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ISSN: 2414-3146

5-(2-Hy­dr­oxy­benzo­yl)-1-methyl-3-nitro­pyridin-2(1H)-one

aDepartment of Physics, Presidency College (Autonomous), Chennai 600 005, India, and bOrganic Chemistry, CSIR Central Leather Research Institute, Adyar, Chennai 600 020, India
*Correspondence e-mail: aspandian59@gmail.com

Edited by K. Fejfarova, Institute of Biotechnology CAS, Czech Republic (Received 7 March 2016; accepted 29 March 2016; online 12 April 2016)

In the title compound, C13H10N2O5, the dihedral angle between the pyridine and phenyl ring is 50.47 (2)°. The hydroxyl H and ketone O atoms form an intra­molecular O—H⋯O hydrogen bond with the hydroxyl group almost coplanar with the phenyl ring. In the crystal, mol­ecules are linked by two C—H⋯O hydrogen bonds, forming dimers. The dimers are linked by further C—H⋯O hydrogen bonds, forming a three-dimensional architecture.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

The title compound is an important nitro­pyridine compound which is widely used in organic synthesis, especially in the synthesis of heterocyclic drugs and cytokine inhibitors (Hu et al., 2011[Hu, Y., Jin, Y. Z., Xiong, Y. P. & Li, Z. C. (2011). Sci. Technol. Eng. 11, 1841-1843.]). Studies of pyridine and pyrimidine derivatives related to the title compound are also of inter­est owing to their putative fluorescence properties (Kawai et al. 2001[Kawai, M., Lee, M. J., Evans, K. O. & Nordlund, T. M. (2001). J. Fluoresc. 11, 23-32.]; Abdullah, 2005[Abdullah, Z. (2005). Int. J. Chem. Sci. 3, 9-15.]). For related crystal structures, see: Aznan et al., (2011[Aznan, A. M. A., Abdullah, Z., Ng, S. W. & Tiekink, E. R. T. (2011). Acta Cryst. E67, o3076.]).

In the title compound the dihedral angle between the pyridine and phenyl ring is 50.47 (2)°. The hydroxyl H and ketone O atoms form an intra­molecular O—H⋯O hydrogen bond with the hydroxyl group almost coplanar with the phenyl ring (Fig. 1[link]). In the crystal, mol­ecules are linked into dimers via two C—H⋯O hydrogen bonds (Table 1[link]), resulting in an [R_{2}^{2}](10) graph-set motif (Fig. 2[link]). The dimers are linked by further C—H⋯O hydrogen bonds, forming a three-dimensional architecture.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯O2 0.82 1.90 2.603 (3) 142
C4—H4⋯O1i 0.93 2.58 3.498 (5) 169
C9—H9⋯O5ii 0.93 2.41 3.311 (3) 164
C13—H13A⋯O4iii 0.96 2.53 3.388 (4) 148
C13—H13B⋯O3ii 0.96 2.59 3.431 (5) 146
Symmetry codes: (i) [-x+{\script{5\over 2}}, y+{\script{1\over 2}}, -z+{\script{5\over 2}}]; (ii) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]; (iii) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}].
[Figure 1]
Figure 1
The mol­ecular structure of the title compound, with the atomic numbering scheme and displacement ellipsoids drawn at 30% probability level.
[Figure 2]
Figure 2
A partial view of the crystal packing of the title compound is viewed along the b axis, showing intra­molecular O—H⋯O hydrogen bonds and mol­ecules linked by C—H⋯O inter­molecular inter­actions (see Table 1[link]).

Synthesis and crystallization

A mixture of 3-formyl­chromone (1 mmol), (Z)-N-methyl-1-(methyl-thio)-2-nitro­ethenamine (1 mmol), and indium tri­fluoro­methane­sulfonate (0.020 mmol) in ethanol (3 ml) were charged in a 25 ml round-bottomed flask and the mixture was heated at reflux. The resulting solution was stirred for 1.5 h. The consumption of the starting material was monitored by TLC. After completion of the reaction, the compound was purified by column chromatography to obtain pure product. The purified compound was recrystallized from ethanol and DMSO-D6 by slow evaporation. The yield of the isolated product was 88%, giving block-like crystals suitable for X-ray diffraction.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C13H10N2O5
Mr 274.23
Crystal system, space group Monoclinic, P21/n
Temperature (K) 293
a, b, c (Å) 7.4998 (8), 13.8350 (14), 12.2324 (12)
β (°) 107.474 (4)
V3) 1210.7 (2)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.12
Crystal size (mm) 0.22 × 0.20 × 0.18
 
Data collection
Diffractometer Bruker Kappa APEXII CCD
Absorption correction Multi-scan (SADABS; Bruker, 2004[Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.974, 0.979
No. of measured, independent and observed [I > 2σ(I)] reflections 18309, 2126, 1288
Rint 0.057
(sin θ/λ)max−1) 0.595
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.056, 0.176, 1.01
No. of reflections 2091
No. of parameters 181
H-atom treatment H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3) 0.42, −0.30
Computer programs: APEX2, SAINT and XPREP (Bruker, 2004[Bruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS97 and SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Structural data


Comment top

The title compound is an important nitropyridine compound which is widely used in organic synthesis, especially in the synthesis of heterocyclic drugs and cytokine inhibitors (Hu et al., 2011). Studies of pyridine and pyrimidine derivatives related to the title compound are of also of interest owing to their putative fluorescence properties (Kawai et al. 2001; Abdullah, 2005).

In the title compound the dihedral angle between the pyridine and phenyl ring is 50.47 (2)°. The hydroxyl H and ketone O atoms form an intra-molecular O-H···O hydrogen bond with the hydroxyl group almost coplanar with the phenyl ring (Figure 1). The molecules are linked into inversion dimers via C-H···O hydrogen bonds resulting in an R22(10) graph-set motif (Bernstein et al., 1995) (Figure 2).

Related literature top

For applications of pyridine derivatives, see: Hu et al. (2011); Kawai et al. (2001); Abdullah, (2005). For related crystal structures, see: Aznan et al., (2011).

Experimental top

A mixture of 3-formylchromone (1 mmol), (Z)-N-methyl-1-(methyl-thio)-2-nitroethenamine (1 mmol), and indium trifluoromethanesulfonate (0.020 mmol) in ethanol (3 ml) were charged in a 25 ml round-bottomed flask and the mixture was heated at reflux. The resulting solution was stirred for 1.5 h. The consumption of the starting material was monitored by TLC. After completion of the reaction, the compound was purified by column chromatography to obtain pure product. The purified compound was recrystallized from ethanol and DMSO-D6 by slow evaporation. The yield of the isolated product was 88%, giving block-like crystals suitable for X-ray diffraction.

Refinement top

Crystal data, data collection and structure refinement details are summarized in Table 2.

Structure description top

The title compound is an important nitropyridine compound which is widely used in organic synthesis, especially in the synthesis of heterocyclic drugs and cytokine inhibitors (Hu et al., 2011). Studies of pyridine and pyrimidine derivatives related to the title compound are also of interest owing to their putative fluorescence properties (Kawai et al. 2001; Abdullah, 2005). For related crystal structures, see: Aznan et al., (2011).

In the title compound the dihedral angle between the pyridine and phenyl ring is 50.47 (2)°. The hydroxyl H and ketone O atoms form an intramolecular O—H···O hydrogen bond with the hydroxyl group almost coplanar with the phenyl ring (Fig. 1). In the crystal, molecules are linked into dimers via two C—H···O hydrogen bonds (Table 1), resulting in an R22(10) graph-set motif (Fig. 2).

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: APEX2 and SAINT (Bruker, 2004); data reduction: SAINT and XPREP (Bruker, 2004); 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, 1997); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with the atomic numbering scheme and displacement ellipsoids drawn at 30% probability level.
[Figure 2] Fig. 2. The crystal packing of the title compound is viewed along the b axis, showing intramolecular O—H···O hydrogen bonds and molecules linked by C—H···O intermolecular interactions along the b axis.
5-(2-Hydroxybenzoyl)-1-methyl-3-nitropyridin-2(1H)-one top
Crystal data top
C13H10N2O5F(000) = 568
Mr = 274.23Dx = 1.505 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1288 reflections
a = 7.4998 (8) Åθ = 2.3–25.0°
b = 13.8350 (14) ŵ = 0.12 mm1
c = 12.2324 (12) ÅT = 293 K
β = 107.474 (4)°Block, colourless
V = 1210.7 (2) Å30.22 × 0.20 × 0.18 mm
Z = 4
Data collection top
Bruker Kappa APEXII CCD
diffractometer
2126 independent reflections
Radiation source: fine-focus sealed tube1288 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.057
ω and φ scanθmax = 25.0°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
h = 88
Tmin = 0.974, Tmax = 0.979k = 1616
18309 measured reflectionsl = 1414
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)] = 0.056Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.176H atoms treated by a mixture of independent and constrained refinement
S = 1.01 w = 1/[σ2(Fo2) + (0.083P)2 + 0.9837P]
where P = (Fo2 + 2Fc2)/3
2091 reflections(Δ/σ)max < 0.001
181 parametersΔρmax = 0.42 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
C13H10N2O5V = 1210.7 (2) Å3
Mr = 274.23Z = 4
Monoclinic, P21/nMo Kα radiation
a = 7.4998 (8) ŵ = 0.12 mm1
b = 13.8350 (14) ÅT = 293 K
c = 12.2324 (12) Å0.22 × 0.20 × 0.18 mm
β = 107.474 (4)°
Data collection top
Bruker Kappa APEXII CCD
diffractometer
2126 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
1288 reflections with I > 2σ(I)
Tmin = 0.974, Tmax = 0.979Rint = 0.057
18309 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0560 restraints
wR(F2) = 0.176H atoms treated by a mixture of independent and constrained refinement
S = 1.01Δρmax = 0.42 e Å3
2091 reflectionsΔρmin = 0.30 e Å3
181 parameters
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
O20.8511 (3)0.05625 (17)1.07410 (18)0.0501 (6)
N20.4933 (3)0.21890 (17)0.95459 (19)0.0352 (6)
O50.2617 (3)0.22615 (17)0.78498 (18)0.0523 (7)
O11.0686 (4)0.0637 (2)1.2845 (2)0.0662 (8)
H10.98080.08231.23070.099*
C80.7065 (4)0.0878 (2)1.0007 (2)0.0338 (7)
C120.6121 (4)0.0460 (2)0.8948 (2)0.0361 (7)
H120.64690.01480.87590.043*
N10.3812 (4)0.0517 (2)0.7088 (2)0.0511 (8)
C90.6406 (4)0.1738 (2)1.0272 (2)0.0357 (7)
H90.69930.20221.09780.043*
C110.4714 (4)0.0938 (2)0.8206 (2)0.0372 (8)
C61.0100 (4)0.0801 (2)1.1684 (2)0.0378 (8)
O30.3589 (5)0.1021 (2)0.6255 (2)0.0864 (10)
C70.8572 (4)0.0327 (2)1.0816 (2)0.0369 (7)
C100.3981 (4)0.1837 (2)0.8458 (2)0.0373 (8)
O40.3364 (4)0.0328 (2)0.7060 (2)0.0750 (9)
C51.0684 (4)0.1731 (3)1.1538 (3)0.0493 (9)
H51.00480.20801.08880.059*
C11.1098 (4)0.0286 (3)1.2664 (3)0.0477 (9)
C130.4218 (5)0.3087 (2)0.9891 (3)0.0538 (10)
H13A0.31730.33120.92770.081*
H13B0.51850.35681.00630.081*
H13C0.38270.29701.05580.081*
C21.2540 (5)0.0719 (4)1.3476 (3)0.0640 (11)
H21.31500.03881.41450.077*
C41.2182 (5)0.2144 (3)1.2333 (3)0.0646 (11)
H41.25820.27611.22160.078*
C31.3088 (5)0.1631 (4)1.3310 (4)0.0726 (13)
H31.40860.19131.38630.087*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O20.0543 (14)0.0430 (15)0.0478 (14)0.0061 (11)0.0074 (11)0.0055 (11)
N20.0360 (14)0.0363 (15)0.0288 (13)0.0027 (11)0.0028 (11)0.0011 (11)
O50.0506 (14)0.0564 (15)0.0388 (13)0.0125 (11)0.0036 (11)0.0050 (11)
O10.0713 (17)0.0667 (19)0.0514 (15)0.0189 (14)0.0047 (13)0.0210 (13)
C80.0338 (16)0.0388 (18)0.0273 (16)0.0004 (13)0.0070 (13)0.0012 (13)
C120.0378 (17)0.0374 (18)0.0327 (17)0.0006 (13)0.0099 (14)0.0022 (13)
N10.0454 (16)0.065 (2)0.0345 (17)0.0050 (15)0.0004 (13)0.0135 (16)
C90.0355 (16)0.0421 (19)0.0247 (15)0.0037 (14)0.0018 (13)0.0010 (13)
C110.0394 (17)0.0409 (19)0.0275 (16)0.0027 (14)0.0042 (14)0.0044 (13)
C60.0337 (16)0.049 (2)0.0291 (17)0.0064 (14)0.0073 (13)0.0012 (14)
O30.121 (3)0.096 (2)0.0275 (14)0.0062 (19)0.0009 (15)0.0046 (15)
C70.0381 (17)0.044 (2)0.0299 (16)0.0054 (14)0.0117 (13)0.0053 (14)
C100.0391 (17)0.0402 (18)0.0285 (16)0.0015 (14)0.0042 (14)0.0036 (14)
O40.0760 (19)0.067 (2)0.0690 (19)0.0128 (15)0.0019 (14)0.0323 (15)
C50.0418 (19)0.056 (2)0.048 (2)0.0010 (16)0.0095 (16)0.0015 (16)
C10.0411 (19)0.065 (2)0.0346 (18)0.0132 (17)0.0078 (15)0.0002 (17)
C130.060 (2)0.048 (2)0.047 (2)0.0135 (17)0.0068 (17)0.0123 (16)
C20.052 (2)0.096 (3)0.036 (2)0.020 (2)0.0003 (18)0.008 (2)
C40.045 (2)0.072 (3)0.072 (3)0.0133 (19)0.010 (2)0.018 (2)
C30.043 (2)0.105 (4)0.058 (3)0.001 (2)0.0036 (19)0.035 (3)
Geometric parameters (Å, º) top
O2—C71.234 (4)C11—C101.431 (4)
N2—C91.345 (4)C6—C51.388 (5)
N2—C101.395 (4)C6—C11.402 (4)
N2—C131.465 (4)C6—C71.463 (4)
O5—C101.219 (3)C5—C41.370 (5)
O1—C11.348 (4)C5—H50.9300
O1—H10.8200C1—C21.367 (5)
C8—C91.364 (4)C13—H13A0.9600
C8—C121.402 (4)C13—H13B0.9600
C8—C71.472 (4)C13—H13C0.9600
C12—C111.342 (4)C2—C31.361 (6)
C12—H120.9300C2—H20.9300
N1—O31.205 (4)C4—C31.381 (6)
N1—O41.214 (4)C4—H40.9300
N1—C111.453 (4)C3—H30.9300
C9—H90.9300
C9—N2—C10123.5 (3)O5—C10—N2120.6 (3)
C9—N2—C13120.2 (2)O5—C10—C11126.4 (3)
C10—N2—C13116.3 (2)N2—C10—C11112.9 (2)
C1—O1—H1109.5C4—C5—C6121.2 (3)
C9—C8—C12117.5 (3)C4—C5—H5119.4
C9—C8—C7123.5 (3)C6—C5—H5119.4
C12—C8—C7118.7 (3)O1—C1—C2117.8 (3)
C11—C12—C8119.8 (3)O1—C1—C6122.2 (3)
C11—C12—H12120.1C2—C1—C6120.0 (4)
C8—C12—H12120.1N2—C13—H13A109.5
O3—N1—O4124.5 (3)N2—C13—H13B109.5
O3—N1—C11118.2 (3)H13A—C13—H13B109.5
O4—N1—C11117.3 (3)N2—C13—H13C109.5
N2—C9—C8122.1 (3)H13A—C13—H13C109.5
N2—C9—H9118.9H13B—C13—H13C109.5
C8—C9—H9118.9C3—C2—C1120.5 (4)
C12—C11—C10123.9 (3)C3—C2—H2119.8
C12—C11—N1119.2 (3)C1—C2—H2119.8
C10—C11—N1116.8 (3)C5—C4—C3119.1 (4)
C5—C6—C1118.3 (3)C5—C4—H4120.5
C5—C6—C7122.0 (3)C3—C4—H4120.5
C1—C6—C7119.6 (3)C2—C3—C4120.8 (3)
O2—C7—C6120.3 (3)C2—C3—H3119.6
O2—C7—C8117.6 (3)C4—C3—H3119.6
C6—C7—C8122.1 (3)
C9—C8—C12—C114.7 (4)C9—N2—C10—O5177.7 (3)
C7—C8—C12—C11178.5 (3)C13—N2—C10—O50.9 (4)
C10—N2—C9—C81.5 (5)C9—N2—C10—C111.1 (4)
C13—N2—C9—C8177.0 (3)C13—N2—C10—C11177.5 (3)
C12—C8—C9—N21.4 (4)C12—C11—C10—O5173.9 (3)
C7—C8—C9—N2174.9 (3)N1—C11—C10—O53.9 (5)
C8—C12—C11—C105.4 (5)C12—C11—C10—N22.4 (4)
C8—C12—C11—N1176.9 (3)N1—C11—C10—N2179.8 (3)
O3—N1—C11—C12131.4 (3)C1—C6—C5—C40.8 (5)
O4—N1—C11—C1247.3 (4)C7—C6—C5—C4176.5 (3)
O3—N1—C11—C1050.7 (4)C5—C6—C1—O1176.5 (3)
O4—N1—C11—C10130.6 (3)C7—C6—C1—O10.7 (5)
C5—C6—C7—O2153.2 (3)C5—C6—C1—C23.5 (5)
C1—C6—C7—O222.5 (4)C7—C6—C1—C2179.4 (3)
C5—C6—C7—C826.8 (4)O1—C1—C2—C3176.3 (3)
C1—C6—C7—C8157.5 (3)C6—C1—C2—C33.7 (5)
C9—C8—C7—O2147.5 (3)C6—C5—C4—C31.7 (6)
C12—C8—C7—O225.8 (4)C1—C2—C3—C41.2 (6)
C9—C8—C7—C632.4 (4)C5—C4—C3—C21.6 (6)
C12—C8—C7—C6154.2 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O20.821.902.603 (3)142
C4—H4···O1i0.932.583.498 (5)169
C9—H9···O5ii0.932.413.311 (3)164
C13—H13A···O4iii0.962.533.388 (4)148
C13—H13B···O3ii0.962.593.431 (5)146
Symmetry codes: (i) x+5/2, y+1/2, z+5/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y+1/2, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O20.821.902.603 (3)142
C4—H4···O1i0.932.583.498 (5)169
C9—H9···O5ii0.932.413.311 (3)164
C13—H13A···O4iii0.962.533.388 (4)148
C13—H13B···O3ii0.962.593.431 (5)146
Symmetry codes: (i) x+5/2, y+1/2, z+5/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y+1/2, z+3/2.

Experimental details

Crystal data
Chemical formulaC13H10N2O5
Mr274.23
Crystal system, space groupMonoclinic, P21/n
Temperature (K)293
a, b, c (Å)7.4998 (8), 13.8350 (14), 12.2324 (12)
β (°) 107.474 (4)
V3)1210.7 (2)
Z4
Radiation typeMo Kα
µ (mm1)0.12
Crystal size (mm)0.22 × 0.20 × 0.18
Data collection
DiffractometerBruker Kappa APEXII CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2004)
Tmin, Tmax0.974, 0.979
No. of measured, independent and
observed [I > 2σ(I)] reflections
18309, 2126, 1288
Rint0.057
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.056, 0.176, 1.01
No. of reflections2091
No. of parameters181
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.42, 0.30

Computer programs: APEX2 (Bruker, 2004), APEX2 and SAINT (Bruker, 2004), SAINT and XPREP (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), PLATON (Spek, 2009).

 

Acknowledgements

The authors thank Dr Babu Varghese, SAIF, IIT, Chennai, India, for the data collection.

References

First citationAbdullah, Z. (2005). Int. J. Chem. Sci. 3, 9–15.  CAS Google Scholar
First citationAznan, A. M. A., Abdullah, Z., Ng, S. W. & Tiekink, E. R. T. (2011). Acta Cryst. E67, o3076.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationBruker (2004). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationHu, Y., Jin, Y. Z., Xiong, Y. P. & Li, Z. C. (2011). Sci. Technol. Eng. 11, 1841–1843.  Google Scholar
First citationKawai, M., Lee, M. J., Evans, K. O. & Nordlund, T. M. (2001). J. Fluoresc. 11, 23–32.  Web of Science CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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