PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2010 February 1; 66(Pt 2): o305–o306.
Published online 2010 January 9. doi:  10.1107/S1600536809055846
PMCID: PMC2979781

2-[(E)-2-(4-Ethoxy­phen­yl)ethen­yl]-1-methyl­pyridinium 4-bromo­benzene­sulfonate monohydrate1

Abstract

In the title compound, C16H18NO+·C6H4BrO3S·H2O, the cation exists in an E configuration with respect to the ethenyl bond and is slightly twisted with a dihedral angle of 8.5 (2)° between pyridinium and benzene rings. In the crystal, the cations are arranged in layers parallel to (100), with π–π inter­actions between pyridinium and benzene rings [centroid–centroid distances = 3.651 (3) and 3.613 (3) Å]. The anions and water mol­ecules are located between the cationic layers. The ions and water mol­ecules are linked into a three-dimensional framework by O—H(...)O and C—H(...)O hydrogen bonds.

Related literature

The title compound was synthesized as part of an investigation of the influence of the counter-ions on non-linear optical (NLO) properties. For background to NLO materials research, see: Coe et al. (2002 [triangle]); Pan et al. (1996 [triangle]). For related structures, see: Chanawanno et al. (2009 [triangle]); Chantrapromma et al. (2006 [triangle], 2009 [triangle]); Laksana et al. (2008 [triangle]). For bond-length data, see: Allen et al. (1987 [triangle]). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0o305-scheme1.jpg

Experimental

Crystal data

  • C16H18NO+·C6H4BrO3S·H2O
  • M r = 494.39
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0o305-efi1.jpg
  • a = 9.8022 (5) Å
  • b = 6.5162 (3) Å
  • c = 34.9982 (17) Å
  • β = 105.102 (3)°
  • V = 2158.24 (18) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 2.04 mm−1
  • T = 100 K
  • 0.34 × 0.31 × 0.19 mm

Data collection

  • Bruker APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.547, T max = 0.703
  • 30564 measured reflections
  • 6286 independent reflections
  • 4937 reflections with I > 2σ(I)
  • R int = 0.076

Refinement

  • R[F 2 > 2σ(F 2)] = 0.071
  • wR(F 2) = 0.224
  • S = 1.15
  • 6286 reflections
  • 275 parameters
  • H-atom parameters constrained
  • Δρmax = 1.26 e Å−3
  • Δρmin = −1.36 e Å−3

Data collection: APEX2 (Bruker, 2005 [triangle]); cell refinement: SAINT (Bruker, 2005 [triangle]); data reduction: SAINT; program(s) used to refine structure: SHELXTL (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809055846/ci5012sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809055846/ci5012Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors thank the Prince of Songkla University for a research grant and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. KC thanks the Development and Promotion of Science and Technology Talents Project (DPST) for a study grant.

supplementary crystallographic information

Comment

Ionic organic crystals are of special interest due to their high second order optical nonlinearities (Coe et al., 2002). The orientation of ionic chromophores can be arranged simply by changing the counter-ions (Pan et al., 1996). During the course of our NLO materials research, we have previously synthesized and reported crystal structures of related pyridinium salts containing the 2-[(E)-2-(4-ethoxyphenyl)ethenyl]-1-methylpyridinium cationic part (Chanawanno et al., 2009; Laksana et al., 2008). The title compound was synthesized by retaining the same cationic part but changing the anion counter part to 4-bromobenzenesulfonate in order to investigate the influence of the counter-ions on the NLO properties. However, it was found that the title compound crystallized in a centrosymmetric space group P21/c and hence no second-order nonlinear optical properties are observed.

In the title compound (Fig. 1), the cation exists in an E configuration with respect to the ethenyl bond [C5—C6—C7—C8 = -179.9 (5)°]. The cation is slightly twisted with a dihedral angle between the pyridinium and benzene rings of 8.5 (2)°. The pyridinium and benzene rings of the cation form dihedral angles of 79.2 (2) and 71.0 (2)°, respectively, with the benzene ring of the anion. Bond distances in both cation and anion have normal values (Allen et al., 1987) and are comparable to those observed in related structures (Chanawanno et al., 2009; Chantrapromma et al., 2009; Laksana et al., 2008).

In the crystal, the cations are stacked along the b axis and are arranged in layers parallel to the (100) with π–π interactions involving pyridinium (centroid Cg1) and benzene (centroid Cg2) rings [Cg1···Cg1ii = 3.651 (3) Å and Cg1···Cg2iii = 3.613 (3) Å; symmetry codes as in Table 1]. The anions and water molecules are located between the cationic layers. The cations are linked with the water molecules and anions by C—H···O weak interactions (Table 1), whereas the anions are linked with water molecules by O—H···O hydrogen bonds (Table 1). These interactions connect the ionic units and water molecules into a three-dimensional network (Fig. 2).

Experimental

2-[(E)-2-(4-Ethoxyphenyl)ethenyl]-1-methylpyridinium iodide (0.21 g, 0.58 mmol) which was prepared according to the previous method (Laksana et al., 2008) was mixed with silver 4-bromobenzenesulfonate (Chantrapromma et al., 2006) (0.20 g, 0.58 mmol) in methanol (100 ml) and stirred for 0.5 h. The precipitate of silver iodide which formed was filtered and the filtrate was evaporated to give the title compound as a yellow solid. Yellow block-shaped single crystals of the title compound suitable for X-ray structure determination were recrystallized from methanol by slow evaporation at room temperature over a few weeks (m.p. 463-465 K).

Refinement

H atoms were positioned geometrically and allowed to ride on their parent atoms, with O–H = 0.85 Å and C–H = 0.93-0.97 Å. The Uiso values were constrained to be 1.5Ueq of the carrier atom for methyl H atoms and 1.2Ueq for the remaining H atoms. A rotating group model was used for the methyl groups. The highest residual electron density peak is located at 0.81 Å from Br1 and the deepest hole is located at 1.90 Å from Br1.

Figures

Fig. 1.
The asymmetric unit of the title compound, with 50% probability displacement ellipsoids and the atom-numbering scheme.
Fig. 2.
The crystal packing of the title compound, viewed down the b axis. Hydrogen bonds are shown as dashed lines.

Crystal data

C16H18NO+·C6H4BrO3S·H2OF(000) = 1016
Mr = 494.39Dx = 1.522 Mg m3
Monoclinic, P21/cMelting point = 463–465 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 9.8022 (5) ÅCell parameters from 6286 reflections
b = 6.5162 (3) Åθ = 2.4–30.0°
c = 34.9982 (17) ŵ = 2.04 mm1
β = 105.102 (3)°T = 100 K
V = 2158.24 (18) Å3Block, yellow
Z = 40.34 × 0.31 × 0.19 mm

Data collection

Bruker APEXII CCD area-detector diffractometer6286 independent reflections
Radiation source: sealed tube4937 reflections with I > 2σ(I)
graphiteRint = 0.076
[var phi] and ω scansθmax = 30.0°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −13→12
Tmin = 0.547, Tmax = 0.703k = −7→9
30564 measured reflectionsl = −49→49

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.071Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.224H-atom parameters constrained
S = 1.15w = 1/[σ2(Fo2) + (0.0686P)2 + 18.6991P] where P = (Fo2 + 2Fc2)/3
6286 reflections(Δ/σ)max = 0.001
275 parametersΔρmax = 1.25 e Å3
0 restraintsΔρmin = −1.36 e Å3

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
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)

xyzUiso*/Ueq
Br10.61259 (6)1.18042 (10)0.235458 (16)0.02660 (17)
S10.57829 (13)0.5608 (2)0.09005 (4)0.0181 (3)
O10.0959 (4)1.1839 (6)0.19616 (10)0.0174 (7)
O20.5793 (5)0.6847 (7)0.05563 (12)0.0308 (9)
O30.6973 (4)0.4215 (7)0.10216 (13)0.0288 (9)
O40.4420 (4)0.4596 (6)0.08582 (11)0.0212 (7)
N1−0.0521 (5)0.0228 (7)0.05416 (12)0.0165 (8)
C1−0.0322 (6)−0.1561 (8)0.03624 (14)0.0190 (10)
H1A−0.1099−0.23790.02480.023*
C20.0992 (6)−0.2181 (8)0.03460 (14)0.0200 (10)
H2A0.1112−0.34180.02260.024*
C30.2145 (6)−0.0946 (8)0.05103 (15)0.0205 (10)
H3A0.3045−0.13290.04970.025*
C40.1943 (6)0.0864 (9)0.06946 (15)0.0201 (10)
H4A0.27180.16890.08070.024*
C50.0596 (5)0.1481 (8)0.07152 (14)0.0159 (9)
C60.0314 (5)0.3379 (8)0.09094 (14)0.0168 (9)
H6A−0.06180.37930.08750.020*
C70.1350 (5)0.4535 (8)0.11338 (14)0.0164 (9)
H7A0.22720.40870.11630.020*
C80.1164 (5)0.6439 (8)0.13376 (14)0.0160 (9)
C90.2375 (5)0.7467 (8)0.15528 (14)0.0173 (9)
H9A0.32620.69380.15590.021*
C100.2276 (5)0.9264 (8)0.17581 (14)0.0175 (9)
H10A0.30920.99220.19010.021*
C110.0950 (5)1.0080 (7)0.17496 (13)0.0142 (8)
C12−0.0272 (5)0.9066 (8)0.15352 (14)0.0151 (9)
H12A−0.11590.95960.15280.018*
C13−0.0152 (5)0.7263 (8)0.13326 (14)0.0161 (9)
H13A−0.09670.65960.11910.019*
C14−0.1979 (5)0.0792 (9)0.05387 (16)0.0207 (10)
H14A−0.2612−0.02820.04150.031*
H14B−0.22330.20440.03930.031*
H14C−0.20420.09810.08060.031*
C15−0.0362 (5)1.2805 (8)0.19457 (14)0.0174 (9)
H15A−0.10051.18430.20190.021*
H15B−0.07921.33080.16810.021*
C16−0.0034 (6)1.4575 (8)0.22382 (15)0.0211 (10)
H16A−0.08911.52960.22350.032*
H16B0.06191.54970.21650.032*
H16C0.03771.40510.24990.032*
C170.5949 (5)0.7380 (8)0.13010 (14)0.0165 (9)
C180.5583 (5)0.9431 (8)0.12275 (15)0.0194 (9)
H18A0.53040.99110.09690.023*
C190.5634 (5)1.0763 (8)0.15409 (16)0.0206 (10)
H19A0.53891.21370.14950.025*
C200.6059 (5)1.0000 (8)0.19242 (15)0.0187 (9)
C210.6451 (5)0.7944 (9)0.20045 (15)0.0203 (10)
H21A0.67450.74650.22630.024*
C220.6388 (5)0.6640 (8)0.16850 (15)0.0194 (9)
H22A0.66410.52680.17290.023*
O1W0.2862 (4)0.4509 (7)0.00213 (12)0.0272 (9)
H2W10.33910.44820.02560.06 (3)*
H1W10.33140.3960−0.01290.04 (2)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Br10.0304 (3)0.0266 (3)0.0250 (3)−0.0038 (2)0.0113 (2)−0.0113 (2)
S10.0172 (5)0.0182 (6)0.0201 (5)−0.0051 (4)0.0070 (4)−0.0055 (4)
O10.0171 (16)0.0143 (16)0.0206 (16)−0.0004 (13)0.0045 (13)−0.0053 (13)
O20.043 (2)0.029 (2)0.0243 (19)−0.011 (2)0.0162 (18)−0.0062 (17)
O30.0190 (18)0.028 (2)0.038 (2)0.0020 (16)0.0049 (16)−0.0159 (18)
O40.0161 (16)0.0216 (19)0.0256 (18)−0.0063 (14)0.0049 (14)−0.0051 (15)
N10.020 (2)0.014 (2)0.0161 (18)−0.0013 (16)0.0057 (15)−0.0011 (15)
C10.028 (3)0.015 (2)0.015 (2)−0.0033 (19)0.0065 (18)−0.0008 (17)
C20.030 (3)0.014 (2)0.016 (2)0.0012 (19)0.0053 (19)−0.0025 (17)
C30.024 (2)0.019 (2)0.019 (2)0.005 (2)0.0057 (18)−0.0003 (19)
C40.021 (2)0.021 (3)0.018 (2)−0.0006 (19)0.0046 (18)−0.0046 (18)
C50.020 (2)0.013 (2)0.0142 (19)−0.0031 (17)0.0036 (16)−0.0017 (16)
C60.018 (2)0.015 (2)0.018 (2)0.0004 (18)0.0046 (17)−0.0012 (17)
C70.018 (2)0.016 (2)0.016 (2)0.0005 (18)0.0070 (17)−0.0011 (17)
C80.018 (2)0.016 (2)0.0148 (19)−0.0022 (17)0.0051 (16)−0.0016 (17)
C90.018 (2)0.016 (2)0.018 (2)−0.0004 (17)0.0060 (17)−0.0034 (17)
C100.016 (2)0.019 (2)0.017 (2)−0.0034 (18)0.0034 (16)−0.0048 (18)
C110.017 (2)0.013 (2)0.0131 (19)−0.0020 (16)0.0043 (16)−0.0019 (16)
C120.014 (2)0.016 (2)0.0152 (19)0.0006 (17)0.0043 (16)−0.0012 (17)
C130.017 (2)0.016 (2)0.015 (2)−0.0011 (17)0.0040 (16)−0.0018 (17)
C140.017 (2)0.018 (2)0.027 (2)−0.0029 (18)0.0048 (18)−0.0055 (19)
C150.022 (2)0.012 (2)0.018 (2)0.0016 (18)0.0047 (17)−0.0020 (17)
C160.025 (2)0.017 (2)0.021 (2)0.006 (2)0.0044 (19)−0.0040 (18)
C170.014 (2)0.017 (2)0.019 (2)−0.0039 (17)0.0065 (17)−0.0058 (17)
C180.018 (2)0.020 (2)0.020 (2)−0.0010 (19)0.0049 (18)−0.0013 (19)
C190.018 (2)0.016 (2)0.026 (2)−0.0003 (18)0.0045 (19)−0.0038 (19)
C200.017 (2)0.020 (2)0.020 (2)−0.0020 (18)0.0061 (17)−0.0057 (18)
C210.020 (2)0.021 (3)0.019 (2)−0.001 (2)0.0047 (18)−0.0016 (19)
C220.019 (2)0.017 (2)0.023 (2)−0.0015 (18)0.0068 (18)−0.0037 (19)
O1W0.0217 (18)0.036 (2)0.0234 (19)−0.0020 (17)0.0056 (15)−0.0065 (17)

Geometric parameters (Å, °)

Br1—C201.898 (5)C10—C111.397 (7)
S1—O31.451 (4)C10—H10A0.93
S1—O21.452 (4)C11—C121.402 (6)
S1—O41.462 (4)C12—C131.393 (7)
S1—C171.790 (5)C12—H12A0.93
O1—C111.365 (6)C13—H13A0.93
O1—C151.427 (6)C14—H14A0.96
N1—C11.361 (6)C14—H14B0.96
N1—C51.374 (6)C14—H14C0.96
N1—C141.473 (7)C15—C161.520 (7)
C1—C21.366 (8)C15—H15A0.97
C1—H1A0.93C15—H15B0.97
C2—C31.385 (8)C16—H16A0.96
C2—H2A0.93C16—H16B0.96
C3—C41.383 (7)C16—H16C0.96
C3—H3A0.93C17—C221.387 (7)
C4—C51.401 (7)C17—C181.390 (8)
C4—H4A0.93C18—C191.390 (7)
C5—C61.471 (7)C18—H18A0.93
C6—C71.341 (7)C19—C201.389 (7)
C6—H6A0.93C19—H19A0.93
C7—C81.466 (7)C20—C211.402 (8)
C7—H7A0.93C21—C221.393 (7)
C8—C131.393 (7)C21—H21A0.93
C8—C91.400 (7)C22—H22A0.93
C9—C101.390 (7)O1W—H2W10.85
C9—H9A0.93O1W—H1W10.85
O3—S1—O2114.3 (3)C13—C12—C11119.7 (4)
O3—S1—O4113.0 (3)C13—C12—H12A120.1
O2—S1—O4111.7 (3)C11—C12—H12A120.1
O3—S1—C17105.8 (2)C12—C13—C8121.3 (5)
O2—S1—C17105.8 (3)C12—C13—H13A119.4
O4—S1—C17105.3 (2)C8—C13—H13A119.4
C11—O1—C15118.2 (4)N1—C14—H14A109.5
C1—N1—C5121.3 (4)N1—C14—H14B109.5
C1—N1—C14117.7 (4)H14A—C14—H14B109.5
C5—N1—C14121.0 (4)N1—C14—H14C109.5
N1—C1—C2121.5 (5)H14A—C14—H14C109.5
N1—C1—H1A119.2H14B—C14—H14C109.5
C2—C1—H1A119.2O1—C15—C16106.1 (4)
C1—C2—C3119.2 (5)O1—C15—H15A110.5
C1—C2—H2A120.4C16—C15—H15A110.5
C3—C2—H2A120.4O1—C15—H15B110.5
C4—C3—C2119.3 (5)C16—C15—H15B110.5
C4—C3—H3A120.4H15A—C15—H15B108.7
C2—C3—H3A120.4C15—C16—H16A109.5
C3—C4—C5121.3 (5)C15—C16—H16B109.5
C3—C4—H4A119.3H16A—C16—H16B109.5
C5—C4—H4A119.3C15—C16—H16C109.5
N1—C5—C4117.4 (4)H16A—C16—H16C109.5
N1—C5—C6118.7 (4)H16B—C16—H16C109.5
C4—C5—C6123.9 (4)C22—C17—C18120.9 (5)
C7—C6—C5122.6 (5)C22—C17—S1118.5 (4)
C7—C6—H6A118.7C18—C17—S1120.6 (4)
C5—C6—H6A118.7C19—C18—C17120.0 (5)
C6—C7—C8126.1 (5)C19—C18—H18A120.0
C6—C7—H7A116.9C17—C18—H18A120.0
C8—C7—H7A116.9C20—C19—C18118.6 (5)
C13—C8—C9118.4 (5)C20—C19—H19A120.7
C13—C8—C7123.5 (4)C18—C19—H19A120.7
C9—C8—C7118.1 (4)C19—C20—C21122.2 (5)
C10—C9—C8121.2 (5)C19—C20—Br1119.0 (4)
C10—C9—H9A119.4C21—C20—Br1118.8 (4)
C8—C9—H9A119.4C22—C21—C20118.0 (5)
C9—C10—C11119.9 (4)C22—C21—H21A121.0
C9—C10—H10A120.0C20—C21—H21A121.0
C11—C10—H10A120.0C17—C22—C21120.2 (5)
O1—C11—C10115.7 (4)C17—C22—H22A119.9
O1—C11—C12124.7 (4)C21—C22—H22A119.9
C10—C11—C12119.5 (4)H2W1—O1W—H1W1107.7
C5—N1—C1—C2−0.3 (7)O1—C11—C12—C13−179.3 (4)
C14—N1—C1—C2178.9 (5)C10—C11—C12—C13−0.2 (7)
N1—C1—C2—C3−1.0 (8)C11—C12—C13—C8−0.1 (7)
C1—C2—C3—C41.4 (8)C9—C8—C13—C120.1 (7)
C2—C3—C4—C5−0.6 (8)C7—C8—C13—C12179.2 (5)
C1—N1—C5—C41.1 (7)C11—O1—C15—C16174.6 (4)
C14—N1—C5—C4−178.1 (5)O3—S1—C17—C22−39.4 (5)
C1—N1—C5—C6−179.1 (4)O2—S1—C17—C22−161.1 (4)
C14—N1—C5—C61.8 (7)O4—S1—C17—C2280.5 (4)
C3—C4—C5—N1−0.6 (7)O3—S1—C17—C18143.5 (4)
C3—C4—C5—C6179.5 (5)O2—S1—C17—C1821.8 (5)
N1—C5—C6—C7170.2 (5)O4—S1—C17—C18−96.6 (4)
C4—C5—C6—C7−10.0 (8)C22—C17—C18—C19−1.0 (7)
C5—C6—C7—C8−179.9 (5)S1—C17—C18—C19176.0 (4)
C6—C7—C8—C132.2 (8)C17—C18—C19—C200.2 (7)
C6—C7—C8—C9−178.7 (5)C18—C19—C20—C210.8 (8)
C13—C8—C9—C100.1 (7)C18—C19—C20—Br1−179.8 (4)
C7—C8—C9—C10−179.0 (5)C19—C20—C21—C22−0.9 (8)
C8—C9—C10—C11−0.4 (8)Br1—C20—C21—C22179.7 (4)
C15—O1—C11—C10176.5 (4)C18—C17—C22—C210.9 (7)
C15—O1—C11—C12−4.3 (7)S1—C17—C22—C21−176.2 (4)
C9—C10—C11—O1179.6 (4)C20—C21—C22—C170.1 (7)
C9—C10—C11—C120.4 (7)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O1W—H2W1···O40.852.092.929 (6)171
O1W—H1W1···O2i0.851.992.827 (6)168
C1—H1A···O1Wii0.932.233.154 (7)176
C2—H2A···O1Wiii0.932.433.223 (7)143
C4—H4A···O40.932.503.378 (7)158
C6—H6A···O3iv0.932.563.442 (7)159
C13—H13A···O3iv0.932.493.387 (7)161
C14—H14A···O2v0.962.573.384 (7)143
C14—H14C···O3iv0.962.513.129 (7)122

Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x, −y, −z; (iii) x, y−1, z; (iv) x−1, y, z; (v) x−1, y−1, z.

Footnotes

1This paper is dedicated to His Majesty King Bhumibol Adulyadej of Thailand (King Rama IX) for his sustainable development of the country.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CI5012).

References

  • 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.
  • Bruker (2005). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Chanawanno, K., Chantrapromma, S. & Fun, H.-K. (2009). Anal. Sci 25, 127–128.
  • Chantrapromma, S., Chanawanno, K. & Fun, H.-K. (2009). Acta Cryst. E65, o1884–o1885. [PMC free article] [PubMed]
  • Chantrapromma, S., Ruanwas, P., Fun, H.-K. & Patil, P. S. (2006). Acta Cryst. E62, o5494–o5496.
  • Coe, B. J., Harris, J. A., Clays, A. K., Olbrechts, G., Persoons, A., Hupp, J. T., Johnson, R. C., Coles, S. J., Hursthouse, M. B. & Nakatani, K. (2002). Adv. Funct. Mater 12, 110–116.
  • Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst.19, 105–107.
  • Laksana, C., Ruanwas, P., Chantrapromma, S. & Fun, H.-K. (2008). Acta Cryst. E64, o145–o146. [PMC free article] [PubMed]
  • Pan, F., Knöpfle, G., Bosshard, C., Follonier, S., Spreiter, R., Wong, M. S. & Günter, P. (1996). Appl. Phys. Lett 69, 13–15.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst D65, 148–155. [PMC free article] [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography