Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Previous article
Next article
Previous article
Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Next article

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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 69| Part 8| August 2013| Page o1296
doi:10.1107/S160053681301934X

3-[1-(2-Hy­dr­oxy­anilino)ethyl­­idene]-3H-chromen-2,4-dione

Ameni Brahmia,a Taicir Ben Ayedb and Rached Ben Hassena*

aUnité de Chimie des Matériaux et de l'Environnement, ISSBAT, Université de Tunis-ElManar, 9 Avenue Dr Zoheir SAFI, 1006 Tunis, Tunisia, and bINSAT, Université de Carthage, Centre Urbain Nord, BP 676, 1080 Tunis Cedex, Tunis, Tunisia
*Correspondence e-mail: rached.benhassen@fss.rnu.tn

(Received 25 June 2013; accepted 12 July 2013; online 24 July 2013)

The title compound is a new amino­coumarin derivative, C17H13NO4, and was synthesized by the condensation of 2-amino­phenol and 3-acetyl-4-hy­droxy­coumarin. An intra­molecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, the molecules are linked into chains extending in the [010] direction by O—H⋯O hydrogen bonds. There is also a π–π stacking inter­action between the bicyclic coumarin fragment and the phenol ring [centroid–centroid distance = 3.7510 (14) Å], and these ring systems form between them a dihedral angle of 53.3 (2)°. Intermolecular hydrogen bond C—H⋯O hydrogen bonding is also observed in the interconnection of the crystal packing.

Related literature

For related structures, see: Traven et al. (2000[Traven, V. F., Manaev, A. V., Safronova, O. B., Chibisova, T. A., Lyssenko, K. A. & Antipin, M. Yu. (2000). Russ. J. Gen. Chem. 70, 798-808.]); Malecka et al. (2004[Malecka, M., Grabowski, S. J. & El_zbieta, B. (2004). Chem. Phys. 297, 235-244.]); Mechi et al. (2009[Mechi, L., Chtiba, S., Hamdi, N. & Ben Hassen, R. (2009). Acta Cryst. E65, o1652-o1653.]); Ghouili et al. (2011[Ghouili, A. & Ben Hassen, R. (2011). Acta Cryst. E67, o2209.]); Ketata et al. (2012[Ketata, I., Mechi, L., Ben Ayed, T., Dusek, M., Petricek, V. & Ben Hassen, R. (2012). Open J. Inorg. Chem. 2, 33-39.]). For the properties of coumarin derivatives, see: Bordin et al. (1995[Bordin, F., Chilin, A., Dall Acqua, F., Guiotto, A. & Manzini, P. (1995). Rod Il Farm. 50, 479-488.]); Hamdi et al. (2010[Hamdi, N., Bouabdallah, F., Romerosa, A. & Ben Hassen, R. (2010). C. R. Chim. 13, 1261-1268.]); Mahidol et al. (2004[Mahidol, C., Ploypradith, P., Sahakitpichan, P. & Wongbundit, S. (2004). Angew. Chem. Int. Ed. 43, 866-868.]).

[Scheme 1]

Experimental

Crystal data

  • C17H13NO4

  • Mr = 295.29

  • Monoclinic, P 21 /n

  • a = 12.5596 (4) Å

  • b = 7.5870 (3) Å

  • c = 14.3433 (6) Å

  • β = 94.660 (2)°

  • V = 1362.25 (9) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 293 K

  • 0.16 × 0.13 × 0.10 mm
Data collection

  • Bruker SMART CCD area-detector diffractometer

  • 11784 measured reflections

  • 3891 independent reflections

  • 1721 reflections with I > 2σ(I)

  • Rint = 0.053
Refinement

  • R[F2 > 2σ(F2)] = 0.058

  • wR(F2) = 0.194

  • S = 0.91

  • 3891 reflections

  • 251 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.23 e Å−3

  • Δρmin = −0.20 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O4—H12⋯O2i 0.82 1.92 2.742 (2) 175
N1—H13⋯O3 0.88 (3) 1.75 (3) 2.537 (3) 148 (3)
C8—H4⋯O2i 0.93 2.59 3.274 (3) 131
Symmetry code: (i) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}].

Data collection: SMART (Bruker, 2001[Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SMART; data reduction: SAINT (Bruker, 2001[Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681301934X/ff2111sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681301934X/ff2111Isup2.hkl

Supporting information file. DOI: 10.1107/S160053681301934X/ff2111Isup3.cml

checkCIF report


Comment top

Coumarin derivatives have a wide range of biological properties. They possess pharmacological activities, mainly anticoagulant. They also have anti-tumor, anti-oxidants and anti-inflammatory properties (Bordin et al., 1995; Mahidol et al., 2004). In continuation of our structural and biological studies of coumarin derivatives (Mechi et al., 2009; Hamdi et al., 2010; Ghouili et al., 2011; Ketata et al., 2012), we present the crystal structure of the title compound, a new derivative of amino coumarins.

In the crystal, the title compounds adopts a conformation where the dihedral angle between the plane of the bicyclic coumarin fragment and the phenol ring is 53.3 (2)°. The structure of our solid compound is stable thanks to the intermolecular hydrogen bonds O4—H12···O2. The crystal structure of C17H13N1O4 shows a π-π stacking interaction alternating between two inverted molecules. The stacking is observed along the b axis with distance 3.361 (4) Å between the layers of coumarin and phenol rings [centroid-centroid distance 3.7510 (14) Å].

The structure exhibits intramolecular hydrogen bonding N1—H13···O3, similar to that observed in amino coumarin analogue (Malecka et al. 2004), and we observe also a strong p-electron delocalization effect when comparing with O—H···O in 3-acetyl-4-hydroxycoumarin (Traven et al. 20000). In fact, the distances C1—C2 = 1.437 (3) Å in the title compound is longer then that one of the 3-acetyl-4-hydroxycoumarin (1.399 (1) Å) and C1—C5 = 1.428 (3) Å is shorter then 1.454 (1) Å. The elongation of N1—C5; C1—C2; C1—C11 and C11—O2 distances (see the table of bond lengths) and the shortening of O4—C6, C6—C4, C4—N1, C5—C1 and C2—O3 bond lengths, in comparison with those of the compound C13H13N1O4 (Malecka et al. 2004) could be related to the electron-donor effect of the phenolic group in the title compound.

The linkage between the coumarin system and aminophenol ring exhibits bond lengths O3—C2 = 1.251 (3) Å, C2—C1 = 1.437 (3) Å, C1—C5 = 1.428 (3) Å, C5—N1 = 1.316 (3) Å and N1—C4 = 1.422 (3) Å, suggesting that all non-hydrogen atoms between the electron-donors and acceptors are highly conjugated, leading to a π-bridge for the charge transfer from aminophenol ring to coumarin system.

Related literature top

For related structures, see: Traven et al. (2000); Malecka et al. (2004); Mechi et al., (2009); Ghouili et al. (2011); Ketata et al. (2012). For the properties of coumarin derivatives, see: Bordin et al. (1995); Hamdi et al. (2010); Mahidol et al. (2004).

Experimental top

The amino coumarin was synthesized by the condensation of an equimolar amount of 2-aminophenol and 3-acetyl-4-hydroxycoumarin in absolute ethanol. After four hours of reflux, the reaction mixture was left crystallizing at room temperature. The compound obtained is presented as transparent crystals of light yellow color with shape and size suitable for the structural study of X-ray single-crystal. Yield:(90%). mp= 446 K. IR: ν 3155 (NH), 2973 (OH), 1666 (>C=O), 1609 (C=C), 1102 (C—O); 1HNMR: δp.p.m.: 2.54 (s, 3H, Hmethyl), 6.51–7.14 (m, 4H, Ar—H), 7.23–8.12 (m, 4H, Ph—H), 10.45 (s, 1H, OH), 15.20 (s, 1H, NH); 13CNMR: (p.p.m.): 20.30 (C methyl), 97.11 (C3), 116.27–134.34 (C arom), 151.40 (C—OH), 161.66 (C=O lactone), 175.90 (C—N), 180.19 (C=O ketone),

Refinement top

The hydrogen atoms are fixed geometrically and refined as riding with the exception of the H13, which was located from electron density difference map and is refined isotropically. Uiso(H) values of the H atoms were set at 1.2Ueq or 1.5Ueq of the parent atom.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound showing 50% probability displacement ellipsoids and the atomic numbering. Dashed line denotes hydrogen bond.
[Figure 2] Fig. 2. Hydrogen bonds between molecules of the title compound.
3-[1-(2-Hydroxyanilino)ethylidene]-3H-chromen-2,4-dione top
Crystal data top
C17H13NO4F(000) = 616
Mr = 295.29Dx = 1.440 Mg m−3
Monoclinic, P21/nMelting point: 446 K
Hall symbol: -P2ynMo Kα radiation, λ = 0.71073 Å
a = 12.5596 (4) ÅCell parameters from 1721 reflections
b = 7.5870 (3) ŵ = 0.10 mm−1
c = 14.3433 (6) ÅT = 293 K
β = 94.660 (2)°Needle, yellow
V = 1362.25 (9) Å30.16 × 0.13 × 0.10 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer		1721 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.053
Graphite monochromatorθmax = 29.8°, θmin = 2.1°
ϕ and ω scansh = −14→17
11784 measured reflectionsk = −9→10
3891 independent reflectionsl = −19→20
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.058Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.194H atoms treated by a mixture of independent and constrained refinement
S = 0.91 w = 1/[σ2(Fo2) + (0.0922P)2 + 0.2201P]
where P = (Fo2 + 2Fc2)/3
3891 reflections(Δ/σ)max < 0.001
251 parametersΔρmax = 0.23 e Å−3
0 restraintsΔρmin = −0.20 e Å−3
Crystal data top
C17H13NO4V = 1362.25 (9) Å3
Mr = 295.29Z = 4
Monoclinic, P21/nMo Kα radiation
a = 12.5596 (4) ŵ = 0.10 mm−1
b = 7.5870 (3) ÅT = 293 K
c = 14.3433 (6) Å0.16 × 0.13 × 0.10 mm
β = 94.660 (2)°
Data collection top
Bruker SMART CCD area-detector
diffractometer		1721 reflections with I > 2σ(I)
11784 measured reflectionsRint = 0.053
3891 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0580 restraints
wR(F2) = 0.194H atoms treated by a mixture of independent and constrained refinement
S = 0.91Δρmax = 0.23 e Å−3
3891 reflectionsΔρmin = −0.20 e Å−3
251 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
xyzUiso*/Ueq
O10.12600 (13)0.1466 (2)0.90032 (12)0.0480 (5)
N10.22554 (16)0.0473 (3)1.22516 (14)0.0375 (5)
C10.17836 (17)0.0955 (3)1.06478 (16)0.0350 (5)
O30.34691 (12)−0.0400 (2)1.09988 (12)0.0484 (5)
C20.27686 (18)0.0180 (3)1.04068 (17)0.0378 (6)
C30.29714 (18)0.0128 (3)0.94130 (17)0.0389 (6)
C40.21353 (18)0.0298 (3)1.32227 (17)0.0368 (6)
O40.38154 (13)0.1659 (2)1.35092 (12)0.0473 (5)
H120.42440.19651.39410.071*
C50.15554 (17)0.1107 (3)1.16048 (17)0.0363 (6)
O20.01364 (14)0.2201 (3)1.00033 (13)0.0556 (5)
C60.29532 (19)0.0900 (3)1.38614 (18)0.0376 (6)
C70.22130 (19)0.0795 (3)0.87552 (18)0.0417 (6)
C80.2850 (2)0.0704 (3)1.48055 (18)0.0439 (6)
H40.33840.11181.52380.053*
C90.05868 (19)0.2032 (4)1.19047 (19)0.0475 (7)
H50.05860.19771.25730.071*
H11−0.00450.14701.16230.071*
H70.05980.32421.17100.071*
C100.2392 (2)0.0838 (4)0.78132 (19)0.0546 (7)
H100.18710.12740.73750.065*
C110.10187 (19)0.1569 (3)0.99164 (18)0.0416 (6)
C120.3922 (2)−0.0510 (3)0.9114 (2)0.0481 (7)
H10.4431−0.09900.95480.058*
C130.12623 (19)−0.0559 (3)1.35386 (19)0.0451 (7)
H20.0735−0.10071.31110.054*
C140.1168 (2)−0.0752 (4)1.4483 (2)0.0503 (7)
H30.0575−0.13141.46950.060*
C150.4121 (2)−0.0446 (4)0.8187 (2)0.0545 (7)
H80.4768−0.08480.79960.065*
C160.1960 (2)−0.0104 (4)1.51091 (19)0.0497 (7)
H60.1893−0.02141.57470.060*
C170.3343 (2)0.0230 (4)0.7537 (2)0.0583 (8)
H90.34710.02680.69080.070*
H130.283 (2)0.007 (4)1.201 (2)0.061 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0451 (10)0.0600 (12)0.0366 (10)0.0120 (9)−0.0099 (8)0.0012 (9)
N10.0327 (11)0.0452 (12)0.0330 (11)0.0007 (9)−0.0072 (9)−0.0010 (9)
C10.0327 (11)0.0370 (13)0.0335 (13)0.0004 (10)−0.0089 (10)0.0011 (10)
O30.0378 (9)0.0621 (12)0.0433 (10)0.0091 (8)−0.0085 (8)0.0041 (9)
C20.0347 (12)0.0368 (13)0.0398 (13)−0.0011 (10)−0.0104 (10)0.0017 (11)
C30.0387 (13)0.0355 (13)0.0413 (14)−0.0040 (11)−0.0045 (11)−0.0031 (11)
C40.0355 (12)0.0391 (13)0.0342 (13)0.0009 (10)−0.0057 (10)−0.0007 (11)
O40.0390 (9)0.0621 (12)0.0390 (10)−0.0135 (8)−0.0080 (8)0.0009 (9)
C50.0339 (12)0.0330 (13)0.0403 (14)−0.0055 (10)−0.0082 (10)−0.0012 (10)
O20.0406 (10)0.0748 (14)0.0484 (11)0.0151 (9)−0.0141 (8)0.0016 (10)
C60.0403 (13)0.0340 (13)0.0375 (13)−0.0002 (10)−0.0032 (10)−0.0001 (11)
C70.0436 (14)0.0406 (14)0.0393 (14)−0.0002 (11)−0.0069 (11)−0.0026 (11)
C80.0474 (14)0.0477 (16)0.0351 (14)−0.0028 (12)−0.0063 (11)−0.0026 (12)
C90.0409 (13)0.0541 (17)0.0462 (16)0.0054 (12)−0.0047 (12)−0.0015 (13)
C100.0630 (18)0.0593 (18)0.0395 (16)0.0063 (15)−0.0078 (13)0.0033 (13)
C110.0399 (13)0.0428 (15)0.0400 (15)−0.0012 (12)−0.0094 (11)0.0003 (12)
C120.0413 (13)0.0493 (16)0.0519 (17)0.0012 (12)−0.0073 (12)−0.0047 (13)
C130.0377 (13)0.0486 (16)0.0475 (16)−0.0029 (11)−0.0056 (12)−0.0019 (12)
C140.0471 (15)0.0493 (16)0.0554 (18)−0.0022 (12)0.0104 (13)0.0016 (14)
C150.0489 (15)0.0655 (19)0.0492 (17)−0.0035 (14)0.0040 (13)−0.0079 (15)
C160.0601 (17)0.0510 (16)0.0384 (14)0.0040 (14)0.0057 (13)0.0006 (13)
C170.0656 (18)0.067 (2)0.0427 (16)−0.0056 (16)0.0035 (14)−0.0031 (15)
Geometric parameters (Å, º) top
O1—C71.374 (3)C7—C101.388 (4)
O1—C111.370 (3)C8—C161.376 (4)
N1—C51.316 (3)C8—H40.9300
N1—C41.419 (3)C9—H50.9600
N1—H130.88 (3)C9—H110.9600
C1—C51.429 (3)C9—H70.9600
C1—C21.437 (3)C10—C171.369 (4)
C1—C111.441 (3)C10—H100.9300
O3—C21.252 (3)C12—C151.373 (4)
C2—C31.469 (3)C12—H10.9300
C3—C71.381 (3)C13—C141.376 (4)
C3—C121.388 (3)C13—H20.9300
C4—C131.382 (3)C14—C161.376 (4)
C4—C61.396 (3)C14—H30.9300
O4—C61.359 (3)C15—C171.393 (4)
O4—H120.8200C15—H80.9300
C5—C91.498 (3)C16—H60.9300
O2—C111.223 (3)C17—H90.9300
C6—C81.379 (3)
C7—O1—C11122.26 (19)C5—C9—H11109.5
C5—N1—C4127.4 (2)H5—C9—H11109.5
C5—N1—H13112 (2)C5—C9—H7109.5
C4—N1—H13121 (2)H5—C9—H7109.5
C5—C1—C2120.5 (2)H11—C9—H7109.5
C5—C1—C11119.9 (2)C17—C10—C7119.2 (3)
C2—C1—C11119.6 (2)C17—C10—H10120.4
O3—C2—C1123.5 (2)C7—C10—H10120.4
O3—C2—C3118.8 (2)O2—C11—O1113.1 (2)
C1—C2—C3117.7 (2)O2—C11—C1127.5 (2)
C7—C3—C12118.6 (2)O1—C11—C1119.4 (2)
C7—C3—C2119.3 (2)C15—C12—C3121.0 (3)
C12—C3—C2122.0 (2)C15—C12—H1119.5
C13—C4—C6120.0 (2)C3—C12—H1119.5
C13—C4—N1121.1 (2)C4—C13—C14120.4 (2)
C6—C4—N1118.8 (2)C4—C13—H2119.8
C6—O4—H12109.5C14—C13—H2119.8
N1—C5—C1118.2 (2)C13—C14—C16119.3 (2)
N1—C5—C9118.7 (2)C13—C14—H3120.4
C1—C5—C9123.0 (2)C16—C14—H3120.4
O4—C6—C8123.5 (2)C12—C15—C17119.3 (3)
O4—C6—C4117.4 (2)C12—C15—H8120.4
C8—C6—C4119.1 (2)C17—C15—H8120.4
O1—C7—C3121.7 (2)C8—C16—C14121.0 (3)
O1—C7—C10117.2 (2)C8—C16—H6119.5
C3—C7—C10121.1 (2)C14—C16—H6119.5
C6—C8—C16120.1 (2)C10—C17—C15120.7 (3)
C6—C8—H4119.9C10—C17—H9119.6
C16—C8—H4119.9C15—C17—H9119.6
C5—C9—H5109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H12···O2i0.821.922.742 (2)175
N1—H13···O30.88 (3)1.75 (3)2.537 (3)148 (3)
C8—H4···O2i0.932.593.274 (3)131
Symmetry code: (i) x+1/2, −y+1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H12···O2i0.821.922.742 (2)174.5
N1—H13···O30.88 (3)1.75 (3)2.537 (3)148 (3)
C8—H4···O2i0.932.593.274 (3)130.8
Symmetry code: (i) x+1/2, −y+1/2, z+1/2.
 

Acknowledgements

Professor A. Ben Salah is acknowledged for his contribution to the X-ray diffraction data collection at the Laboratory of Materials Science and the Environment, University of Sfax, Tunisia.

References

First citationBordin, F., Chilin, A., Dall Acqua, F., Guiotto, A. & Manzini, P. (1995). Rod Il Farm. 50, 479–488.  Google Scholar
 First citationBruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationGhouili, A. & Ben Hassen, R. (2011). Acta Cryst. E67, o2209.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationHamdi, N., Bouabdallah, F., Romerosa, A. & Ben Hassen, R. (2010). C. R. Chim. 13, 1261–1268.  Web of Science CrossRef CAS Google Scholar
 First citationKetata, I., Mechi, L., Ben Ayed, T., Dusek, M., Petricek, V. & Ben Hassen, R. (2012). Open J. Inorg. Chem. 2, 33–39.  CrossRef CAS Google Scholar
 First citationMahidol, C., Ploypradith, P., Sahakitpichan, P. & Wongbundit, S. (2004). Angew. Chem. Int. Ed. 43, 866–868.  Google Scholar
 First citationMalecka, M., Grabowski, S. J. & El_zbieta, B. (2004). Chem. Phys. 297, 235–244.  Google Scholar
 First citationMechi, L., Chtiba, S., Hamdi, N. & Ben Hassen, R. (2009). Acta Cryst. E65, o1652–o1653.  Web of Science CSD 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 citationTraven, V. F., Manaev, A. V., Safronova, O. B., Chibisova, T. A., Lyssenko, K. A. & Antipin, M. Yu. (2000). Russ. J. Gen. Chem. 70, 798–808.  CAS 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
Volume 69| Part 8| August 2013| Page o1296
doi:10.1107/S160053681301934X
Follow Acta Cryst. E
Sign up for e-alerts
E-alerts
Follow Acta Cryst. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS