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 June 1; 64(Pt 6): o1049.
Published online 2008 May 10. doi:  10.1107/S1600536808012324
PMCID: PMC2961437

5,7-Bis(1-benzothio­phen-2-yl)-2,3-dihydro­thieno[3,4-b][1,4]dioxine

Abstract

In the title compound, C22H14O2S3, the dioxane ring is disordered over two sites [site occupancies = 0.623 (3) and 0.377 (3)]; both components adopt half-chair conformations. The two benzothio­phene ring systems are asymmetrically twisted away from the attached thio­phene ring [dihedral angles = 20.57 (3) and 6.70 (3)°] and are oriented at an angle of 26.83 (3)°. No significant hydrogen bonding or π–π inter­actions are observed in the crystal structure.

Related literature

For related literature, see: Cohen et al. (1977 [triangle]); Csaszar & Morvay (1983 [triangle]); Dzhurayev et al. (1992 [triangle]); EI-Maghraby et al. (1984 [triangle]); Gewald et al. (1996 [triangle]); Lakshmi et al. (1985 [triangle]); Pellis & West (1968 [triangle]). For the synthesis, see: Amaladass et al. (2007 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-64-o1049-scheme1.jpg

Experimental

Crystal data

  • C22H14O2S3
  • M r = 406.51
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-o1049-efi1.jpg
  • a = 16.1602 (5) Å
  • b = 8.3524 (3) Å
  • c = 14.1814 (4) Å
  • β = 107.428 (2)°
  • V = 1826.28 (10) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.42 mm−1
  • T = 293 (2) K
  • 0.15 × 0.13 × 0.10 mm

Data collection

  • Bruker Kappa APEXII area-detector diffractometer
  • Absorption correction: none
  • 26571 measured reflections
  • 7059 independent reflections
  • 4551 reflections with I > 2σ(I)
  • R int = 0.028

Refinement

  • R[F 2 > 2σ(F 2)] = 0.044
  • wR(F 2) = 0.142
  • S = 0.99
  • 7059 reflections
  • 251 parameters
  • 3 restraints
  • H-atom parameters constrained
  • Δρmax = 0.61 e Å−3
  • Δρmin = −0.43 e Å−3

Data collection: APEX2 (Bruker, 2004 [triangle]); cell refinement: APEX2; data reduction: SAINT (Bruker, 2004 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: PLATON (Spek, 2003 [triangle]); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995 [triangle]).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808012324/ci2577sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808012324/ci2577Isup2.hkl

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

Acknowledgments

PS and SR thank Mr P. Charles for his help in solving the structure.

supplementary crystallographic information

Comment

Sulfur containing Schiff bases (Pellis & West, 1968; Cohen et al., 1977; Csaszar & Morvay,1983; Lakshmi et al., 1985) and their thiophen derivatives (EI-Maghraby et al., 1984; Dzhurayev et al., 1992) possess pharmacological activities such as anti-bacterial, anti-cancer, anti-inflammatory and anti-toxic properties (Gewald et al., 1996). Benzo[b]thiophene analogs have been shown to possess interesting estrogenic and antiestrogenic effects. We report here the crystal structure of the title compound.

The C1—C8/S3 and C15—C22/S2 benzothiophene ring systems are essentially planar and are oriented at angles of 20.57 (3)° and 6.70 (3)°, respectively, with respect to the thiophene ring. The dihedral angle between the two benzothiophene ring systems is 26.83 (3)°. Both the major and minor conformers of the disordered dioxane ring adopt half-chair conformations. The crystal packing is stabilized by van der Waals forces.

Experimental

The title compound was prepared according to the procedure reported by Amaladass et al. (2007). Single crystals suitable for X-ray analysis were obtained by slow evaporation method.

Refinement

The methylene C atoms of the dioxane ring are disordered over two positions (C11A/C11B and C12A/C12B) with refined occupancies of 0.623 (3) and 0.377 (3). The corresponding bond distances involving the disordered atoms were restrained to be equal, and also the same Uij parameters were used for atoms C11A and C11B, and C12A and C12B. H atoms were positioned geometrically (C—H = 0.93 Å or 0.97 Å) and were treated as riding on their parent atoms, with Uiso(H) = 1.2Ueq(C).

Figures

Fig. 1.
The molecular structure of the title compound, showing 30% probability displacement ellipsoids. Both disorder components are shown.

Crystal data

C22H14O2S3F000 = 840
Mr = 406.51Dx = 1.478 Mg m3
Monoclinic, P21/cMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 4583 reflections
a = 16.1602 (5) Åθ = 2.8–33.8º
b = 8.3524 (3) ŵ = 0.42 mm1
c = 14.1814 (4) ÅT = 293 (2) K
β = 107.428 (2)ºBlock, light green
V = 1826.28 (10) Å30.15 × 0.13 × 0.10 mm
Z = 4

Data collection

Bruker Kappa APEXII area-detector diffractometer4551 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.028
Monochromator: graphiteθmax = 33.4º
T = 293(2) Kθmin = 2.8º
ω and [var phi] scansh = −24→24
Absorption correction: nonek = −12→10
26571 measured reflectionsl = −21→19
7059 independent 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)] = 0.044H-atom parameters constrained
wR(F2) = 0.143  w = 1/[σ2(Fo2) + (0.0749P)2 + 0.444P] where P = (Fo2 + 2Fc2)/3
S = 0.99(Δ/σ)max < 0.001
7059 reflectionsΔρmax = 0.61 e Å3
251 parametersΔρmin = −0.43 e Å3
3 restraintsExtinction correction: none
Primary atom site location: structure-invariant direct methods

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*/UeqOcc. (<1)
C1−0.28863 (11)0.4031 (2)−0.01894 (14)0.0499 (4)
H1−0.29490.3569−0.08040.060*
C2−0.35994 (12)0.4572 (3)0.00498 (16)0.0578 (5)
H2−0.41450.4490−0.04120.069*
C3−0.35223 (12)0.5241 (2)0.09694 (18)0.0597 (5)
H3−0.40170.55900.11150.072*
C4−0.27258 (12)0.5395 (2)0.16681 (16)0.0533 (4)
H4−0.26740.58370.22850.064*
C5−0.19971 (10)0.48665 (19)0.14227 (13)0.0419 (3)
C6−0.20599 (10)0.41809 (19)0.05007 (12)0.0400 (3)
C7−0.12301 (10)0.3765 (2)0.03966 (13)0.0430 (3)
H7−0.11530.3287−0.01640.052*
C8−0.05619 (10)0.41564 (19)0.12239 (11)0.0374 (3)
C90.03586 (9)0.39615 (18)0.13747 (11)0.0364 (3)
C100.07580 (9)0.29651 (18)0.08760 (11)0.0357 (3)
C11A0.08383 (17)0.1322 (5)−0.0432 (2)0.0502 (8)0.623 (3)
H11A0.09370.2125−0.08810.060*0.623 (3)
H11B0.05430.0420−0.08200.060*0.623 (3)
C12A0.16828 (17)0.0790 (3)0.0260 (2)0.0485 (6)0.623 (3)
H12A0.1574−0.00050.07070.058*0.623 (3)
H12B0.20220.0283−0.01170.058*0.623 (3)
C11B0.0915 (3)0.0850 (5)−0.0061 (4)0.0502 (8)0.377 (3)
H11C0.06230.0295−0.06700.060*0.377 (3)
H11D0.10460.00590.04640.060*0.377 (3)
C12B0.1754 (3)0.1472 (7)−0.0147 (2)0.0485 (6)0.377 (3)
H12C0.20920.0622−0.03180.058*0.377 (3)
H12D0.16580.2309−0.06430.058*0.377 (3)
C130.16712 (9)0.30254 (18)0.12251 (11)0.0365 (3)
C140.19858 (9)0.40987 (19)0.19816 (11)0.0362 (3)
C150.28812 (9)0.44752 (19)0.24924 (11)0.0352 (3)
C160.36041 (10)0.3755 (2)0.23942 (12)0.0416 (3)
H160.35870.28930.19730.050*
C170.43920 (10)0.44442 (19)0.29966 (11)0.0380 (3)
C180.52506 (11)0.4008 (2)0.30912 (15)0.0512 (4)
H180.53660.31590.27250.061*
C190.59199 (11)0.4840 (2)0.37253 (15)0.0521 (4)
H190.64890.45580.37810.062*
C200.57576 (11)0.6105 (2)0.42876 (14)0.0483 (4)
H200.62200.66450.47220.058*
C210.49236 (11)0.6563 (2)0.42076 (13)0.0469 (4)
H210.48160.74140.45780.056*
C220.42398 (9)0.57260 (19)0.35592 (11)0.0374 (3)
O10.03162 (7)0.19777 (15)0.01304 (9)0.0476 (3)
O20.21883 (7)0.21067 (15)0.08407 (9)0.0467 (3)
S10.11311 (2)0.50367 (5)0.22588 (3)0.04068 (11)
S20.31369 (3)0.60648 (5)0.33305 (3)0.04677 (12)
S3−0.09260 (3)0.49989 (6)0.21576 (3)0.04834 (13)

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0415 (8)0.0560 (10)0.0467 (9)−0.0071 (7)0.0047 (7)0.0089 (8)
C20.0338 (8)0.0654 (12)0.0667 (12)−0.0030 (8)0.0037 (8)0.0162 (10)
C30.0355 (8)0.0585 (11)0.0856 (15)0.0057 (8)0.0188 (9)0.0054 (10)
C40.0418 (9)0.0515 (10)0.0684 (12)0.0037 (7)0.0192 (8)−0.0063 (9)
C50.0336 (7)0.0393 (8)0.0529 (9)−0.0002 (6)0.0131 (6)0.0001 (7)
C60.0355 (7)0.0390 (8)0.0445 (8)−0.0019 (6)0.0103 (6)0.0061 (6)
C70.0352 (7)0.0473 (9)0.0470 (8)0.0003 (6)0.0132 (6)0.0079 (7)
C80.0331 (7)0.0393 (8)0.0401 (7)0.0004 (5)0.0114 (5)0.0008 (6)
C90.0316 (6)0.0395 (8)0.0378 (7)−0.0003 (5)0.0098 (5)0.0003 (6)
C100.0332 (6)0.0376 (7)0.0353 (7)−0.0025 (5)0.0086 (5)−0.0015 (6)
C11A0.0450 (11)0.070 (2)0.0369 (17)−0.0104 (12)0.0148 (13)−0.0198 (14)
C12A0.0432 (11)0.0540 (18)0.0478 (15)0.0009 (11)0.0128 (11)−0.0150 (11)
C11B0.0450 (11)0.070 (2)0.0369 (17)−0.0104 (12)0.0148 (13)−0.0198 (14)
C12B0.0432 (11)0.0540 (18)0.0478 (15)0.0009 (11)0.0128 (11)−0.0150 (11)
C130.0340 (7)0.0378 (8)0.0383 (7)0.0019 (5)0.0116 (5)−0.0024 (6)
C140.0317 (6)0.0395 (8)0.0368 (7)−0.0001 (5)0.0095 (5)−0.0018 (6)
C150.0338 (7)0.0372 (7)0.0349 (7)−0.0016 (5)0.0106 (5)−0.0026 (6)
C160.0363 (7)0.0423 (8)0.0461 (8)−0.0022 (6)0.0122 (6)−0.0089 (7)
C170.0338 (7)0.0402 (8)0.0411 (7)−0.0023 (6)0.0130 (6)−0.0008 (6)
C180.0364 (8)0.0547 (10)0.0645 (11)0.0013 (7)0.0181 (7)−0.0109 (8)
C190.0328 (8)0.0577 (11)0.0659 (11)−0.0027 (7)0.0153 (7)−0.0001 (9)
C200.0360 (8)0.0509 (10)0.0535 (9)−0.0103 (7)0.0066 (7)0.0011 (8)
C210.0402 (8)0.0486 (9)0.0495 (9)−0.0081 (7)0.0096 (7)−0.0090 (7)
C220.0324 (7)0.0401 (8)0.0394 (7)−0.0029 (6)0.0103 (5)−0.0005 (6)
O10.0379 (6)0.0534 (7)0.0495 (6)−0.0055 (5)0.0100 (5)−0.0169 (5)
O20.0355 (5)0.0520 (7)0.0520 (6)0.0028 (5)0.0121 (5)−0.0160 (5)
S10.03413 (18)0.0475 (2)0.0409 (2)−0.00031 (15)0.01199 (14)−0.00916 (16)
S20.03469 (19)0.0501 (2)0.0539 (2)−0.00041 (16)0.01081 (16)−0.01687 (18)
S30.0361 (2)0.0621 (3)0.0464 (2)0.00043 (17)0.01175 (16)−0.01084 (19)

Geometric parameters (Å, °)

C1—C21.372 (3)C11B—O11.434 (2)
C1—C61.405 (2)C11B—C12B1.490 (3)
C1—H10.93C11B—H11C0.97
C2—C31.390 (3)C11B—H11D0.97
C2—H20.93C12B—O21.465 (3)
C3—C41.375 (3)C12B—H12C0.97
C3—H30.93C12B—H12D0.97
C4—C51.396 (2)C13—O21.3627 (18)
C4—H40.93C13—C141.373 (2)
C5—C61.403 (2)C14—C151.445 (2)
C5—S31.7361 (17)C14—S11.7325 (15)
C6—C71.435 (2)C15—C161.358 (2)
C7—C81.375 (2)C15—S21.7470 (15)
C7—H70.93C16—C171.425 (2)
C8—C91.447 (2)C16—H160.93
C8—S31.7496 (16)C17—C221.400 (2)
C9—C101.372 (2)C17—C181.401 (2)
C9—S11.7318 (15)C18—C191.371 (3)
C10—O11.3622 (18)C18—H180.93
C10—C131.410 (2)C19—C201.395 (3)
C11A—O11.433 (2)C19—H190.93
C11A—C12A1.490 (3)C20—C211.373 (2)
C11A—H11A0.97C20—H200.93
C11A—H11B0.97C21—C221.395 (2)
C12A—O21.467 (2)C21—H210.93
C12A—H12A0.97C22—S21.7365 (15)
C12A—H12B0.97
C2—C1—C6119.47 (18)C12B—C11B—H11D107.8
C2—C1—H1120.3H11C—C11B—H11D107.2
C6—C1—H1120.3O2—C12B—C11B103.6 (3)
C1—C2—C3121.26 (17)O2—C12B—H12C111.0
C1—C2—H2119.4C11B—C12B—H12C111.0
C3—C2—H2119.4O2—C12B—H12D111.0
C4—C3—C2121.00 (18)C11B—C12B—H12D111.0
C4—C3—H3119.5H12C—C12B—H12D109.0
C2—C3—H3119.5O2—C13—C14123.51 (13)
C3—C4—C5117.93 (19)O2—C13—C10122.83 (13)
C3—C4—H4121.0C14—C13—C10113.66 (13)
C5—C4—H4121.0C13—C14—C15127.90 (14)
C4—C5—C6122.04 (16)C13—C14—S1109.79 (11)
C4—C5—S3126.46 (15)C15—C14—S1122.30 (12)
C6—C5—S3111.48 (12)C16—C15—C14127.96 (14)
C5—C6—C1118.29 (16)C16—C15—S2111.78 (11)
C5—C6—C7112.69 (14)C14—C15—S2120.24 (11)
C1—C6—C7129.00 (17)C15—C16—C17113.66 (14)
C8—C7—C6111.96 (15)C15—C16—H16123.2
C8—C7—H7124.0C17—C16—H16123.2
C6—C7—H7124.0C22—C17—C18118.81 (15)
C7—C8—C9127.53 (14)C22—C17—C16111.87 (13)
C7—C8—S3112.65 (12)C18—C17—C16129.32 (16)
C9—C8—S3119.82 (11)C19—C18—C17119.69 (17)
C10—C9—C8127.84 (14)C19—C18—H18120.2
C10—C9—S1109.84 (11)C17—C18—H18120.2
C8—C9—S1122.33 (12)C18—C19—C20120.82 (16)
O1—C10—C9123.31 (13)C18—C19—H19119.6
O1—C10—C13122.97 (13)C20—C19—H19119.6
C9—C10—C13113.69 (13)C21—C20—C19120.79 (16)
O1—C11A—C12A108.9 (2)C21—C20—H20119.6
O1—C11A—H11A109.9C19—C20—H20119.6
C12A—C11A—H11A109.9C20—C21—C22118.62 (17)
O1—C11A—H11B109.9C20—C21—H21120.7
C12A—C11A—H11B109.9C22—C21—H21120.7
H11A—C11A—H11B108.3C21—C22—C17121.27 (15)
O2—C12A—C11A113.1 (2)C21—C22—S2127.40 (13)
O2—C12A—H12A109.0C17—C22—S2111.34 (11)
C11A—C12A—H12A109.0C10—O1—C11A113.88 (16)
O2—C12A—H12B109.0C10—O1—C11B108.6 (3)
C11A—C12A—H12B109.0C13—O2—C12B114.2 (2)
H12A—C12A—H12B107.8C13—O2—C12A109.99 (15)
O1—C11B—C12B117.9 (4)C9—S1—C1492.98 (7)
O1—C11B—H11C107.8C22—S2—C1591.35 (7)
C12B—C11B—H11C107.8C5—S3—C891.20 (8)
O1—C11B—H11D107.8
C6—C1—C2—C3−1.2 (3)C15—C16—C17—C18179.46 (17)
C1—C2—C3—C40.6 (3)C22—C17—C18—C19−0.2 (3)
C2—C3—C4—C50.4 (3)C16—C17—C18—C19−179.69 (18)
C3—C4—C5—C6−0.7 (3)C17—C18—C19—C200.8 (3)
C3—C4—C5—S3177.48 (15)C18—C19—C20—C21−1.0 (3)
C4—C5—C6—C10.1 (2)C19—C20—C21—C220.7 (3)
S3—C5—C6—C1−178.33 (13)C20—C21—C22—C17−0.1 (3)
C4—C5—C6—C7178.37 (16)C20—C21—C22—S2179.76 (14)
S3—C5—C6—C7−0.02 (18)C18—C17—C22—C21−0.2 (2)
C2—C1—C6—C50.8 (2)C16—C17—C22—C21179.43 (15)
C2—C1—C6—C7−177.15 (17)C18—C17—C22—S2179.96 (13)
C5—C6—C7—C8−0.8 (2)C16—C17—C22—S2−0.43 (18)
C1—C6—C7—C8177.27 (16)C9—C10—O1—C11A166.6 (2)
C6—C7—C8—C9−177.96 (15)C13—C10—O1—C11A−15.2 (3)
C6—C7—C8—S31.29 (18)C9—C10—O1—C11B−166.3 (3)
C7—C8—C9—C10−20.4 (3)C13—C10—O1—C11B11.9 (3)
S3—C8—C9—C10160.45 (14)C12A—C11A—O1—C1043.7 (3)
C7—C8—C9—S1159.31 (14)C12A—C11A—O1—C11B−39.6 (5)
S3—C8—C9—S1−19.89 (18)C12B—C11B—O1—C10−46.7 (5)
C8—C9—C10—O10.2 (3)C12B—C11B—O1—C11A60.0 (5)
S1—C9—C10—O1−179.48 (12)C14—C13—O2—C12B−160.2 (3)
C8—C9—C10—C13−178.15 (15)C10—C13—O2—C12B19.4 (3)
S1—C9—C10—C132.15 (17)C14—C13—O2—C12A163.91 (19)
O1—C11A—C12A—O2−62.3 (4)C10—C13—O2—C12A−16.4 (2)
O1—C11B—C12B—O264.4 (6)C11B—C12B—O2—C13−46.1 (4)
O1—C10—C13—O20.4 (2)C11B—C12B—O2—C12A43.8 (2)
C9—C10—C13—O2178.81 (14)C11A—C12A—O2—C1347.1 (3)
O1—C10—C13—C14−179.88 (14)C11A—C12A—O2—C12B−56.9 (4)
C9—C10—C13—C14−1.5 (2)C10—C9—S1—C14−1.77 (12)
O2—C13—C14—C150.8 (3)C8—C9—S1—C14178.51 (13)
C10—C13—C14—C15−178.84 (15)C13—C14—S1—C90.95 (13)
O2—C13—C14—S1179.79 (12)C15—C14—S1—C9179.96 (13)
C10—C13—C14—S10.11 (17)C21—C22—S2—C15−179.22 (16)
C13—C14—C15—C16−6.2 (3)C17—C22—S2—C150.63 (13)
S1—C14—C15—C16174.99 (14)C16—C15—S2—C22−0.69 (13)
C13—C14—C15—S2171.90 (13)C14—C15—S2—C22−179.06 (13)
S1—C14—C15—S2−6.92 (19)C4—C5—S3—C8−177.68 (17)
C14—C15—C16—C17178.79 (15)C6—C5—S3—C80.63 (13)
S2—C15—C16—C170.57 (19)C7—C8—S3—C5−1.11 (13)
C15—C16—C17—C22−0.1 (2)C9—C8—S3—C5178.20 (13)

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CI2577).

References

  • Amaladass, P., Clement, J. A. & Mohanakrishnan, A. K. (2007). Tetrahedron, 63, 10363–1067.
  • Bruker (2004). SAINT and APEX2 Bruker AXS Inc., Madison, Wisconsin, USA.
  • Cohen, V. I., Rist, N. & Duponchel, C. (1977). J. Pharm. Sci.66, 1322–1334. [PubMed]
  • Csaszar, J. & Morvay, J. (1983). Acta Pharm. Hung.53, 121–128. [PubMed]
  • Dzhurayev, A. D., Karimkulov, K. M., Makhsumov, A. G. & Amanov, N. (1992). Khim. Farm. Zh.26, 73–75.
  • EI-Maghraby, A. A., Haroun, B. & Mohammed, N. A. (1984). Egypt. J. Pharm. Sci.23, 327–336.
  • Gewald, K., Schinke, E. & Botcher, H. (1996). Chem. Ber.99, 99–100.
  • Lakshmi, V. V., Sridhar, P. & Polasa, H. (1985). Indian J. Pharm. Sci.47, 202–204.
  • Nardelli, M. (1995). J. Appl. Cryst.28, 659.
  • Pellis, G. & West, G. B. (1968). Progress in Medicinal Chemistry, Vol. 5, pp. 320–324. London: Butterworth & Co. Ltd.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2003). J. Appl. Cryst.36, 7–13.

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