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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 9| September 2010| Page o2349
https://doi.org/10.1107/S1600536810032198

(1E,2E)-1,2-Bis(2,2-di­phenyl­hydrazin-1-yl­­idene)ethane

Angel Mendoza,a* Blanca M. Cabrera-Vivas,b Ruth Meléndrez-Luevano,b Juan C. Ramírezb and Marcos Flores-Alamoc

aCentro de Química, ICUAP, Benemérita Universidad Autónoma de Puebla, Puebla, Pue., Mexico, bFacultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, Pue., Mexico, and cFacultad de Química, Universidad Nacional Autónoma de México, 04510 México DF, Mexico
*Correspondence e-mail: angel.mendoza.m@gmail.com

(Received 3 August 2010; accepted 10 August 2010; online 18 August 2010)

In the crystal structure of the title compound, C26H22N4, the mol­ecule is located on an inversion centre and shows an E configuration with respect to each C=N bond. The dihedral angle between the phenyl rings in the diphenyl­hydrazone group is 83.69 (11)°. These two rings make dihedral angles of 30.53 (15) and 84.53 (16)° with the central N—N=C—C=N—N dihydrazonoethane plane. Inter­molecular C—H⋯π inter­actions are observed.

Related literature

For applications of hydrazones, see: Angell et al. (2006[Angell, S. E., Rogers, C. W., Zhang, Y., Wolf, M. O. & Jones, W. E. Jr (2006). Coord. Chem. Rev. 250, 1829-1841.]); Ibañez et al. (2002[Ibañez, G. A., Escandar, G. M. & Olivieri, A. C. (2002). J. Mol. Struct. 605, 17-26.]). For related structures, see: Clulow et al. (2008[Clulow, A. J., Selby, J. D., Cushion, M. G., Schwarz, A. D. & Mountford, P. (2008). Inorg. Chem. 47, 12049-12062.]); Mendoza et al. (2010[Mendoza, A., Cabrera-Vivas, B. M., Meléndrez-Luevano, R., Pacheco-Álvarez, T. & Carranza, V. (2010). Acta Cryst. E66, o2058.]). For bond-length data, see: Allen et al. (1987[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.]).

[Scheme 1]

Experimental

Crystal data

  • C26H22N4

  • Mr = 390.48

  • Monoclinic, P 21 /n

  • a = 12.2210 (19) Å

  • b = 5.612 (1) Å

  • c = 15.731 (3) Å

  • β = 103.924 (16)°

  • V = 1047.2 (3) Å3

  • Z = 2

  • Cu Kα radiation

  • μ = 0.58 mm−1

  • T = 298 K

  • 0.19 × 0.11 × 0.05 mm
Data collection

  • Oxford Xcalibur Atlas Gemini diffractometer

  • Absorption correction: analytical (CrysAlis PRO; Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]) Tmin = 0.978, Tmax = 0.993

  • 3621 measured reflections

  • 1892 independent reflections

  • 1163 reflections with I > 2σ(I)

  • Rint = 0.038
Refinement

  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.113

  • S = 1.01

  • 1892 reflections

  • 137 parameters

  • H-atom parameters constrained

  • Δρmax = 0.13 e Å−3

  • Δρmin = −0.14 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 and Cg2 are the centroids of the C1–C6 and C7–C12 rings, respectively.
D—H⋯A D—H H⋯A D⋯A D—H⋯A
C3—H3⋯Cg2i 0.93 2.85 3.728 (3) 159
C8—H8⋯Cg1ii 0.93 2.88 3.785 (3) 164
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) x-1, y, z.

Data collection: CrysAlis CCD (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]); cell refinement: CrysAlis RED (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]); data reduction: CrysAlis RED; 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, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810032198/is2589sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810032198/is2589Isup2.hkl

checkCIF report


Comment top

Among the most interesting applications of hydrazones, molecular sensing is worth mentioning. They are being used widely to detect chemical and biological species (Angell et al., 2006). Also, hydrazones are being applied as plasticizer agents, polymerization initiators and antioxidants (Ibañez et al., 2002). There are pigments, as 1-fenilazo-2-naftol, that show an azo/hydrazone tautomery in which the main tautomer exist as hydrazone form.

The asymmetric unit of the title compound I consist of C13H11N2 with a Z' = 0.5 showing a centrosymmetrical structure. The compound I (C26H22N4) present an E configuration for each C═N double bond (Fig. 1), with N,N-diphenyl group opposite to second C═N group. The molecule shows a non-planar structure for phenyl rings respect to N—N group, with a torsion angle between them C2—C1—N1—C7 = 46.6 (3)°. The torsion angle of phenyl ring C1/C2/C3/C4/C5/C6 to N—N═C group is -173.48 (18)°, and the other ring C7/C8/C9/C10/C11/C12 shows a torsion angle of -14.9 (3)° to the same group. The N—N distance [1.364 (2) Å] is shorter than found in free diphenylhydrazine [1.418 (2) Å] (Clulow et al., 2008). Imine bond distance, N2═C13 [1.287 (2) Å], is longer than N═C typical bond (Allen et al., 1987), but similar [1.286 (3) Å] to related structures with N,N-diphenylhidrazone group (Mendoza et al., 2010).

Related literature top

For applications of hydrazones, see: Angell et al. (2006); Ibañez et al. (2002). For related structures, see: Clulow et al. (2008); Mendoza et al. (2010). For bond-length data, see: Allen et al. (1987).

Experimental top

N,N-diphenylhydrazine (2.74 mg, 12.4 mmol) was dissolved in ethanol and acetic acid (0.5 ml) was added slowly into this solution while stirring. Glyoxal (300 mg, 5.1 mmol) was added drop by drop into the above solution with strong stirring and the resulting mixture was kept at atmospheric temperature until it became yellow solution. After three hours, the amber solution turns to be precipitated. The mixture was separated with filtration in vacuum system and the precipitate was washed three times with cold methanol. Recrystallization was performed several times with acetonitrile, to obtain needle crystals suitable for X-ray analysis. Yield: 1.79 g (90%) at 25 °C, mp. 185–189 °C. FT–IR (film): (cm-1): 3062 ν(C—H), 1750–2000 ν(Ph), 1591, 1544, 1490 ν(C═N). EI–MS: m/z 390 M+.

Refinement top

H atoms were placed in geometrical idealized positions (C—H = 0.93 Å) and refined as riding on their parent atoms, with Uiso(H) = 1.2Ueq(C).

Structure description top

Among the most interesting applications of hydrazones, molecular sensing is worth mentioning. They are being used widely to detect chemical and biological species (Angell et al., 2006). Also, hydrazones are being applied as plasticizer agents, polymerization initiators and antioxidants (Ibañez et al., 2002). There are pigments, as 1-fenilazo-2-naftol, that show an azo/hydrazone tautomery in which the main tautomer exist as hydrazone form.

The asymmetric unit of the title compound I consist of C13H11N2 with a Z' = 0.5 showing a centrosymmetrical structure. The compound I (C26H22N4) present an E configuration for each C═N double bond (Fig. 1), with N,N-diphenyl group opposite to second C═N group. The molecule shows a non-planar structure for phenyl rings respect to N—N group, with a torsion angle between them C2—C1—N1—C7 = 46.6 (3)°. The torsion angle of phenyl ring C1/C2/C3/C4/C5/C6 to N—N═C group is -173.48 (18)°, and the other ring C7/C8/C9/C10/C11/C12 shows a torsion angle of -14.9 (3)° to the same group. The N—N distance [1.364 (2) Å] is shorter than found in free diphenylhydrazine [1.418 (2) Å] (Clulow et al., 2008). Imine bond distance, N2═C13 [1.287 (2) Å], is longer than N═C typical bond (Allen et al., 1987), but similar [1.286 (3) Å] to related structures with N,N-diphenylhidrazone group (Mendoza et al., 2010).

For applications of hydrazones, see: Angell et al. (2006); Ibañez et al. (2002). For related structures, see: Clulow et al. (2008); Mendoza et al. (2010). For bond-length data, see: Allen et al. (1987).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); 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: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The molecular structure of compound I, with atom labels and 50% probability displacement ellipsoids for non-H atoms.
(1E,2E)-1,2-Bis(2,2-diphenylhydrazin-1-ylidene)ethane top
Crystal data top
C26H22N4F(000) = 412
Mr = 390.48Dx = 1.238 Mg m−3
Monoclinic, P21/nCu Kα radiation, λ = 1.5418 Å
a = 12.2210 (19) ÅCell parameters from 864 reflections
b = 5.612 (1) Åθ = 3.7–68.0°
c = 15.731 (3) ŵ = 0.58 mm−1
β = 103.924 (16)°T = 298 K
V = 1047.2 (3) Å3Prism, colourless
Z = 20.19 × 0.11 × 0.05 mm
Data collection top
Oxford Xcalibur Atlas Gemini
diffractometer		1892 independent reflections
Graphite monochromator1163 reflections with I > 2σ(I)
Detector resolution: 10.4685 pixels mm-1Rint = 0.038
ω scansθmax = 68.2°, θmin = 4.1°
Absorption correction: analytical
(CrysAlis PRO; Oxford Diffraction, 2010)		h = −14→14
Tmin = 0.978, Tmax = 0.993k = −4→6
3621 measured reflectionsl = −18→10
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)] = 0.044H-atom parameters constrained
wR(F2) = 0.113 w = 1/[σ2(Fo2) + (0.0496P)2 + 0.0674P]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
1892 reflectionsΔρmax = 0.13 e Å−3
137 parametersΔρmin = −0.14 e Å−3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0134 (9)
Crystal data top
C26H22N4V = 1047.2 (3) Å3
Mr = 390.48Z = 2
Monoclinic, P21/nCu Kα radiation
a = 12.2210 (19) ŵ = 0.58 mm−1
b = 5.612 (1) ÅT = 298 K
c = 15.731 (3) Å0.19 × 0.11 × 0.05 mm
β = 103.924 (16)°
Data collection top
Oxford Xcalibur Atlas Gemini
diffractometer		1892 independent reflections
Absorption correction: analytical
(CrysAlis PRO; Oxford Diffraction, 2010)		1163 reflections with I > 2σ(I)
Tmin = 0.978, Tmax = 0.993Rint = 0.038
3621 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.113H-atom parameters constrained
S = 1.01Δρmax = 0.13 e Å−3
1892 reflectionsΔρmin = −0.14 e Å−3
137 parameters
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
N20.09341 (13)0.1892 (3)0.46419 (10)0.0451 (5)
N10.20416 (13)0.2544 (3)0.48657 (10)0.0481 (5)
C10.23555 (16)0.4384 (4)0.43534 (12)0.0421 (5)
C130.05715 (15)0.0396 (4)0.51307 (13)0.0451 (5)
H130.1046−0.01610.56460.054*
C120.27665 (18)0.3696 (4)0.63743 (14)0.0541 (6)
H120.23070.50370.62650.065*
C70.27471 (15)0.2080 (4)0.57158 (12)0.0415 (5)
C60.16000 (18)0.6077 (4)0.39339 (13)0.0494 (5)
H60.08590.60440.39880.059*
C20.34652 (17)0.4494 (4)0.42837 (13)0.0532 (6)
H20.39880.33820.45740.064*
C50.1938 (2)0.7827 (4)0.34321 (14)0.0587 (6)
H50.14220.89560.31470.07*
C80.33966 (18)0.0069 (4)0.58755 (15)0.0572 (6)
H80.3374−0.10490.54350.069*
C30.3793 (2)0.6255 (4)0.37837 (15)0.0623 (7)
H30.45380.63190.37390.075*
C40.3036 (2)0.7904 (4)0.33537 (15)0.0640 (7)
H40.32610.90690.30110.077*
C100.4116 (2)0.1382 (6)0.73586 (17)0.0726 (8)
H100.45850.1150.79130.087*
C90.40936 (19)−0.0277 (5)0.67093 (19)0.0722 (8)
H90.4544−0.1630.68270.087*
C110.3458 (2)0.3350 (5)0.71930 (15)0.0708 (8)
H110.34730.44650.76330.085*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N20.0382 (9)0.0534 (11)0.0436 (10)−0.0137 (8)0.0099 (7)−0.0026 (8)
N10.0372 (9)0.0609 (11)0.0446 (10)−0.0163 (8)0.0066 (7)0.0080 (9)
C10.0439 (11)0.0468 (12)0.0357 (10)−0.0134 (10)0.0096 (8)−0.0006 (9)
C130.0391 (10)0.0537 (13)0.0428 (11)−0.0106 (10)0.0101 (9)0.0036 (11)
C120.0544 (13)0.0597 (14)0.0500 (13)−0.0014 (12)0.0161 (10)0.0011 (12)
C70.0352 (10)0.0470 (12)0.0438 (11)−0.0101 (10)0.0125 (8)0.0036 (10)
C60.0480 (12)0.0532 (13)0.0470 (12)−0.0083 (11)0.0113 (10)−0.0035 (11)
C20.0461 (12)0.0587 (14)0.0564 (13)−0.0081 (11)0.0157 (10)0.0069 (11)
C50.0705 (16)0.0501 (14)0.0523 (13)−0.0041 (12)0.0087 (11)0.0069 (11)
C80.0512 (13)0.0509 (13)0.0713 (16)−0.0074 (12)0.0184 (12)0.0017 (13)
C30.0574 (14)0.0731 (16)0.0640 (15)−0.0158 (13)0.0297 (12)0.0068 (13)
C40.0806 (17)0.0612 (16)0.0540 (14)−0.0189 (14)0.0234 (12)0.0076 (12)
C100.0544 (14)0.102 (2)0.0554 (16)−0.0156 (16)0.0024 (12)0.0226 (16)
C90.0484 (13)0.0676 (17)0.098 (2)0.0028 (13)0.0116 (14)0.0304 (16)
C110.0731 (16)0.092 (2)0.0463 (14)−0.0098 (16)0.0125 (12)−0.0014 (14)
Geometric parameters (Å, º) top
N2—C131.287 (2)C2—C31.381 (3)
N2—N11.364 (2)C2—H20.93
N1—C11.418 (2)C5—C41.377 (3)
N1—C71.430 (2)C5—H50.93
C1—C61.377 (3)C8—C91.395 (3)
C1—C21.388 (3)C8—H80.93
C13—C13i1.429 (4)C3—C41.367 (3)
C13—H130.93C3—H30.93
C12—C71.373 (3)C4—H40.93
C12—C111.373 (3)C10—C111.354 (3)
C12—H120.93C10—C91.377 (4)
C7—C81.368 (3)C10—H100.93
C6—C51.384 (3)C9—H90.93
C6—H60.93C11—H110.93
C13—N2—N1118.93 (16)C4—C5—C6120.3 (2)
N2—N1—C1115.85 (16)C4—C5—H5119.9
N2—N1—C7122.01 (14)C6—C5—H5119.9
C1—N1—C7118.63 (15)C7—C8—C9118.9 (2)
C6—C1—C2119.11 (19)C7—C8—H8120.5
C6—C1—N1122.18 (18)C9—C8—H8120.5
C2—C1—N1118.71 (19)C4—C3—C2120.8 (2)
N2—C13—C13i119.0 (2)C4—C3—H3119.6
N2—C13—H13120.5C2—C3—H3119.6
C13i—C13—H13120.5C3—C4—C5119.5 (2)
C7—C12—C11120.6 (2)C3—C4—H4120.2
C7—C12—H12119.7C5—C4—H4120.2
C11—C12—H12119.7C11—C10—C9120.2 (2)
C8—C7—C12120.2 (2)C11—C10—H10119.9
C8—C7—N1120.98 (19)C9—C10—H10119.9
C12—C7—N1118.86 (19)C10—C9—C8120.1 (2)
C1—C6—C5120.3 (2)C10—C9—H9119.9
C1—C6—H6119.8C8—C9—H9119.9
C5—C6—H6119.8C10—C11—C12119.9 (2)
C3—C2—C1120.0 (2)C10—C11—H11120.1
C3—C2—H2120C12—C11—H11120.1
C1—C2—H2120
C13—N2—N1—C1−173.48 (18)N1—C1—C6—C5−179.26 (18)
C13—N2—N1—C7−14.9 (3)C6—C1—C2—C3−1.3 (3)
N2—N1—C1—C626.8 (3)N1—C1—C2—C3179.48 (18)
C7—N1—C1—C6−132.5 (2)C1—C6—C5—C4−0.6 (3)
N2—N1—C1—C2−154.06 (18)C12—C7—C8—C9−1.5 (3)
C7—N1—C1—C246.6 (3)N1—C7—C8—C9178.36 (18)
N1—N2—C13—C13i−176.3 (2)C1—C2—C3—C40.0 (3)
C11—C12—C7—C81.7 (3)C2—C3—C4—C51.0 (4)
C11—C12—C7—N1−178.09 (18)C6—C5—C4—C3−0.8 (3)
N2—N1—C7—C893.9 (2)C11—C10—C9—C80.4 (4)
C1—N1—C7—C8−108.1 (2)C7—C8—C9—C100.4 (3)
N2—N1—C7—C12−86.3 (2)C9—C10—C11—C12−0.1 (4)
C1—N1—C7—C1271.7 (2)C7—C12—C11—C10−0.9 (3)
C2—C1—C6—C51.6 (3)
Symmetry code: (i) −x, −y, −z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···Cg2ii0.932.853.728 (3)159
C8—H8···Cg1iii0.932.883.785 (3)164
Symmetry codes: (ii) −x+1, −y+1, −z+1; (iii) x−1, y, z.

Experimental details

Crystal data
Chemical formulaC26H22N4
Mr390.48
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)12.2210 (19), 5.612 (1), 15.731 (3)
β (°) 103.924 (16)
V (Å3)1047.2 (3)
Z2
Radiation typeCu Kα
µ (mm−1)0.58
Crystal size (mm)0.19 × 0.11 × 0.05
Data collection
DiffractometerOxford Xcalibur Atlas Gemini
Absorption correctionAnalytical
(CrysAlis PRO; Oxford Diffraction, 2010)
Tmin, Tmax0.978, 0.993
No. of measured, independent and
observed [I > 2σ(I)] reflections		3621, 1892, 1163
Rint0.038
(sin θ/λ)max (Å−1)0.602
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.113, 1.01
No. of reflections1892
No. of parameters137
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.13, −0.14

Computer programs: CrysAlis CCD (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···Cg2i0.932.853.728 (3)159
C8—H8···Cg1ii0.932.883.785 (3)164
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x−1, y, z.
 

Acknowledgements

The authors gratefully acknowledge financial support from the Facultad de Ciencias Químicas (BUAP).

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CSD CrossRef Web of Science Google Scholar
 First citationAngell, S. E., Rogers, C. W., Zhang, Y., Wolf, M. O. & Jones, W. E. Jr (2006). Coord. Chem. Rev. 250, 1829–1841.  Web of Science CrossRef CAS Google Scholar
 First citationClulow, A. J., Selby, J. D., Cushion, M. G., Schwarz, A. D. & Mountford, P. (2008). Inorg. Chem. 47, 12049–12062.  Web of Science CSD CrossRef PubMed CAS Google Scholar
 First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
 First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
 First citationIbañez, G. A., Escandar, G. M. & Olivieri, A. C. (2002). J. Mol. Struct. 605, 17–26.  Google Scholar
 First citationMendoza, A., Cabrera-Vivas, B. M., Meléndrez-Luevano, R., Pacheco-Álvarez, T. & Carranza, V. (2010). Acta Cryst. E66, o2058.  Web of Science CrossRef IUCr Journals Google Scholar
 First citationOxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.  Google Scholar
 First citationOxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.  Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
Volume 66| Part 9| September 2010| Page o2349
https://doi.org/10.1107/S1600536810032198
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