1-Benzyl-3-phenyl­imidazolium hexa­fluoro­phosphate

Ping Jiang

doi:10.1107/S1600536809031584

. 2009 Aug 19;65(Pt 9):o2177. doi: 10.1107/S1600536809031584

1-Benzyl-3-phenylimidazolium hexafluorophosphate

Ping Jiang ^a,^*

PMCID: PMC2969867 PMID: 21577583

Abstract

in the title compound, C₁₆H₁₅N₂ ⁺·PF₆ ⁻, a precursor of N-heterocyclic carbene, the phenyl and benzyl rings are twisted away from the central imidazolium ring system, making dihedral angles of 70.30 (8) and 32.03 (10)°, respectively. The crystal structure is stabilized by C—H⋯F hydrogen bonds. Furthermore, P—F⋯π interactions involving imidazolium rings are observed [F⋯π = 2.9857 (16), P⋯π = 4.1630 (16) Å, P—F⋯π = 127.92 (6)°].

Related literature

The first stable N-heterocyclic carbene was isolated by Arduengo et al. (1991 ▶). For the synthesis, see: Liu et al. (2003 ▶). For related structures, see: Wan et al. (2008 ▶). For related structures, see: Newman et al. (2007 ▶); Herrmann (2002 ▶); Yang et al. (2009 ▶).

Experimental

Crystal data

C₁₆H₁₅N₂ ⁺·PF₆ ⁻
M _r = 380.27
Triclinic,
a = 9.221 (2) Å
b = 10.046 (3) Å
c = 10.108 (2) Å
α = 110.733 (2)°
β = 91.969 (2)°
γ = 110.315 (2)°
V = 807.9 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 93 K
0.43 × 0.40 × 0.37 mm

Data collection

Rigaku SPIDER diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.905, T _max = 0.919
4739 measured reflections
2902 independent reflections
2361 reflections with I > 2σ(I)
R _int = 0.017

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.084
S = 1.00
2902 reflections
226 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: RAPID-AUTO (Rigaku/MSC, 2004 ▶); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809031584/at2854sup1.cif

e-65-o2177-sup1.cif^{(18.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809031584/at2854Isup2.hkl

e-65-o2177-Isup2.hkl^{(142.4KB, 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
C7—H7⋯F1ⁱ	0.95	2.50	3.099 (2)	121
C8—H8⋯F6ⁱ	0.95	2.50	3.392 (2)	156
C9—H9⋯F5ⁱⁱ	0.95	2.34	3.247 (2)	159
C10—H10A⋯F4ⁱⁱ	0.99	2.49	3.444 (2)	161
C10—H10B⋯F3ⁱⁱⁱ	0.99	2.49	3.455 (3)	164

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

Acknowledgments

The authors thank the Fund Projects of Sichuan Educational department (grant No. 2005 A104).

supplementary crystallographic information

Comment

Initiated by the isolation of the first stable N-heterocyclic carbene (NHC) by Arduengo et al. (1991), numerous stable NHC ligands has been prepared. 1,3-Disubstitutedimidazolium salts are considerable good precursor for synthesis of transition metal NHCs. In addition, the study of biological activities of imidazolium salts have been reported during these years. We report herein the synthesis and crystal structure of the title compound (I).

In (I), bond lengths and angles in title molecule (Fig. 1) are normal. The phenyl ring make dihedral angles with the benzyl ring and the imidazolium ring of 70.30 (8)° and 32.03 (10)°, respectively.

The crystal structure is stabilized by C—H···F hydrogen bonds (Table 1). Furthermore, P—F···π interactions involving imidazolium rings [F1···Cg1^iv = 2.9857 (16) Å, P1···Cg1^iv = 4.1630 (16) Å, P1—F1··· Cg1^iv = 127.92 (6)°, where Cg1 is a centroid of the N1/N2/C7–C9 ring; symmetry code: (iv) -x+2, -y+1, -z+1] are observed.

Experimental

The title compound was prepared according to the reported procedure of Liu et al. (2003). Colourless single crystals suitable for X-ray diffraction were obtained by recrystallization from dichloromethane and pPetroleum ether.