organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

1-Benzyl-3-methyl­imidazolium bromide

aLeibniz-Institut für Katalyse e. V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
*Correspondence e-mail: tim.peppel@catalysis.de

Edited by W. Imhof, University Koblenz-Landau, Germany (Received 27 May 2020; accepted 5 June 2020; online 9 June 2020)

The title compound, (BenzMIm)Br (BenzMIm=1-benzyl-3-methyl­imidazo­l­ium), C11H13N2+·Br, was obtained as single crystals directly from a pure and liquid sample of the compound over several weeks. The mol­ecular structure of (BenzMIm)Br consists of separated bromide anions and 1-benzyl-3-methyl­imidazolium cations connected via short C—H⋯Br contacts. The compound exhibits a relatively low melting point (m.p. = 72°C) and is a supercooled, highly viscous transparent liquid at ambient conditions. The title compound crystallizes with two unique ion pairs in the asymmetric unit of the orthorhombic unit cell.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

For the last 20 years, ionic liquids as salts with low melting points have attracted great inter­est because of their unique properties and applications. These properties include, for instance, large liquid ranges, broad electrochemical windows as well as low vapor pressures (Hallett & Welton, 2011[Hallett, J. P. & Welton, T. (2011). Chem. Rev. 111, 3508-3576.]; Welton, 1999[Welton, T. (1999). Chem. Rev. 99, 2071-2084.]). The title compound, which is a useful starting material in our ongoing efforts to investigate metal-containing ionic liquids (Peppel et al., 2010[Peppel, T., Köckerling, M., Geppert-Rybczyńska, M., Ralys, R. V., Lehmann, J. K., Verevkin, S. P. & Heintz, A. (2010). Angew. Chem. Int. Ed. 49, 7116-7119.]; Peppel et al., 2017[Peppel, T., Hinz, A., Thiele, P., Geppert-Rybczyńska, M., Lehmann, J. K. & Köckerling, M. (2017). Eur. J. Inorg. Chem. pp. 885-893.]; Peppel et al., 2019[Peppel, T., Geppert-Rybczyńska, M., Neise, C., Kragl, U. & Köckerling, M. (2019). Materials 12, 3764.]) was obtained as single crystals over a period of several weeks directly from its pure, highly viscous and supercooled liquid. 1-Benzyl-3-methyl­imidazolium bromide expands the range of known single-crystal X-ray structures of ionic liquids of the general formula (BenzMIm)X (X = Cl, PF6 (Ji et al., 2010[Ji, X., Cheng, B., Song, J. & Liu, C. (2010). Acta Cryst. E66, o218.]; Hillesheim & Scipione, 2014[Hillesheim, P. C. & Scipione, K. A. (2014). Acta Cryst. E70, o1248-o1249.]) with a third example (X = Br). It can be seen from Fig. 1[link] that the (BenzMIm)Br is characterized by discrete 1-benzyl-3-methyl­imidazolium cations and bromide anions. The shortest C—H⋯Br contacts equal 2.740 Å (sum of van der Waals radii for H and Br: 3.0 Å). All bond lengths and angles within the cation are in expected ranges (Leclercq et al., 2009[Leclercq, L., Simard, M. & Schmitzer, A. R. (2009). J. Mol. Struct. 918, 101-107.]). The two symmetry-independent mol­ecular units mainly differ by the angle between the phenyl and the imidazolium ring which is 84.02 (7)° in one of the cations and to 80.47 (7)° in the other. The title compound crystallizes with two unique ion pairs in the asymmetric unit of the orthorhombic unit cell.

[Figure 1]
Figure 1
Mol­ecular structure of the title compound. Displacement ellipsoids correspond to 30% probability.

Synthesis and crystallization

The title compound, (BenzMIm)Br, was obtained in high purity as a transparent, supercooled, highly viscous liquid in multi-gram scale from N-methyl­imidazole and benzyl bromide in ethyl acetate solution under ambient conditions. Benzyl bromide (15.0 g, 87.7 mmol) was added in one portion to a vigorously stirred solution of N-methyl­imidazole (5.0 g, 60.9 mmol) in 100 ml ethyl acetate at room temperature. The clear solution became turbid after a few minutes and was stirred at room temperature overnight. Afterwards, the product was washed several times with portions of ethyl acetate and dried in vacuo (T = 90°C, p = 20 mbar, yield: 13.1 g, 85%).

Analytic data for (BenzMIm)Br: m.p. 72°C, EA for C11H13BrN2 % (calc.): C 52.47 (52.19); H 4.93 (5.18); N 10.91 (11.07); Br 31.63 (31.56).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1[link].

Table 1
Experimental details

Crystal data
Chemical formula C11H13N2+·Br
Mr 253.14
Crystal system, space group Orthorhombic, Pbca
Temperature (K) 150
a, b, c (Å) 10.9070 (8), 18.8993 (14), 21.6608 (15)
V3) 4465.0 (6)
Z 16
Radiation type Mo Kα
μ (mm−1) 3.65
Crystal size (mm) 0.40 × 0.32 × 0.22
 
Data collection
Diffractometer Bruker APEXII CCD
Absorption correction Multi-scan (SADABS; Bruker, 2014[Bruker (2014). APEX2 and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.33, 0.51
No. of measured, independent and observed [I > 2σ(I)] reflections 51842, 5934, 5054
Rint 0.028
(sin θ/λ)max−1) 0.682
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.020, 0.051, 1.03
No. of reflections 5934
No. of parameters 255
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.32, −0.32
Computer programs: APEX2 (Bruker, 2014[Bruker (2014). APEX2 and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SAINT (Bruker, 2013[Bruker (2013). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2018/3 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), XP in SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Structural data


Computing details top

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2018/3 (Sheldrick, 2015); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

1-Benzyl-3-methylimidazolium bromide top
Crystal data top
C11H13N2+·BrDx = 1.506 Mg m3
Mr = 253.14Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PbcaCell parameters from 9498 reflections
a = 10.9070 (8) Åθ = 2.4–30.4°
b = 18.8993 (14) ŵ = 3.65 mm1
c = 21.6608 (15) ÅT = 150 K
V = 4465.0 (6) Å3Prism, colourless
Z = 160.40 × 0.32 × 0.22 mm
F(000) = 2048
Data collection top
Bruker APEXII CCD
diffractometer
5934 independent reflections
Radiation source: fine-focus sealed tube5054 reflections with I > 2σ(I)
Detector resolution: 8.3333 pixels mm-1Rint = 0.028
φ and ω scansθmax = 29.0°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Bruker, 2014)
h = 1414
Tmin = 0.33, Tmax = 0.51k = 2525
51842 measured reflectionsl = 2929
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.020H-atom parameters constrained
wR(F2) = 0.051 w = 1/[σ2(Fo2) + (0.0243P)2 + 1.6832P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max = 0.002
5934 reflectionsΔρmax = 0.32 e Å3
255 parametersΔρmin = 0.31 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.22716 (2)0.01486 (2)0.46713 (2)0.02635 (4)
Br20.78396 (2)0.20634 (2)0.71589 (2)0.02478 (4)
C10.17556 (12)0.07637 (7)0.67512 (6)0.0210 (3)
H10.2349510.0761700.7072030.025*
C20.10465 (12)0.13162 (7)0.65814 (6)0.0205 (3)
H20.1044660.1775290.6760070.025*
C30.05902 (12)0.04116 (7)0.59817 (6)0.0204 (3)
H30.0222300.0126620.5671540.024*
C40.19785 (14)0.05091 (8)0.63992 (7)0.0286 (3)
H4A0.1476990.0805640.6671210.043*
H4B0.2817130.0485220.6560220.043*
H4C0.1989860.0714060.5983630.043*
C50.05432 (12)0.15224 (7)0.57392 (6)0.0228 (3)
H5A0.1187760.1709490.6016530.027*
H5B0.0944220.1227860.5419700.027*
C60.01252 (12)0.21301 (7)0.54350 (6)0.0213 (3)
C70.00238 (14)0.28059 (8)0.56795 (7)0.0271 (3)
H70.0482380.2886200.6029460.033*
C80.06598 (14)0.33662 (8)0.54144 (8)0.0337 (3)
H80.0588580.3827790.5584350.040*
C90.13959 (14)0.32536 (9)0.49039 (8)0.0349 (4)
H90.1831550.3637150.4724310.042*
C100.14976 (13)0.25800 (9)0.46543 (7)0.0332 (3)
H100.1998320.2503300.4301710.040*
C110.08660 (13)0.20158 (8)0.49200 (6)0.0261 (3)
H110.0940210.1554160.4750520.031*
C120.86546 (12)0.13770 (8)0.92679 (6)0.0247 (3)
H120.8076870.1432300.9592540.030*
C130.93090 (12)0.07900 (8)0.91414 (6)0.0231 (3)
H130.9280980.0354090.9359400.028*
C140.98114 (12)0.16068 (7)0.84610 (6)0.0216 (3)
H141.0187340.1844420.8124050.026*
C150.84898 (15)0.26012 (8)0.87971 (7)0.0327 (3)
H15A0.9106580.2937940.8945240.049*
H15B0.7749220.2640140.9051020.049*
H15C0.8287300.2707630.8366210.049*
C161.08871 (12)0.04543 (7)0.83297 (6)0.0220 (3)
H16A1.1393460.0216780.8647450.026*
H16B1.1443450.0727020.8058110.026*
C171.02277 (12)0.01005 (7)0.79499 (6)0.0194 (3)
C180.94292 (12)0.00932 (7)0.74732 (6)0.0205 (3)
H180.9283000.0579370.7389510.025*
C190.88501 (12)0.04227 (8)0.71223 (6)0.0253 (3)
H190.8317070.0288680.6795700.030*
C200.90486 (14)0.11361 (8)0.72479 (7)0.0314 (3)
H200.8638940.1488640.7012930.038*
C210.98439 (15)0.13301 (8)0.77157 (7)0.0320 (3)
H210.9987340.1816660.7798950.038*
C221.04355 (13)0.08133 (7)0.80652 (7)0.0256 (3)
H221.0984280.0949630.8384390.031*
N10.14580 (10)0.02040 (6)0.63731 (5)0.0199 (2)
N20.03241 (10)0.10849 (6)0.60977 (5)0.0190 (2)
N30.89775 (10)0.18811 (6)0.88402 (5)0.0229 (2)
N41.00287 (10)0.09437 (6)0.86338 (5)0.0196 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.02669 (8)0.02857 (8)0.02379 (7)0.00178 (6)0.00049 (5)0.00815 (5)
Br20.02648 (7)0.02405 (7)0.02380 (7)0.00402 (6)0.00081 (5)0.00084 (5)
C10.0192 (6)0.0264 (7)0.0175 (6)0.0047 (5)0.0002 (5)0.0005 (5)
C20.0216 (6)0.0225 (7)0.0175 (6)0.0051 (5)0.0006 (5)0.0012 (5)
C30.0212 (6)0.0213 (7)0.0186 (6)0.0025 (5)0.0009 (5)0.0004 (5)
C40.0297 (7)0.0229 (7)0.0331 (7)0.0038 (6)0.0004 (6)0.0018 (6)
C50.0206 (6)0.0235 (7)0.0243 (6)0.0001 (5)0.0023 (5)0.0022 (5)
C60.0197 (6)0.0223 (7)0.0221 (6)0.0010 (5)0.0044 (5)0.0034 (5)
C70.0272 (7)0.0255 (7)0.0286 (7)0.0018 (6)0.0040 (6)0.0005 (6)
C80.0321 (8)0.0213 (7)0.0477 (9)0.0010 (6)0.0119 (7)0.0043 (7)
C90.0231 (7)0.0342 (9)0.0473 (9)0.0041 (6)0.0090 (6)0.0203 (7)
C100.0211 (7)0.0478 (10)0.0307 (7)0.0035 (6)0.0009 (6)0.0150 (7)
C110.0237 (7)0.0298 (8)0.0246 (6)0.0051 (6)0.0013 (5)0.0022 (6)
C120.0204 (6)0.0349 (8)0.0190 (6)0.0056 (6)0.0010 (5)0.0042 (5)
C130.0241 (7)0.0272 (7)0.0179 (6)0.0067 (6)0.0010 (5)0.0009 (5)
C140.0229 (6)0.0222 (7)0.0197 (6)0.0023 (5)0.0010 (5)0.0004 (5)
C150.0351 (8)0.0265 (8)0.0365 (8)0.0071 (7)0.0044 (6)0.0079 (6)
C160.0194 (6)0.0239 (7)0.0227 (6)0.0021 (5)0.0003 (5)0.0008 (5)
C170.0176 (6)0.0203 (6)0.0203 (6)0.0003 (5)0.0042 (5)0.0007 (5)
C180.0184 (6)0.0212 (6)0.0218 (6)0.0016 (5)0.0036 (5)0.0026 (5)
C190.0198 (6)0.0322 (8)0.0240 (6)0.0006 (6)0.0008 (5)0.0007 (6)
C200.0319 (8)0.0272 (8)0.0350 (8)0.0043 (6)0.0039 (6)0.0095 (6)
C210.0377 (8)0.0179 (7)0.0404 (8)0.0030 (6)0.0052 (7)0.0011 (6)
C220.0267 (7)0.0230 (7)0.0273 (6)0.0038 (6)0.0013 (6)0.0056 (5)
N10.0195 (5)0.0213 (6)0.0189 (5)0.0012 (4)0.0014 (4)0.0008 (4)
N20.0191 (5)0.0202 (6)0.0176 (5)0.0021 (4)0.0005 (4)0.0004 (4)
N30.0212 (5)0.0249 (6)0.0226 (5)0.0005 (5)0.0004 (4)0.0050 (5)
N40.0195 (5)0.0216 (6)0.0178 (5)0.0015 (4)0.0004 (4)0.0007 (4)
Geometric parameters (Å, º) top
C1—C21.3504 (19)C12—C131.347 (2)
C1—N11.3767 (17)C12—N31.3747 (18)
C1—H10.9500C12—H120.9500
C2—N21.3820 (16)C13—N41.3819 (16)
C2—H20.9500C13—H130.9500
C3—N21.3291 (17)C14—N41.3293 (17)
C3—N11.3298 (16)C14—N31.3307 (17)
C3—H30.9500C14—H140.9500
C4—N11.4636 (18)C15—N31.4643 (19)
C4—H4A0.9800C15—H15A0.9800
C4—H4B0.9800C15—H15B0.9800
C4—H4C0.9800C15—H15C0.9800
C5—N21.4771 (17)C16—N41.4717 (17)
C5—C61.5115 (19)C16—C171.5144 (18)
C5—H5A0.9900C16—H16A0.9900
C5—H5B0.9900C16—H16B0.9900
C6—C71.3871 (19)C17—C221.3887 (19)
C6—C111.3943 (19)C17—C181.3995 (18)
C7—C81.390 (2)C18—C191.388 (2)
C7—H70.9500C18—H180.9500
C8—C91.383 (2)C19—C201.392 (2)
C8—H80.9500C19—H190.9500
C9—C101.388 (2)C20—C211.383 (2)
C9—H90.9500C20—H200.9500
C10—C111.394 (2)C21—C221.394 (2)
C10—H100.9500C21—H210.9500
C11—H110.9500C22—H220.9500
C2—C1—N1107.28 (11)N4—C14—N3108.38 (12)
C2—C1—H1126.4N4—C14—H14125.8
N1—C1—H1126.4N3—C14—H14125.8
C1—C2—N2106.76 (12)N3—C15—H15A109.5
C1—C2—H2126.6N3—C15—H15B109.5
N2—C2—H2126.6H15A—C15—H15B109.5
N2—C3—N1108.50 (11)N3—C15—H15C109.5
N2—C3—H3125.7H15A—C15—H15C109.5
N1—C3—H3125.7H15B—C15—H15C109.5
N1—C4—H4A109.5N4—C16—C17112.10 (10)
N1—C4—H4B109.5N4—C16—H16A109.2
H4A—C4—H4B109.5C17—C16—H16A109.2
N1—C4—H4C109.5N4—C16—H16B109.2
H4A—C4—H4C109.5C17—C16—H16B109.2
H4B—C4—H4C109.5H16A—C16—H16B107.9
N2—C5—C6110.22 (11)C22—C17—C18119.21 (13)
N2—C5—H5A109.6C22—C17—C16119.76 (12)
C6—C5—H5A109.6C18—C17—C16121.01 (12)
N2—C5—H5B109.6C19—C18—C17120.22 (13)
C6—C5—H5B109.6C19—C18—H18119.9
H5A—C5—H5B108.1C17—C18—H18119.9
C7—C6—C11119.62 (13)C18—C19—C20120.15 (13)
C7—C6—C5119.66 (12)C18—C19—H19119.9
C11—C6—C5120.70 (13)C20—C19—H19119.9
C6—C7—C8120.26 (14)C21—C20—C19119.82 (14)
C6—C7—H7119.9C21—C20—H20120.1
C8—C7—H7119.9C19—C20—H20120.1
C9—C8—C7120.18 (15)C20—C21—C22120.15 (14)
C9—C8—H8119.9C20—C21—H21119.9
C7—C8—H8119.9C22—C21—H21119.9
C8—C9—C10119.95 (14)C17—C22—C21120.42 (13)
C8—C9—H9120.0C17—C22—H22119.8
C10—C9—H9120.0C21—C22—H22119.8
C9—C10—C11120.09 (14)C3—N1—C1108.69 (11)
C9—C10—H10120.0C3—N1—C4124.92 (12)
C11—C10—H10120.0C1—N1—C4126.38 (11)
C10—C11—C6119.89 (14)C3—N2—C2108.76 (11)
C10—C11—H11120.1C3—N2—C5125.20 (11)
C6—C11—H11120.1C2—N2—C5125.92 (11)
C13—C12—N3107.33 (12)C14—N3—C12108.73 (12)
C13—C12—H12126.3C14—N3—C15124.82 (12)
N3—C12—H12126.3C12—N3—C15126.45 (12)
C12—C13—N4106.84 (12)C14—N4—C13108.72 (11)
C12—C13—H13126.6C14—N4—C16125.44 (11)
N4—C13—H13126.6C13—N4—C16125.83 (12)
N1—C1—C2—N20.17 (14)C20—C21—C22—C170.4 (2)
N2—C5—C6—C7103.83 (14)N2—C3—N1—C10.01 (14)
N2—C5—C6—C1174.65 (15)N2—C3—N1—C4178.70 (12)
C11—C6—C7—C80.2 (2)C2—C1—N1—C30.12 (14)
C5—C6—C7—C8178.27 (13)C2—C1—N1—C4178.57 (12)
C6—C7—C8—C90.2 (2)N1—C3—N2—C20.10 (14)
C7—C8—C9—C100.2 (2)N1—C3—N2—C5176.21 (11)
C8—C9—C10—C110.5 (2)C1—C2—N2—C30.17 (14)
C9—C10—C11—C60.4 (2)C1—C2—N2—C5176.11 (12)
C7—C6—C11—C100.1 (2)C6—C5—N2—C3116.36 (14)
C5—C6—C11—C10178.54 (12)C6—C5—N2—C259.32 (16)
N3—C12—C13—N40.04 (15)N4—C14—N3—C120.03 (15)
N4—C16—C17—C22123.69 (13)N4—C14—N3—C15179.51 (12)
N4—C16—C17—C1857.74 (16)C13—C12—N3—C140.01 (15)
C22—C17—C18—C190.23 (19)C13—C12—N3—C15179.54 (13)
C16—C17—C18—C19178.81 (12)N3—C14—N4—C130.05 (14)
C17—C18—C19—C200.8 (2)N3—C14—N4—C16179.45 (11)
C18—C19—C20—C211.3 (2)C12—C13—N4—C140.06 (15)
C19—C20—C21—C220.7 (2)C12—C13—N4—C16179.44 (12)
C18—C17—C22—C210.8 (2)C17—C16—N4—C14105.12 (14)
C16—C17—C22—C21179.41 (13)C17—C16—N4—C1374.30 (15)
 

Acknowledgements

The publication of this article was funded by the Open Access Fund of the Leibniz Association.

References

First citationBruker (2013). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2014). APEX2 and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationHallett, J. P. & Welton, T. (2011). Chem. Rev. 111, 3508–3576.  Web of Science CrossRef CAS PubMed Google Scholar
First citationHillesheim, P. C. & Scipione, K. A. (2014). Acta Cryst. E70, o1248–o1249.  CSD CrossRef IUCr Journals Google Scholar
First citationJi, X., Cheng, B., Song, J. & Liu, C. (2010). Acta Cryst. E66, o218.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationLeclercq, L., Simard, M. & Schmitzer, A. R. (2009). J. Mol. Struct. 918, 101–107.  Web of Science CSD CrossRef CAS Google Scholar
First citationPeppel, T., Geppert-Rybczyńska, M., Neise, C., Kragl, U. & Köckerling, M. (2019). Materials 12, 3764.  Web of Science CrossRef Google Scholar
First citationPeppel, T., Hinz, A., Thiele, P., Geppert-Rybczyńska, M., Lehmann, J. K. & Köckerling, M. (2017). Eur. J. Inorg. Chem. pp. 885–893.  Web of Science CSD CrossRef Google Scholar
First citationPeppel, T., Köckerling, M., Geppert-Rybczyńska, M., Ralys, R. V., Lehmann, J. K., Verevkin, S. P. & Heintz, A. (2010). Angew. Chem. Int. Ed. 49, 7116–7119.  Web of Science CSD CrossRef CAS 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
First citationWelton, T. (1999). Chem. Rev. 99, 2071–2084.  Web of Science CrossRef PubMed CAS Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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