1-[6-(Hydroxy­meth­yl)-2-pyrid­yl]-3-(2,4,6-trimethyl­benz­yl)-1H-imidazol-3-ium bromide

Chuang Zhou; Xiang-Ge Zhou; Yu-Ping Qiu; Mei-Ming Luo

doi:10.1107/S1600536808034764

. 2008 Oct 31;64(Pt 11):o2225. doi: 10.1107/S1600536808034764

1-[6-(Hydroxymethyl)-2-pyridyl]-3-(2,4,6-trimethylbenzyl)-1H-imidazol-3-ium bromide

Chuang Zhou ^a, Xiang-Ge Zhou ^a, Yu-Ping Qiu ^a, Mei-Ming Luo ^a,^*

PMCID: PMC2959624 PMID: 21581080

Abstract

In the title compound, C₁₉H₂₂N₃O⁺·Br⁻, the imidazole ring is approximately coplanar with the pyridine ring [dihedral angle = 0.88 (13)°] and nearly perpendicular to the benzene ring [dihedral angle = 81.70 (13)°]. O—H⋯Br and C—H⋯Br hydrogen bonding helps to stabilize the crystal structure.

Related literature

For general background, see: Liddle et al. (2007 ▶); Ren et al. (2007 ▶); Arnold & Wilson (2007 ▶); Chianese & Crabtree (2005 ▶); Dyson et al. (2008 ▶); Patel et al. (2006 ▶). For synthesis, see: Hosseinzadeh et al. (2006 ▶).

Experimental

Crystal data

C₁₉H₂₂N₃O⁺·Br⁻
M _r = 388.31
Monoclinic,
a = 11.2315 (3) Å
b = 11.5390 (3) Å
c = 14.3673 (4) Å
β = 100.833 (2)°
V = 1828.82 (9) Å³
Z = 4
Mo Kα radiation
μ = 2.26 mm⁻¹
T = 296 (2) K
0.50 × 0.48 × 0.40 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.320, T _max = 0.405
13818 measured reflections
4184 independent reflections
2287 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.116
S = 1.01
4184 reflections
220 parameters
H-atom parameters constrained
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.60 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808034764/xu2459sup1.cif

e-64-o2225-sup1.cif^{(20.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808034764/xu2459Isup2.hkl

e-64-o2225-Isup2.hkl^{(205.1KB, hkl)}

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
O1—H1A⋯Br1	0.82	2.49	3.227 (2)	151
C7—H7A⋯Br1ⁱ	0.93	2.75	3.598 (2)	152
C8—H8A⋯Br1ⁱⁱ	0.93	2.89	3.745 (2)	154
C10—H10B⋯Br1ⁱ	0.97	2.91	3.813 (2)	155

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

Financial support of this work by the Natural Science Foundation of Sichuan Province of China is gratefully acknowledged.

supplementary crystallographic information

Comment

The range of N-heterocyclic carbenes (NHCs) is expanding rapidly since many homogeneous catalysts rely on NHC-based supporting ligands for steric and electronic control. Recently the study of [C, O] chelating NHC ligands have attracted increasing attention. The bonding between the NHC and metal can be enhanced by alkoxide or phenoxide as a sidearm through the incorporation of chelating anionic oxygen (Liddle et al., 2007; Ren et al., 2007). These kind of ligands are of great significance to early metal catalysis and carbene chemistry (Arnold & Wilson, 2007; Chianese & Crabtree, 2005; Dyson et al., 2008; Patel et al., 2006). The title compound, a stable precursor imidazolium salt of a tridentate alkoxide-functionalized NHC ligands, was synthesized in moderate yield by reacting [6-(1H-imidazol-1-yl)pyridin-2-yl]methanol with 2-(bromomethyl)-1,3,5-trimethylbenzene in acetonitrile.

In the title compound (Fig. 1), the pyridine and imidazole rings are coplanar, the dihedral angle between the plane of the pyridine ring and the plane of the imidazole ring is 0.88°. In addition, the dihedral angle between the imidazole ring and the benzene ring is 81.70 °. This might be a result of intermolecular O—H···Br interactions and steric effects. The O—H···Br and C—H···Br hydrogen bonding (Table 1) helps to stabilize the crystal structure.

Experimental

[6-(1H-Imidazol-1-yl)pyridin-2-yl]methanol was prepared with the reported methods (Hosseinzadeh et al., 2006). The title compound was synthesized by dissolving [6-(1H-imidazol-1-yl)pyridin-2-yl]methanol (0.35 g, 2.0 mmol) and 2-(bromomethyl)-1,3,5-trimethylbenzene (0.85 g, 4.0 mmol) in 10 ml of acetonitrile. The mixture was stirred at 333 K for 15 h and the resulting precipitate was filtered, washed with ether. After removal of the solvent in vacuo the off-white crude product was purified by flash chromatography (CH₂Cl₂/CH₃OH (5/1, v/v)) to afford the product as a white solid (0.60 g, 77%). Colorless single crystals suitable for X-ray diffraction were obtained at ambient temperature by slow evaporation of a CH₂Cl₂/CH₃OH solution (5/1, v/v)) over a period of several days.