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 64| Part 12| December 2008| Page o2353
doi:10.1107/S1600536808037148

4-(Di­methyl­amino)benzaldehyde 4-ethyl­thio­semicarbazone

Abdussalam Salhin,a* Norfarhah Abdul Razaka and I. A. Rahmana

aSchool of Chemical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: email: abdussalam@usm.my

(Received 30 October 2008; accepted 10 November 2008; online 13 November 2008)

The title thio­semicarbazone derivative, C12H18N4S, features intra­molecular N—H⋯N and C—H⋯S hydrogen bonds which generate S(5) ring motifs. The dihedral angle between the benzene ring and the thio­urea unit is 6.30 (6)° indicating planarity in the mol­ecule. Inter­molecular N—H⋯S hydrogen bonds generate dimers with an R22(8) ring motif. The methyl group of the N-ethyl residue is disordered and was refined with site occupancies of 0.521 (5) and 0.479 (5).

Related literature

For details of hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For related structures and applications see: Beraldo et al. (2001[Beraldo, H., Lima, R., Teixeira, L. R., Moura, A. A. & West, D. X. (2001). J. Mol. Struct. 559, 99-106.]); Kayed et al. (2008[Kayed, S. F., Farina, Y., Baba, I. & Simpson, J. (2008). Acta Cryst. E64, o824-o825.]); Valdes-Martinez et al. (1990[Valdes-Martinez, J., Toscano, R. A., Salcedo, R., Cea-Olivarres, R. & Melendez, A. (1990). Monatsh. Chem. 121, 641-647.]).

[Scheme 1]

Experimental

Crystal data

  • C12H18N4S

  • Mr = 250.36

  • Monoclinic, P 21 /c

  • a = 9.3687 (2) Å

  • b = 14.1872 (3) Å

  • c = 10.2318 (2) Å

  • β = 96.699 (1)°

  • V = 1350.68 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.23 mm−1

  • T = 100 (1) K

  • 0.59 × 0.36 × 0.22 mm
Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.879, Tmax = 0.953

  • 30229 measured reflections

  • 6825 independent reflections

  • 5566 reflections with I > 2σ(I)

  • Rint = 0.036
Refinement

  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.119

  • S = 1.04

  • 6825 reflections

  • 176 parameters

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

  • Δρmax = 0.74 e Å−3

  • Δρmin = −0.39 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N3—H1N3⋯S1i 0.891 (15) 2.613 (15) 3.4910 (7) 168.8 (12)
N4—H1N4⋯N2 0.885 (14) 2.193 (14) 2.6140 (10) 108.7 (11)
C9—H9B⋯S1 0.96 2.78 3.1225 (9) 102
Symmetry code: (i) -x, -y, -z.

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808037148/tk2323sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808037148/tk2323Isup2.hkl

checkCIF report


Comment top

Thiosemicarbazones have been a subject of extensive investigation (Kayed et al., 2008) because of their ability to coordinate metal ions and their wide range of chemical and biological activities (Valdes-Martinez et al., 1990 & Beraldo et al., 2001). We present herein the X-ray structure of the title thiosemicarbazone derivative, (I).

Compound (I), Fig. I, displays bond lengths and angles comparable to those in related structures (Beraldo et al., 2001; Kayed et al., 2008; Valdes-Martinez et al., 1990). Intramolecular N—H···N and C—H···S contacts generate S(5) ring motifs (Bernstein et al. 1995), Table 1. The dihedral angle between the phenyl ring and the thiourea unit is 6.30 (6)° which indicates the molecule is almost planar. Intermolecular N—H···S hydrogen bonds generate R22(8) ring motifs to link molecules into dimers, Fig. 2. The methyl group of the N-ethyl residue is disordered and was refined with site occupancies of 0.521 (5)/0.479 (5).

Related literature top

For details of hydrogen-bond motifs, see: Bernstein et al. (1995). For related structures and applications see: Beraldo et al. (2001); Kayed et al. (2008); Valdes-Martinez et al. (1990).

Experimental top

To 4-ethyl-3-thiosemicarbazide (ca. 0.119 g, 1 mmol) dissolved in ethanol (10 ml) was added dropwise an ethanol solution (5 ml) of 4-dimethylaminobenzaldehyde (0.149 g, 1 mmol) with continuous stirring. The solution was heated on a water bath for few minutes until the solution became clear. After cooling to room temperature, yellow crystals of (I) appeared.

Refinement top

The N-bound H atoms were located from a difference Fourier map and refined freely. The remaining H were placed in their calculated positions in the riding model approximation with C–H 0.93–0.96 Å, and with U(H) set to 1.2–1.5 times Ueq(C). The presence of large peaks in the difference Fourier map near to the methyl group of (I) was suspected to be due to positional disorder of this fragment. The refined ratio of the site occupancy factors for the disorder parts were calculated to be 0.521 (5)/0.479 (5).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids and the atomic numbering. The intramolecular contacts are shown as dashed lines.
[Figure 2] Fig. 2. Unit cell contents for the major component of (I), viewed down the b-axis showing dimers linked by R22(8) ring motifs. Intermolecular hydrogen bonds are shown as dashed lines.
4-(Dimethylamino)benzaldehyde 4-ethylthiosemicarbazone top
Crystal data top
C12H18N4SF(000) = 536
Mr = 250.36Dx = 1.231 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 9949 reflections
a = 9.3687 (2) Åθ = 2.5–39.5°
b = 14.1872 (3) ŵ = 0.23 mm−1
c = 10.2318 (2) ÅT = 100 K
β = 96.699 (1)°Block, yellow
V = 1350.68 (5) Å30.59 × 0.36 × 0.22 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		6825 independent reflections
Radiation source: fine-focus sealed tube5566 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.036
ϕ and ω scansθmax = 37.0°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		h = −15→13
Tmin = 0.879, Tmax = 0.953k = −24→20
30229 measured reflectionsl = −15→17
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)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.119H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.0651P)2 + 0.2126P]
where P = (Fo2 + 2Fc2)/3
6825 reflections(Δ/σ)max = 0.001
176 parametersΔρmax = 0.74 e Å−3
0 restraintsΔρmin = −0.39 e Å−3
Crystal data top
C12H18N4SV = 1350.68 (5) Å3
Mr = 250.36Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.3687 (2) ŵ = 0.23 mm−1
b = 14.1872 (3) ÅT = 100 K
c = 10.2318 (2) Å0.59 × 0.36 × 0.22 mm
β = 96.699 (1)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		6825 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		5566 reflections with I > 2σ(I)
Tmin = 0.879, Tmax = 0.953Rint = 0.036
30229 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.119H atoms treated by a mixture of independent and constrained refinement
S = 1.04Δρmax = 0.74 e Å−3
6825 reflectionsΔρmin = −0.39 e Å−3
176 parameters
Special details top

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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)
S10.16244 (2)0.114147 (15)−0.039117 (18)0.01984 (6)
N1−0.30894 (9)0.10562 (6)0.82869 (8)0.02457 (15)
N2−0.01025 (7)0.10572 (5)0.29168 (6)0.01690 (12)
N30.02454 (7)0.08428 (5)0.16770 (6)0.01731 (12)
N40.18487 (7)0.20579 (5)0.19197 (7)0.01837 (12)
C1−0.09174 (8)0.13272 (6)0.55310 (7)0.01760 (13)
H1A−0.01380.16800.53230.021*
C2−0.14161 (8)0.14561 (6)0.67363 (7)0.01834 (13)
H2A−0.09770.19000.73190.022*
C3−0.25861 (8)0.09230 (6)0.70986 (7)0.01732 (13)
C4−0.32165 (9)0.02550 (6)0.61854 (8)0.01997 (14)
H4A−0.3979−0.01130.63960.024*
C5−0.27073 (9)0.01429 (6)0.49756 (8)0.01935 (14)
H5A−0.3142−0.03000.43880.023*
C6−0.15624 (8)0.06743 (5)0.46132 (7)0.01601 (12)
C7−0.10836 (8)0.05380 (6)0.33282 (7)0.01745 (13)
H7A−0.14980.00620.27860.021*
C80.12430 (8)0.13664 (6)0.11598 (7)0.01551 (12)
C90.29288 (10)0.27026 (6)0.15428 (9)0.02484 (16)
H9A0.28670.32790.20240.030*0.521 (5)
H9B0.27020.28480.06260.030*0.521 (5)
H9C0.28770.32910.19990.030*0.479 (5)
H9D0.27670.28230.06140.030*0.479 (5)
C10A0.4427 (11)0.2356 (8)0.1674 (8)0.0361 (12)0.521 (5)
H10A0.50450.28410.14030.054*0.521 (5)
H10B0.44860.18100.11280.054*0.521 (5)
H10C0.47240.21920.25750.054*0.521 (5)
C10B0.4457 (14)0.2268 (10)0.1992 (9)0.0394 (15)0.479 (5)
H10D0.45580.21600.29250.059*0.479 (5)
H10E0.51880.26980.17820.059*0.479 (5)
H10F0.45540.16810.15440.059*0.479 (5)
C11−0.43497 (11)0.05588 (7)0.86103 (10)0.02942 (19)
H11A−0.51070.06190.78980.044*
H11B−0.46570.08230.93950.044*
H11C−0.4121−0.00960.87530.044*
C12−0.24779 (10)0.17816 (8)0.91858 (9)0.02932 (19)
H12A−0.14520.17100.93250.044*
H12B−0.28640.17221.00110.044*
H12C−0.27130.23920.88150.044*
H1N40.1570 (14)0.2111 (10)0.2711 (14)0.032 (3)*
H1N3−0.0171 (15)0.0353 (11)0.1243 (14)0.035 (4)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.02294 (10)0.02210 (11)0.01529 (9)−0.00401 (7)0.00569 (6)−0.00261 (6)
N10.0315 (4)0.0243 (4)0.0202 (3)−0.0016 (3)0.0121 (3)−0.0011 (2)
N20.0198 (3)0.0176 (3)0.0137 (2)−0.0005 (2)0.0038 (2)−0.0006 (2)
N30.0206 (3)0.0178 (3)0.0141 (2)−0.0036 (2)0.0043 (2)−0.0018 (2)
N40.0212 (3)0.0178 (3)0.0166 (3)−0.0039 (2)0.0044 (2)−0.0022 (2)
C10.0179 (3)0.0185 (3)0.0166 (3)−0.0026 (2)0.0028 (2)−0.0005 (2)
C20.0199 (3)0.0199 (3)0.0152 (3)−0.0015 (3)0.0024 (2)−0.0015 (2)
C30.0205 (3)0.0157 (3)0.0166 (3)0.0026 (2)0.0057 (2)0.0018 (2)
C40.0215 (3)0.0171 (3)0.0226 (3)−0.0025 (3)0.0082 (3)−0.0007 (3)
C50.0213 (3)0.0167 (3)0.0208 (3)−0.0040 (2)0.0060 (2)−0.0031 (2)
C60.0181 (3)0.0149 (3)0.0153 (3)−0.0008 (2)0.0032 (2)−0.0001 (2)
C70.0199 (3)0.0168 (3)0.0160 (3)−0.0013 (2)0.0034 (2)−0.0013 (2)
C80.0162 (3)0.0156 (3)0.0148 (3)0.0000 (2)0.0017 (2)0.0010 (2)
C90.0294 (4)0.0199 (4)0.0269 (4)−0.0092 (3)0.0107 (3)−0.0057 (3)
C10A0.0211 (12)0.032 (2)0.057 (3)−0.0087 (13)0.011 (2)−0.015 (2)
C10B0.0265 (14)0.036 (2)0.057 (4)−0.0113 (14)0.009 (3)−0.011 (3)
C110.0374 (5)0.0252 (4)0.0291 (4)−0.0005 (4)0.0190 (4)0.0033 (3)
C120.0275 (4)0.0409 (6)0.0199 (3)0.0028 (4)0.0037 (3)−0.0083 (3)
Geometric parameters (Å, º) top
S1—C81.6971 (7)C6—C71.4508 (10)
N1—C31.3675 (10)C7—H7A0.9300
N1—C111.4466 (12)C9—C10A1.479 (10)
N1—C121.4528 (13)C9—C10B1.577 (13)
N2—C71.2864 (10)C9—H9A0.9600
N2—N31.3800 (9)C9—H9B0.9600
N3—C81.3494 (10)C9—H9C0.9600
N3—H1N30.890 (15)C9—H9D0.9600
N4—C81.3365 (10)C10A—H10A0.9600
N4—C91.4492 (11)C10A—H10B0.9600
N4—H1N40.883 (14)C10A—H10C0.9600
C1—C21.3810 (10)C10B—H10D0.9600
C1—C61.4045 (11)C10B—H10E0.9600
C1—H1A0.9300C10B—H10F0.9600
C2—C31.4162 (11)C11—H11A0.9600
C2—H2A0.9300C11—H11B0.9600
C3—C41.4111 (12)C11—H11C0.9600
C4—C51.3867 (11)C12—H12A0.9600
C4—H4A0.9300C12—H12B0.9600
C5—C61.3961 (11)C12—H12C0.9600
C5—H5A0.9300
C3—N1—C11120.75 (8)C10A—C9—H9A110.5
C3—N1—C12120.62 (8)C10B—C9—H9A106.9
C11—N1—C12118.22 (7)N4—C9—H9B108.3
C7—N2—N3115.40 (7)C10A—C9—H9B105.1
C8—N3—N2119.20 (7)C10B—C9—H9B117.3
C8—N3—H1N3121.2 (9)H9A—C9—H9B107.4
N2—N3—H1N3119.6 (9)N4—C9—H9C110.0
C8—N4—C9124.80 (7)C10A—C9—H9C110.3
C8—N4—H1N4116.4 (9)C10B—C9—H9C107.1
C9—N4—H1N4118.7 (9)H9B—C9—H9C105.7
C2—C1—C6121.36 (7)N4—C9—H9D110.0
C2—C1—H1A119.3C10A—C9—H9D100.8
C6—C1—H1A119.3C10B—C9—H9D113.0
C1—C2—C3121.05 (7)H9A—C9—H9D110.1
C1—C2—H2A119.5H9C—C9—H9D108.4
C3—C2—H2A119.5C9—C10A—H10A109.5
N1—C3—C4121.35 (7)C9—C10A—H10B109.5
N1—C3—C2121.11 (7)C9—C10A—H10C109.5
C4—C3—C2117.53 (7)C9—C10B—H10D109.5
C5—C4—C3120.47 (7)C9—C10B—H10E109.5
C5—C4—H4A119.8H10D—C10B—H10E109.5
C3—C4—H4A119.8C9—C10B—H10F109.5
C4—C5—C6122.02 (7)H10D—C10B—H10F109.5
C4—C5—H5A119.0H10E—C10B—H10F109.5
C6—C5—H5A119.0N1—C11—H11A109.5
C5—C6—C1117.54 (7)N1—C11—H11B109.5
C5—C6—C7119.81 (7)H11A—C11—H11B109.5
C1—C6—C7122.65 (7)N1—C11—H11C109.5
N2—C7—C6121.90 (7)H11A—C11—H11C109.5
N2—C7—H7A119.1H11B—C11—H11C109.5
C6—C7—H7A119.1N1—C12—H12A109.5
N4—C8—N3116.26 (6)N1—C12—H12B109.5
N4—C8—S1124.10 (6)H12A—C12—H12B109.5
N3—C8—S1119.62 (6)N1—C12—H12C109.5
N4—C9—C10A116.8 (4)H12A—C12—H12C109.5
N4—C9—C10B108.3 (4)H12B—C12—H12C109.5
N4—C9—H9A108.4
C7—N2—N3—C8178.60 (7)C4—C5—C6—C7−179.19 (8)
C6—C1—C2—C30.93 (12)C2—C1—C6—C5−1.47 (12)
C11—N1—C3—C4−4.17 (13)C2—C1—C6—C7178.59 (8)
C12—N1—C3—C4−176.68 (8)N3—N2—C7—C6179.78 (7)
C11—N1—C3—C2175.45 (8)C5—C6—C7—N2174.99 (8)
C12—N1—C3—C22.93 (13)C1—C6—C7—N2−5.08 (12)
C1—C2—C3—N1−179.39 (8)C9—N4—C8—N3−179.39 (8)
C1—C2—C3—C40.24 (12)C9—N4—C8—S1−1.06 (12)
N1—C3—C4—C5178.80 (8)N2—N3—C8—N41.21 (11)
C2—C3—C4—C5−0.82 (12)N2—N3—C8—S1−177.20 (5)
C3—C4—C5—C60.26 (13)C8—N4—C9—C10A−81.0 (4)
C4—C5—C6—C10.88 (12)C8—N4—C9—C10B−90.9 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H1N3···S1i0.891 (15)2.613 (15)3.4910 (7)168.8 (12)
N4—H1N4···N20.885 (14)2.193 (14)2.6140 (10)108.7 (11)
C9—H9B···S10.962.783.1225 (9)102
Symmetry code: (i) −x, −y, −z.

Experimental details

Crystal data
Chemical formulaC12H18N4S
Mr250.36
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)9.3687 (2), 14.1872 (3), 10.2318 (2)
β (°) 96.699 (1)
V (Å3)1350.68 (5)
Z4
Radiation typeMo Kα
µ (mm−1)0.23
Crystal size (mm)0.59 × 0.36 × 0.22
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.879, 0.953
No. of measured, independent and
observed [I > 2σ(I)] reflections		30229, 6825, 5566
Rint0.036
(sin θ/λ)max (Å−1)0.847
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.119, 1.04
No. of reflections6825
No. of parameters176
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.74, −0.39

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H1N3···S1i0.891 (15)2.613 (15)3.4910 (7)168.8 (12)
N4—H1N4···N20.885 (14)2.193 (14)2.6140 (10)108.7 (11)
C9—H9B···S10.96002.78003.1225 (9)102.00
Symmetry code: (i) −x, −y, −z.
 

Acknowledgements

We thank the Malysian Government and Universiti Sains Malaysia for Science Fund grant No. 1001/229/PKIMIA/811055

References

First citationBeraldo, H., Lima, R., Teixeira, L. R., Moura, A. A. & West, D. X. (2001). J. Mol. Struct. 559, 99–106.  Web of Science CSD CrossRef CAS Google Scholar
 First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
 First citationBruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationKayed, S. F., Farina, Y., Baba, I. & Simpson, J. (2008). Acta Cryst. E64, o824–o825.  Web of Science CSD CrossRef IUCr Journals 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. (2003). J. Appl. Cryst. 36, 7–13.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationValdes-Martinez, J., Toscano, R. A., Salcedo, R., Cea-Olivarres, R. & Melendez, A. (1990). Monatsh. Chem. 121, 641–647.  CSD CrossRef CAS Web of Science 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 64| Part 12| December 2008| Page o2353
doi:10.1107/S1600536808037148
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