Acta Cryst. (2008). E64, m1028 [ doi:10.1107/S1600536808021521 ]
The title compound, (C22H22F2N4)[CuBr3], crystallizes with the cation situated on an inversion center and the anion on a twofold rotation axis along one Cu-Br bond. The two imidazole rings are in an anti configuration. The anion has a trigonal planar coordination geometry.
The compound was prepared by heating a mixture of 1,1'-bis(4-fluorobenzyl)-3,3'-ethylenediimidazolium dibromide (0.10 g, 18.5 mmol), copper dibromide (0.0496 g, 22.2 mmol), and sodium acetate (0.0304 g, 37.0 mmol) in DMSO (5 ml) at 353 K for 4 h. After cooling, the solvent was removed completely under vacuum. The residual solid was washed with water and dichloromethane. Crystals were obtained by vapor diffusion of diethyl ether into a DMF solution of the compound.
All H atoms were positioned geometrically and refined with a riding model, with Uiso(H) = 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) for all other H atoms.
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
![[Figure 1]](./cf2209fig1thm.gif)
| Fig. 1. The structure of (I), showing 50% probability displacement ellipsoids for non-H atoms. H atoms are of arbitrary size. Unlabeled atoms of the imidazolium cation are related to labeled atoms by 3/2-x, 3/2-y, -z; for the anion, the symmetry operation for Br1 is 1-x + 1, y, 1/2-z. |
| (C22H22F2N4)[CuBr3] | F000 = 1336 |
| Mr = 683.71 | Dx = 1.931 Mg m−3 |
| Monoclinic, C2/c | Mo Kα radiation λ = 0.71073 Å |
| Hall symbol: -C 2yc | Cell parameters from 3837 reflections |
| a = 15.4994 (11) Å | θ = 2.4–27.1º |
| b = 11.0825 (8) Å | µ = 6.06 mm−1 |
| c = 15.4464 (12) Å | T = 150 (2) K |
| β = 117.582 (4)º | Prism, colorless |
| V = 2351.7 (3) Å3 | 0.30 × 0.21 × 0.19 mm |
| Z = 4 |
| Bruker SMART 1000 diffractometer | 2686 independent reflections |
| Monochromator: graphite | 2242 reflections with I > 2σ(I) |
| Detector resolution: 8.3 pixels mm-1 | Rint = 0.023 |
| T = 150(2) K | θmax = 27.5º |
| ω scans | θmin = 2.4º |
| Absorption correction: multi-scan (SADABS; Sheldrick, 2001) | h = −20→20 |
| Tmin = 0.214, Tmax = 0.318 | k = −14→14 |
| 11647 measured reflections | l = −20→20 |
| 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)] = 0.032 | H-atom parameters constrained |
| wR(F2) = 0.091 | w = 1/[σ2(Fo2) + (0.0522P)2 + 7.4402P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.03 | (Δ/σ)max < 0.001 |
| 2686 reflections | Δρmax = 1.51 e Å−3 |
| 146 parameters | Δρmin = −0.73 e Å−3 |
| Primary atom site location: structure-invariant direct methods | Extinction correction: none |
| (C22H22F2N4)[CuBr3] | V = 2351.7 (3) Å3 |
| Mr = 683.71 | Z = 4 |
| Monoclinic, C2/c | Mo Kα |
| a = 15.4994 (11) Å | µ = 6.06 mm−1 |
| b = 11.0825 (8) Å | T = 150 (2) K |
| c = 15.4464 (12) Å | 0.30 × 0.21 × 0.19 mm |
| β = 117.582 (4)º |
| Bruker SMART 1000 diffractometer | 2686 independent reflections |
| Absorption correction: multi-scan (SADABS; Sheldrick, 2001) | 2242 reflections with I > 2σ(I) |
| Tmin = 0.214, Tmax = 0.318 | Rint = 0.023 |
| 11647 measured reflections |
| R[F2 > 2σ(F2)] = 0.032 | 146 parameters |
| wR(F2) = 0.091 | H-atom parameters constrained |
| S = 1.03 | Δρmax = 1.51 e Å−3 |
| 2686 reflections | Δρmin = −0.73 e Å−3 |
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 used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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. |
| x | y | z | Uiso*/Ueq | ||
| Cu1 | 0.5000 | 0.18316 (6) | 0.2500 | 0.03387 (17) | |
| Br1 | 0.48562 (2) | 0.06476 (3) | 0.11487 (2) | 0.02810 (12) | |
| Br2 | 0.5000 | 0.39352 (5) | 0.2500 | 0.03037 (14) | |
| F1 | 0.8176 (2) | 0.0493 (2) | 0.03890 (16) | 0.0474 (6) | |
| N1 | 0.71155 (19) | 0.6850 (2) | 0.08805 (18) | 0.0213 (6) | |
| N2 | 0.7085 (2) | 0.5320 (2) | 0.17325 (18) | 0.0213 (5) | |
| C1 | 0.7483 (2) | 0.7770 (3) | 0.0448 (2) | 0.0224 (6) | |
| H1A | 0.8143 | 0.8030 | 0.0933 | 0.027* | |
| H1B | 0.7050 | 0.8484 | 0.0254 | 0.027* | |
| C2 | 0.7660 (2) | 0.6007 (3) | 0.1510 (2) | 0.0241 (7) | |
| H2A | 0.8343 | 0.5911 | 0.1759 | 0.029* | |
| C3 | 0.6162 (2) | 0.6686 (3) | 0.0690 (3) | 0.0286 (7) | |
| H3A | 0.5618 | 0.7158 | 0.0264 | 0.034* | |
| C4 | 0.6148 (3) | 0.5730 (3) | 0.1223 (3) | 0.0287 (7) | |
| H4A | 0.5591 | 0.5401 | 0.1241 | 0.034* | |
| C5 | 0.7439 (3) | 0.4259 (3) | 0.2389 (2) | 0.0254 (7) | |
| H5A | 0.6941 | 0.4014 | 0.2586 | 0.030* | |
| H5B | 0.8039 | 0.4478 | 0.2986 | 0.030* | |
| C6 | 0.7651 (2) | 0.3216 (3) | 0.1889 (2) | 0.0229 (7) | |
| C7 | 0.6915 (3) | 0.2417 (3) | 0.1315 (2) | 0.0290 (7) | |
| H7A | 0.6286 | 0.2509 | 0.1268 | 0.035* | |
| C8 | 0.7084 (3) | 0.1489 (3) | 0.0809 (3) | 0.0355 (9) | |
| H8A | 0.6581 | 0.0945 | 0.0416 | 0.043* | |
| C9 | 0.8001 (3) | 0.1388 (3) | 0.0898 (2) | 0.0325 (8) | |
| C10 | 0.8756 (3) | 0.2142 (3) | 0.1463 (3) | 0.0324 (8) | |
| H10A | 0.9386 | 0.2033 | 0.1513 | 0.039* | |
| C11 | 0.8573 (2) | 0.3071 (3) | 0.1961 (2) | 0.0268 (7) | |
| H11A | 0.9082 | 0.3610 | 0.2352 | 0.032* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Cu1 | 0.0247 (3) | 0.0338 (4) | 0.0381 (3) | 0.000 | 0.0102 (3) | 0.000 |
| Br1 | 0.02629 (19) | 0.0309 (2) | 0.02709 (18) | −0.00222 (13) | 0.01230 (14) | −0.00081 (13) |
| Br2 | 0.0272 (2) | 0.0304 (3) | 0.0374 (3) | 0.000 | 0.0182 (2) | 0.000 |
| F1 | 0.0816 (19) | 0.0265 (12) | 0.0329 (11) | 0.0060 (11) | 0.0254 (12) | −0.0055 (9) |
| N1 | 0.0236 (13) | 0.0230 (14) | 0.0183 (12) | −0.0005 (11) | 0.0107 (10) | 0.0001 (10) |
| N2 | 0.0242 (13) | 0.0216 (13) | 0.0204 (12) | 0.0010 (11) | 0.0123 (10) | 0.0022 (10) |
| C1 | 0.0282 (16) | 0.0202 (16) | 0.0216 (14) | −0.0029 (13) | 0.0138 (12) | 0.0006 (12) |
| C2 | 0.0242 (16) | 0.0266 (17) | 0.0220 (15) | 0.0003 (13) | 0.0112 (12) | 0.0039 (12) |
| C3 | 0.0228 (16) | 0.0292 (18) | 0.0350 (18) | 0.0036 (14) | 0.0144 (14) | 0.0086 (14) |
| C4 | 0.0233 (16) | 0.0311 (18) | 0.0371 (18) | 0.0013 (14) | 0.0185 (14) | 0.0046 (15) |
| C5 | 0.0322 (18) | 0.0232 (17) | 0.0238 (15) | 0.0011 (14) | 0.0156 (14) | 0.0059 (13) |
| C6 | 0.0271 (16) | 0.0210 (16) | 0.0208 (14) | −0.0014 (13) | 0.0112 (12) | 0.0042 (12) |
| C7 | 0.0268 (17) | 0.0274 (18) | 0.0300 (17) | −0.0066 (14) | 0.0107 (13) | 0.0044 (14) |
| C8 | 0.044 (2) | 0.0245 (18) | 0.0269 (17) | −0.0103 (16) | 0.0068 (15) | 0.0037 (14) |
| C9 | 0.055 (2) | 0.0176 (16) | 0.0223 (15) | 0.0036 (16) | 0.0151 (15) | 0.0021 (13) |
| C10 | 0.0349 (19) | 0.031 (2) | 0.0313 (17) | 0.0040 (15) | 0.0155 (15) | −0.0002 (15) |
| C11 | 0.0260 (17) | 0.0248 (17) | 0.0259 (15) | −0.0017 (13) | 0.0089 (13) | −0.0024 (13) |
| Cu1—Br2 | 2.3314 (9) | C3—H3A | 0.950 |
| Cu1—Br1 | 2.3869 (5) | C4—H4A | 0.950 |
| Cu1—Br1i | 2.3869 (5) | C5—C6 | 1.508 (5) |
| F1—C9 | 1.368 (4) | C5—H5A | 0.990 |
| N1—C2 | 1.331 (4) | C5—H5B | 0.990 |
| N1—C3 | 1.379 (4) | C6—C7 | 1.390 (5) |
| N1—C1 | 1.470 (4) | C6—C11 | 1.391 (5) |
| N2—C2 | 1.333 (4) | C7—C8 | 1.388 (6) |
| N2—C4 | 1.370 (4) | C7—H7A | 0.950 |
| N2—C5 | 1.482 (4) | C8—C9 | 1.369 (6) |
| C1—C1ii | 1.532 (6) | C8—H8A | 0.950 |
| C1—H1A | 0.990 | C9—C10 | 1.373 (5) |
| C1—H1B | 0.990 | C10—C11 | 1.390 (5) |
| C2—H2A | 0.950 | C10—H10A | 0.950 |
| C3—C4 | 1.349 (5) | C11—H11A | 0.950 |
| Br2—Cu1—Br1 | 123.349 (16) | N2—C5—C6 | 110.9 (3) |
| Br2—Cu1—Br1i | 123.349 (16) | N2—C5—H5A | 109.5 |
| Br1—Cu1—Br1i | 113.30 (3) | C6—C5—H5A | 109.5 |
| C2—N1—C3 | 108.6 (3) | N2—C5—H5B | 109.5 |
| C2—N1—C1 | 124.8 (3) | C6—C5—H5B | 109.5 |
| C3—N1—C1 | 126.6 (3) | H5A—C5—H5B | 108.0 |
| C2—N2—C4 | 108.7 (3) | C7—C6—C11 | 119.1 (3) |
| C2—N2—C5 | 123.3 (3) | C7—C6—C5 | 120.4 (3) |
| C4—N2—C5 | 127.9 (3) | C11—C6—C5 | 120.5 (3) |
| N1—C1—C1ii | 108.8 (3) | C8—C7—C6 | 121.2 (3) |
| N1—C1—H1A | 109.9 | C8—C7—H7A | 119.4 |
| C1ii—C1—H1A | 109.9 | C6—C7—H7A | 119.4 |
| N1—C1—H1B | 109.9 | C9—C8—C7 | 117.5 (3) |
| C1ii—C1—H1B | 109.9 | C9—C8—H8A | 121.2 |
| H1A—C1—H1B | 108.3 | C7—C8—H8A | 121.2 |
| N1—C2—N2 | 108.4 (3) | F1—C9—C8 | 118.3 (3) |
| N1—C2—H2A | 125.8 | F1—C9—C10 | 118.0 (4) |
| N2—C2—H2A | 125.8 | C8—C9—C10 | 123.6 (4) |
| C4—C3—N1 | 107.0 (3) | C9—C10—C11 | 118.0 (4) |
| C4—C3—H3A | 126.5 | C9—C10—H10A | 121.0 |
| N1—C3—H3A | 126.5 | C11—C10—H10A | 121.0 |
| C3—C4—N2 | 107.4 (3) | C10—C11—C6 | 120.5 (3) |
| C3—C4—H4A | 126.3 | C10—C11—H11A | 119.8 |
| N2—C4—H4A | 126.3 | C6—C11—H11A | 119.8 |
| Symmetry codes: (i) −x+1, y, −z+1/2; (ii) −x+3/2, −y+3/2, −z. |
| Cu1—Br2 | 2.3314 (9) | Cu1—Br1 | 2.3869 (5) |
| Br2—Cu1—Br1 | 123.349 (16) | Br1—Cu1—Br1i | 113.30 (3) |
| Symmetry codes: (i) −x+1, y, −z+1/2. |
The authors are grateful to the National Science Council of Taiwan for financial support of this work.
Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Lee, H. M., Chen, C.-Y., Chen, W.-L. & Lin, H.-C. (2007). Acta Cryst. E63, o315–o316.
Liao, C.-Y., Chan, K.-T., Zeng, J.-Y., Hu, C.-H., Tu, C.-Y. & Lee, H. M. (2007). Organometallics, 26, 1692–1702.
Sheldrick, G. M. (2001). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Our group is interested in the preparation of imidazolium salts, which can be employed as ligand precursors for N-heterocyclic carbenes (Liao et al., 2007). In an unsuccessful attempt to prepare a copper carbene complex using 1,1'-bis(4-fluorobenzyl)-3,3'-ethylenediimidazolium dibromide, we isolated the title compound (I). Here we present its structure (Fig. 1). In our previous work (Lee et al., 2007), we reported the structure of 1,1'-bis(4-fluorobenzyl)-3,3'-ethylenediimidazolium dichloride monohydrate (II), which features the same imidazolium cation with chloride anions.
Compound (I) crystallizes in the monoclinic space group C2/c with the imidazolium cation situated on a center of inversion. An notable feature is the anti configuration of the two imdazole rings, which is in contrast to the structure of (II). Also, there is no guest water incorporation as in the structure of (II). The anion lies on a twofold rotation axis and has trigonal-planar geometry.