PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2009 August 1; 65(Pt 8): o1951–o1952.
Published online 2009 July 22. doi:  10.1107/S1600536809027858
PMCID: PMC2977320

Methyl N-[(4-chloro­phen­yl)(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl­idene)meth­yl]glycinate

Abstract

The title compound, C20H18ClN3O3, is in an enamine–keto form, stabilized by two strong intra­molecular N—H(...)O hydrogen bonds. The pyrazole ring is oriented at dihedral angles of 4.13 (3) and 85.60 (3)° with respect to the aromatic rings. The dihedral angle between the aromatic rings is 81.79 (3)°. In the crystal structure, inter­molecular C—H(...)O hydrogen bonds link the mol­ecules into double chains, which are further linked by weak C—H(...)π inter­actions, forming a two-dimensional network.

Related literature

For general background to Schiff base compounds in coord­ination chemistry, catalysis and enzymatic reactions, magnetism and mol­ecular architectures, see: Habibi et al. (2007 [triangle]). For the anti-bacterial properties of Schiff bases derived from 4-acyl-5-pyrazolones and their metal complexes, see: Li et al. (1997 [triangle], 2004 [triangle]). For the anti-bacterial and biological activity of amino acid esters, see: Xiong et al. (1993 [triangle]). For related structures, see: Pettinari et al. (1994 [triangle]); Wang et al. (2003 [triangle]); Zhang et al. (2005 [triangle]); Zhu et al. (2005 [triangle]). For bond-length data, see: Allen et al. (1987 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-o1951-scheme1.jpg

Experimental

Crystal data

  • C20H18ClN3O3
  • M r = 383.82
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o1951-efi1.jpg
  • a = 9.309 (4) Å
  • b = 10.222 (4) Å
  • c = 10.685 (5) Å
  • α = 86.275 (8)°
  • β = 82.772 (8)°
  • γ = 71.749 (5)°
  • V = 957.6 (7) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.23 mm−1
  • T = 296 K
  • 0.24 × 0.20 × 0.18 mm

Data collection

  • Bruker APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.947, T max = 0.960
  • 4927 measured reflections
  • 3364 independent reflections
  • 1975 reflections with I > 2σ(I)
  • R int = 0.019

Refinement

  • R[F 2 > 2σ(F 2)] = 0.075
  • wR(F 2) = 0.229
  • S = 1.05
  • 3364 reflections
  • 246 parameters
  • H-atom parameters constrained
  • Δρmax = 0.54 e Å−3
  • Δρmin = −0.44 e Å−3

Data collection: APEX2 (Bruker, 2003 [triangle]); cell refinement: SAINT (Bruker, 2001 [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 (Sheldrick, 2008 [triangle]) and DIAMOND (Brandenburg & Berndt, 1999 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809027858/hk2736sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809027858/hk2736Isup2.hkl

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

supplementary crystallographic information

Comment

Schiff base compounds play an important role in the development of coordination chemistry related to catalysis and enzymatic reactions, magnetism, and molecular architectures [Habibi et al., 2007]. In recent years, the Schiff bases derived from 4-acyl-5-pyrazolones and their metal complexes have been studied widely for their high antibacterial activation [Li et al., 1997, 2004]. Amino acid esters also possess good antibacterial and biological activations [Xiong et al., 1993]. Structures of Schiff bases derived from 4-acyl-5-pyrazolones and amino acid esters and closely related to the title compound have been reported [Zhu et al., 2005; Zhang et al., 2005]. We report herein the crystal structure of the title compound, (I).

In the molecule of the title compound, (I), (Fig. 1) the bond lengths (Allen et al., 1987) and angles are within normal ranges. Rings A (C1-C6), B (N1/N2/C7/C9/C10) and C (C12-C17) are, of course, planar, and they are oriented at a dihedral angles of A/B = 4.13 (3), A/C = 81.79 (3) and B/C = 85.60 (3) °. Intramolecular N-H···O hydrogen bonds (Table 1) stabilize the enamine-keto form as in 4-{[3,4-dihydro-5-methyl-3-oxo-2-phenyl-2H-pyrazol-4-ylidene]-(phenyl)methyl]amino}-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one, (II) (Wang et al., 2003), and result in the formations of planar five- and six-membered rings: D (O2/N3/C18/C19/H3) and E (O1/N3/C9-C11/H3), in which the dihedral angle between them is D/E = 3.83 (4)°. Ring D is oriented with respect to the adjacent ring B at a dihedral angle of 3.12 (4)°. The dihedral angle between ring B and planar (O1/N3/C9-C11) moiety is 0.94 (3)°, which is reported as 3.56 (3)° in (II).

In the crystal structure, intermolecular C-H···O hydrogen bonds (Table 1) link the molecules into double chains (Fig. 2), in which they are further linked by weak C—H···π interactions (Table 1) to form a two-dimensional network (Fig. 3), in which they may be effective in the stabilization of the structure.

Experimental

The title compound was synthesized by refluxing a mixture of 1-phenyl-3-methyl-4-(p-chlor-benzyl)-5-pyrazolone (15 mmol) (Pettinari et al., 1994) and glycine methyl ester (15 mmol) in ethanol (100 ml) over a steam bath for about 5 h. The product was recrystallized from ethanol, affording pale yellow crystals suitable for X-ray analysis. Analysis calculated for C20H18ClN3O3:C 62.58, H 4.73, N 10.95%; found: C 62.55, H 4.70, N 10.91%.

Refinement

H atoms were positioned geometrically with N-H = 0.86 Å (for NH) and C-H = 0.93, 0.97 and 0.96 Å, for aromatic, methylene and methyl H atoms, respectively, and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C,N), where x = 1.5 for methyl H and x = 1.2 for all other H atoms.

Figures

Fig. 1.
The molecular structure of the title molecule with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Hydrogen bonds are shown as dashed lines.
Fig. 2.
The one-dimensional plane formed by the intermolecular C–H···O hydrogen bonds.
Fig. 3.
The two-dimensional network produced by the intermolecular C–H···π interactions.

Crystal data

C20H18ClN3O3Z = 2
Mr = 383.82F(000) = 400
Triclinic, P1Dx = 1.331 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 9.309 (4) ÅCell parameters from 1323 reflections
b = 10.222 (4) Åθ = 2.3–25.9°
c = 10.685 (5) ŵ = 0.23 mm1
α = 86.275 (8)°T = 296 K
β = 82.772 (8)°Block, colorless
γ = 71.749 (5)°0.24 × 0.20 × 0.18 mm
V = 957.6 (7) Å3

Data collection

Bruker APEXII CCD area-detector diffractometer3364 independent reflections
Radiation source: fine-focus sealed tube1975 reflections with I > 2σ(I)
graphiteRint = 0.019
[var phi] and ω scansθmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)h = −11→10
Tmin = 0.947, Tmax = 0.960k = −11→12
4927 measured reflectionsl = −11→12

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.075Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.229H-atom parameters constrained
S = 1.05w = 1/[σ2(Fo2) + (0.1339P)2] where P = (Fo2 + 2Fc2)/3
3364 reflections(Δ/σ)max < 0.001
246 parametersΔρmax = 0.54 e Å3
0 restraintsΔρmin = −0.44 e Å3

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
Cl1−0.55778 (16)0.32750 (16)0.61403 (15)0.1056 (6)
O10.2121 (3)0.5392 (3)0.8771 (2)0.0536 (7)
O20.2655 (4)0.1981 (3)1.0279 (3)0.0771 (9)
O30.1496 (3)0.0367 (3)1.0650 (3)0.0716 (9)
N10.1065 (3)0.7252 (3)0.7427 (3)0.0520 (8)
N2−0.0161 (4)0.7657 (3)0.6679 (3)0.0573 (9)
N30.0591 (3)0.3478 (3)0.8789 (3)0.0510 (8)
H30.13410.37060.89980.061*
C10.3191 (5)0.7807 (4)0.8132 (4)0.0666 (12)
H10.33990.70160.86470.080*
C20.4086 (5)0.8654 (5)0.8087 (5)0.0801 (14)
H20.48950.84240.85740.096*
C30.3824 (6)0.9811 (6)0.7354 (6)0.0890 (15)
H3A0.44491.03680.73270.107*
C40.2603 (7)1.0159 (5)0.6639 (5)0.0880 (15)
H40.24051.09600.61380.106*
C50.1672 (5)0.9319 (5)0.6663 (4)0.0697 (12)
H50.08550.95520.61840.084*
C60.1992 (4)0.8118 (4)0.7424 (3)0.0525 (9)
C7−0.0797 (4)0.6684 (4)0.6807 (3)0.0526 (10)
C8−0.2151 (5)0.6816 (5)0.6135 (4)0.0776 (14)
H8A−0.25120.77330.57840.116*
H8B−0.29420.66340.67200.116*
H8C−0.18700.61650.54700.116*
C9−0.0021 (4)0.5568 (4)0.7624 (3)0.0458 (9)
C100.1185 (4)0.5995 (4)0.8021 (3)0.0450 (8)
C11−0.0299 (4)0.4347 (4)0.8029 (3)0.0432 (8)
C12−0.1577 (4)0.3973 (4)0.7612 (3)0.0454 (9)
C13−0.1405 (5)0.3365 (5)0.6462 (4)0.0683 (12)
H13−0.04570.31080.59860.082*
C14−0.2631 (6)0.3136 (5)0.6015 (4)0.0770 (14)
H14−0.25130.27200.52440.092*
C15−0.4031 (5)0.3528 (4)0.6722 (4)0.0591 (11)
C16−0.4215 (4)0.4092 (4)0.7886 (4)0.0604 (11)
H16−0.51550.43140.83730.072*
C17−0.2987 (4)0.4323 (4)0.8322 (3)0.0526 (10)
H17−0.31070.47190.91030.063*
C180.0428 (4)0.2179 (4)0.9305 (4)0.0545 (10)
H18A0.04930.15730.86250.065*
H18B−0.05600.23360.97940.065*
C190.1662 (4)0.1521 (4)1.0130 (4)0.0561 (10)
C200.2628 (6)−0.0381 (5)1.1457 (5)0.0911 (16)
H20A0.3615−0.06311.09790.137*
H20B0.2404−0.11991.17910.137*
H20C0.26200.01881.21400.137*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cl10.0921 (10)0.1261 (12)0.1282 (12)−0.0573 (9)−0.0643 (9)0.0046 (9)
O10.0457 (14)0.0636 (16)0.0557 (15)−0.0186 (12)−0.0205 (12)0.0069 (13)
O20.0713 (19)0.075 (2)0.098 (2)−0.0316 (17)−0.0458 (17)0.0202 (17)
O30.0718 (19)0.0580 (18)0.091 (2)−0.0220 (15)−0.0336 (16)0.0132 (16)
N10.0506 (18)0.058 (2)0.0516 (18)−0.0206 (15)−0.0159 (14)0.0053 (15)
N20.0513 (18)0.068 (2)0.0531 (19)−0.0161 (17)−0.0172 (15)0.0106 (16)
N30.0406 (16)0.059 (2)0.0574 (18)−0.0180 (14)−0.0197 (14)0.0065 (16)
C10.060 (3)0.066 (3)0.080 (3)−0.025 (2)−0.021 (2)0.006 (2)
C20.066 (3)0.080 (3)0.104 (4)−0.032 (3)−0.022 (3)−0.001 (3)
C30.091 (4)0.077 (3)0.110 (4)−0.044 (3)−0.012 (3)0.007 (3)
C40.107 (4)0.074 (3)0.089 (4)−0.040 (3)−0.016 (3)0.024 (3)
C50.078 (3)0.067 (3)0.064 (3)−0.022 (2)−0.018 (2)0.010 (2)
C60.054 (2)0.055 (2)0.049 (2)−0.0177 (19)−0.0023 (17)−0.0072 (18)
C70.046 (2)0.068 (3)0.045 (2)−0.018 (2)−0.0144 (17)0.0054 (19)
C80.067 (3)0.101 (4)0.074 (3)−0.033 (3)−0.038 (2)0.031 (3)
C90.0382 (19)0.061 (2)0.0395 (18)−0.0157 (17)−0.0096 (15)0.0030 (17)
C100.0407 (19)0.052 (2)0.0415 (19)−0.0110 (16)−0.0096 (15)−0.0003 (17)
C110.0347 (17)0.057 (2)0.0381 (18)−0.0138 (16)−0.0038 (14)−0.0054 (16)
C120.0424 (19)0.055 (2)0.0407 (18)−0.0156 (17)−0.0115 (15)−0.0021 (16)
C130.058 (3)0.098 (4)0.052 (2)−0.027 (2)−0.0022 (19)−0.022 (2)
C140.086 (3)0.101 (4)0.057 (3)−0.038 (3)−0.020 (2)−0.020 (2)
C150.060 (3)0.064 (3)0.063 (3)−0.026 (2)−0.032 (2)0.008 (2)
C160.042 (2)0.071 (3)0.069 (3)−0.0180 (19)−0.0127 (18)−0.001 (2)
C170.040 (2)0.068 (2)0.049 (2)−0.0129 (18)−0.0076 (16)−0.0108 (19)
C180.054 (2)0.056 (2)0.060 (2)−0.0224 (19)−0.0170 (19)0.0012 (19)
C190.054 (2)0.053 (2)0.064 (3)−0.017 (2)−0.0137 (19)−0.004 (2)
C200.093 (4)0.068 (3)0.111 (4)−0.013 (3)−0.053 (3)0.027 (3)

Geometric parameters (Å, °)

Cl1—C151.734 (4)C7—C81.494 (5)
O1—C101.248 (4)C8—H8A0.9600
O2—C191.191 (4)C8—H8B0.9600
O3—C191.316 (5)C8—H8C0.9600
O3—C201.442 (5)C9—C111.384 (5)
N1—C101.374 (5)C9—C101.443 (5)
N1—C61.416 (5)C11—C121.484 (5)
N1—N21.416 (4)C12—C131.382 (5)
N2—C71.300 (5)C12—C171.385 (5)
N3—C111.323 (4)C13—C141.380 (6)
N3—C181.449 (5)C13—H130.9300
N3—H30.8600C14—C151.376 (6)
C1—C61.371 (5)C14—H140.9300
C1—C21.372 (6)C15—C161.373 (6)
C1—H10.9300C16—C171.377 (5)
C2—C31.349 (7)C16—H160.9300
C2—H20.9300C17—H170.9300
C3—C41.389 (7)C18—C191.498 (5)
C3—H3A0.9300C18—H18A0.9700
C4—C51.396 (7)C18—H18B0.9700
C4—H40.9300C20—H20A0.9600
C5—C61.399 (6)C20—H20B0.9600
C5—H50.9300C20—H20C0.9600
C7—C91.449 (5)
C19—O3—C20115.9 (3)O1—C10—C9128.3 (3)
C10—N1—C6130.1 (3)N1—C10—C9105.4 (3)
C10—N1—N2111.5 (3)N3—C11—C9120.2 (3)
C6—N1—N2118.3 (3)N3—C11—C12118.5 (3)
C7—N2—N1106.7 (3)C9—C11—C12121.2 (3)
C11—N3—C18126.5 (3)C13—C12—C17119.2 (3)
C11—N3—H3116.8C13—C12—C11120.2 (3)
C18—N3—H3116.8C17—C12—C11120.5 (3)
C6—C1—C2120.5 (4)C14—C13—C12120.4 (4)
C6—C1—H1119.7C14—C13—H13119.8
C2—C1—H1119.7C12—C13—H13119.8
C3—C2—C1121.7 (5)C15—C14—C13119.4 (4)
C3—C2—H2119.2C15—C14—H14120.3
C1—C2—H2119.2C13—C14—H14120.3
C2—C3—C4118.9 (5)C16—C15—C14121.1 (4)
C2—C3—H3A120.5C16—C15—Cl1119.6 (3)
C4—C3—H3A120.5C14—C15—Cl1119.2 (3)
C3—C4—C5120.8 (5)C15—C16—C17119.1 (4)
C3—C4—H4119.6C15—C16—H16120.5
C5—C4—H4119.6C17—C16—H16120.5
C4—C5—C6118.6 (4)C16—C17—C12120.8 (3)
C4—C5—H5120.7C16—C17—H17119.6
C6—C5—H5120.7C12—C17—H17119.6
C1—C6—C5119.5 (4)N3—C18—C19109.4 (3)
C1—C6—N1122.0 (4)N3—C18—H18A109.8
C5—C6—N1118.5 (4)C19—C18—H18A109.8
N2—C7—C9111.6 (3)N3—C18—H18B109.8
N2—C7—C8119.7 (3)C19—C18—H18B109.8
C9—C7—C8128.7 (4)H18A—C18—H18B108.2
C7—C8—H8A109.5O2—C19—O3125.3 (4)
C7—C8—H8B109.5O2—C19—C18124.3 (4)
H8A—C8—H8B109.5O3—C19—C18110.3 (3)
C7—C8—H8C109.5O3—C20—H20A109.5
H8A—C8—H8C109.5O3—C20—H20B109.5
H8B—C8—H8C109.5H20A—C20—H20B109.5
C11—C9—C10123.5 (3)O3—C20—H20C109.5
C11—C9—C7131.6 (3)H20A—C20—H20C109.5
C10—C9—C7104.9 (3)H20B—C20—H20C109.5
O1—C10—N1126.3 (3)
C10—N1—N2—C70.4 (4)C7—C9—C10—N1−1.0 (4)
C6—N1—N2—C7177.9 (3)C18—N3—C11—C9178.9 (3)
C6—C1—C2—C30.0 (7)C18—N3—C11—C12−2.0 (5)
C1—C2—C3—C40.7 (8)C10—C9—C11—N3−2.2 (5)
C2—C3—C4—C5−0.8 (8)C7—C9—C11—N3180.0 (4)
C3—C4—C5—C60.0 (7)C10—C9—C11—C12178.7 (3)
C2—C1—C6—C5−0.8 (6)C7—C9—C11—C120.8 (6)
C2—C1—C6—N1178.6 (4)N3—C11—C12—C13−96.3 (4)
C4—C5—C6—C10.8 (6)C9—C11—C12—C1382.8 (5)
C4—C5—C6—N1−178.7 (4)N3—C11—C12—C1788.6 (4)
C10—N1—C6—C1−3.6 (6)C9—C11—C12—C17−92.2 (4)
N2—N1—C6—C1179.3 (3)C17—C12—C13—C141.4 (7)
C10—N1—C6—C5175.8 (4)C11—C12—C13—C14−173.8 (4)
N2—N1—C6—C5−1.2 (5)C12—C13—C14—C150.5 (7)
N1—N2—C7—C9−1.0 (4)C13—C14—C15—C16−2.7 (7)
N1—N2—C7—C8179.4 (3)C13—C14—C15—Cl1178.5 (4)
N2—C7—C9—C11179.4 (4)C14—C15—C16—C173.0 (6)
C8—C7—C9—C11−1.0 (7)Cl1—C15—C16—C17−178.2 (3)
N2—C7—C9—C101.3 (4)C15—C16—C17—C12−1.1 (6)
C8—C7—C9—C10−179.2 (4)C13—C12—C17—C16−1.0 (6)
C6—N1—C10—O15.2 (6)C11—C12—C17—C16174.1 (4)
N2—N1—C10—O1−177.6 (3)C11—N3—C18—C19−179.5 (3)
C6—N1—C10—C9−176.7 (3)C20—O3—C19—O2−0.2 (6)
N2—N1—C10—C90.5 (4)C20—O3—C19—C18179.2 (4)
C11—C9—C10—O1−1.3 (6)N3—C18—C19—O2−3.2 (6)
C7—C9—C10—O1177.0 (3)N3—C18—C19—O3177.4 (3)
C11—C9—C10—N1−179.3 (3)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N3—H3···O10.862.062.755 (4)138
N3—H3···O20.862.292.679 (4)108
C16—H16···O1i0.932.423.287 (5)155
C17—H17···O1ii0.932.543.359 (4)147
C20—H20B···Cg3iii0.962.693.604 (4)160

Symmetry codes: (i) x−1, y, z; (ii) −x, −y+1, −z+2; (iii) −x, −y, −z+2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HK2736).

References

  • Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.
  • Brandenburg, K. & Berndt, M. (1999). DIAMOND Crystal Impact GbR, Bonn, Germany.
  • Bruker (2001). SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Bruker (2003). APEX2 Bruker AXS Inc., Madison, Wisconsin, USA.
  • Habibi, M. H., Mokhtari, R., Harrington, R. W. & Clegg, W. (2007). Acta Cryst. E63, o2881.
  • Li, J. Z., Jiang, L. & An, Y. M. (2004). Chin. J. Appl. Chem.21, 150–153.
  • Li, J. Z., Yu, W. J. & Du, X. Y. (1997). Chin. J. Appl. Chem.14, 98–100.
  • Pettinari, C., Marchetti, F. & Augusto, C. (1994). Polyhedron, 13, 939–950.
  • Sheldrick, G. M. (1996). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Wang, J.-L., Yang, Y., Zhang, X. & Miao, F.-M. (2003). Acta Cryst. E59, o430–o432.
  • Xiong, G. H., Yang, Z. M. & Guo, A. L. (1993). Fine Chem.6, 1–3.
  • Zhang, X., Zhu, H.-L., Xu, H.-Z. & Dong, M. (2005). Acta Cryst. E61, o1629–o1630.
  • Zhu, H. L., Zhang, X., Song, Y. J., Xu, H. Z. & Dong, M. (2005). Acta Cryst. E61, o2387–o2388.

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