organic compounds
N′-(2,4-Dimethoxybenzylidene)-3,4,5-trihydroxybenzohydrazide ethanol solvate
aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and bDepartment of Molecular Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: hapipah@um.edu.my
The title compound, C16H16N2O6·C2H5OH, was synthesized from 3,4,5-trihydroxybenzoylhydrazide and 2,4-dimethoxybenzaldehyde in ethanol. The compound is not planar, with the two aromatic planes of the two aromatic rings twisted by 15.6 (1)°. The hydroxy groups are involved in both intramolecular O—H⋯O and intermolecular O—H⋯N and O—H⋯O hydrogen bonds and a C—H⋯O interaction also occurs.
Related literature
For related compounds, see Abdul Alhadi et al. (2009). For the parent N′-(2-hydroxybenzylidene)benzohydrazide, see Lyubchova et al. (1995).
Experimental
Crystal data
|
Refinement
|
Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2008).
Supporting information
10.1107/S1600536809018947/hg2510sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809018947/hg2510Isup2.hkl
A mixture of 3,4,5-trihydroxybenzoylhydrazide and 2,4-dimethoxybenzaldehyde were heated in ethanol (50 ml) for 12 h. The yellow crystals were obtained by recrystallization from ethanol.
All H atoms were placed at calculated positions (C— H 0.95 - 0.99, N—H 0.88, and O—H 0.84 Å) with Uiso(H) set to 1.2 - 1.5times Ueq (C,N,O)
Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2008).Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of C16H16N2O6.C2H5OH at 70% probability level. Hydrogen atoms are drawn as sphere of arbitrary radius. |
C16H16N2O6·C2H6O | F(000) = 800 |
Mr = 378.38 | Dx = 1.408 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 3445 reflections |
a = 7.8347 (1) Å | θ = 2.8–29.1° |
b = 17.5412 (3) Å | µ = 0.11 mm−1 |
c = 13.0230 (2) Å | T = 100 K |
β = 93.936 (1)° | Block, yellow |
V = 1785.53 (5) Å3 | 0.31 × 0.16 × 0.12 mm |
Z = 4 |
Bruker APEXII CCD area-detector diffractometer | 5188 independent reflections |
Radiation source: fine-focus sealed tube | 3586 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.041 |
ω scans | θmax = 30.5°, θmin = 2.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −11→10 |
Tmin = 0.967, Tmax = 0.987 | k = −24→24 |
19580 measured reflections | l = −18→18 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.121 | H-atom parameters constrained |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0566P)2 + 0.3538P] where P = (Fo2 + 2Fc2)/3 |
5188 reflections | (Δ/σ)max = 0.001 |
253 parameters | Δρmax = 0.41 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
C16H16N2O6·C2H6O | V = 1785.53 (5) Å3 |
Mr = 378.38 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.8347 (1) Å | µ = 0.11 mm−1 |
b = 17.5412 (3) Å | T = 100 K |
c = 13.0230 (2) Å | 0.31 × 0.16 × 0.12 mm |
β = 93.936 (1)° |
Bruker APEXII CCD area-detector diffractometer | 5188 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 3586 reflections with I > 2σ(I) |
Tmin = 0.967, Tmax = 0.987 | Rint = 0.041 |
19580 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.121 | H-atom parameters constrained |
S = 1.02 | Δρmax = 0.41 e Å−3 |
5188 reflections | Δρmin = −0.27 e Å−3 |
253 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 1.15941 (17) | 0.21466 (7) | 0.76768 (10) | 0.0156 (3) | |
H1 | 1.1458 | 0.2583 | 0.7248 | 0.019* | |
C2 | 1.25203 (17) | 0.22016 (7) | 0.86245 (10) | 0.0153 (3) | |
C3 | 1.26837 (17) | 0.15678 (8) | 0.92716 (10) | 0.0154 (3) | |
C4 | 1.19696 (18) | 0.08744 (8) | 0.89317 (10) | 0.0170 (3) | |
C5 | 1.10756 (18) | 0.08150 (8) | 0.79830 (10) | 0.0176 (3) | |
H5 | 1.0605 | 0.0339 | 0.7760 | 0.021* | |
C6 | 1.08672 (17) | 0.14571 (7) | 0.73529 (10) | 0.0154 (3) | |
C7 | 0.98683 (17) | 0.14395 (8) | 0.63409 (10) | 0.0159 (3) | |
C8 | 0.74521 (17) | 0.00842 (8) | 0.49550 (10) | 0.0168 (3) | |
H8 | 0.7539 | −0.0296 | 0.5476 | 0.023 (4)* | |
C9 | 0.64100 (17) | −0.00596 (8) | 0.40063 (10) | 0.0165 (3) | |
C10 | 0.57036 (17) | −0.07846 (8) | 0.38154 (10) | 0.0163 (3) | |
C11 | 0.47202 (17) | −0.09404 (8) | 0.29061 (10) | 0.0172 (3) | |
H11 | 0.4236 | −0.1431 | 0.2785 | 0.021* | |
C12 | 0.44633 (18) | −0.03640 (8) | 0.21828 (11) | 0.0188 (3) | |
C13 | 0.51352 (19) | 0.03637 (8) | 0.23587 (11) | 0.0209 (3) | |
H13 | 0.4939 | 0.0754 | 0.1859 | 0.025* | |
C14 | 0.60860 (18) | 0.05093 (8) | 0.32640 (11) | 0.0190 (3) | |
H14 | 0.6533 | 0.1007 | 0.3389 | 0.023* | |
C15 | 0.2879 (2) | −0.11915 (8) | 0.09897 (11) | 0.0227 (3) | |
H15A | 0.3824 | −0.1557 | 0.0978 | 0.034* | |
H15B | 0.2270 | −0.1169 | 0.0307 | 0.034* | |
H15C | 0.2087 | −0.1354 | 0.1498 | 0.034* | |
C16 | 0.5321 (2) | −0.20516 (8) | 0.44383 (12) | 0.0247 (3) | |
H16A | 0.4072 | −0.2007 | 0.4358 | 0.037* | |
H16B | 0.5647 | −0.2364 | 0.5044 | 0.037* | |
H16C | 0.5737 | −0.2292 | 0.3824 | 0.037* | |
C17 | 0.7901 (2) | 0.81507 (9) | 0.72385 (14) | 0.0313 (4) | |
H19A | 0.6929 | 0.8370 | 0.6826 | 0.047* | |
H19B | 0.7482 | 0.7866 | 0.7818 | 0.047* | |
H19C | 0.8531 | 0.7806 | 0.6809 | 0.047* | |
C18 | 0.9073 (2) | 0.87827 (9) | 0.76416 (12) | 0.0259 (3) | |
H18A | 0.8458 | 0.9110 | 0.8113 | 0.031* | |
H18B | 1.0074 | 0.8559 | 0.8038 | 0.031* | |
N1 | 0.92094 (15) | 0.07647 (6) | 0.60343 (9) | 0.0168 (2) | |
H1' | 0.9379 | 0.0357 | 0.6422 | 0.030 (5)* | |
N2 | 0.82556 (15) | 0.07168 (6) | 0.50974 (9) | 0.0174 (2) | |
O1 | 0.96209 (13) | 0.20261 (5) | 0.58110 (7) | 0.0219 (2) | |
O2 | 1.32670 (14) | 0.28879 (5) | 0.88620 (7) | 0.0218 (2) | |
H2 | 1.3569 | 0.2901 | 0.9493 | 0.033* | |
O3 | 1.35316 (13) | 0.15568 (6) | 1.02261 (7) | 0.0209 (2) | |
H3 | 1.3877 | 0.1998 | 1.0381 | 0.031* | |
O4 | 1.21299 (15) | 0.02350 (6) | 0.95174 (8) | 0.0273 (3) | |
H4 | 1.2718 | 0.0332 | 1.0065 | 0.041* | |
O5 | 0.60584 (13) | −0.13118 (6) | 0.45673 (7) | 0.0224 (2) | |
O6 | 0.35424 (14) | −0.04532 (6) | 0.12604 (8) | 0.0264 (3) | |
O7 | 0.96498 (14) | 0.92367 (6) | 0.68270 (8) | 0.0229 (2) | |
H7 | 1.0291 | 0.8975 | 0.6475 | 0.034* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0190 (6) | 0.0138 (6) | 0.0137 (6) | 0.0025 (5) | −0.0015 (5) | 0.0010 (5) |
C2 | 0.0187 (6) | 0.0123 (6) | 0.0148 (6) | −0.0006 (5) | 0.0000 (5) | −0.0015 (5) |
C3 | 0.0175 (6) | 0.0163 (6) | 0.0119 (6) | 0.0006 (5) | −0.0021 (5) | −0.0010 (5) |
C4 | 0.0214 (7) | 0.0143 (6) | 0.0147 (6) | 0.0000 (5) | −0.0029 (5) | 0.0027 (5) |
C5 | 0.0223 (7) | 0.0140 (6) | 0.0159 (7) | −0.0007 (5) | −0.0034 (5) | −0.0003 (5) |
C6 | 0.0171 (6) | 0.0156 (6) | 0.0131 (6) | 0.0011 (5) | −0.0020 (5) | −0.0006 (5) |
C7 | 0.0175 (6) | 0.0157 (6) | 0.0141 (6) | 0.0019 (5) | −0.0016 (5) | −0.0005 (5) |
C8 | 0.0194 (7) | 0.0158 (6) | 0.0148 (6) | 0.0008 (5) | −0.0021 (5) | 0.0007 (5) |
C9 | 0.0170 (6) | 0.0168 (6) | 0.0151 (7) | −0.0002 (5) | −0.0021 (5) | −0.0009 (5) |
C10 | 0.0187 (7) | 0.0162 (6) | 0.0139 (6) | 0.0010 (5) | −0.0010 (5) | 0.0013 (5) |
C11 | 0.0188 (7) | 0.0162 (6) | 0.0161 (6) | −0.0014 (5) | −0.0020 (5) | −0.0015 (5) |
C12 | 0.0201 (7) | 0.0192 (7) | 0.0162 (7) | 0.0000 (5) | −0.0059 (5) | −0.0012 (5) |
C13 | 0.0274 (8) | 0.0156 (6) | 0.0186 (7) | −0.0001 (6) | −0.0065 (6) | 0.0026 (5) |
C14 | 0.0208 (7) | 0.0141 (6) | 0.0212 (7) | −0.0009 (5) | −0.0040 (5) | −0.0008 (5) |
C15 | 0.0287 (8) | 0.0186 (7) | 0.0197 (7) | −0.0034 (6) | −0.0074 (6) | −0.0025 (6) |
C16 | 0.0339 (8) | 0.0158 (7) | 0.0236 (8) | −0.0045 (6) | −0.0042 (6) | 0.0033 (6) |
C17 | 0.0369 (9) | 0.0197 (7) | 0.0381 (10) | −0.0044 (7) | 0.0079 (7) | −0.0009 (7) |
C18 | 0.0344 (8) | 0.0217 (7) | 0.0212 (7) | 0.0002 (6) | −0.0020 (6) | 0.0049 (6) |
N1 | 0.0215 (6) | 0.0151 (5) | 0.0129 (5) | −0.0010 (4) | −0.0063 (4) | 0.0013 (4) |
N2 | 0.0199 (6) | 0.0172 (6) | 0.0142 (6) | 0.0000 (5) | −0.0064 (4) | −0.0011 (4) |
O1 | 0.0323 (6) | 0.0142 (5) | 0.0176 (5) | 0.0012 (4) | −0.0101 (4) | 0.0016 (4) |
O2 | 0.0353 (6) | 0.0145 (5) | 0.0145 (5) | −0.0057 (4) | −0.0070 (4) | 0.0012 (4) |
O3 | 0.0310 (6) | 0.0167 (5) | 0.0137 (5) | −0.0028 (4) | −0.0079 (4) | 0.0011 (4) |
O4 | 0.0446 (7) | 0.0167 (5) | 0.0184 (5) | −0.0065 (5) | −0.0141 (5) | 0.0056 (4) |
O5 | 0.0320 (6) | 0.0162 (5) | 0.0177 (5) | −0.0042 (4) | −0.0076 (4) | 0.0030 (4) |
O6 | 0.0382 (6) | 0.0176 (5) | 0.0209 (5) | −0.0043 (4) | −0.0160 (5) | 0.0010 (4) |
O7 | 0.0295 (6) | 0.0163 (5) | 0.0232 (6) | 0.0001 (4) | 0.0034 (4) | −0.0001 (4) |
C1—C6 | 1.3900 (18) | C13—C14 | 1.3745 (19) |
C1—C2 | 1.3914 (18) | C13—H13 | 0.9500 |
C1—H1 | 0.9500 | C14—H14 | 0.9500 |
C2—O2 | 1.3647 (15) | C15—O6 | 1.4308 (16) |
C2—C3 | 1.3958 (18) | C15—H15A | 0.9800 |
C3—O3 | 1.3687 (15) | C15—H15B | 0.9800 |
C3—C4 | 1.3979 (18) | C15—H15C | 0.9800 |
C4—O4 | 1.3574 (16) | C16—O5 | 1.4258 (17) |
C4—C5 | 1.3818 (18) | C16—H16A | 0.9800 |
C5—C6 | 1.3965 (18) | C16—H16B | 0.9800 |
C5—H5 | 0.9500 | C16—H16C | 0.9800 |
C6—C7 | 1.4862 (18) | C17—C18 | 1.511 (2) |
C7—O1 | 1.2466 (16) | C17—H19A | 0.9800 |
C7—N1 | 1.3412 (17) | C17—H19B | 0.9800 |
C8—N2 | 1.2830 (17) | C17—H19C | 0.9800 |
C8—C9 | 1.4554 (18) | C18—O7 | 1.4247 (18) |
C8—H8 | 0.9500 | C18—H18A | 0.9900 |
C9—C14 | 1.4004 (19) | C18—H18B | 0.9900 |
C9—C10 | 1.4023 (18) | N1—N2 | 1.3889 (15) |
C10—O5 | 1.3615 (16) | N1—H1' | 0.8800 |
C10—C11 | 1.3948 (18) | O2—H2 | 0.8400 |
C11—C12 | 1.3869 (19) | O3—H3 | 0.8400 |
C11—H11 | 0.9500 | O4—H4 | 0.8400 |
C12—O6 | 1.3672 (16) | O7—H7 | 0.8400 |
C12—C13 | 1.3938 (19) | ||
C6—C1—C2 | 120.50 (12) | C12—C13—H13 | 120.4 |
C6—C1—H1 | 119.8 | C13—C14—C9 | 121.44 (13) |
C2—C1—H1 | 119.8 | C13—C14—H14 | 119.3 |
O2—C2—C1 | 116.85 (12) | C9—C14—H14 | 119.3 |
O2—C2—C3 | 123.07 (11) | O6—C15—H15A | 109.5 |
C1—C2—C3 | 120.06 (12) | O6—C15—H15B | 109.5 |
O3—C3—C2 | 125.32 (12) | H15A—C15—H15B | 109.5 |
O3—C3—C4 | 115.73 (11) | O6—C15—H15C | 109.5 |
C2—C3—C4 | 118.93 (11) | H15A—C15—H15C | 109.5 |
O4—C4—C5 | 117.51 (12) | H15B—C15—H15C | 109.5 |
O4—C4—C3 | 121.43 (12) | O5—C16—H16A | 109.5 |
C5—C4—C3 | 121.07 (12) | O5—C16—H16B | 109.5 |
C4—C5—C6 | 119.75 (12) | H16A—C16—H16B | 109.5 |
C4—C5—H5 | 120.1 | O5—C16—H16C | 109.5 |
C6—C5—H5 | 120.1 | H16A—C16—H16C | 109.5 |
C1—C6—C5 | 119.63 (12) | H16B—C16—H16C | 109.5 |
C1—C6—C7 | 117.84 (11) | C18—C17—H19A | 109.5 |
C5—C6—C7 | 122.52 (12) | C18—C17—H19B | 109.5 |
O1—C7—N1 | 121.44 (12) | H19A—C17—H19B | 109.5 |
O1—C7—C6 | 121.75 (12) | C18—C17—H19C | 109.5 |
N1—C7—C6 | 116.79 (12) | H19A—C17—H19C | 109.5 |
N2—C8—C9 | 120.91 (12) | H19B—C17—H19C | 109.5 |
N2—C8—H8 | 119.5 | O7—C18—C17 | 111.58 (13) |
C9—C8—H8 | 119.5 | O7—C18—H18A | 109.3 |
C14—C9—C10 | 118.24 (12) | C17—C18—H18A | 109.3 |
C14—C9—C8 | 121.81 (12) | O7—C18—H18B | 109.3 |
C10—C9—C8 | 119.95 (12) | C17—C18—H18B | 109.3 |
O5—C10—C11 | 123.45 (12) | H18A—C18—H18B | 108.0 |
O5—C10—C9 | 115.45 (11) | C7—N1—N2 | 119.19 (11) |
C11—C10—C9 | 121.09 (12) | C7—N1—H1' | 120.4 |
C12—C11—C10 | 118.67 (12) | N2—N1—H1' | 120.4 |
C12—C11—H11 | 120.7 | C8—N2—N1 | 114.10 (11) |
C10—C11—H11 | 120.7 | C2—O2—H2 | 109.5 |
O6—C12—C11 | 123.82 (12) | C3—O3—H3 | 109.5 |
O6—C12—C13 | 114.82 (12) | C4—O4—H4 | 109.5 |
C11—C12—C13 | 121.36 (12) | C10—O5—C16 | 118.18 (11) |
C14—C13—C12 | 119.17 (13) | C12—O6—C15 | 118.75 (11) |
C14—C13—H13 | 120.4 | C18—O7—H7 | 109.5 |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3 | 0.84 | 2.54 | 2.9325 (13) | 109 |
O3—H3···O2 | 0.84 | 2.54 | 2.9325 (13) | 110 |
O4—H4···O3 | 0.84 | 2.25 | 2.7009 (14) | 114 |
N1—H1′···O7i | 0.88 | 2.04 | 2.8844 (15) | 160 |
O2—H2···O1ii | 0.84 | 1.86 | 2.6871 (13) | 170 |
O2—H2···N2ii | 0.84 | 2.57 | 2.9293 (15) | 107 |
O3—H3···O1ii | 0.84 | 1.88 | 2.7200 (13) | 177 |
O4—H4···O6iii | 0.84 | 2.14 | 2.7366 (14) | 127 |
C14—H14···O2iv | 0.95 | 2.42 | 3.3539 (17) | 167 |
Symmetry codes: (i) x, y−1, z; (ii) x+1/2, −y+1/2, z+1/2; (iii) x+1, y, z+1; (iv) x−1/2, −y+1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C16H16N2O6·C2H6O |
Mr | 378.38 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 100 |
a, b, c (Å) | 7.8347 (1), 17.5412 (3), 13.0230 (2) |
β (°) | 93.936 (1) |
V (Å3) | 1785.53 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.31 × 0.16 × 0.12 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.967, 0.987 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 19580, 5188, 3586 |
Rint | 0.041 |
(sin θ/λ)max (Å−1) | 0.714 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.121, 1.02 |
No. of reflections | 5188 |
No. of parameters | 253 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.41, −0.27 |
Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3 | 0.84 | 2.54 | 2.9325 (13) | 109.4 |
O3—H3···O2 | 0.84 | 2.54 | 2.9325 (13) | 109.8 |
O4—H4···O3 | 0.84 | 2.25 | 2.7009 (14) | 114.2 |
N1—H1'···O7i | 0.88 | 2.04 | 2.8844 (15) | 160 |
O2—H2···O1ii | 0.84 | 1.86 | 2.6871 (13) | 169.7 |
O2—H2···N2ii | 0.84 | 2.57 | 2.9293 (15) | 107.4 |
O3—H3···O1ii | 0.84 | 1.88 | 2.7200 (13) | 176.5 |
O4—H4···O6iii | 0.84 | 2.14 | 2.7366 (14) | 127.3 |
C14—H14···O2iv | 0.95 | 2.42 | 3.3539 (17) | 166.5 |
Symmetry codes: (i) x, y−1, z; (ii) x+1/2, −y+1/2, z+1/2; (iii) x+1, y, z+1; (iv) x−1/2, −y+1/2, z−1/2. |
Acknowledgements
The authors thank the University of Malaya for funding this study (Science Fund Grant 12-0-03-2031, 12-02-03-2051 and PJP FS350-2008)
References
Abdul Alhadi, A. A., Ali, H. M. & Ng, S. W. (2009). Acta Cryst. E65, o909. Web of Science CSD CrossRef IUCr Journals Google Scholar
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Lyubchova, A., Cossé-Barbi, A., Doucet, J. P., Robert, F., Souron, J.-P. & Quarton, M. (1995). Acta Cryst. C51, 1893–1895. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2008). publCIF. In preparation. 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.