1,3-Di-n-butyl­thio­urea

Okuniewski, A.; Dąbrowska, A.; Chojnacki, J.

doi:10.1107/S1600536811009743

organic compounds

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ISSN: 2056-9890

Volume 67| Part 4| April 2011| Page o925

doi:10.1107/S1600536811009743

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1,3-Di-n-butylthiourea

Andrzej Okuniewski,^a Agnieszka Dąbrowska ^a and Jaroslaw Chojnacki ^a ^*

^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 ); 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

Crystal data

C₉H₂₀N₂S
M_r = 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 )] T_min = 0.94, T_max = 0.978
5268 measured reflections
2247 independent reflections
1656 reflections with I > 2σ(I)
R_int = 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
Δρ_max = 0.45 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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 ); 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 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811009743/si2344sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811009743/si2344Isup2.hkl

checkCIF report

Comment top

N,N'-Di-n-butylthiourea, S═C(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 C═S 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···S1ⁱ═C1ⁱ hydrogen bonds [symmetry code: (i): –x, –y + 1, –z + 2]. Namely, motif R₂²(8) is formed. Furthermore, there are additional N2—H···S1ⁱⁱ═C1ⁱⁱ 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.

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

	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.
	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

C₉H₂₀N₂S	F(000) = 416
M_r = 188.33	D_x = 1.089 Mg m⁻³
Monoclinic, P2₁/c	Melting point: 336(1) K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 12.6395 (6) Å	Cell parameters from 2942 reflections
b = 10.0836 (6) Å	θ = 2.6–28.6°
c = 9.0128 (5) Å	µ = 0.24 mm⁻¹
β = 90.476 (5)°	T = 120 K
V = 1148.66 (11) Å³	Prism, clear colourless
Z = 4	0.48 × 0.29 × 0.09 mm

Data collection top

Oxford Diffraction Xcalibur Sapphire2 diffractometer	2247 independent reflections
Graphite monochromator	1656 reflections with I > 2σ(I)
Detector resolution: 8.1883 pixels mm^-1	R_int = 0.038
ω scans	θ_max = 26°, θ_min = 2.6°
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2010; based on Clark & Reid, 1995)]	h = −15→15
T_min = 0.94, T_max = 0.978	k = −12→12
5268 measured reflections	l = −10→11

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.116	H atoms treated by a mixture of independent and constrained refinement
S = 0.97	w = 1/[σ²(F_o²) + (0.0753P)²] where P = (F_o² + 2F_c²)/3
2247 reflections	(Δ/σ)_max < 0.001
119 parameters	Δρ_max = 0.45 e Å⁻³
2 restraints	Δρ_min = −0.27 e Å⁻³

Crystal data top

C₉H₂₀N₂S	V = 1148.66 (11) Å³
M_r = 188.33	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.6395 (6) Å	µ = 0.24 mm⁻¹
b = 10.0836 (6) Å	T = 120 K
c = 9.0128 (5) Å	0.48 × 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)
T_min = 0.94, T_max = 0.978	R_int = 0.038
5268 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	2 restraints
wR(F²) = 0.116	H atoms treated by a mixture of independent and constrained refinement
S = 0.97	Δρ_max = 0.45 e Å⁻³
2247 reflections	Δρ_min = −0.27 e Å⁻³
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

	x	y	z	U_iso*/U_eq
S1	0.16510 (4)	0.55610 (5)	1.03064 (5)	0.02246 (18)
N1	0.03660 (13)	0.60898 (18)	0.80521 (17)	0.0218 (4)
N2	0.19164 (13)	0.72585 (17)	0.80620 (18)	0.0229 (4)
C1	0.12922 (15)	0.63626 (19)	0.8705 (2)	0.0209 (4)
C2	−0.00052 (15)	0.6657 (2)	0.6656 (2)	0.0225 (5)
H2A	0.0525	0.649	0.5877	0.027*
H2B	−0.0082	0.7629	0.6769	0.027*
C3	−0.10604 (15)	0.6065 (2)	0.6181 (2)	0.0232 (5)
H3A	−0.1004	0.5086	0.6174	0.028*
H3B	−0.1608	0.6314	0.6909	0.028*
C4	−0.13954 (16)	0.6542 (2)	0.4653 (2)	0.0260 (5)
H4A	−0.0831	0.6327	0.3938	0.031*
H4B	−0.1475	0.7518	0.4676	0.031*
C5	−0.24282 (17)	0.5926 (2)	0.4116 (2)	0.0332 (5)
H5A	−0.2359	0.4959	0.4103	0.05*
H5B	−0.259	0.6244	0.3112	0.05*
H5C	−0.3001	0.618	0.4785	0.05*
C6	0.29696 (15)	0.7629 (2)	0.8598 (2)	0.0239 (5)
H6A	0.296	0.7677	0.9695	0.029*
H6B	0.3145	0.8523	0.8218	0.029*
C7	0.38310 (15)	0.6662 (2)	0.8128 (2)	0.0254 (5)
H7A	0.365	0.5764	0.8489	0.03*
H7B	0.3855	0.6629	0.7031	0.03*
C8	0.49139 (17)	0.7044 (2)	0.8722 (3)	0.0355 (6)
H8A	0.489	0.7081	0.9819	0.043*
H8B	0.5097	0.7941	0.8357	0.043*
C9	0.57675 (19)	0.6074 (3)	0.8255 (3)	0.0469 (7)
H9A	0.5583	0.5182	0.8596	0.07*
H9B	0.6446	0.634	0.8697	0.07*
H9C	0.5824	0.6075	0.7172	0.07*
H1	−0.0032 (14)	0.5586 (19)	0.854 (2)	0.028 (6)*
H2	0.1715 (15)	0.7675 (18)	0.7292 (15)	0.019 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0254 (3)	0.0207 (3)	0.0213 (3)	0.0005 (2)	0.00074 (19)	0.0018 (2)
N1	0.0218 (9)	0.0250 (9)	0.0188 (8)	−0.0043 (8)	0.0011 (7)	0.0019 (7)
N2	0.0238 (9)	0.0227 (9)	0.0221 (9)	−0.0016 (7)	−0.0019 (7)	0.0047 (7)
C1	0.0251 (10)	0.0180 (10)	0.0197 (10)	0.0039 (8)	0.0051 (8)	−0.0024 (8)
C2	0.0257 (10)	0.0213 (11)	0.0206 (10)	0.0003 (9)	0.0037 (8)	0.0015 (8)
C3	0.0234 (10)	0.0223 (10)	0.0238 (11)	−0.0007 (8)	0.0013 (8)	0.0018 (8)
C4	0.0325 (12)	0.0223 (11)	0.0232 (11)	−0.0027 (9)	−0.0003 (9)	0.0014 (8)
C5	0.0325 (12)	0.0355 (13)	0.0313 (12)	−0.0036 (10)	−0.0068 (10)	0.0028 (10)
C6	0.0226 (10)	0.0219 (11)	0.0272 (11)	−0.0047 (9)	−0.0010 (8)	0.0011 (8)
C7	0.0251 (11)	0.0280 (11)	0.0230 (10)	0.0000 (9)	−0.0003 (8)	0.0020 (9)
C8	0.0276 (12)	0.0329 (13)	0.0460 (14)	−0.0016 (10)	−0.0010 (10)	0.0020 (11)
C9	0.0292 (13)	0.0475 (16)	0.0641 (18)	0.0056 (12)	0.0016 (12)	0.0049 (14)

Geometric parameters (Å, º) top

S1—C1	1.712 (2)	C5—H5A	0.98
N1—C1	1.334 (2)	C5—H5B	0.98
N1—C2	1.456 (2)	C5—H5C	0.98
N1—H1	0.844 (9)	C6—C7	1.524 (3)
N2—C1	1.335 (3)	C6—H6A	0.99
N2—C6	1.461 (3)	C6—H6B	0.99
N2—H2	0.849 (9)	C7—C8	1.515 (3)
C2—C3	1.519 (3)	C7—H7A	0.99
C2—H2A	0.99	C7—H7B	0.99
C2—H2B	0.99	C8—C9	1.518 (3)
C3—C4	1.515 (3)	C8—H8A	0.99
C3—H3A	0.99	C8—H8B	0.99
C3—H3B	0.99	C9—H9A	0.98
C4—C5	1.521 (3)	C9—H9B	0.98
C4—H4A	0.99	C9—H9C	0.98
C4—H4B	0.99

C1—N1—C2	125.10 (17)	H5A—C5—H5B	109.5
C1—N1—H1	114.7 (15)	C4—C5—H5C	109.5
C2—N1—H1	120.1 (15)	H5A—C5—H5C	109.5
C1—N2—C6	124.74 (17)	H5B—C5—H5C	109.5
C1—N2—H2	121.0 (14)	N2—C6—C7	113.32 (17)
C6—N2—H2	114.2 (14)	N2—C6—H6A	108.9
N1—C1—N2	117.90 (18)	C7—C6—H6A	108.9
N1—C1—S1	119.96 (15)	N2—C6—H6B	108.9
N2—C1—S1	122.13 (15)	C7—C6—H6B	108.9
N1—C2—C3	111.42 (16)	H6A—C6—H6B	107.7
N1—C2—H2A	109.3	C8—C7—C6	112.61 (18)
C3—C2—H2A	109.3	C8—C7—H7A	109.1
N1—C2—H2B	109.3	C6—C7—H7A	109.1
C3—C2—H2B	109.3	C8—C7—H7B	109.1
H2A—C2—H2B	108	C6—C7—H7B	109.1
C4—C3—C2	111.70 (16)	H7A—C7—H7B	107.8
C4—C3—H3A	109.3	C7—C8—C9	112.3 (2)
C2—C3—H3A	109.3	C7—C8—H8A	109.1
C4—C3—H3B	109.3	C9—C8—H8A	109.1
C2—C3—H3B	109.3	C7—C8—H8B	109.1
H3A—C3—H3B	107.9	C9—C8—H8B	109.1
C3—C4—C5	113.14 (17)	H8A—C8—H8B	107.9
C3—C4—H4A	109	C8—C9—H9A	109.5
C5—C4—H4A	109	C8—C9—H9B	109.5
C3—C4—H4B	109	H9A—C9—H9B	109.5
C5—C4—H4B	109	C8—C9—H9C	109.5
H4A—C4—H4B	107.8	H9A—C9—H9C	109.5
C4—C5—H5A	109.5	H9B—C9—H9C	109.5
C4—C5—H5B	109.5

C2—N1—C1—N2	2.5 (3)	N1—C2—C3—C4	−173.97 (16)
C2—N1—C1—S1	−176.99 (15)	C2—C3—C4—C5	177.74 (17)
C6—N2—C1—N1	−177.36 (17)	C1—N2—C6—C7	81.5 (2)
C6—N2—C1—S1	2.1 (3)	N2—C6—C7—C8	−178.71 (17)
C1—N1—C2—C3	176.27 (17)	C6—C7—C8—C9	179.74 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	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+3/2, z−1/2.

Experimental details

Crystal data
Chemical formula	C₉H₂₀N₂S
M_r	188.33
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	120
a, b, c (Å)	12.6395 (6), 10.0836 (6), 9.0128 (5)
β (°)	90.476 (5)
V (Å³)	1148.66 (11)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.24
Crystal size (mm)	0.48 × 0.29 × 0.09

Data collection
Diffractometer	Oxford Diffraction Xcalibur Sapphire2 diffractometer
Absorption correction	Analytical [CrysAlis PRO (Oxford Diffraction, 2010; based on Clark & Reid, 1995)]
T_min, T_max	0.94, 0.978
No. of measured, independent and observed [I > 2σ(I)] reflections	5268, 2247, 1656
R_int	0.038
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.116, 0.97
No. of reflections	2247
No. of parameters	119
No. of restraints	2
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	D—H···A
N1—H1···S1ⁱ	0.844 (9)	2.575 (11)	3.3943 (17)	164.0 (19)
N2—H2···S1ⁱⁱ	0.849 (9)	2.524 (12)	3.3319 (17)	159.4 (18)

Symmetry codes: (i) −x, −y+1, −z+2; (ii) x, −y+3/2, z−1/2.

Acknowledgements

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

References

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