3,3′-Bis(4-fluoro­benz­yl)-1,1′-ethyl­enediimidazolium tribromidocuprate(I)

Lee, H.M.; Lu, C.-Y.; Cheng, P.-Y.

doi:10.1107/S1600536808021521

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 8| August 2008| Page m1028

doi:10.1107/S1600536808021521

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3,3′-Bis(4-fluorobenzyl)-1,1′-ethylenediimidazolium tribromidocuprate(I)

Hon Man Lee,^a ^* Chi-Ying Lu ^a and Pi-Yun Cheng ^a

^aNational Changhua University of Education, Department of Chemistry, Changhua 50058, Taiwan
^*Correspondence e-mail: leehm@cc.ncue.edu.tw

(Received 8 July 2008; accepted 11 July 2008; online 16 July 2008)

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.

Related literature

For general background, see: Liao et al. (2007 ). For the structure of another salt of this cation, see: Lee et al. (2007 ).

Experimental

Crystal data

(C₂₂H₂₂F₂N₄)[CuBr₃]
M_r = 683.71
Monoclinic, C 2/c
a = 15.4994 (11) Å
b = 11.0825 (8) Å
c = 15.4464 (12) Å
β = 117.582 (4)°
V = 2351.7 (3) Å³
Z = 4
Mo Kα radiation
μ = 6.06 mm⁻¹
T = 150 (2) K
0.30 × 0.21 × 0.19 mm

Data collection

Bruker SMART 1000 diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ) T_min = 0.213, T_max = 0.318
11647 measured reflections
2686 independent reflections
2242 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.032
wR(F²) = 0.091
S = 1.03
2686 reflections
146 parameters
H-atom parameters constrained
Δρ_max = 1.51 e Å⁻³
Δρ_min = −0.73 e Å⁻³

Table 1
Selected geometric parameters (Å, °)

Cu1—Br2	2.3314 (9)
Cu1—Br1	2.3869 (5)

Br2—Cu1—Br1	123.349 (16)
Br1—Cu1—Br1ⁱ	113.30 (3)
Symmetry code: (i) $[-x+1, y, -z+{\script{1\over 2}}]$ .

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808021521/cf2209sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808021521/cf2209Isup2.hkl

checkCIF report

Comment top

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.

Related literature top

For general background, see: Liao et al. (2007). For the structure of another salt of this cation, see: Lee et al. (2007).

Experimental top

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.

Computing details top

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).

Figures top

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.

3,3'-Bis(4-fluorobenzyl)-1,1'-ethylenediimidazolium tribromidocuprate(I) top

Crystal data top

(C₂₂H₂₂F₂N₄)[CuBr₃]	F(000) = 1336
M_r = 683.71	D_x = 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 = 2.4–27.1°
b = 11.0825 (8) Å	µ = 6.06 mm⁻¹
c = 15.4464 (12) Å	T = 150 K
β = 117.582 (4)°	Prism, colorless
V = 2351.7 (3) Å³	0.30 × 0.21 × 0.19 mm
Z = 4

Data collection top

Bruker SMART 1000 diffractometer	2686 independent reflections
Radiation source: fine-focus sealed tube	2242 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
Detector resolution: 8.3 pixels mm^-1	θ_max = 27.5°, θ_min = 2.4°
ω scans	h = −20→20
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	k = −14→14
T_min = 0.214, T_max = 0.318	l = −20→20
11647 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.091	H-atom parameters constrained
S = 1.03	w = 1/[σ²(F_o²) + (0.0522P)² + 7.4402P] where P = (F_o² + 2F_c²)/3
2686 reflections	(Δ/σ)_max < 0.001
146 parameters	Δρ_max = 1.51 e Å⁻³
0 restraints	Δρ_min = −0.74 e Å⁻³

Crystal data top

(C₂₂H₂₂F₂N₄)[CuBr₃]	V = 2351.7 (3) Å³
M_r = 683.71	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 15.4994 (11) Å	µ = 6.06 mm⁻¹
b = 11.0825 (8) Å	T = 150 K
c = 15.4464 (12) Å	0.30 × 0.21 × 0.19 mm
β = 117.582 (4)°

Data collection top

Bruker SMART 1000 diffractometer	2686 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	2242 reflections with I > 2σ(I)
T_min = 0.214, T_max = 0.318	R_int = 0.023
11647 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.032	0 restraints
wR(F²) = 0.091	H-atom parameters constrained
S = 1.03	Δρ_max = 1.51 e Å⁻³
2686 reflections	Δρ_min = −0.74 e Å⁻³
146 parameters

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
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*

Atomic displacement parameters (Å²) top

	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)

Geometric parameters (Å, º) top

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.

Experimental details

Crystal data
Chemical formula	(C₂₂H₂₂F₂N₄)[CuBr₃]
M_r	683.71
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	150
a, b, c (Å)	15.4994 (11), 11.0825 (8), 15.4464 (12)
β (°)	117.582 (4)
V (Å³)	2351.7 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	6.06
Crystal size (mm)	0.30 × 0.21 × 0.19

Data collection
Diffractometer	Bruker SMART 1000 diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2001)
T_min, T_max	0.214, 0.318
No. of measured, independent and observed [I > 2σ(I)] reflections	11647, 2686, 2242
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.091, 1.03
No. of reflections	2686
No. of parameters	146
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.51, −0.74

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXTL (Sheldrick, 2008).

Selected geometric parameters (Å, º) top

Cu1—Br2	2.3314 (9)	Cu1—Br1	2.3869 (5)

Br2—Cu1—Br1	123.349 (16)	Br1—Cu1—Br1ⁱ	113.30 (3)

Symmetry code: (i) −x+1, y, −z+1/2.

Acknowledgements

The authors are grateful to the National Science Council of Taiwan for financial support of this work.

References

Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Lee, H. M., Chen, C.-Y., Chen, W.-L. & Lin, H.-C. (2007). Acta Cryst. E63, o315–o316. Web of Science CSD CrossRef IUCr Journals Google Scholar
Liao, C.-Y., Chan, K.-T., Zeng, J.-Y., Hu, C.-H., Tu, C.-Y. & Lee, H. M. (2007). Organometallics, 26, 1692–1702. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2001). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar