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

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1,3-Di-n-butyl­thio­urea

aDepartment of Inorganic Chemistry, Gdansk University of Technology, 11/12 Narutowicza Str., 80-233 Gdańsk, Poland
*Correspondence e-mail: jaroslaw.chojnacki@pg.gda.pl

(Received 11 March 2011; accepted 15 March 2011; online 19 March 2011)

In the title compound, C9H20N2S, the n-butyl groups are in syn and anti positions in relation to the C=S bond. In the crystal, two mol­ecules are connected by two N—H⋯S=C hydrogen bonds into a centrosymmetric dimer. Another N—H⋯S=C hydrogen bond links the dimers, forming layers with a hydro­philic inter­ior and a hydro­phobic exterior, which spread across the (100) plane. Inter­lacing of the external butyl groups combines these layers into a three-dimensional structure.

Related literature

For structures of N,N′-di-n-butyl­thio­urea complexes with mercury and copper, see: Ahmad et al. (2009[Ahmad, S., Sadaf, H., Akkurt, M., Sharif, S. & Khan, I. U. (2009). Acta Cryst. E65, m1191-m1192.]); Khan et al. (2007[Khan, I. U., Mufakkar, M., Ahmad, S., Fun, H.-K. & Chantrapromma, S. (2007). Acta Cryst. E63, m2550-m2551.]); Warda (1998[Warda, S. A. (1998). Acta Cryst. C54, 460-462.]). For structures of other symmetrically substituted thio­urea derivatives, see: Custelcean et al. (2005[Custelcean, R., Gorbunova, M. G. & Bonnesen, P. V. (2005). Chem. Eur. J. 11, 1459-1466.]); Djurdjevic et al. (2007[Djurdjevic, S., Leigh, D. & Parsons, S. (2007). Private communication to the Cambridge Structural Database (Refcode JIPKAV). CCDC, Union Road, Cambridge, England.]); Ramnathan et al. (1995[Ramnathan, A., Sivakumar, K., Subramanian, K., Janarthanan, N., Ramadas, K. & Fun, H.-K. (1995). Acta Cryst. C51, 2446-2450.]). For synthetic methods, see: Herr et al. (2000[Herr, R. J., Kuhler, L., Meckler, H. & Opalka, C. J. (2000). Synthesis, pp. 1569-1574.]); Kricheldorf (1970[Kricheldorf, H. R. (1970). Synthesis, pp. 539-540.]); Ranu et al. (2003[Ranu, B. C., Dey, S. S. & Bag, S. (2003). ARKIVOC, ix, 14-20.]).

[Scheme 1]

Experimental

Crystal data
  • C9H20N2S

  • Mr = 188.33

  • Monoclinic, P 21 /c

  • a = 12.6395 (6) Å

  • b = 10.0836 (6) Å

  • c = 9.0128 (5) Å

  • β = 90.476 (5)°

  • V = 1148.66 (11) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.24 mm−1

  • T = 120 K

  • 0.48 × 0.29 × 0.09 mm

Data collection
  • Oxford Diffraction Xcalibur Sapphire2 diffractometer

  • Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]; based on Clark & Reid, 1995[Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897.])] Tmin = 0.94, Tmax = 0.978

  • 5268 measured reflections

  • 2247 independent reflections

  • 1656 reflections with I > 2σ(I)

  • Rint = 0.038

Refinement
  • R[F2 > 2σ(F2)] = 0.046

  • wR(F2) = 0.116

  • S = 0.97

  • 2247 reflections

  • 119 parameters

  • 2 restraints

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

  • Δρmax = 0.45 e Å−3

  • Δρmin = −0.27 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯S1i 0.84 (1) 2.58 (1) 3.3943 (17) 164 (2)
N2—H2⋯S1ii 0.85 (1) 2.52 (1) 3.3319 (17) 159 (2)
Symmetry codes: (i) -x, -y+1, -z+2; (ii) [x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}].

Data collection: CrysAlis PRO (Oxford Diffraction, 2010[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, 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: OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]) and Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

N,N'-Di-n-butylthiourea, SC(NHnBu)2, is commonly used as a vulcanization accelerator in rubber processing, as an insecticide, as an additive to fertilizers, as a corrosion inhibitor, as an agent for metal treatments, etc.

No X-ray structure of pure compound was known until now, although the Cambridge Structural Database contains data on its mercury(ii) (Ahmad et al., 2009), copper(i) (Khan et al., 2007) and copper(ii) (Warda, 1998) complexes. In their structures one of the n-butyl groups of N,N'-di-n-butylthiourea molecule is in the syn position and the second is in the anti position in relation to the CS bond. The same conformation is present in the title compound and this allows the formation of the centrosymmetric dimers (see Fig. 1) held together by two N1—H···S1iC1i hydrogen bonds [symmetry code: (i): –x, –y + 1, –z + 2]. Namely, motif R22(8) is formed. Furthermore, there are additional N2—H···S1iiC1ii hydrogen bonds [symmetry code: (ii): x, –y + 3/2, z–1/2], which link the dimers to form the two-dimensional layers (see Fig. 2). Hydrogen bonds parameters are summarized in Tab. 1. Hydrocarbon chains pointing outside the layer interact with those from the neighbouring ones by van der Waals forces to form a three-dimensional crystal structure. The same packing patterns can be found in syn,anti isomers of other analogues: N,N'-diethylthiourea and N,N'-diisopropylthiourea (Ramnathan et al., 1995) and similar in N,N'-bis(prop-2-en-1-yl)thiourea (Djurdjevic et al., 2007). The case of N,N'-di-tert-butylthiourea is different, because the molecules adopt syn,syn conformation (Custelcean et al., 2005).

There are several synthetic methods to obtain symmetrical thioureas. For example condensation of amine hydrochlorides with potassium thiocyanate (Herr et al., 2000) or reaction of N-silylated amines with carbon disulfide (Kricheldorf, 1970). The very simple, quick and solvent-free method was proposed by Ranu et al. (2003) incorporating addition of amines to carbon disulfide on the surface of alumina under microwave irradition. In the case of n-butylamine, mixture was irradiated for 2 minutes and the yield was 89%.

We found that good quality crystals can be obtained by recrystallization from ethyl acetate or acetylacetone (2,4-pentanedione).

Related literature top

For structures of N,N'-di-n-butylthiourea complexes with mercury and copper, see: Ahmad et al. (2009); Khan et al. (2007); Warda (1998). For structures of other symmetrically substituted thiourea derivatives, see: Custelcean et al. (2005); Djurdjevic et al. (2007); Ramnathan et al. (1995). For synthetic methods, see: Herr et al. (2000); Kricheldorf (1970); Ranu et al. (2003).

Experimental top

0.25 g (1.33 mmol) of commercially available N,N'-di-n-butylthiourea was dissolved in 2 ml of freshly distilled acetylacetone. The mixture was filtered and the filtrate was left for crystallization in a refrigerator. After several days well formed, colorless crystals were collected. Melting point: 335 - 337 K.

Refinement top

Hydrogen atoms were placed at the calculated positions (dCH = 0.98–0.99 Å) and were treated as riding on their parent atoms, with Uiso(H) set to 1.2–1.5 times Ueq(C). The N—H distances were restrained to 0.85 (1) Å.

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. Structure of [SC(NHnBu)2]2 dimer with the thermal ellipsoids drawn at 50% probability level. Hydrogen bonds marked with dotted lines. Symmetry code (i): –x, –y + 1, –z + 2.
[Figure 2] Fig. 2. Layers of SC(NHnBu)2 seen in the a) [001] and b) [010] direction. Hydrogen bonds marked with dotted lines, hydrogen atoms omitted for clarity.
1,3-Di-n-butylthiourea top
Crystal data top
C9H20N2SF(000) = 416
Mr = 188.33Dx = 1.089 Mg m3
Monoclinic, P21/cMelting point: 336(1) K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 12.6395 (6) ÅCell parameters from 2942 reflections
b = 10.0836 (6) Åθ = 2.6–28.6°
c = 9.0128 (5) ŵ = 0.24 mm1
β = 90.476 (5)°T = 120 K
V = 1148.66 (11) Å3Prism, clear colourless
Z = 40.48 × 0.29 × 0.09 mm
Data collection top
Oxford Diffraction Xcalibur Sapphire2
diffractometer
2247 independent reflections
Graphite monochromator1656 reflections with I > 2σ(I)
Detector resolution: 8.1883 pixels mm-1Rint = 0.038
ω scansθmax = 26°, θmin = 2.6°
Absorption correction: analytical
[CrysAlis PRO (Oxford Diffraction, 2010; based on Clark & Reid, 1995)]
h = 1515
Tmin = 0.94, Tmax = 0.978k = 1212
5268 measured reflectionsl = 1011
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)] = 0.046Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.116H atoms treated by a mixture of independent and constrained refinement
S = 0.97 w = 1/[σ2(Fo2) + (0.0753P)2]
where P = (Fo2 + 2Fc2)/3
2247 reflections(Δ/σ)max < 0.001
119 parametersΔρmax = 0.45 e Å3
2 restraintsΔρmin = 0.27 e Å3
Crystal data top
C9H20N2SV = 1148.66 (11) Å3
Mr = 188.33Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.6395 (6) ŵ = 0.24 mm1
b = 10.0836 (6) ÅT = 120 K
c = 9.0128 (5) Å0.48 × 0.29 × 0.09 mm
β = 90.476 (5)°
Data collection top
Oxford Diffraction Xcalibur Sapphire2
diffractometer
2247 independent reflections
Absorption correction: analytical
[CrysAlis PRO (Oxford Diffraction, 2010; based on Clark & Reid, 1995)]
1656 reflections with I > 2σ(I)
Tmin = 0.94, Tmax = 0.978Rint = 0.038
5268 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0462 restraints
wR(F2) = 0.116H atoms treated by a mixture of independent and constrained refinement
S = 0.97Δρmax = 0.45 e Å3
2247 reflectionsΔρmin = 0.27 e Å3
119 parameters
Special details top

Experimental. CrysAlisPro, Oxford Diffraction Ltd., Version 1.171.33.66 (Oxford Diffraction, 2010) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid (1995).

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
S10.16510 (4)0.55610 (5)1.03064 (5)0.02246 (18)
N10.03660 (13)0.60898 (18)0.80521 (17)0.0218 (4)
N20.19164 (13)0.72585 (17)0.80620 (18)0.0229 (4)
C10.12922 (15)0.63626 (19)0.8705 (2)0.0209 (4)
C20.00052 (15)0.6657 (2)0.6656 (2)0.0225 (5)
H2A0.05250.6490.58770.027*
H2B0.00820.76290.67690.027*
C30.10604 (15)0.6065 (2)0.6181 (2)0.0232 (5)
H3A0.10040.50860.61740.028*
H3B0.16080.63140.69090.028*
C40.13954 (16)0.6542 (2)0.4653 (2)0.0260 (5)
H4A0.08310.63270.39380.031*
H4B0.14750.75180.46760.031*
C50.24282 (17)0.5926 (2)0.4116 (2)0.0332 (5)
H5A0.23590.49590.41030.05*
H5B0.2590.62440.31120.05*
H5C0.30010.6180.47850.05*
C60.29696 (15)0.7629 (2)0.8598 (2)0.0239 (5)
H6A0.2960.76770.96950.029*
H6B0.31450.85230.82180.029*
C70.38310 (15)0.6662 (2)0.8128 (2)0.0254 (5)
H7A0.3650.57640.84890.03*
H7B0.38550.66290.70310.03*
C80.49139 (17)0.7044 (2)0.8722 (3)0.0355 (6)
H8A0.4890.70810.98190.043*
H8B0.50970.79410.83570.043*
C90.57675 (19)0.6074 (3)0.8255 (3)0.0469 (7)
H9A0.55830.51820.85960.07*
H9B0.64460.6340.86970.07*
H9C0.58240.60750.71720.07*
H10.0032 (14)0.5586 (19)0.854 (2)0.028 (6)*
H20.1715 (15)0.7675 (18)0.7292 (15)0.019 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0254 (3)0.0207 (3)0.0213 (3)0.0005 (2)0.00074 (19)0.0018 (2)
N10.0218 (9)0.0250 (9)0.0188 (8)0.0043 (8)0.0011 (7)0.0019 (7)
N20.0238 (9)0.0227 (9)0.0221 (9)0.0016 (7)0.0019 (7)0.0047 (7)
C10.0251 (10)0.0180 (10)0.0197 (10)0.0039 (8)0.0051 (8)0.0024 (8)
C20.0257 (10)0.0213 (11)0.0206 (10)0.0003 (9)0.0037 (8)0.0015 (8)
C30.0234 (10)0.0223 (10)0.0238 (11)0.0007 (8)0.0013 (8)0.0018 (8)
C40.0325 (12)0.0223 (11)0.0232 (11)0.0027 (9)0.0003 (9)0.0014 (8)
C50.0325 (12)0.0355 (13)0.0313 (12)0.0036 (10)0.0068 (10)0.0028 (10)
C60.0226 (10)0.0219 (11)0.0272 (11)0.0047 (9)0.0010 (8)0.0011 (8)
C70.0251 (11)0.0280 (11)0.0230 (10)0.0000 (9)0.0003 (8)0.0020 (9)
C80.0276 (12)0.0329 (13)0.0460 (14)0.0016 (10)0.0010 (10)0.0020 (11)
C90.0292 (13)0.0475 (16)0.0641 (18)0.0056 (12)0.0016 (12)0.0049 (14)
Geometric parameters (Å, º) top
S1—C11.712 (2)C5—H5A0.98
N1—C11.334 (2)C5—H5B0.98
N1—C21.456 (2)C5—H5C0.98
N1—H10.844 (9)C6—C71.524 (3)
N2—C11.335 (3)C6—H6A0.99
N2—C61.461 (3)C6—H6B0.99
N2—H20.849 (9)C7—C81.515 (3)
C2—C31.519 (3)C7—H7A0.99
C2—H2A0.99C7—H7B0.99
C2—H2B0.99C8—C91.518 (3)
C3—C41.515 (3)C8—H8A0.99
C3—H3A0.99C8—H8B0.99
C3—H3B0.99C9—H9A0.98
C4—C51.521 (3)C9—H9B0.98
C4—H4A0.99C9—H9C0.98
C4—H4B0.99
C1—N1—C2125.10 (17)H5A—C5—H5B109.5
C1—N1—H1114.7 (15)C4—C5—H5C109.5
C2—N1—H1120.1 (15)H5A—C5—H5C109.5
C1—N2—C6124.74 (17)H5B—C5—H5C109.5
C1—N2—H2121.0 (14)N2—C6—C7113.32 (17)
C6—N2—H2114.2 (14)N2—C6—H6A108.9
N1—C1—N2117.90 (18)C7—C6—H6A108.9
N1—C1—S1119.96 (15)N2—C6—H6B108.9
N2—C1—S1122.13 (15)C7—C6—H6B108.9
N1—C2—C3111.42 (16)H6A—C6—H6B107.7
N1—C2—H2A109.3C8—C7—C6112.61 (18)
C3—C2—H2A109.3C8—C7—H7A109.1
N1—C2—H2B109.3C6—C7—H7A109.1
C3—C2—H2B109.3C8—C7—H7B109.1
H2A—C2—H2B108C6—C7—H7B109.1
C4—C3—C2111.70 (16)H7A—C7—H7B107.8
C4—C3—H3A109.3C7—C8—C9112.3 (2)
C2—C3—H3A109.3C7—C8—H8A109.1
C4—C3—H3B109.3C9—C8—H8A109.1
C2—C3—H3B109.3C7—C8—H8B109.1
H3A—C3—H3B107.9C9—C8—H8B109.1
C3—C4—C5113.14 (17)H8A—C8—H8B107.9
C3—C4—H4A109C8—C9—H9A109.5
C5—C4—H4A109C8—C9—H9B109.5
C3—C4—H4B109H9A—C9—H9B109.5
C5—C4—H4B109C8—C9—H9C109.5
H4A—C4—H4B107.8H9A—C9—H9C109.5
C4—C5—H5A109.5H9B—C9—H9C109.5
C4—C5—H5B109.5
C2—N1—C1—N22.5 (3)N1—C2—C3—C4173.97 (16)
C2—N1—C1—S1176.99 (15)C2—C3—C4—C5177.74 (17)
C6—N2—C1—N1177.36 (17)C1—N2—C6—C781.5 (2)
C6—N2—C1—S12.1 (3)N2—C6—C7—C8178.71 (17)
C1—N1—C2—C3176.27 (17)C6—C7—C8—C9179.74 (19)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···S1i0.84 (1)2.58 (1)3.3943 (17)164 (2)
N2—H2···S1ii0.85 (1)2.52 (1)3.3319 (17)159 (2)
Symmetry codes: (i) x, y+1, z+2; (ii) x, y+3/2, z1/2.

Experimental details

Crystal data
Chemical formulaC9H20N2S
Mr188.33
Crystal system, space groupMonoclinic, P21/c
Temperature (K)120
a, b, c (Å)12.6395 (6), 10.0836 (6), 9.0128 (5)
β (°) 90.476 (5)
V3)1148.66 (11)
Z4
Radiation typeMo Kα
µ (mm1)0.24
Crystal size (mm)0.48 × 0.29 × 0.09
Data collection
DiffractometerOxford Diffraction Xcalibur Sapphire2
diffractometer
Absorption correctionAnalytical
[CrysAlis PRO (Oxford Diffraction, 2010; based on Clark & Reid, 1995)]
Tmin, Tmax0.94, 0.978
No. of measured, independent and
observed [I > 2σ(I)] reflections
5268, 2247, 1656
Rint0.038
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.046, 0.116, 0.97
No. of reflections2247
No. of parameters119
No. of restraints2
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.45, 0.27

Computer programs: CrysAlis PRO (Oxford Diffraction, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···S1i0.844 (9)2.575 (11)3.3943 (17)164.0 (19)
N2—H2···S1ii0.849 (9)2.524 (12)3.3319 (17)159.4 (18)
Symmetry codes: (i) x, y+1, z+2; (ii) x, y+3/2, z1/2.
 

Acknowledgements

Financial support from the Polish Ministry of Science and Higher Education to AO (project No. N N204 543339) is gratefully acknowledged.

References

First citationAhmad, S., Sadaf, H., Akkurt, M., Sharif, S. & Khan, I. U. (2009). Acta Cryst. E65, m1191–m1192.  Web of Science CSD CrossRef IUCr Journals
First citationClark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887–897.  CrossRef CAS Web of Science IUCr Journals
First citationCustelcean, R., Gorbunova, M. G. & Bonnesen, P. V. (2005). Chem. Eur. J. 11, 1459–1466.  Web of Science CSD CrossRef PubMed CAS
First citationDjurdjevic, S., Leigh, D. & Parsons, S. (2007). Private communication to the Cambridge Structural Database (Refcode JIPKAV). CCDC, Union Road, Cambridge, England.
First citationDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.  Web of Science CrossRef CAS IUCr Journals
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals
First citationHerr, R. J., Kuhler, L., Meckler, H. & Opalka, C. J. (2000). Synthesis, pp. 1569–1574.  CrossRef
First citationKhan, I. U., Mufakkar, M., Ahmad, S., Fun, H.-K. & Chantrapromma, S. (2007). Acta Cryst. E63, m2550–m2551.  Web of Science CSD CrossRef IUCr Journals
First citationKricheldorf, H. R. (1970). Synthesis, pp. 539–540.  CrossRef
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CrossRef CAS IUCr Journals
First citationOxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.
First citationRamnathan, A., Sivakumar, K., Subramanian, K., Janarthanan, N., Ramadas, K. & Fun, H.-K. (1995). Acta Cryst. C51, 2446–2450.  CSD CrossRef CAS Web of Science IUCr Journals
First citationRanu, B. C., Dey, S. S. & Bag, S. (2003). ARKIVOC, ix, 14–20.  CrossRef
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals
First citationWarda, S. A. (1998). Acta Cryst. C54, 460–462.  Web of Science CSD CrossRef CAS IUCr Journals

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