)-2-(4-chlorophenyl)-1H-benzimidazole. Benzimidazole ligands are used to prepare iridium complexes which have electroluminescent properties and are highly efficient phosphorescent materials (Li et al., 2009). Since our group is doing research in organic light emitting devices (OLED's), we are interested in using the title compound as a ligand in the preparation of Ir(III) complexes and in studying the photophysical properties of these complexes.

The title compound, C₂₂H₂₀N₂, crystallizes with two independent molecules (A and B) in the asymmetric unit. The benzimidazole units are almost planar [maximum deviations = 0.0161 (8) for N1A and 0.0276 (8) Å for C2B]. The dihedral angles between the planes of the benzimidazole and the benzene rings of the 4-methylbenzyl and the p-tolyl groups are 76.64 (3) and 46.87 (4)°, respectively, in molecule A. The corresponding values in molecule B are 86.31 (2) and 39.14 (4)°. The dihedral angle between the planes of the two benzene rings is 73.73 (3) and 80.69 (4)° in molecules A and B, respectively. Weak intermolecular C4B—H4B···N3B hydrogen bonds link pairs of B molecules to form centrosymmetric dimers with the R²₂(8) (Bernstein et al., 1995) hydrogen-bonding ring motif (Table 1, Fig. 3). There are no significant corresponding interactions involving the A molecules.

Experimental

The pure o-phenylenediamine (1.62 g, 15 mmol) in ethanol (10 ml), ammonium acetate (1.66 g, 15 mmol) and p-tolualdehyde (1.6 g, 15 mmol) was added over about 1 h by maintaining the temperature at 353 K. The reaction mixture was refluxed for 5 days and extracted with dichloromethane. The obtained solid was purified by column chromatography using hexane:ethyl acetate as the eluent. Yield: 1.91 g (40%). The compound was dissolved in acetonitrile and the solution was allowed to evaporate slowly at room temperature to obtain crystals suitable for X-ray diffraction studies.