PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2008 July 1; 64(Pt 7): m954.
Published online 2008 June 21. doi:  10.1107/S1600536808015936
PMCID: PMC2961847

Tetra­kis(1-ethyl-3-methyl­imidazolium) β-hexa­cosa­oxidoocta­molybdate

Abstract

The title compound, (C6H11N2)4[Mo8O26] or (emim)4[β-Mo8O26] (emim is 1-ethyl-3-methyl­imidazolium), was obtained from the ionic liquid [emim]BF4. The asymmetric unit contains two [emim]+ cations and one-half of the [β-Mo8O26]4− tetra­anion, which occupies a special position on an inversion centre. The β-[Mo8O26]4− tetra­anion features eight distorted MoO6 coordination octa­hedra linked together through bridging O atoms.

Related literature

For related literature, see: Aguado et al. (2005 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-64-0m954-scheme1.jpg

Experimental

Crystal data

  • (C6H11N2)4[Mo8O26]
  • M r = 1628.19
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-64-0m954-efi1.jpg
  • a = 15.6338 (6) Å
  • b = 16.9231 (6) Å
  • c = 17.9380 (7) Å
  • V = 4745.9 (3) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 2.13 mm−1
  • T = 296 (2) K
  • 0.24 × 0.22 × 0.21 mm

Data collection

  • Bruker APEX CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.629, T max = 0.663
  • 27619 measured reflections
  • 5677 independent reflections
  • 4568 reflections with I > 2σ(I)
  • R int = 0.027

Refinement

  • R[F 2 > 2σ(F 2)] = 0.026
  • wR(F 2) = 0.070
  • S = 1.04
  • 5677 reflections
  • 298 parameters
  • H-atom parameters constrained
  • Δρmax = 0.66 e Å−3
  • Δρmin = −0.61 e Å−3

Data collection: SMART (Bruker, 1997 [triangle]); cell refinement: SAINT (Bruker, 1999 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL-Plus (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808015936/ya2072sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808015936/ya2072Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

This work was supported by the Postdoctoral Station Foundation of the Ministry of Education of China (No. 20060200002) and the Testing Foundation of Northeast Normal University.

supplementary crystallographic information

Comment

The asymmetric unit of the title compound, [emim]4[β-Mo8O26] (emim = 1-ethyl-3-methylimidazolium), (1), contains two [emim]+ cations and one half of the [β-Mo8O26]4- anion, which occupies a special position in the inversion centre (Fig. 1). The anion has eight molybdenum atoms with distorted octahedral coordinations and 26 oxygen atoms which fall into four categories, i.e. terminal, µ2–, µ3 - and µ5-bridging atoms. The geometry of tetra-anion is characterized by a wide range of Mo—O distances varying from 1.683 (2) Å for one of the terminal bonds (Mo1—O5) to 2.510 (2) Å for one of the bonds involving 5-coordinated oxygen atom (Mo4—O1). The geometry of the anion is similar to that observed in previous structures, e.g. Aguado et al. (2005).

Experimental

A mixture of sodium molydbate, Na2MoO4.2H2O (0.3 mmol), and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate, [emim]BF4 (8 ml) was stirred at 170 °C for 24 h in air. The resulting clear solution was filtered and left at room temperature for 3 days. The colourless block crystals were filtered off, washed with cool distilled water and dried in a desiccator at room temperature.

Refinement

All H-atoms were included in the refinement in a riding model approximation with Uiso=1.2Ueq (C) for aromatic (C—H 0.93 Å) and methylene (C—H 0.97 Å) H-atoms, Uiso = 1.5Ueq (C) for methyl H-atoms (C—H 0.96 Å).

Figures

Fig. 1.
The cations and anion in the structure of the title compound. Thermal displacement ellipsoids are drawn at 30% probability level; H atoms are shown as small circles of arbitrary radius. The unlabeled atoms are related to their symmetry related counterparts ...

Crystal data

(C6H11N2)4[Mo8O26]F000 = 3152
Mr = 1628.19Dx = 2.279 Mg m3
Orthorhombic, PbcaMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 27619 reflections
a = 15.6338 (6) Åθ = 2.1–28.3º
b = 16.9231 (6) ŵ = 2.13 mm1
c = 17.9380 (7) ÅT = 296 (2) K
V = 4745.9 (3) Å3Block, colourless
Z = 40.24 × 0.22 × 0.21 mm

Data collection

Bruker APEX CCD area-detector diffractometer5677 independent reflections
Radiation source: fine-focus sealed tube4568 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.027
Detector resolution: 0.01 pixels mm-1θmax = 28.3º
T = 296(2) Kθmin = 2.1º
ω scansh = −20→14
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)k = −22→22
Tmin = 0.629, Tmax = 0.663l = −20→23
27619 measured reflections

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.026H-atom parameters constrained
wR(F2) = 0.070  w = 1/[σ2(Fo2) + (0.0327P)2 + 3.2572P] where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max = 0.002
5677 reflectionsΔρmax = 0.66 e Å3
298 parametersΔρmin = −0.61 e Å3
Primary atom site location: structure-invariant direct methodsExtinction correction: none

Special details

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)

xyzUiso*/Ueq
Mo10.919942 (16)0.001136 (16)0.429035 (13)0.03331 (7)
Mo21.078576 (18)−0.118127 (18)0.408995 (16)0.04219 (8)
Mo31.048047 (18)0.149211 (16)0.436802 (15)0.03908 (8)
Mo41.212312 (18)0.030332 (19)0.417154 (16)0.04370 (8)
O11.05538 (13)0.01203 (12)0.44123 (11)0.0345 (4)
O20.95510 (13)−0.10911 (12)0.43767 (11)0.0385 (5)
O30.93026 (12)0.11030 (12)0.46027 (12)0.0372 (5)
O40.81442 (14)−0.01285 (13)0.45821 (12)0.0436 (5)
O50.91133 (15)0.01019 (14)0.33592 (12)0.0490 (6)
O61.19117 (14)−0.08062 (14)0.42354 (12)0.0456 (5)
O71.16753 (14)0.13133 (13)0.44644 (13)0.0470 (5)
O81.03691 (16)0.15263 (15)0.34304 (13)0.0546 (6)
O91.04161 (16)0.24423 (14)0.46552 (15)0.0579 (6)
O101.20274 (17)0.04091 (16)0.32313 (14)0.0617 (7)
O111.31854 (16)0.03784 (17)0.43493 (15)0.0641 (7)
O121.06442 (16)−0.10397 (17)0.31615 (14)0.0631 (7)
O131.09196 (18)−0.21648 (16)0.41944 (16)0.0644 (7)
N11.5874 (2)0.0109 (2)0.35763 (17)0.0562 (8)
N21.2156 (2)0.28339 (19)0.6125 (2)0.0619 (8)
N31.48859 (19)0.09691 (18)0.33891 (15)0.0513 (7)
N41.1552 (2)0.23736 (18)0.71109 (19)0.0599 (8)
C11.5344 (2)0.0403 (2)0.3079 (2)0.0551 (9)
H1A1.52990.02370.25870.066*
C21.5147 (3)0.1051 (3)0.4115 (2)0.0647 (11)
H2A1.49410.14130.44610.078*
C31.4202 (3)0.1411 (3)0.3036 (2)0.0635 (11)
H3A1.41510.12510.25250.095*
H3B1.43300.19660.30580.095*
H3C1.36740.13100.32920.095*
C41.5752 (3)0.0513 (3)0.4230 (2)0.0702 (12)
H4A1.60420.04270.46750.084*
C51.6476 (3)−0.0559 (3)0.3444 (2)0.0754 (13)
H5A1.6575−0.06140.29130.091*
H5B1.7020−0.04430.36800.091*
C61.1661 (2)0.2273 (2)0.6388 (2)0.0596 (10)
H6A1.14230.18660.61070.072*
C71.1062 (3)0.1867 (2)0.7611 (2)0.0708 (11)
H7A1.07020.21940.79250.085*
H7B1.06930.15280.73180.085*
C81.2360 (3)0.3315 (3)0.6708 (3)0.0759 (13)
H8A1.26980.37660.66810.091*
C91.2417 (3)0.2920 (3)0.5351 (3)0.0872 (15)
H9A1.21830.24940.50620.131*
H9B1.30300.29090.53200.131*
H9C1.22100.34140.51600.131*
C101.1999 (3)0.3033 (3)0.7313 (3)0.0806 (14)
H10A1.20410.32430.77900.097*
C111.6139 (4)−0.1312 (3)0.3742 (4)0.115 (2)
H11A1.6539−0.17290.36400.172*
H11B1.5602−0.14300.35080.172*
H11C1.6059−0.12650.42700.172*
C121.1603 (4)0.1381 (4)0.8080 (3)0.118 (2)
H12A1.12520.10540.83920.177*
H12B1.19550.17140.83850.177*
H12C1.19590.10540.77720.177*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Mo10.03345 (14)0.03938 (14)0.02710 (13)−0.00539 (11)−0.00506 (9)−0.00023 (10)
Mo20.04347 (17)0.04620 (16)0.03690 (15)−0.00116 (13)0.00226 (11)−0.00868 (12)
Mo30.04015 (16)0.03777 (14)0.03932 (15)−0.00623 (12)−0.00155 (11)0.00535 (11)
Mo40.03562 (15)0.05413 (18)0.04136 (16)−0.00311 (13)0.00151 (11)0.00798 (13)
O10.0351 (11)0.0394 (11)0.0289 (10)−0.0030 (9)−0.0017 (8)0.0008 (8)
O20.0416 (12)0.0382 (11)0.0357 (11)−0.0072 (9)−0.0048 (9)−0.0064 (9)
O30.0364 (11)0.0367 (11)0.0385 (12)0.0003 (9)−0.0014 (9)0.0001 (9)
O40.0362 (12)0.0553 (13)0.0392 (12)−0.0066 (10)−0.0057 (9)0.0017 (10)
O50.0548 (14)0.0600 (15)0.0322 (12)−0.0031 (11)−0.0100 (10)0.0004 (10)
O60.0393 (12)0.0519 (13)0.0456 (13)0.0050 (11)0.0061 (9)0.0019 (10)
O70.0383 (12)0.0488 (13)0.0540 (14)−0.0123 (10)−0.0017 (10)0.0065 (11)
O80.0538 (15)0.0651 (16)0.0450 (14)−0.0102 (12)−0.0027 (11)0.0139 (12)
O90.0633 (16)0.0413 (13)0.0689 (17)−0.0040 (12)−0.0009 (13)−0.0003 (12)
O100.0706 (18)0.0699 (17)0.0446 (14)0.0031 (14)0.0051 (12)0.0117 (12)
O110.0398 (14)0.083 (2)0.0689 (17)−0.0065 (13)0.0012 (12)0.0155 (14)
O120.0624 (17)0.089 (2)0.0376 (13)−0.0027 (14)0.0031 (11)−0.0157 (13)
O130.0703 (18)0.0481 (15)0.0748 (19)0.0002 (13)0.0033 (14)−0.0174 (13)
N10.0514 (18)0.072 (2)0.0457 (17)−0.0034 (15)−0.0109 (14)−0.0023 (15)
N20.0543 (19)0.0583 (19)0.073 (2)−0.0168 (16)−0.0121 (16)0.0017 (17)
N30.0540 (18)0.0637 (18)0.0363 (15)−0.0049 (15)0.0002 (13)−0.0049 (14)
N40.0528 (18)0.0563 (18)0.070 (2)−0.0094 (15)−0.0104 (16)−0.0100 (16)
C10.055 (2)0.072 (2)0.0383 (18)0.0020 (19)−0.0073 (16)−0.0061 (17)
C20.069 (3)0.085 (3)0.041 (2)−0.002 (2)0.0005 (18)−0.013 (2)
C30.063 (3)0.078 (3)0.049 (2)0.016 (2)0.0034 (18)−0.004 (2)
C40.077 (3)0.098 (4)0.036 (2)−0.010 (3)−0.0116 (18)−0.004 (2)
C50.064 (3)0.097 (3)0.065 (3)0.016 (3)−0.024 (2)−0.011 (2)
C60.061 (2)0.055 (2)0.064 (2)−0.0145 (19)−0.0155 (19)−0.0003 (19)
C70.063 (3)0.073 (3)0.076 (3)−0.004 (2)−0.004 (2)−0.004 (2)
C80.069 (3)0.058 (2)0.100 (4)−0.023 (2)−0.006 (3)−0.017 (2)
C90.088 (3)0.097 (4)0.077 (3)−0.038 (3)−0.011 (3)0.015 (3)
C100.076 (3)0.079 (3)0.087 (3)−0.017 (2)−0.003 (3)−0.033 (3)
C110.124 (5)0.087 (4)0.134 (5)0.016 (4)−0.007 (4)0.019 (4)
C120.099 (4)0.143 (5)0.112 (5)0.022 (4)−0.008 (4)0.047 (4)

Geometric parameters (Å, °)

Mo1—O51.683 (2)N2—C81.363 (5)
Mo1—O41.747 (2)N2—C91.454 (6)
Mo1—O31.937 (2)N3—C11.319 (5)
Mo1—O21.951 (2)N3—C21.372 (4)
Mo1—O12.137 (2)N3—C31.451 (5)
Mo1—O1i2.370 (2)N4—C61.319 (5)
Mo1—Mo33.2109 (4)N4—C101.366 (5)
Mo1—Mo23.2177 (4)N4—C71.458 (5)
Mo2—O131.688 (3)C1—H1A0.9300
Mo2—O121.697 (3)C2—C41.328 (6)
Mo2—O61.889 (2)C2—H2A0.9300
Mo2—O22.004 (2)C3—H3A0.9600
Mo2—O12.306 (2)C3—H3B0.9600
Mo2—O3i2.353 (2)C3—H3C0.9600
Mo3—O91.692 (2)C4—H4A0.9300
Mo3—O81.692 (2)C5—C111.478 (7)
Mo3—O71.900 (2)C5—H5A0.9700
Mo3—O32.000 (2)C5—H5B0.9700
Mo3—O12.326 (2)C6—H6A0.9300
Mo3—O2i2.352 (2)C7—C121.448 (6)
Mo4—O111.696 (3)C7—H7A0.9700
Mo4—O101.703 (2)C7—H7B0.9700
Mo4—O61.910 (2)C8—C101.313 (6)
Mo4—O71.920 (2)C8—H8A0.9300
Mo4—O4i2.294 (2)C9—H9A0.9600
Mo4—O12.510 (2)C9—H9B0.9600
O1—Mo1i2.370 (2)C9—H9C0.9600
O2—Mo3i2.352 (2)C10—H10A0.9300
O3—Mo2i2.353 (2)C11—H11A0.9600
O4—Mo4i2.294 (2)C11—H11B0.9600
N1—C11.315 (4)C11—H11C0.9600
N1—C41.371 (5)C12—H12A0.9600
N1—C51.490 (5)C12—H12B0.9600
N2—C61.313 (5)C12—H12C0.9600
O5—Mo1—O4103.54 (11)Mo1—O1—Mo292.74 (7)
O5—Mo1—O3101.94 (10)Mo1—O1—Mo391.94 (8)
O4—Mo1—O396.96 (9)Mo2—O1—Mo3162.30 (10)
O5—Mo1—O2100.86 (10)Mo1—O1—Mo1i104.70 (8)
O4—Mo1—O296.47 (10)Mo2—O1—Mo1i97.52 (7)
O3—Mo1—O2149.93 (8)Mo3—O1—Mo1i97.78 (7)
O5—Mo1—O199.96 (10)Mo1—O1—Mo4164.07 (10)
O4—Mo1—O1156.48 (9)Mo2—O1—Mo485.47 (7)
O3—Mo1—O178.79 (8)Mo3—O1—Mo485.36 (6)
O2—Mo1—O178.18 (8)Mo1i—O1—Mo491.23 (7)
O5—Mo1—O1i175.21 (10)Mo1—O2—Mo2108.90 (10)
O4—Mo1—O1i81.19 (8)Mo1—O2—Mo3i110.24 (9)
O3—Mo1—O1i78.00 (8)Mo2—O2—Mo3i104.12 (9)
O2—Mo1—O1i77.66 (8)Mo1—O3—Mo3109.25 (10)
O1—Mo1—O1i75.30 (8)Mo1—O3—Mo2i109.70 (9)
O5—Mo1—Mo391.25 (8)Mo3—O3—Mo2i104.20 (9)
O4—Mo1—Mo3132.98 (7)Mo1—O4—Mo4i118.79 (10)
O3—Mo1—Mo336.03 (6)Mo2—O6—Mo4118.90 (12)
O2—Mo1—Mo3124.55 (6)Mo3—O7—Mo4118.38 (11)
O1—Mo1—Mo346.38 (5)C1—N1—C4107.6 (4)
O1i—Mo1—Mo385.94 (5)C1—N1—C5125.2 (3)
O5—Mo1—Mo290.45 (8)C4—N1—C5127.1 (3)
O4—Mo1—Mo2132.56 (7)C6—N2—C8107.1 (4)
O3—Mo1—Mo2124.49 (6)C6—N2—C9125.5 (3)
O2—Mo1—Mo236.09 (6)C8—N2—C9127.4 (4)
O1—Mo1—Mo245.71 (5)C1—N3—C2108.1 (3)
O1i—Mo1—Mo285.71 (5)C1—N3—C3126.2 (3)
Mo3—Mo1—Mo290.780 (10)C2—N3—C3125.6 (3)
O13—Mo2—O12105.32 (14)C6—N4—C10107.5 (4)
O13—Mo2—O6101.56 (12)C6—N4—C7126.6 (3)
O12—Mo2—O6102.10 (11)C10—N4—C7125.9 (4)
O13—Mo2—O299.56 (11)N1—C1—N3109.4 (3)
O12—Mo2—O296.63 (10)N1—C1—H1A125.3
O6—Mo2—O2146.78 (9)N3—C1—H1A125.3
O13—Mo2—O1159.00 (11)C4—C2—N3106.9 (4)
O12—Mo2—O195.20 (11)C4—C2—H2A126.6
O6—Mo2—O177.94 (9)N3—C2—H2A126.6
O2—Mo2—O173.22 (8)N3—C3—H3A109.5
O13—Mo2—O3i87.26 (11)N3—C3—H3B109.5
O12—Mo2—O3i164.26 (11)H3A—C3—H3B109.5
O6—Mo2—O3i84.15 (8)N3—C3—H3C109.5
O2—Mo2—O3i71.54 (7)H3A—C3—H3C109.5
O1—Mo2—O3i71.77 (7)H3B—C3—H3C109.5
O13—Mo2—Mo1134.56 (10)C2—C4—N1108.0 (3)
O12—Mo2—Mo185.45 (9)C2—C4—H4A126.0
O6—Mo2—Mo1119.47 (7)N1—C4—H4A126.0
O2—Mo2—Mo135.01 (6)C11—C5—N1111.8 (4)
O1—Mo2—Mo141.55 (5)C11—C5—H5A109.3
O3i—Mo2—Mo178.94 (5)N1—C5—H5A109.3
O9—Mo3—O8105.31 (13)C11—C5—H5B109.3
O9—Mo3—O7100.50 (11)N1—C5—H5B109.3
O8—Mo3—O7101.36 (11)H5A—C5—H5B107.9
O9—Mo3—O3101.19 (11)N2—C6—N4109.6 (3)
O8—Mo3—O397.23 (10)N2—C6—H6A125.2
O7—Mo3—O3146.45 (9)N4—C6—H6A125.2
O9—Mo3—O1160.30 (10)C12—C7—N4112.6 (4)
O8—Mo3—O194.20 (10)C12—C7—H7A109.1
O7—Mo3—O177.85 (8)N4—C7—H7A109.1
O3—Mo3—O173.12 (8)C12—C7—H7B109.1
O9—Mo3—O2i88.94 (10)N4—C7—H7B109.1
O8—Mo3—O2i163.60 (10)H7A—C7—H7B107.8
O7—Mo3—O2i83.54 (9)C10—C8—N2108.5 (4)
O3—Mo3—O2i71.60 (8)C10—C8—H8A125.8
O1—Mo3—O2i71.36 (7)N2—C8—H8A125.8
O9—Mo3—Mo1135.89 (9)N2—C9—H9A109.5
O8—Mo3—Mo185.38 (8)N2—C9—H9B109.5
O7—Mo3—Mo1119.53 (7)H9A—C9—H9B109.5
O3—Mo3—Mo134.72 (6)N2—C9—H9C109.5
O1—Mo3—Mo141.69 (5)H9A—C9—H9C109.5
O2i—Mo3—Mo178.66 (5)H9B—C9—H9C109.5
O11—Mo4—O10105.33 (13)C8—C10—N4107.3 (4)
O11—Mo4—O6103.41 (12)C8—C10—H10A126.3
O10—Mo4—O698.49 (11)N4—C10—H10A126.3
O11—Mo4—O7103.82 (12)C5—C11—H11A109.5
O10—Mo4—O798.36 (11)C5—C11—H11B109.5
O6—Mo4—O7142.70 (9)H11A—C11—H11B109.5
O11—Mo4—O4i90.28 (10)C5—C11—H11C109.5
O10—Mo4—O4i164.39 (11)H11A—C11—H11C109.5
O6—Mo4—O4i77.48 (8)H11B—C11—H11C109.5
O7—Mo4—O4i77.39 (9)C7—C12—H12A109.5
O11—Mo4—O1159.07 (10)C7—C12—H12B109.5
O10—Mo4—O195.59 (10)H12A—C12—H12B109.5
O6—Mo4—O172.50 (8)C7—C12—H12C109.5
O7—Mo4—O172.93 (8)H12A—C12—H12C109.5
O4i—Mo4—O168.80 (7)H12B—C12—H12C109.5

Symmetry codes: (i) −x+2, −y, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: YA2072).

References

  • Aguado, R., Pedrosa, M. R. & Arnáiz, F. J. (2005). Z. Anorg. Allg. Chem.631, 1995–1999.
  • Bruker (1997). SMART Bruker AXS Inc., Madison, Wisconsin, USA.
  • Bruker (1999). SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Sheldrick, G. M. (1996). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography