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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

1-[(E)-Anthracen-9-yl­methyl­­idene]-2-(2,4-di­nitro­phen­yl)hydrazine

aChemistry Department, University of Coimbra, P-3004-530 Coimbra, Portugal, and bCEMDRX, Physics Department, University of Coimbra, P-3004-516 Coimbra, Portugal
*Correspondence e-mail: xelo@teor.fis.uc.pt

(Received 15 February 2013; accepted 4 April 2013; online 13 April 2013)

In the title Schiff base, C21H14N4O4, the dihedral angle between the two nitro groups and the central benzene ring are 83.6 (5) and 2.6 (6)°. The anthracene ring system and the benzene ring make a dihedral angle of 0.7 (2)°. Intra­molecular N—H⋯O and C—H⋯N hydrogen bonds occur. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules, forming chains along the b-axis direction.

Related literature

For general background to hydrazone derivatives, see: Kahwa et al. (1986[Kahwa, I. A., Selbin, J., Hsieh, T. C.-Y. & Laine, R. A. (1986). Inorg. Chim. Acta, 118, 179-185.]). For the structures of 2,4-di­nitro­phenyl­hydrazine and 9-anthraldehyde, see: Okabe et al. (1993[Okabe, N., Nakamura, T. & Fukuda, H. (1993). Acta Cryst. C49, 1678-1680.]) and Trotter (1959[Trotter, J. (1959). Acta Cryst. 12, 922-928.]), respectively.

[Scheme 1]

Experimental

Crystal data
  • C21H14N4O4

  • Mr = 386.36

  • Orthorhombic, P 21 21 21

  • a = 5.6355 (4) Å

  • b = 8.1597 (5) Å

  • c = 36.794 (2) Å

  • V = 1691.95 (19) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 293 K

  • 0.08 × 0.02 × 0.01 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2000[Sheldrick, G. M. (2000). SADABS. University of Göttingen, Germany.]) Tmin = 0.764, Tmax = 0.999

  • 18174 measured reflections

  • 3708 independent reflections

  • 1466 reflections with I > 2σ(I)

  • Rint = 0.132

Refinement
  • R[F2 > 2σ(F2)] = 0.074

  • wR(F2) = 0.242

  • S = 0.88

  • 3708 reflections

  • 263 parameters

  • H-atom parameters constrained

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.22 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N3—H03⋯O4 0.86 1.99 2.617 (7) 129
C11—H11⋯O4i 0.93 2.47 3.251 (8) 142
C20—H20⋯N4 0.93 2.25 2.894 (8) 126
Symmetry code: (i) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z].

Data collection: APEX2 (Bruker, 2003[Bruker (2003). APEX2 and SAINT. Bruker AXS Inc., Madison, Winsconsin, USA.]); cell refinement: SAINT (Bruker, 2003[Bruker (2003). APEX2 and SAINT. Bruker AXS Inc., Madison, Winsconsin, USA.]); data reduction: SAINT; 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: DIAMOND (Brandenburg, 2006[Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: WinGX publication routines (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).

Supporting information


Comment top

The title compound was synthesized as part of an investigation of the coordination properties of Schiff bases functioning as ligands. Metal complexes based on Schiff bases have been developed in biology and macromolecular chemistry in the last years (Kahwa et al., 1986).

The three dimensional arrangement of the molecules is held together by weak hydrogen bonds interactions between C—H and nitro-oxygen atoms.

Each unit is almost planar with a maximum deviation of 0.179 (6) A for O2, bond lengths varying in the ranges of [1.331 (9)–1.463 (8), 1.215 (7)–1.242 (6), 1.294 (7)–1.461 (8) and 1.389 (7) A for C—C, N—O, C—N and N—N respectively] and bond angles agreeing with those for the initial ligands. Molecules grow along the a-axis giving layers in the plane bc with an ABAB disposition, as well as each A and B layers are actually an alternating double layer. Two neighbor units of compound 1 create an angle of 68.92 (3)° between them along the c-axis.

The angle between the two nitro groups and the central benzene ring by 83.6 (5) and 2.6 (6)°, and the angle between these two nitro groups is 11.1 (7)°. Dihedral angle between the two aromatic parts of the molecule are 179.7 (6) and -171.7 (6)°, for C8—C7—N4—N3 and C7—N4—N3—C1 respectively.

Related literature top

For general background to hydrazone derivatives, see: Kahwa et al. (1986). For structural and coordination information for 2,4-dinitrophenylhydrazine and 9-anthraldehyde, see: Okabe et al. (1993) and Trotter (1959), respectively.

Experimental top

All reagents were obtained from commercial sources and used wirh no further purifications.

The compound was obtained when 1 g of (2,4-dinitrophenyl) hydrazine was dissolved in 5 mL of concentrated H2SO4.7.5 mL of water where added very slowly to the solution, after this were also added 25 mL of ethanol. In other flask, 4 mL of ethanol 0.05 g of anthracene-9-carbaldehyde where dissolved, and then, 1.80 mL of (2,4-dinitrophenyl)hydrazine was added to the solution. The two solutions were mixed and left to stand, at room temperature, for 24 h and then the solid compound was filtered., 049 g (52,7%)of the final product were obtained.

Refinement top

All H atoms could be located in a difference Fourier synthesis but were placed in calculated positions and refined as riding on their parent atoms, using SHELXL97 (Sheldrick, 2008) defaults. Due to the absence of anomalous scatterers, the absolute structure could not be determined.

Structure description top

The title compound was synthesized as part of an investigation of the coordination properties of Schiff bases functioning as ligands. Metal complexes based on Schiff bases have been developed in biology and macromolecular chemistry in the last years (Kahwa et al., 1986).

The three dimensional arrangement of the molecules is held together by weak hydrogen bonds interactions between C—H and nitro-oxygen atoms.

Each unit is almost planar with a maximum deviation of 0.179 (6) A for O2, bond lengths varying in the ranges of [1.331 (9)–1.463 (8), 1.215 (7)–1.242 (6), 1.294 (7)–1.461 (8) and 1.389 (7) A for C—C, N—O, C—N and N—N respectively] and bond angles agreeing with those for the initial ligands. Molecules grow along the a-axis giving layers in the plane bc with an ABAB disposition, as well as each A and B layers are actually an alternating double layer. Two neighbor units of compound 1 create an angle of 68.92 (3)° between them along the c-axis.

The angle between the two nitro groups and the central benzene ring by 83.6 (5) and 2.6 (6)°, and the angle between these two nitro groups is 11.1 (7)°. Dihedral angle between the two aromatic parts of the molecule are 179.7 (6) and -171.7 (6)°, for C8—C7—N4—N3 and C7—N4—N3—C1 respectively.

For general background to hydrazone derivatives, see: Kahwa et al. (1986). For structural and coordination information for 2,4-dinitrophenylhydrazine and 9-anthraldehyde, see: Okabe et al. (1993) and Trotter (1959), respectively.

Computing details top

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: WinGX publication routines (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. : Asymmetric unit of the title compound, showing the atom-labelling scheme and displacement ellipsoids drawn at the 50% probability level.
[Figure 2] Fig. 2. : View of the crystal packing of the title compound, projected along c.
[Figure 3] Fig. 3. : A view showing part of the three-dimensional supramolecular network linked by weak hydrogen-bond interactions (yellow dotted lines).
1-[(E)-Anthracen-9-ylmethylidene]-2-(2,4-dinitrophenyl)hydrazine top
Crystal data top
C21H14N4O4F(000) = 146
Mr = 386.36Dx = 1.517 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 1164 reflections
a = 5.6355 (4) Åθ = 3.0–18.8°
b = 8.1597 (5) ŵ = 0.11 mm1
c = 36.794 (2) ÅT = 293 K
V = 1691.95 (19) Å3Needle, colorless
Z = 40.08 × 0.02 × 0.01 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
3708 independent reflections
Radiation source: fine-focus sealed tube1466 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.132
φ and ω scansθmax = 27.3°, θmin = 3.3°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2000)
h = 77
Tmin = 0.764, Tmax = 0.999k = 109
18174 measured reflectionsl = 4646
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.074H-atom parameters constrained
wR(F2) = 0.242 w = 1/[σ2(Fo2) + (0.1212P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.88(Δ/σ)max < 0.001
3708 reflectionsΔρmax = 0.25 e Å3
263 parametersΔρmin = 0.22 e Å3
0 restraintsExtinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.036 (5)
Crystal data top
C21H14N4O4V = 1691.95 (19) Å3
Mr = 386.36Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 5.6355 (4) ŵ = 0.11 mm1
b = 8.1597 (5) ÅT = 293 K
c = 36.794 (2) Å0.08 × 0.02 × 0.01 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
3708 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2000)
1466 reflections with I > 2σ(I)
Tmin = 0.764, Tmax = 0.999Rint = 0.132
18174 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0740 restraints
wR(F2) = 0.242H-atom parameters constrained
S = 0.88Δρmax = 0.25 e Å3
3708 reflectionsΔρmin = 0.22 e Å3
263 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
O10.2253 (10)0.1891 (7)0.26020 (13)0.0951 (18)
O20.0875 (10)0.1412 (7)0.22882 (14)0.0932 (17)
O30.1033 (8)0.2666 (5)0.10426 (11)0.0669 (13)
O40.1605 (8)0.4177 (5)0.07843 (12)0.0703 (13)
N10.1114 (12)0.2008 (7)0.23234 (16)0.0725 (16)
N20.0789 (10)0.3493 (6)0.10576 (14)0.0558 (14)
N30.5138 (9)0.5396 (6)0.11586 (14)0.0559 (14)
H030.44700.53850.09480.067*
N40.7204 (9)0.6275 (6)0.12078 (13)0.0561 (14)
C10.4148 (10)0.4550 (7)0.14367 (16)0.0475 (14)
C20.2018 (10)0.3647 (7)0.13979 (15)0.0481 (15)
C30.1020 (12)0.2848 (7)0.16947 (17)0.0554 (16)
H30.03980.22750.16710.066*
C40.2148 (11)0.2921 (8)0.20181 (16)0.0536 (16)
C50.4246 (11)0.3756 (8)0.20701 (17)0.0582 (17)
H50.49830.37710.22960.070*
C60.5215 (11)0.4563 (8)0.17795 (17)0.0562 (16)
H60.66260.51370.18110.067*
C70.7784 (10)0.7172 (7)0.09321 (16)0.0497 (15)
H70.67950.71360.07300.060*
C80.9857 (10)0.8234 (7)0.09117 (16)0.0490 (15)
C91.0328 (10)0.8946 (7)0.05641 (16)0.0482 (15)
C100.8823 (13)0.8738 (8)0.02552 (16)0.0609 (17)
H100.74770.80830.02740.073*
C110.9330 (12)0.9482 (8)0.00647 (18)0.0667 (19)
H110.82850.93550.02580.080*
C121.1380 (13)1.0440 (8)0.0115 (2)0.070 (2)
H121.17241.09050.03390.084*
C131.2834 (13)1.0664 (7)0.01730 (19)0.0652 (18)
H131.41821.13090.01450.078*
C141.2364 (12)0.9944 (7)0.05161 (17)0.0519 (15)
C151.3859 (11)1.0226 (7)0.08107 (18)0.0583 (17)
H151.52091.08620.07770.070*
C211.1340 (10)0.8580 (7)0.12098 (15)0.0466 (14)
C161.3403 (10)0.9587 (7)0.11560 (17)0.0525 (16)
C171.4973 (12)0.9911 (8)0.14472 (18)0.0591 (17)
H171.63041.05600.14070.071*
C181.4578 (12)0.9301 (8)0.1779 (2)0.0660 (19)
H181.56530.94910.19660.079*
C191.2511 (12)0.8366 (8)0.18424 (18)0.0635 (18)
H191.22020.79700.20750.076*
C201.0978 (12)0.8040 (8)0.15704 (17)0.0604 (17)
H200.96230.74330.16220.073*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.097 (4)0.130 (5)0.059 (3)0.006 (4)0.007 (3)0.025 (3)
O20.080 (4)0.121 (4)0.079 (3)0.027 (4)0.010 (3)0.016 (3)
O30.056 (3)0.074 (3)0.070 (3)0.017 (3)0.005 (2)0.000 (2)
O40.069 (3)0.085 (3)0.057 (3)0.020 (3)0.000 (2)0.010 (2)
N10.071 (4)0.086 (4)0.061 (4)0.004 (4)0.007 (4)0.004 (3)
N20.054 (3)0.057 (3)0.057 (3)0.005 (3)0.004 (3)0.002 (3)
N30.053 (3)0.055 (3)0.059 (3)0.004 (3)0.002 (3)0.001 (3)
N40.045 (3)0.059 (3)0.065 (3)0.001 (3)0.002 (3)0.001 (3)
C10.043 (3)0.050 (3)0.050 (4)0.000 (3)0.000 (3)0.001 (3)
C20.044 (4)0.052 (4)0.048 (3)0.003 (3)0.002 (3)0.002 (3)
C30.047 (3)0.054 (4)0.066 (4)0.002 (3)0.008 (3)0.008 (3)
C40.052 (4)0.065 (4)0.045 (4)0.002 (4)0.003 (3)0.004 (3)
C50.056 (4)0.068 (4)0.051 (4)0.006 (4)0.005 (3)0.004 (3)
C60.050 (4)0.058 (4)0.061 (4)0.004 (3)0.005 (3)0.001 (3)
C70.049 (4)0.051 (4)0.049 (3)0.001 (3)0.003 (3)0.002 (3)
C80.044 (3)0.039 (3)0.064 (4)0.002 (3)0.006 (3)0.001 (3)
C90.045 (3)0.042 (3)0.059 (4)0.006 (3)0.001 (3)0.001 (3)
C100.063 (4)0.063 (4)0.056 (4)0.001 (4)0.002 (4)0.002 (3)
C110.064 (5)0.076 (5)0.060 (4)0.006 (4)0.004 (4)0.005 (4)
C120.084 (5)0.062 (4)0.065 (4)0.003 (4)0.014 (4)0.011 (4)
C130.072 (4)0.045 (4)0.079 (5)0.007 (4)0.014 (4)0.007 (3)
C140.058 (4)0.040 (3)0.058 (4)0.002 (3)0.002 (3)0.001 (3)
C150.053 (4)0.046 (4)0.076 (5)0.000 (3)0.013 (4)0.002 (3)
C210.044 (3)0.040 (3)0.055 (4)0.001 (3)0.002 (3)0.003 (3)
C160.043 (4)0.045 (3)0.069 (4)0.009 (3)0.000 (3)0.007 (3)
C170.046 (4)0.060 (4)0.072 (5)0.002 (3)0.004 (4)0.006 (4)
C180.057 (4)0.070 (5)0.071 (5)0.007 (4)0.010 (4)0.006 (4)
C190.067 (5)0.065 (4)0.059 (4)0.007 (4)0.001 (4)0.006 (3)
C200.057 (4)0.058 (4)0.067 (4)0.006 (4)0.000 (4)0.001 (3)
Geometric parameters (Å, º) top
O1—N11.214 (7)C9—C141.418 (8)
O2—N11.229 (7)C9—C101.428 (8)
O3—N21.230 (6)C10—C111.355 (8)
O4—N21.238 (6)C10—H100.9300
N1—C41.469 (8)C11—C121.407 (9)
N2—C21.436 (7)C11—H110.9300
N3—C11.355 (7)C12—C131.351 (9)
N3—N41.379 (6)C12—H120.9300
N3—H030.8600C13—C141.418 (8)
N4—C71.293 (7)C13—H130.9300
C1—C61.397 (8)C14—C151.392 (8)
C1—C21.416 (8)C15—C161.397 (8)
C2—C31.390 (8)C15—H150.9300
C3—C41.350 (8)C21—C201.413 (7)
C3—H30.9300C21—C161.437 (8)
C4—C51.378 (8)C16—C171.414 (8)
C5—C61.369 (8)C17—C181.337 (9)
C5—H50.9300C17—H170.9300
C6—H60.9300C18—C191.412 (9)
C7—C81.456 (7)C18—H180.9300
C7—H70.9300C19—C201.348 (8)
C8—C211.408 (8)C19—H190.9300
C8—C91.430 (8)C20—H200.9300
O1—N1—O2122.7 (6)C11—C10—C9120.8 (7)
O1—N1—C4118.4 (6)C11—C10—H10119.6
O2—N1—C4118.8 (6)C9—C10—H10119.6
O3—N2—O4121.4 (5)C10—C11—C12122.4 (7)
O3—N2—C2119.3 (5)C10—C11—H11118.8
O4—N2—C2119.3 (5)C12—C11—H11118.8
C1—N3—N4120.9 (5)C13—C12—C11118.1 (6)
C1—N3—H03119.6C13—C12—H12121.0
N4—N3—H03119.6C11—C12—H12121.0
C7—N4—N3113.9 (5)C12—C13—C14121.9 (7)
N3—C1—C6120.0 (6)C12—C13—H13119.0
N3—C1—C2122.6 (6)C14—C13—H13119.0
C6—C1—C2117.4 (5)C15—C14—C13120.8 (6)
C3—C2—C1120.5 (5)C15—C14—C9119.2 (6)
C3—C2—N2116.7 (5)C13—C14—C9120.0 (6)
C1—C2—N2122.8 (5)C14—C15—C16122.4 (6)
C4—C3—C2118.8 (6)C14—C15—H15118.8
C4—C3—H3120.6C16—C15—H15118.8
C2—C3—H3120.6C8—C21—C20125.7 (6)
C3—C4—C5123.2 (6)C8—C21—C16119.2 (5)
C3—C4—N1117.7 (6)C20—C21—C16115.1 (6)
C5—C4—N1119.0 (6)C15—C16—C17120.3 (6)
C6—C5—C4118.1 (6)C15—C16—C21119.2 (6)
C6—C5—H5120.9C17—C16—C21120.6 (6)
C4—C5—H5120.9C18—C17—C16121.2 (6)
C5—C6—C1122.0 (6)C18—C17—H17119.4
C5—C6—H6119.0C16—C17—H17119.4
C1—C6—H6119.0C17—C18—C19119.3 (6)
N4—C7—C8125.5 (6)C17—C18—H18120.4
N4—C7—H7117.3C19—C18—H18120.4
C8—C7—H7117.3C20—C19—C18120.8 (6)
C21—C8—C9120.4 (5)C20—C19—H19119.6
C21—C8—C7123.7 (5)C18—C19—H19119.6
C9—C8—C7115.9 (5)C19—C20—C21122.9 (6)
C14—C9—C10116.7 (5)C19—C20—H20118.6
C14—C9—C8119.7 (5)C21—C20—H20118.6
C10—C9—C8123.6 (6)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H03···O40.861.992.617 (7)129
C11—H11···O4i0.932.473.251 (8)142
C20—H20···N40.932.252.894 (8)126
Symmetry code: (i) x+1/2, y+3/2, z.

Experimental details

Crystal data
Chemical formulaC21H14N4O4
Mr386.36
Crystal system, space groupOrthorhombic, P212121
Temperature (K)293
a, b, c (Å)5.6355 (4), 8.1597 (5), 36.794 (2)
V3)1691.95 (19)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.08 × 0.02 × 0.01
Data collection
DiffractometerBruker APEXII CCD area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2000)
Tmin, Tmax0.764, 0.999
No. of measured, independent and
observed [I > 2σ(I)] reflections
18174, 3708, 1466
Rint0.132
(sin θ/λ)max1)0.646
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.074, 0.242, 0.88
No. of reflections3708
No. of parameters263
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.22

Computer programs: APEX2 (Bruker, 2003), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006), WinGX publication routines (Farrugia, 2012).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H03···O40.861.992.617 (7)129.4
C11—H11···O4i0.932.473.251 (8)142.2
C20—H20···N40.932.252.894 (8)125.5
Symmetry code: (i) x+1/2, y+3/2, z.
 

Acknowledgements

This work was supported by the Fundo Europeu de Desenvolvimento Regional-QREN-Compete through projects SFRH/BD/61637/2009, PTDC/AAC-CLI/098308/2008, PTDC/AAC-CLI/118092/2010, PTDC/FIS/102284/2008 and PEst-C/FIS/UI0036/2011 – Fundação para a Ciência e Tecnologia (FCT).

References

First citationBrandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationBruker (2003). APEX2 and SAINT. Bruker AXS Inc., Madison, Winsconsin, USA.  Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationKahwa, I. A., Selbin, J., Hsieh, T. C.-Y. & Laine, R. A. (1986). Inorg. Chim. Acta, 118, 179–185.  CrossRef CAS Web of Science Google Scholar
First citationOkabe, N., Nakamura, T. & Fukuda, H. (1993). Acta Cryst. C49, 1678–1680.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationSheldrick, G. M. (2000). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationTrotter, J. (1959). Acta Cryst. 12, 922–928.  CSD CrossRef CAS IUCr Journals Web of Science 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
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds