Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Previous article
Next article
Previous article
Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Next article

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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 7| July 2012| Pages o2293-o2294
https://doi.org/10.1107/S1600536812028309

4-(Prop-2-yn-1-yl­­oxy)benzene-1,2-dicarbo­nitrile

Yee Jan Chin,a Ai Ling Tan,a Franz L. Wimmer,a Aminul Huq Mirza,a David J. Young,a‡ Seik Weng Ngb,c and Edward R. T. Tiekinkb*

aFaculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link BE 1410, Negara, Brunei Darussalam, bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and cChemistry Department and Faculty of Science, King Abdulaziz University, PO Box 80203 Jeddah, Saudi Arabia
*Correspondence e-mail: edward.tiekink@gmail.com

(Received 19 June 2012; accepted 22 June 2012; online 30 June 2012)

In the title compound, C11H6N2O, the complete mol­ecule is generated by the application of crystallographic twofold symmetry (the mol­ecule is disordered about this axis). The prop-2-yn-1-yl residue is slightly twisted out of the plane of the benzene ring [C—O—C—C torsion angle = 173.1 (3)°] and is orientated away from the nitrile substituents. In the crystal, supra­molecular chains along the a axis, arising from C—H⋯N inter­actions, are connected into stacks along the c axis by π–π inter­actions between the benzene rings [centroid–centroid distance = 3.6978 (6) Å = length of the c axis].

Related literature

For the solubilization and some applications of phthanocyanine dyes, see: Jiang et al. (2011[Jiang, X.-J., Yeung, S.-L., Lo, P.-C., Fong, W. P. & Ng, D. K. P. (2011). J. Med. Chem. 54, 320-330.]); Sleven et al. (2001[Sleven, J., Görller-Walrand, C. & Binnemans, K. (2001). Mater. Sci. Eng. C, 18, 229-238.]). For the synthesis of substituted phthalonitriles, see: Wöhrle et al. (1993[Wöhrle, D., Eskes, M., Shigehara, K. & Yamada, A. (1993). Synthesis, pp. 194-196.]); Wu et al. (1998[Wu, Y., Tian, H., Chen, K., Liu, Y. & Zhu, D. (1998). Dyes Pigm. 37, 317-325.]); Li & Lieberman (2001[Li, Z. & Lieberman, M. (2001). Inorg. Chem. 40, 932-939.]); Sleven et al. (2001[Sleven, J., Görller-Walrand, C. & Binnemans, K. (2001). Mater. Sci. Eng. C, 18, 229-238.]); Li et al. (2008[Li, H., Jensen, T. J., Fronczek, F. R. & Vicente, G. H. (2008). J. Med. Chem. 51, 502-511.]); Seven et al. (2009[Seven, O., Dindar, B. & Gultekin, B. (2009). Turk. J. Chem. 33, 123-134.]); Foo et al. (2012[Foo, C. C., Tan, A. L., Wimmer, F. L., Mirza, A. H., Young, D. J., Ng, S. W. & Tiekink, E. R. T. (2012). Acta Cryst. E68, o601.]).

[Scheme 1]

Experimental

Crystal data

  • C11H6N2O

  • Mr = 182.18

  • Monoclinic, C 2/m

  • a = 11.4809 (9) Å

  • b = 22.2091 (16) Å

  • c = 3.6978 (6) Å

  • β = 91.304 (10)°

  • V = 942.62 (18) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 100 K

  • 0.15 × 0.05 × 0.05 mm
Data collection

  • Agilent SuperNova Dual diffractometer with an Atlas detector

  • Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, Oxfordshire, England.]) Tmin = 0.792, Tmax = 1.000

  • 3258 measured reflections

  • 1114 independent reflections

  • 840 reflections with I > 2σ(I)

  • Rint = 0.038
Refinement

  • R[F2 > 2σ(F2)] = 0.059

  • wR(F2) = 0.163

  • S = 1.08

  • 1114 reflections

  • 86 parameters

  • 12 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.41 e Å−3

  • Δρmin = −0.28 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
C3—H3⋯N1i 0.95 2.62 3.509 (3) 155
Symmetry code: (i) [-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1].

Data collection: CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, Oxfordshire, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and DIAMOND (Brandenburg, 2006[Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536812028309/hb6862sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812028309/hb6862Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536812028309/hb6862Isup3.cml

checkCIF report


Comment top

Phthalocyanine dyes can be made soluble in water and organic solvents by addition of suitable alkoxy or aryloxy groups (Jiang et al., 2011; Sleven et al., 2001). This is most easily achieved from the correspondingly substituted phthalonitriles which, in turn, are either prepared by Sandmeyer reaction of alkyl or alkoxy functionalized dihalobenzenes (Li & Lieberman, 2001; Sleven et al., 2001) or aryloxy / alkoxy displacement of the corresponding halophthalonitrile (Wöhrle et al., 1993; Li et al., 2008; Foo et al., 2012) or 4-nitrophthalonitrile (Wu et al., 1998; Seven et al., 2009). The latter method is most suitable for preparing 4-alkoxyphthalonitriles and was used for preparing the title compound, 4-(prop-2-ylnyloxy)phthalonitrile (I).

In (I), Fig. 1, the complete molecule is generated by the application of 2-fold symmetry; the molecule is disordered about this axis. The O1 and C1 atoms lie -0.067 (3) and 0.059 (2) Å out of the plane through the benzene ring, respectively. The prop-2-yn-1-yl is twisted out of the plane of the benzene ring as seen in the value of the C4—O1—C5—C6 torsion angle of 173.1 (3)° and is orientated in the opposite direction to the nitrile substituents.

In the crystal packing, supramolecular chains along the a axis feature owing to C—H···N interactions, Table 1, and 10-membered {···HC3N}2 synthons, Fig. 2. Chains are connected into stacks along the c axis by π—π interactions between the benzene rings [inter-centroid distance = 3.6978 (6) Å = length of the c axis]. The layers inter-digitate along the b axis with no specific intermolecular interactions between them.

Related literature top

For the solubilization and some applications of phthanocyanine dyes, see: Jiang et al. (2011); Sleven et al. (2001). For the synthesis of substituted phthalonitriles, see: Wöhrle et al. (1993); Wu et al. (1998); Li & Lieberman (2001); Sleven et al. (2001); Li et al. (2008); Seven et al. (2009); Foo et al. (2012).

Experimental top

The title compound was prepared by modification of literature procedures (Wu et al., 1998; Seven et al., 2009). Under a nitrogen atmosphere, anhydrous potassium carbonate (1.12 g, 8.1 mmol) was added in two portions at 1 h intervals to a solution of propargyl alcohol (1.5 ml, 26.0 mmol) and 4-nitrophthalonitrile (0.70 g, 4.04 mmol) in dry N,N-dimethylformamide (7 ml). After 96 h, the crude reaction mixture was poured into water (140 ml). The green precipitate was collected by vacuum filtration, washed with water and dried. The crude product was purified by silica gel column chromatography using dichloromethane as eluent to provide 0.4 g (63.9%) of a faintly coloured solid that was recrystallized from CH2Cl2 / hexane as colourless prisms. Melting point = 383 K. IR ν/cm-1: 3287, 3119, 3077, 2231, 2135, 1596, 1494, 1321, 1260. 1H NMR 400 MHz (CDCl3) δ: 7.75 (1H, d), 7.35 (1H, s), 7.28 (1H, d), 4.80 (2H, s), 2.62 (1H, s).

Refinement top

With the exception of the acetylenic H-atom which was refined freely, carbon-bound H-atoms were placed in calculated positions [C—H = 0.95–0.99 Å, Uiso(H) = 1.2Ueq(C)] and were included in the refinement in the riding model approximation. The molecule is disordered over a 2-fold rotation axis in an exact 1:1 ratio. The anisotropic displacement parameters of the O1 and C4 atoms were tightly restrained to be nearly isotropic.

Structure description top

Phthalocyanine dyes can be made soluble in water and organic solvents by addition of suitable alkoxy or aryloxy groups (Jiang et al., 2011; Sleven et al., 2001). This is most easily achieved from the correspondingly substituted phthalonitriles which, in turn, are either prepared by Sandmeyer reaction of alkyl or alkoxy functionalized dihalobenzenes (Li & Lieberman, 2001; Sleven et al., 2001) or aryloxy / alkoxy displacement of the corresponding halophthalonitrile (Wöhrle et al., 1993; Li et al., 2008; Foo et al., 2012) or 4-nitrophthalonitrile (Wu et al., 1998; Seven et al., 2009). The latter method is most suitable for preparing 4-alkoxyphthalonitriles and was used for preparing the title compound, 4-(prop-2-ylnyloxy)phthalonitrile (I).

In (I), Fig. 1, the complete molecule is generated by the application of 2-fold symmetry; the molecule is disordered about this axis. The O1 and C1 atoms lie -0.067 (3) and 0.059 (2) Å out of the plane through the benzene ring, respectively. The prop-2-yn-1-yl is twisted out of the plane of the benzene ring as seen in the value of the C4—O1—C5—C6 torsion angle of 173.1 (3)° and is orientated in the opposite direction to the nitrile substituents.

In the crystal packing, supramolecular chains along the a axis feature owing to C—H···N interactions, Table 1, and 10-membered {···HC3N}2 synthons, Fig. 2. Chains are connected into stacks along the c axis by π—π interactions between the benzene rings [inter-centroid distance = 3.6978 (6) Å = length of the c axis]. The layers inter-digitate along the b axis with no specific intermolecular interactions between them.

For the solubilization and some applications of phthanocyanine dyes, see: Jiang et al. (2011); Sleven et al. (2001). For the synthesis of substituted phthalonitriles, see: Wöhrle et al. (1993); Wu et al. (1998); Li & Lieberman (2001); Sleven et al. (2001); Li et al. (2008); Seven et al. (2009); Foo et al. (2012).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) showing displacement ellipsoids at the 50% probability level. The molecule is disordered about the 2-fold axis - only one orientation is shown.
[Figure 2] Fig. 2. A view of the supramolecular chain along the a axis in (I). The C—H···N and interactions are shown as blue dashed lines.
[Figure 3] Fig. 3. A view of the supramolecular layer in the ac plane in (I). The C—H···O and π—π interactions are shown as blue and purple dashed lines, respectively.
4-(Prop-2-yn-1-yloxy)benzene-1,2-dicarbonitrile top
Crystal data top
C11H6N2OF(000) = 376
Mr = 182.18Dx = 1.284 Mg m−3
Monoclinic, C2/mMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yCell parameters from 938 reflections
a = 11.4809 (9) Åθ = 3.3–27.5°
b = 22.2091 (16) ŵ = 0.09 mm−1
c = 3.6978 (6) ÅT = 100 K
β = 91.304 (10)°Prism, colourless
V = 942.62 (18) Å30.15 × 0.05 × 0.05 mm
Z = 4
Data collection top
Agilent SuperNova Dual
diffractometer with an Atlas detector		1114 independent reflections
Radiation source: fine-focus sealed tube840 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.038
Detector resolution: 10.4041 pixels mm-1θmax = 27.6°, θmin = 3.3°
ω scanh = −14→14
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2012)		k = −26→28
Tmin = 0.792, Tmax = 1.000l = −4→4
3258 measured reflections
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)] = 0.059Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.163H atoms treated by a mixture of independent and constrained refinement
S = 1.08 w = 1/[σ2(Fo2) + (0.0718P)2 + 0.8054P]
where P = (Fo2 + 2Fc2)/3
1114 reflections(Δ/σ)max < 0.001
86 parametersΔρmax = 0.41 e Å−3
12 restraintsΔρmin = −0.28 e Å−3
Crystal data top
C11H6N2OV = 942.62 (18) Å3
Mr = 182.18Z = 4
Monoclinic, C2/mMo Kα radiation
a = 11.4809 (9) ŵ = 0.09 mm−1
b = 22.2091 (16) ÅT = 100 K
c = 3.6978 (6) Å0.15 × 0.05 × 0.05 mm
β = 91.304 (10)°
Data collection top
Agilent SuperNova Dual
diffractometer with an Atlas detector		1114 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2012)		840 reflections with I > 2σ(I)
Tmin = 0.792, Tmax = 1.000Rint = 0.038
3258 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.05912 restraints
wR(F2) = 0.163H atoms treated by a mixture of independent and constrained refinement
S = 1.08Δρmax = 0.41 e Å−3
1114 reflectionsΔρmin = −0.28 e Å−3
86 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*/UeqOcc. (<1)
O10.1308 (2)0.45076 (11)0.1768 (8)0.0273 (7)0.50
N10.15188 (16)0.19174 (9)0.2675 (6)0.0376 (6)
C10.10982 (16)0.23658 (9)0.1829 (6)0.0260 (5)
C20.05529 (16)0.29272 (8)0.0857 (5)0.0219 (5)
C30.1103 (2)0.34676 (10)0.1663 (6)0.0349 (6)
H30.18530.34690.28010.042*
C40.0555 (3)0.40028 (10)0.0803 (7)0.0446 (7)
H40.09360.43740.13090.054*0.50
C50.2499 (3)0.44609 (17)0.3108 (13)0.0274 (10)0.50
H5A0.29620.42110.14580.033*0.50
H5B0.25220.42720.55350.033*0.50
C60.2980 (3)0.5082 (7)0.3303 (12)0.030 (3)0.50
C70.3440 (4)0.5544 (2)0.3459 (17)0.0463 (14)0.50
H70.386 (5)0.595 (3)0.363 (16)0.054 (16)*0.50
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0258 (13)0.0187 (12)0.0370 (15)0.0001 (10)−0.0069 (11)−0.0008 (11)
N10.0332 (10)0.0410 (11)0.0383 (12)0.0126 (9)−0.0029 (8)0.0074 (9)
C10.0191 (9)0.0345 (12)0.0242 (11)−0.0003 (8)−0.0019 (8)0.0004 (8)
C20.0206 (10)0.0234 (10)0.0217 (10)−0.0009 (7)−0.0001 (8)−0.0007 (7)
C30.0401 (12)0.0399 (13)0.0251 (12)−0.0182 (10)0.0071 (9)−0.0077 (9)
C40.0728 (15)0.0262 (10)0.0355 (13)−0.0161 (10)0.0172 (11)−0.0063 (9)
C50.0220 (19)0.0167 (19)0.043 (3)0.0005 (17)−0.0104 (17)−0.0001 (16)
C60.0262 (16)0.013 (9)0.051 (2)−0.004 (2)−0.0130 (15)−0.001 (2)
C70.033 (3)0.027 (2)0.078 (4)0.001 (2)−0.019 (2)−0.001 (2)
Geometric parameters (Å, º) top
O1—C51.447 (5)C4—C4i1.393 (6)
O1—C41.455 (3)C4—H40.9500
N1—C11.147 (3)C5—C61.487 (14)
C1—C21.437 (3)C5—H5A0.9900
C2—C31.385 (3)C5—H5B0.9900
C2—C2i1.406 (4)C6—C71.155 (16)
C3—C41.379 (3)C7—H71.02 (6)
C3—H30.9500
C5—O1—C4125.5 (3)C3—C4—H4119.8
N1—C1—C2178.4 (2)C4i—C4—H4119.8
C3—C2—C2i119.96 (13)O1—C5—C6107.3 (3)
C3—C2—C1120.26 (18)O1—C5—H5A110.3
C2i—C2—C1119.77 (10)C6—C5—H5A110.3
C4—C3—C2119.6 (2)O1—C5—H5B110.3
C4—C3—H3120.2C6—C5—H5B110.3
C2—C3—H3120.2H5A—C5—H5B108.5
C3—C4—C4i120.43 (14)C7—C6—C5174.6 (7)
C3—C4—O1110.0 (2)C6—C7—H7178 (3)
C4i—C4—O1129.56 (15)
C2i—C2—C3—C40.6 (4)C5—O1—C4—C35.5 (5)
C1—C2—C3—C4−178.2 (2)C5—O1—C4—C4i−173.5 (4)
C2—C3—C4—C4i1.2 (4)C4—O1—C5—C6173.1 (3)
C2—C3—C4—O1−177.9 (2)
Symmetry code: (i) −x, y, −z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···N1ii0.952.623.509 (3)155
Symmetry code: (ii) −x+1/2, −y+1/2, −z+1.

Experimental details

Crystal data
Chemical formulaC11H6N2O
Mr182.18
Crystal system, space groupMonoclinic, C2/m
Temperature (K)100
a, b, c (Å)11.4809 (9), 22.2091 (16), 3.6978 (6)
β (°) 91.304 (10)
V (Å3)942.62 (18)
Z4
Radiation typeMo Kα
µ (mm−1)0.09
Crystal size (mm)0.15 × 0.05 × 0.05
Data collection
DiffractometerAgilent SuperNova Dual
diffractometer with an Atlas detector
Absorption correctionMulti-scan
(CrysAlis PRO; Agilent, 2012)
Tmin, Tmax0.792, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections		3258, 1114, 840
Rint0.038
(sin θ/λ)max (Å−1)0.651
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.059, 0.163, 1.08
No. of reflections1114
No. of parameters86
No. of restraints12
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.41, −0.28

Computer programs: CrysAlis PRO (Agilent, 2012), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···N1i0.952.623.509 (3)155
Symmetry code: (i) −x+1/2, −y+1/2, −z+1.
 

Footnotes

‡Additional correspondence author: david.young@ubd.edu.bn.

Acknowledgements

The authors gratefully acknowledge funding from the Brunei Research Council, and thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

References

First citationAgilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, Oxfordshire, England.  Google Scholar
 First citationBrandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
 First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
 First citationFoo, C. C., Tan, A. L., Wimmer, F. L., Mirza, A. H., Young, D. J., Ng, S. W. & Tiekink, E. R. T. (2012). Acta Cryst. E68, o601.  CSD CrossRef IUCr Journals Google Scholar
 First citationJiang, X.-J., Yeung, S.-L., Lo, P.-C., Fong, W. P. & Ng, D. K. P. (2011). J. Med. Chem. 54, 320–330.  Web of Science CrossRef CAS PubMed Google Scholar
 First citationLi, H., Jensen, T. J., Fronczek, F. R. & Vicente, G. H. (2008). J. Med. Chem. 51, 502–511.  Web of Science CSD CrossRef PubMed CAS Google Scholar
 First citationLi, Z. & Lieberman, M. (2001). Inorg. Chem. 40, 932–939.  Web of Science CrossRef CAS Google Scholar
 First citationSeven, O., Dindar, B. & Gultekin, B. (2009). Turk. J. Chem. 33, 123–134.  CAS Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSleven, J., Görller-Walrand, C. & Binnemans, K. (2001). Mater. Sci. Eng. C, 18, 229–238.  Web of Science CrossRef Google Scholar
 First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationWöhrle, D., Eskes, M., Shigehara, K. & Yamada, A. (1993). Synthesis, pp. 194–196.  Google Scholar
 First citationWu, Y., Tian, H., Chen, K., Liu, Y. & Zhu, D. (1998). Dyes Pigm. 37, 317–325.  CAS 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
Volume 68| Part 7| July 2012| Pages o2293-o2294
https://doi.org/10.1107/S1600536812028309
Follow Acta Cryst. E
Sign up for e-alerts
E-alerts
Follow Acta Cryst. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS