research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Synthesis and crystal structures of 2-bromo-1,3-di­methyl­imidazolium iodides

CROSSMARK_Color_square_no_text.svg

aUniversity of Innsbruck, Faculty of Chemistry and Pharmacy, Innrain 80–82, 6020 Innsbruck, Austria, and bUniversity of Innsbruck, Institute of Mineralogy and Petrography, Innrain 52, 6020 Innsbruck, Austria
*Correspondence e-mail: lampl.martin@uibk.ac.at

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 15 November 2017; accepted 27 February 2018; online 9 March 2018)

Attempts at direct bromination of 1,3-di­methyl­imidazolium salts were futile. The title compounds, 2-bromo-1,3-di­methyl­imidazolium iodide chloro­form 0.33-solvate, C5H8BrN2+·I·0.33CHCl3, 2-bromo-1,3-di­methyl­imidazolium iodide di­chloro­methane hemisolvate, C5H8BrN2+·I·0.5CH2Cl2, and 2-bromo-1,3-di­methyl­imidazolium iodide hemi(diiodide), C5H8BrN2+·I·0.5I2, were obtained by methyl­ation of 2-bromo-1-methyl­imidazole. They crystallized as CHCl3, CH2Cl2 or I2 solvates/adducts. The Br atom acts as a σ-hole to accept short C—Br⋯I inter­actions. C—H⋯I hydrogen bonds are observed in each structure.

1. Chemical context

Salts containing 2-bromo-1,3-di­methyl­imidazolium (C5H8N2Br+) cations are the objective of this work. They are presumed to be valuable precursors for substitution reactions. This cation, despite its simplicity, has not yet been described. Since brominations in the 1,3-di­meth­oxy­imidazolium series (Laus et al., 2007[Laus, G., Schwärzler, A., Schuster, P., Bentivoglio, G., Hummel, M., Wurst, K., Kahlenberg, V., Lörting, T., Schütz, J., Peringer, P., Bonn, G., Nauer, G. & Schottenberger, H. (2007). Z. Naturforsch. Teil B, 62, 295-308.]) and also bromination of 1-hy­droxy­imidazole-3-oxide (Laus et al., 2012[Laus, G., Wurst, K., Kahlenberg, V. & Schottenberger, H. (2012). Z. Naturforsch. Teil B, 67, 354-358.]) gave the respective 2-bromo derivatives, we hoped that in the present case bromination would also yield the desired 2-bromo­imidazolium salts. However, on attempted bromination of 1,3-di­methyl­imidazolium hexa­fluorido­phosphate (Holbrey et al., 2002[Holbrey, J. D., Reichert, W. M., Swatloski, R. P., Broker, G. A., Pitner, W. R., Seddon, K. R. & Rogers, R. D. (2002). Green Chem. 4, 407-413.]), no substitution occurred in the 2-position as indicated by NMR. The absence of P—F vibrations in the infrared spectra suggested the formation of a different anion, which was confirmed by X-ray diffraction. Though direct bromination of the quaternary salt did not yield the desired product, it was discovered that an altered sequence of reaction was successful. Thus, the reaction between the 2-li­thio derivative of 1-methyl­imidazole and an equimolar amount of CBr4 (Boga et al., 2000[Boga, C., Del Vecchio, E., Forlani, L. & Todesco, P. E. (2000). J. Organomet. Chem. 601, 233-236.]) or Br2 (El Borai et al., 1981[El Borai, M., Moustafa, A. H., Anwar, M. & Abdel Hay, F. I. (1981). Pol. J. Chem. 55, 1659-1665.]) gave 2-bromo-1-methyl­imidazole in good yield, followed by methyl­ation using MeI to afford the desired quaternary salt as an iodide.

Now that the elusive title cation has been secured, further modifications are envisioned, giving access to a plethora of new 2-substituted imidazolium derivatives.

2. Structural commentary

The 2-bromo-1,3-di­methyl­imidazolium cations and iodide counter-ions crystallize as a CHCl3 1/3-solvate (1) (Fig. 1[link]), a CH2Cl2 monosolvate (2) (Fig. 2[link]) and an I2 adduct (3) (Fig. 3[link]). In every case, the cation is almost planar. In the asymmetric unit of 1, there are one and a half ion pairs, which are completed by mirror symmetry; the chloro­form mol­ecule also lies on a crystallographic mirror plane. In 2, there are two cations, two anions and two half-mol­ecules of di­chloro­methane (both completed by crystallographic twofold symmetry) in the asymmetric unit. In 3, the iodine mol­ecule is generated by crystallographic inversion symmetry.

[Scheme 1]
[Figure 1]
Figure 1
The mol­ecular structure of the chloro­form solvate 1, showing the atom labels and 50% probability displacement ellipsoids for non-H atoms. [Symmetry code: (i) x, 1 − y, z.]
[Figure 2]
Figure 2
The mol­ecular structure of the iodide 2, showing the atom labels and 50% probability displacement ellipsoids for non-H atoms. [Symmetry codes: (i) [{1\over 2}] − x, y, [{3\over 2}] − z, (ii) [{1\over 2}] − x, y, [{1\over 2}] − z.]
[Figure 3]
Figure 3
The mol­ecular structure of the iodide 3, showing the atom labels and 50% probability displacement ellipsoids for non-H atoms. [Symmetry code: (i) 1 − x, 1 − y, −z.]

3. Supra­molecular features

Halogen–halogen inter­actions constitute the main supra­molecular features of the three compounds. The cations in 1 are arranged in a tridimensional array of chains by C—H⋯I1 inter­actions. The chloro­form mol­ecule bridges these chains by C—H7⋯Cl1 and C—H9⋯I2 hydrogen bonds (Table 1[link]). Inter­halogen Br1⋯I2(x, y, −1 + z) [3.544 (1) Å] and Br2⋯I2 [3.546 (2) Å] contacts complete the network (Fig. 4[link]). The respective C—Br⋯I angles are 173.4 (2) and 173.6 (3)°, indicating an inter­action involving the positive end cap (σ-hole) of the terminal Br atom (Awwadi et al., 2006[Awwadi, F. F., Willett, R. D., Peterson, K. A. & Twamley, B. (2006). Chem. Eur. J. 12, 8952-8960.]; Clark et al., 2007[Clark, T., Hennemann, M., Murray, J. S. & Politzer, P. (2007). J. Mol. Model. 13, 291-296.]).

Table 1
Hydrogen-bond geometry (Å, °) for 1[link]

D—H⋯A D—H H⋯A DA D—H⋯A
C7—H7⋯Cl1i 0.95 2.82 3.623 (7) 142
C8—H8C⋯I1i 0.98 3.02 3.935 (6) 156
C9—H9⋯I2ii 1.00 2.77 3.760 (8) 169
C2—H2⋯I1iii 0.95 3.01 3.932 (6) 165
C3—H3⋯I1iv 0.95 3.12 3.952 (9) 147
Symmetry codes: (i) x, -y+1, z; (ii) x+1, y, z; (iii) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z]; (iv) x-1, y, z-1.
[Figure 4]
Figure 4
The crystal packing of compound 1 viewed along the c axis showing the C—H⋯Cl and C—H⋯I hydrogen bonds (see Table 1[link]) and Br⋯I short contacts as dashed lines.

This type of inter­action is also identified in the structures of compounds 2 and 3. In the di­chloro­methane solvate 2, almost linear halogen inter­actions Br1⋯I1 [3.483 (1) Å] and Br2⋯I2 [3.411 (1) Å] exhibit C—Br⋯I angles of 173.7 (1) and 176.7 (1)°, respectively (Fig. 5[link]). The I1 and I2 anions are linked by hydrogen bonds donated by the solvent mol­ecules (Table 2[link]).

Table 2
Hydrogen-bond geometry (Å, °) for 2[link]

D—H⋯A D—H H⋯A DA D—H⋯A
C11—H11A⋯I2i 0.99 2.86 3.834 (2) 169
C12—H12A⋯I1ii 0.99 2.89 3.862 (2) 170
Symmetry codes: (i) x, y-1, z; (ii) -x+1, -y+1, -z+1.
[Figure 5]
Figure 5
The crystal packing of compound 2 viewed along the b axis showing the C—H⋯I hydrogen bonds involving the solvent (see Table 2[link]) and Br⋯I short contacts as dashed lines.

In 3, a mol­ecular addition compound with iodine (Fig. 6[link]), inter­actions I1⋯I2 [3.426 (1) Å] and I2—I2 [related by inversion, bond length 2.826 (1) Å] are present. The I1⋯Br(1 + x, y, z) [3.499 (1) Å] inter­action displays a C—Br⋯I angle of 168.0 (2)° (Fig. 6[link]) and the iodide anion (I1) accepts a hydrogen bond from the methyl group (Table 3[link]).

Table 3
Hydrogen-bond geometry (Å, °) for 3[link]

D—H⋯A D—H H⋯A DA D—H⋯A
C5—H5B⋯I1i 0.98 3.03 3.986 (8) 166
Symmetry code: (i) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}].
[Figure 6]
Figure 6
The crystal packing of compound 3 viewed along the a axis showing the C—H⋯I hydrogen bonds (see Table 3[link]) and Br⋯I and I⋯I short contacts as dashed lines.

4. Database survey

A search of the Cambridge Structural Database (Version 5.38; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) for 2-halogeno-1,3-dialkyl or di­aryl­imidazolium salts gave 30 hits. When carbon substituents were allowed in positions 4 and 5, the tally was 34. Of these 64 compounds, there were 11 containing chlorine, 19 bromine and 33 iodine. Closely related imidazolin-2-yl­idene–iodine (Kuhn et al., 1993[Kuhn, N., Kratz, T. & Henkel, G. (1993). J. Chem. Soc. Chem. Commun. pp. 1778-1779.]) and imidazolin-2-yl­idene–bromine (Kuhn et al., 2004[Kuhn, N., Abu-Rayyan, A., Eichele, K., Schwarz, S. & Steimann, M. (2004). Inorg. Chim. Acta, 357, 1799-1804.]) coordination compounds have been reported.

5. Synthesis and crystallization

Compound 1: A solution of 2-bromo-1-methyl­imidazole (150 µl, 1.54 mmol) in CHCl3 (1 ml) was carefully layered over a solution of CH3I (190 µl, 3.07 mmol) in CHCl3 (2 ml). The mixture was kept at room temperature and protected from light. After 2 h, the formation of colourless crystals of 1 was observed. The product was collected after seven days at 278 K, yielding 252 mg (48%); m.p. 453 K (decomposition). 1H NMR (300 MHz, DMSO-d6): δ 3.81 (s, 6H), 7.90 (s, 2H), 8.31 (s) ppm. 13C NMR (75 MHz, DMSO-d6): δ 36.8 (2C), 79.3, 123.5, 124.5 (2C) ppm. IR (neat): ν 3066, 2931, 1521, 1240, 1098, 765, 738, 652, 635 cm−1.

Compound 2: A solution of 2-bromo-1-methyl­imidazole (150 µl, 1.54 mmol) in CH2Cl2 (1 ml) was carefully layered over a solution of CH3I (190 µl, 3.07 mmol) in CH2Cl2 (2 ml). The mixture was kept at room temperature and protected from light. After 2 h, the formation of colourless crystals of 2 was observed. The product was collected after 18 h, yielding 145 mg (27%); m.p. 452–453 K (decomposition). 1H NMR (300 MHz, DMSO-d6): δ 3.81 (s, 6H), 5.75, 7.90 (s, 2H) ppm. 13C NMR (75 MHz, DMSO-d6): δ 36.8 (2C), 55.0, 123.3, 124.7 (2C) ppm. IR (neat): ν 3066, 3011, 2944, 1523, 1240, 1101, 779, 728, 696, 635 cm−1.

Compound 3: The I2 adduct was obtained as a byproduct of 1 and 2 in the form of brown crystals of 3; approximate yield 10%; m.p. 451 K (decomposition). 1H NMR (300 MHz, DMSO-d6): δ 3.81 (s, 6H), 7.89 (d, 2H) ppm IR (neat): ν 3063, 1523, 1226, 739, 634 cm−1.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4[link]. All H atoms were poisitioned geometrically (C—H = 0.95–1.0 Å) and treated as riding with Uiso(H) = 1.2–1.5Ueq(C).

Table 4
Experimental details

  1 2 3
Crystal data
Chemical formula 3C5H8BrN2+·3I·CHCl3 2C5H8BrN2+·2I·CH2Cl2 C5H8BrN2+·I·0.5I2
Mr 1028.20 690.79 429.83
Crystal system, space group Monoclinic, Cm Monoclinic, P2/n Monoclinic, P21/n
Temperature (K) 173 193 173
a, b, c (Å) 13.9135 (14), 21.9492 (10), 6.4529 (6) 16.0223 (8), 8.5334 (4), 16.2881 (8) 6.0861 (4), 14.4773 (11), 12.0303 (7)
β (°) 128.314 (16) 101.590 (1) 97.812 (5)
V3) 1546.2 (3) 2181.58 (18) 1050.16 (12)
Z 2 4 4
Radiation type Mo Kα Mo Kα Mo Kα
μ (mm−1) 7.18 6.79 9.74
Crystal size (mm) 0.26 × 0.14 × 0.06 0.18 × 0.16 × 0.14 0.36 × 0.10 × 0.08
 
Data collection
Diffractometer Gemini-R Ultra Quest Photon 100 Gemini-R Ultra
Absorption correction Multi-scan (CrysAlis PRO; Oxford Diffraction, 2014[Oxford Diffraction (2014). CrysAlis PRO. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]) Multi-scan (SADABS; Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Analytical
Tmin, Tmax 0.427, 1 0.296, 0.433 0.065, 0.446
No. of measured, independent and observed [I > 2σ(I)] reflections 4904, 2522, 2426 62055, 4302, 3952 6287, 1912, 1746
Rint 0.026 0.028 0.030
(sin θ/λ)max−1) 0.602 0.617 0.602
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.018, 0.035, 0.95 0.022, 0.063, 1.09 0.036, 0.080, 1.34
No. of reflections 2522 4302 1912
No. of parameters 151 196 93
No. of restraints 2 0 0
H-atom treatment H-atom parameters constrained H-atom parameters constrained H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.41, −0.44 1.07, −0.76 0.76, −0.97
Absolute structure Flack x determined using 961 quotients [(I+)−(I)]/[(I+)+(I)] (Parsons et al., 2013[Parsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249-259.])
Absolute structure parameter 0.038 (8)
Computer programs: APEX2 and SAINT (Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), CrysAlis PRO (Oxford Diffraction, 2014[Oxford Diffraction (2014). CrysAlis PRO. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]), SIR2002 (Burla et al., 2003[Burla, M. C., Camalli, M., Carrozzini, B., Cascarano, G. L., Giacovazzo, C., Polidori, G. & Spagna, R. (2003). J. Appl. Cryst. 36, 1103.]), SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2014 and SHELXL2017 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]).

Supporting information


Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2014) for (1); APEX2 (Bruker, 2014) for (2); CrysAlis PRO (Oxford Diffraction, 2014). for (3). Cell refinement: CrysAlis PRO (Oxford Diffraction, 2014) for (1); SAINT (Bruker, 2014) for (2); CrysAlis PRO (Oxford Diffraction, 2014). for (3). Data reduction: CrysAlis PRO (Oxford Diffraction, 2014) for (1); SAINT (Bruker, 2014) for (2); CrysAlis PRO (Oxford Diffraction, 2014). for (3). Program(s) used to solve structure: SIR2002 (Burla et al., 2003) for (1), (3); SHELXTL (Sheldrick, 2008) for (2). Program(s) used to refine structure: SHELXL2017 (Sheldrick, 2015) for (1), (3); SHELXL2014 (Sheldrick, 2015) for (2). For all structures, molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: Mercury (Macrae et al., 2008).

2-Bromo-1,3-dimethylimidazolium iodide chloroform 0.33-solvate (1) top
Crystal data top
3C5H8BrN2+·3I·CHCl3F(000) = 956
Mr = 1028.20Dx = 2.208 Mg m3
Monoclinic, CmMo Kα radiation, λ = 0.71073 Å
a = 13.9135 (14) ÅCell parameters from 3263 reflections
b = 21.9492 (10) Åθ = 3.3–28.4°
c = 6.4529 (6) ŵ = 7.18 mm1
β = 128.314 (16)°T = 173 K
V = 1546.2 (3) Å3Prismatic, colourless
Z = 20.26 × 0.14 × 0.06 mm
Data collection top
Gemini-R Ultra
diffractometer
2426 reflections with I > 2σ(I)
Radiation source: Enhance (Mo) X-ray SourceRint = 0.026
ω scansθmax = 25.3°, θmin = 3.4°
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2014)
h = 1613
Tmin = 0.427, Tmax = 1k = 2226
4904 measured reflectionsl = 77
2522 independent reflections
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.018 w = 1/[σ2(Fo2) + (0.0049P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.035(Δ/σ)max < 0.001
S = 0.95Δρmax = 0.41 e Å3
2522 reflectionsΔρmin = 0.43 e Å3
151 parametersAbsolute structure: Flack x determined using 961 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
2 restraintsAbsolute structure parameter: 0.038 (8)
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.12194 (6)0.39565 (3)0.07927 (14)0.03269 (15)
C20.0731 (6)0.2987 (3)0.3714 (13)0.0354 (15)
H20.1009220.2796340.5320980.042*
C30.0414 (6)0.2992 (3)0.1483 (14)0.0353 (16)
H30.1102680.2809700.1212510.042*
C10.0731 (5)0.3488 (2)0.0790 (11)0.0246 (14)
N10.1435 (4)0.3305 (2)0.3284 (9)0.0284 (11)
C40.2778 (6)0.3372 (3)0.5169 (14)0.0405 (17)
H4A0.3133450.3258570.4304070.061*
H4B0.3107510.3105820.6693970.061*
H4C0.2985880.3796370.5762660.061*
N20.0420 (4)0.3308 (2)0.0364 (10)0.0283 (12)
C50.1452 (5)0.3358 (3)0.3220 (12)0.0353 (15)
H5A0.1447010.3763650.3851020.053*
H5B0.2226610.3297530.3515740.053*
H5C0.1366540.3047320.4185100.053*
I10.62590 (4)0.29885 (2)0.94514 (6)0.02823 (10)
I20.21304 (5)0.5000000.65285 (9)0.02890 (13)
Br20.40367 (7)0.5000000.46275 (15)0.0313 (2)
C80.4948 (7)0.6124 (3)0.2888 (14)0.0462 (18)
H8A0.4059610.6182880.1774870.069*
H8B0.5293390.6397480.2301240.069*
H8C0.5314810.6213710.4729550.069*
N30.5211 (4)0.5494 (2)0.2675 (9)0.0315 (12)
C60.4874 (7)0.5000000.3242 (15)0.0269 (19)
C70.5758 (6)0.5305 (3)0.1602 (12)0.0399 (16)
H70.6078220.5560860.0972680.048*
C90.8764 (8)0.5000000.0794 (19)0.038 (2)
H90.9623040.5000000.2479650.045*
Cl10.8016 (2)0.43407 (7)0.0686 (5)0.0569 (5)
Cl20.8806 (3)0.5000000.1852 (6)0.0636 (8)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0383 (3)0.0293 (3)0.0368 (3)0.0004 (3)0.0265 (3)0.0013 (3)
C20.052 (4)0.032 (3)0.033 (4)0.001 (3)0.031 (4)0.001 (3)
C30.046 (4)0.031 (4)0.050 (4)0.002 (3)0.040 (4)0.003 (3)
C10.029 (3)0.019 (3)0.023 (3)0.003 (3)0.015 (3)0.003 (3)
N10.032 (3)0.025 (3)0.026 (3)0.003 (2)0.017 (2)0.003 (2)
C40.043 (4)0.032 (3)0.038 (4)0.006 (3)0.021 (4)0.002 (3)
N20.028 (3)0.024 (3)0.035 (3)0.002 (2)0.021 (2)0.001 (2)
C50.022 (3)0.033 (3)0.031 (4)0.003 (3)0.007 (3)0.005 (3)
I10.03254 (19)0.02663 (18)0.0289 (2)0.00359 (18)0.02071 (17)0.00012 (18)
I20.0286 (3)0.0344 (3)0.0280 (3)0.0000.0196 (3)0.000
Br20.0373 (5)0.0385 (5)0.0292 (5)0.0000.0262 (4)0.000
C80.059 (5)0.044 (4)0.052 (5)0.021 (3)0.043 (4)0.015 (3)
N30.028 (3)0.045 (3)0.023 (3)0.011 (2)0.016 (2)0.005 (2)
C60.021 (4)0.044 (5)0.018 (4)0.0000.013 (4)0.000
C70.031 (3)0.064 (4)0.031 (4)0.008 (3)0.022 (3)0.004 (3)
C90.034 (5)0.031 (5)0.053 (6)0.0000.030 (5)0.000
Cl10.0748 (12)0.0285 (7)0.1059 (15)0.0015 (10)0.0751 (12)0.0040 (11)
Cl20.102 (2)0.0363 (14)0.097 (2)0.0000.084 (2)0.000
Geometric parameters (Å, º) top
Br1—C11.850 (6)C5—H5C0.9800
C2—C31.329 (9)Br2—C61.857 (8)
C2—N11.364 (8)C8—N31.457 (8)
C2—H20.9500C8—H8A0.9800
C3—N21.374 (8)C8—H8B0.9800
C3—H30.9500C8—H8C0.9800
C1—N11.325 (7)N3—C61.321 (6)
C1—N21.340 (7)N3—C71.372 (7)
N1—C41.475 (8)C7—C7i1.340 (13)
C4—H4A0.9800C7—H70.9500
C4—H4B0.9800C9—Cl21.744 (9)
C4—H4C0.9800C9—Cl1i1.759 (5)
N2—C51.480 (8)C9—Cl11.759 (5)
C5—H5A0.9800C9—H91.0000
C5—H5B0.9800
C3—C2—N1107.7 (6)N2—C5—H5C109.5
C3—C2—H2126.1H5A—C5—H5C109.5
N1—C2—H2126.1H5B—C5—H5C109.5
C2—C3—N2107.6 (6)N3—C8—H8A109.5
C2—C3—H3126.2N3—C8—H8B109.5
N2—C3—H3126.2H8A—C8—H8B109.5
N1—C1—N2108.3 (5)N3—C8—H8C109.5
N1—C1—Br1126.2 (4)H8A—C8—H8C109.5
N2—C1—Br1125.3 (4)H8B—C8—H8C109.5
C1—N1—C2108.6 (5)C6—N3—C7107.1 (5)
C1—N1—C4125.2 (5)C6—N3—C8126.8 (5)
C2—N1—C4125.8 (5)C7—N3—C8125.8 (5)
N1—C4—H4A109.5N3i—C6—N3110.5 (7)
N1—C4—H4B109.5N3i—C6—Br2124.8 (4)
H4A—C4—H4B109.5N3—C6—Br2124.8 (4)
N1—C4—H4C109.5C7i—C7—N3107.6 (4)
H4A—C4—H4C109.5C7i—C7—H7126.2
H4B—C4—H4C109.5N3—C7—H7126.2
C1—N2—C3107.7 (5)Cl2—C9—Cl1i109.8 (4)
C1—N2—C5125.0 (5)Cl2—C9—Cl1109.8 (4)
C3—N2—C5126.6 (5)Cl1i—C9—Cl1110.8 (5)
N2—C5—H5A109.5Cl2—C9—H9108.8
N2—C5—H5B109.5Cl1i—C9—H9108.8
H5A—C5—H5B109.5Cl1—C9—H9108.8
N1—C2—C3—N20.8 (7)Br1—C1—N2—C511.5 (8)
N2—C1—N1—C21.8 (6)C2—C3—N2—C10.3 (7)
Br1—C1—N1—C2178.1 (4)C2—C3—N2—C5171.0 (5)
N2—C1—N1—C4175.1 (5)C7—N3—C6—N3i2.1 (8)
Br1—C1—N1—C48.6 (8)C8—N3—C6—N3i176.4 (4)
C3—C2—N1—C11.6 (7)C7—N3—C6—Br2177.6 (5)
C3—C2—N1—C4174.9 (6)C8—N3—C6—Br23.3 (10)
N1—C1—N2—C31.3 (6)C6—N3—C7—C7i1.3 (5)
Br1—C1—N2—C3177.6 (4)C8—N3—C7—C7i175.7 (5)
N1—C1—N2—C5172.2 (5)
Symmetry code: (i) x, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7···Cl1i0.952.823.623 (7)142
C8—H8C···I1i0.983.023.935 (6)156
C9—H9···I2ii1.002.773.760 (8)169
C2—H2···I1iii0.953.013.932 (6)165
C3—H3···I1iv0.953.123.952 (9)147
Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z; (iii) x1/2, y+1/2, z; (iv) x1, y, z1.
2-Bromo-1,3-dimethylimidazolium iodide dichloromethane hemisolvate (2) top
Crystal data top
2C5H8BrN2+·2I·CH2Cl2F(000) = 1288
Mr = 690.79Dx = 2.103 Mg m3
Monoclinic, P2/nMo Kα radiation, λ = 0.71073 Å
a = 16.0223 (8) ÅCell parameters from 9539 reflections
b = 8.5334 (4) Åθ = 2.5–26.8°
c = 16.2881 (8) ŵ = 6.79 mm1
β = 101.590 (1)°T = 193 K
V = 2181.58 (18) Å3Prism, colourless
Z = 40.18 × 0.16 × 0.14 mm
Data collection top
Quest Photon 100
diffractometer
4302 independent reflections
Radiation source: Incoatec Microfocus3952 reflections with I > 2σ(I)
Multi layered optics monochromatorRint = 0.028
Detector resolution: 10.4 pixels mm-1θmax = 26.0°, θmin = 2.4°
φ and ω scansh = 1919
Absorption correction: multi-scan
(SADABS; Bruker, 2014)
k = 1010
Tmin = 0.296, Tmax = 0.433l = 2020
62055 measured reflections
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.022 w = 1/[σ2(Fo2) + (0.0332P)2 + 2.6592P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.063(Δ/σ)max = 0.001
S = 1.09Δρmax = 1.07 e Å3
4302 reflectionsΔρmin = 0.76 e Å3
196 parametersExtinction correction: SHELXL2014 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.00234 (11)
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
I10.67871 (2)0.51565 (2)0.93259 (2)0.03524 (8)
I20.43487 (2)1.00139 (2)0.67926 (2)0.03507 (8)
Br10.58435 (2)0.60778 (4)0.72654 (2)0.04235 (10)
Br20.23431 (2)0.90371 (4)0.57720 (2)0.03775 (10)
N10.44318 (17)0.5987 (3)0.58815 (16)0.0365 (6)
N20.54830 (15)0.7333 (3)0.55936 (15)0.0345 (5)
N30.06441 (15)0.7732 (3)0.54179 (15)0.0344 (5)
N40.09163 (16)0.9098 (3)0.43839 (16)0.0347 (5)
C10.52208 (19)0.6502 (4)0.61831 (18)0.0347 (6)
C20.4178 (2)0.6538 (4)0.50716 (19)0.0387 (7)
H20.36440.63560.47080.046*
C30.4831 (2)0.7381 (4)0.48965 (19)0.0389 (7)
H30.48410.79130.43860.047*
C40.3892 (3)0.5077 (5)0.6337 (3)0.0550 (10)
H4A0.42110.41670.66020.083*
H4B0.33820.47200.59450.083*
H4C0.37240.57370.67690.083*
C50.6292 (2)0.8180 (4)0.5680 (2)0.0494 (8)
H5A0.63450.89270.61450.074*
H5B0.63050.87470.51600.074*
H5C0.67650.74330.57930.074*
C60.12335 (18)0.8585 (3)0.51581 (19)0.0334 (6)
C70.00661 (19)0.7668 (4)0.4784 (2)0.0383 (7)
H70.05800.71220.47970.046*
C80.01002 (19)0.8519 (4)0.4140 (2)0.0387 (7)
H80.02740.86890.36170.046*
C90.0746 (2)0.6917 (5)0.6219 (2)0.0503 (8)
H9A0.12540.62510.62980.075*
H9B0.02430.62660.62240.075*
H9C0.08090.76860.66740.075*
C100.1357 (3)1.0097 (5)0.3880 (3)0.0530 (10)
H10A0.15101.10910.41720.080*
H10B0.09821.03010.33360.080*
H10C0.18750.95690.37920.080*
C110.25000.2120 (5)0.75000.0409 (10)
H11A0.29310.14370.73240.049*0.5
H11B0.20690.14360.76760.049*0.5
Cl10.29912 (8)0.32404 (14)0.83510 (8)0.0829 (4)
C120.25000.7005 (5)0.25000.0416 (10)
H12A0.26890.63220.20810.050*0.5
H12B0.23110.63220.29190.050*0.5
Cl20.16400 (7)0.81502 (12)0.20000 (7)0.0695 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.03410 (12)0.03872 (13)0.03155 (12)0.00227 (8)0.00338 (9)0.00373 (7)
I20.03022 (12)0.04024 (13)0.03290 (12)0.00221 (7)0.00191 (8)0.00410 (7)
Br10.04481 (19)0.04589 (19)0.03212 (17)0.01593 (14)0.00236 (13)0.00018 (13)
Br20.03094 (16)0.04058 (18)0.03833 (17)0.00138 (12)0.00111 (12)0.01062 (12)
N10.0399 (14)0.0358 (14)0.0331 (13)0.0018 (11)0.0057 (11)0.0024 (10)
N20.0315 (12)0.0374 (13)0.0331 (13)0.0056 (10)0.0025 (10)0.0051 (11)
N30.0320 (13)0.0379 (13)0.0326 (13)0.0021 (10)0.0050 (10)0.0042 (11)
N40.0326 (13)0.0356 (13)0.0349 (13)0.0003 (10)0.0046 (10)0.0052 (10)
C10.0382 (16)0.0325 (15)0.0317 (15)0.0085 (12)0.0032 (12)0.0038 (12)
C20.0384 (16)0.0429 (17)0.0315 (15)0.0033 (14)0.0004 (12)0.0052 (13)
C30.0413 (17)0.0454 (18)0.0282 (15)0.0076 (14)0.0026 (12)0.0018 (13)
C40.058 (2)0.057 (2)0.051 (2)0.0060 (17)0.0125 (19)0.0077 (17)
C50.0364 (17)0.054 (2)0.055 (2)0.0011 (15)0.0048 (15)0.0014 (17)
C60.0317 (14)0.0315 (14)0.0356 (15)0.0037 (12)0.0032 (12)0.0082 (12)
C70.0270 (14)0.0438 (18)0.0428 (17)0.0011 (12)0.0039 (12)0.0061 (14)
C80.0306 (15)0.0435 (17)0.0383 (16)0.0011 (13)0.0019 (12)0.0042 (14)
C90.054 (2)0.058 (2)0.0390 (18)0.0011 (17)0.0089 (16)0.0067 (16)
C100.051 (2)0.061 (2)0.046 (2)0.0109 (17)0.0077 (17)0.0060 (16)
C110.034 (2)0.042 (2)0.046 (3)0.0000.0059 (19)0.000
Cl10.0724 (7)0.0690 (7)0.0889 (8)0.0138 (6)0.0277 (6)0.0346 (6)
C120.044 (2)0.040 (2)0.037 (2)0.0000.0023 (19)0.000
Cl20.0684 (6)0.0583 (6)0.0657 (6)0.0183 (5)0.0249 (5)0.0070 (5)
Geometric parameters (Å, º) top
Br1—C11.878 (3)C4—H4C0.9800
Br2—C61.896 (3)C5—H5A0.9800
N1—C11.335 (4)C5—H5B0.9800
N1—C21.382 (4)C5—H5C0.9800
N1—C41.469 (5)C7—C81.345 (5)
N2—C11.328 (4)C7—H70.9500
N2—C31.380 (4)C8—H80.9500
N2—C51.465 (4)C9—H9A0.9800
N3—C61.327 (4)C9—H9B0.9800
N3—C71.376 (4)C9—H9C0.9800
N3—C91.459 (4)C10—H10A0.9800
N4—C61.335 (4)C10—H10B0.9800
N4—C81.380 (4)C10—H10C0.9800
N4—C101.460 (4)C11—Cl11.737 (3)
C2—C31.347 (5)C11—H11A0.9900
C2—H20.9500C11—H11B0.9900
C3—H30.9500C12—Cl21.751 (3)
C4—H4A0.9800C12—H12A0.9900
C4—H4B0.9800C12—H12B0.9900
C1—N1—C2108.3 (3)N3—C6—N4108.7 (3)
C1—N1—C4126.7 (3)N3—C6—Br2126.5 (2)
C2—N1—C4124.8 (3)N4—C6—Br2124.7 (2)
C1—N2—C3108.3 (3)C8—C7—N3107.5 (3)
C1—N2—C5126.6 (3)C8—C7—H7126.3
C3—N2—C5124.9 (3)N3—C7—H7126.3
C6—N3—C7108.5 (3)C7—C8—N4107.1 (3)
C6—N3—C9126.0 (3)C7—C8—H8126.4
C7—N3—C9125.4 (3)N4—C8—H8126.4
C6—N4—C8108.2 (3)N3—C9—H9A109.5
C6—N4—C10126.0 (3)N3—C9—H9B109.5
C8—N4—C10125.8 (3)H9A—C9—H9B109.5
N2—C1—N1108.9 (3)N3—C9—H9C109.5
N2—C1—Br1126.6 (2)H9A—C9—H9C109.5
N1—C1—Br1124.5 (2)H9B—C9—H9C109.5
C3—C2—N1106.9 (3)N4—C10—H10A109.5
C3—C2—H2126.5N4—C10—H10B109.5
N1—C2—H2126.5H10A—C10—H10B109.5
C2—C3—N2107.6 (3)N4—C10—H10C109.5
C2—C3—H3126.2H10A—C10—H10C109.5
N2—C3—H3126.2H10B—C10—H10C109.5
N1—C4—H4A109.5Cl1i—C11—Cl1113.2 (3)
N1—C4—H4B109.5Cl1i—C11—H11A108.9
H4A—C4—H4B109.5Cl1—C11—H11A108.9
N1—C4—H4C109.5Cl1i—C11—H11B108.9
H4A—C4—H4C109.5Cl1—C11—H11B108.9
H4B—C4—H4C109.5H11A—C11—H11B107.7
N2—C5—H5A109.5Cl2—C12—Cl2ii112.1 (3)
N2—C5—H5B109.5Cl2—C12—H12A109.2
H5A—C5—H5B109.5Cl2ii—C12—H12A109.2
N2—C5—H5C109.5Cl2—C12—H12B109.2
H5A—C5—H5C109.5Cl2ii—C12—H12B109.2
H5B—C5—H5C109.5H12A—C12—H12B107.9
C3—N2—C1—N11.4 (3)C7—N3—C6—N41.4 (3)
C5—N2—C1—N1176.4 (3)C9—N3—C6—N4177.9 (3)
C3—N2—C1—Br1179.2 (2)C7—N3—C6—Br2179.2 (2)
C5—N2—C1—Br14.3 (4)C9—N3—C6—Br22.6 (4)
C2—N1—C1—N21.1 (3)C8—N4—C6—N31.2 (3)
C4—N1—C1—N2177.4 (3)C10—N4—C6—N3178.9 (3)
C2—N1—C1—Br1179.5 (2)C8—N4—C6—Br2179.3 (2)
C4—N1—C1—Br13.2 (4)C10—N4—C6—Br20.5 (4)
C1—N1—C2—C30.3 (3)C6—N3—C7—C81.0 (3)
C4—N1—C2—C3176.7 (3)C9—N3—C7—C8177.5 (3)
N1—C2—C3—N20.5 (3)N3—C7—C8—N40.2 (4)
C1—N2—C3—C21.2 (3)C6—N4—C8—C70.6 (3)
C5—N2—C3—C2176.2 (3)C10—N4—C8—C7179.6 (3)
Symmetry codes: (i) x+1/2, y, z+3/2; (ii) x+1/2, y, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C11—H11A···I2iii0.992.863.834 (2)169
C12—H12A···I1iv0.992.893.862 (2)170
Symmetry codes: (iii) x, y1, z; (iv) x+1, y+1, z+1.
2-Bromo-1,3-dimethylimidazolium iodide hemi(diiodide) (3) top
Crystal data top
C5H8BrN2+·I·0.5I2F(000) = 772
Mr = 429.83Dx = 2.719 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 6.0861 (4) ÅCell parameters from 3142 reflections
b = 14.4773 (11) Åθ = 3.3–27.6°
c = 12.0303 (7) ŵ = 9.74 mm1
β = 97.812 (5)°T = 173 K
V = 1050.16 (12) Å3Lath shaped, red-brown
Z = 40.36 × 0.10 × 0.08 mm
Data collection top
Gemini-R Ultra
diffractometer
1746 reflections with I > 2σ(I)
ω scansRint = 0.030
Absorption correction: analyticalθmax = 25.4°, θmin = 3.3°
Tmin = 0.065, Tmax = 0.446h = 67
6287 measured reflectionsk = 1713
1912 independent reflectionsl = 1411
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.036H-atom parameters constrained
wR(F2) = 0.080 w = 1/[σ2(Fo2) + (0.0102P)2 + 8.6812P]
where P = (Fo2 + 2Fc2)/3
S = 1.34(Δ/σ)max < 0.001
1912 reflectionsΔρmax = 0.76 e Å3
93 parametersΔρmin = 0.97 e Å3
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2σ(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
xyzUiso*/Ueq
I10.59338 (9)0.17085 (4)0.05590 (4)0.02835 (16)
I20.51595 (9)0.40299 (5)0.01140 (5)0.03726 (18)
Br0.04393 (13)0.28681 (6)0.20566 (7)0.0274 (2)
N20.4459 (11)0.3501 (5)0.3339 (5)0.0246 (15)
N10.2322 (11)0.4618 (5)0.2630 (5)0.0269 (15)
C10.2538 (13)0.3703 (6)0.2721 (6)0.0236 (17)
C40.0471 (14)0.5121 (6)0.1973 (7)0.034 (2)
H4A0.0767710.5187930.1196100.051*
H4B0.0326290.5733560.2301310.051*
H4C0.0909580.4774580.1983770.051*
C30.5500 (14)0.4327 (6)0.3649 (7)0.031 (2)
H30.6906010.4395360.4091970.037*
C50.5298 (14)0.2578 (6)0.3667 (7)0.0293 (19)
H5A0.4224730.2258170.4068870.044*
H5B0.6715330.2633960.4157470.044*
H5C0.5513380.2225950.2995190.044*
C20.4191 (15)0.5011 (6)0.3217 (7)0.032 (2)
H20.4490930.5653100.3299580.039*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.0248 (3)0.0341 (3)0.0254 (3)0.0032 (2)0.0007 (2)0.0003 (2)
I20.0282 (3)0.0522 (4)0.0320 (3)0.0097 (3)0.0062 (2)0.0096 (3)
Br0.0267 (4)0.0248 (5)0.0306 (4)0.0047 (3)0.0028 (3)0.0036 (3)
N20.025 (3)0.030 (4)0.020 (3)0.005 (3)0.005 (3)0.003 (3)
N10.030 (4)0.024 (4)0.026 (4)0.001 (3)0.002 (3)0.006 (3)
C10.031 (4)0.021 (4)0.021 (4)0.005 (4)0.011 (3)0.003 (3)
C40.035 (5)0.033 (5)0.033 (5)0.008 (4)0.003 (4)0.007 (4)
C30.024 (4)0.034 (5)0.034 (5)0.013 (4)0.002 (3)0.003 (4)
C50.029 (4)0.023 (5)0.036 (5)0.002 (4)0.003 (4)0.001 (3)
C20.041 (5)0.023 (5)0.031 (5)0.008 (4)0.002 (4)0.003 (4)
Geometric parameters (Å, º) top
I2—I2i2.8265 (14)C4—H4B0.9800
Br—C11.858 (8)C4—H4C0.9800
N2—C11.330 (10)C3—C21.331 (12)
N2—C31.380 (11)C3—H30.9500
N2—C51.465 (11)C5—H5A0.9800
N1—C11.335 (11)C5—H5B0.9800
N1—C21.377 (11)C5—H5C0.9800
N1—C41.477 (10)C2—H20.9500
C4—H4A0.9800
C1—N2—C3107.3 (7)H4B—C4—H4C109.5
C1—N2—C5126.7 (7)C2—C3—N2108.1 (7)
C3—N2—C5125.9 (7)C2—C3—H3125.9
C1—N1—C2107.6 (7)N2—C3—H3125.9
C1—N1—C4126.3 (7)N2—C5—H5A109.5
C2—N1—C4126.0 (7)N2—C5—H5B109.5
N2—C1—N1109.4 (7)H5A—C5—H5B109.5
N2—C1—Br126.8 (6)N2—C5—H5C109.5
N1—C1—Br123.8 (6)H5A—C5—H5C109.5
N1—C4—H4A109.5H5B—C5—H5C109.5
N1—C4—H4B109.5C3—C2—N1107.6 (8)
H4A—C4—H4B109.5C3—C2—H2126.2
N1—C4—H4C109.5N1—C2—H2126.2
H4A—C4—H4C109.5
C3—N2—C1—N10.1 (8)C4—N1—C1—Br2.2 (11)
C5—N2—C1—N1178.0 (7)C1—N2—C3—C20.2 (9)
C3—N2—C1—Br179.2 (6)C5—N2—C3—C2177.9 (7)
C5—N2—C1—Br2.7 (11)N2—C3—C2—N10.2 (10)
C2—N1—C1—N20.0 (9)C1—N1—C2—C30.2 (9)
C4—N1—C1—N2177.1 (7)C4—N1—C2—C3177.0 (8)
C2—N1—C1—Br179.4 (6)
Symmetry code: (i) x+1, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C5—H5B···I1ii0.983.033.986 (8)166
Symmetry code: (ii) x+1/2, y+1/2, z+1/2.
 

Acknowledgements

We are grateful to H. Kopacka for the NMR spectra.

References

First citationAwwadi, F. F., Willett, R. D., Peterson, K. A. & Twamley, B. (2006). Chem. Eur. J. 12, 8952–8960.  Web of Science CrossRef PubMed CAS Google Scholar
First citationBoga, C., Del Vecchio, E., Forlani, L. & Todesco, P. E. (2000). J. Organomet. Chem. 601, 233–236.  Web of Science CrossRef CAS Google Scholar
First citationBruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBurla, M. C., Camalli, M., Carrozzini, B., Cascarano, G. L., Giacovazzo, C., Polidori, G. & Spagna, R. (2003). J. Appl. Cryst. 36, 1103.  CrossRef IUCr Journals Google Scholar
First citationClark, T., Hennemann, M., Murray, J. S. & Politzer, P. (2007). J. Mol. Model. 13, 291–296.  Web of Science CrossRef PubMed CAS Google Scholar
First citationEl Borai, M., Moustafa, A. H., Anwar, M. & Abdel Hay, F. I. (1981). Pol. J. Chem. 55, 1659–1665.  CAS Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationGroom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationHolbrey, J. D., Reichert, W. M., Swatloski, R. P., Broker, G. A., Pitner, W. R., Seddon, K. R. & Rogers, R. D. (2002). Green Chem. 4, 407–413.  Web of Science CSD CrossRef CAS Google Scholar
First citationKuhn, N., Abu-Rayyan, A., Eichele, K., Schwarz, S. & Steimann, M. (2004). Inorg. Chim. Acta, 357, 1799–1804.  Web of Science CSD CrossRef CAS Google Scholar
First citationKuhn, N., Kratz, T. & Henkel, G. (1993). J. Chem. Soc. Chem. Commun. pp. 1778–1779.  CSD CrossRef Web of Science Google Scholar
First citationLaus, G., Schwärzler, A., Schuster, P., Bentivoglio, G., Hummel, M., Wurst, K., Kahlenberg, V., Lörting, T., Schütz, J., Peringer, P., Bonn, G., Nauer, G. & Schottenberger, H. (2007). Z. Naturforsch. Teil B, 62, 295–308.  CAS Google Scholar
First citationLaus, G., Wurst, K., Kahlenberg, V. & Schottenberger, H. (2012). Z. Naturforsch. Teil B, 67, 354–358.  Web of Science CSD CrossRef CAS Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationOxford Diffraction (2014). CrysAlis PRO. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.  Google Scholar
First citationParsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249–259.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds