1-Cyclo­hexyl-3-{(E)-[1-(pyridin-2-yl)ethyl­idene]amino}­thio­urea

Md Abdus Salam; Md Abu Affan; Fasihuddin B Ahmad; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536811009317

. 2011 Mar 23;67(Pt 4):o955. doi: 10.1107/S1600536811009317

1-Cyclohexyl-3-{(E)-[1-(pyridin-2-yl)ethylidene]amino}thiourea

Md Abdus Salam ^a, Md Abu Affan ^a,^‡, Fasihuddin B Ahmad ^a, Seik Weng Ng ^b, Edward R T Tiekink ^b,^*

PMCID: PMC3099887 PMID: 21754220

Abstract

In the title thiourea derivative, C₁₄H₂₀N₄S, the non-ring non-H atoms are approximately planar, with an r.m.s. deviation of 0.0720 Å. The pyridine ring is twisted out of this plane and makes a dihedral angle of 16.85 (13)° with it. The mean plane passing through the cyclohexyl ring is almost normal to the central plane [dihedral angle = 69.23 (8)°]. An intramolecular N—H⋯N(imine) hydrogen bond occurs. Centrosymmetric dimers are formed in the crystal structure via pairs of N—H⋯S hydrogen bonds, and these are connected into a supramolecular chain along the a axis via C—H⋯π(pyridyl) interactions.

Related literature

For related thiourea structures, see: Tiekink (1989 ▶); Lai & Tiekink (2002 ▶); Muramulla et al. (2009 ▶).

Experimental

Crystal data

C₁₄H₂₀N₄S
M _r = 276.40
Triclinic,
a = 5.8824 (6) Å
b = 10.2410 (9) Å
c = 12.3902 (14) Å
α = 94.718 (8)°
β = 90.427 (9)°
γ = 90.979 (8)°
V = 743.74 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 295 K
0.25 × 0.20 × 0.15 mm

Data collection

Agilent Supernova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent Technologies, 2010 ▶) T _min = 0.842, T _max = 1.000
5817 measured reflections
3292 independent reflections
2355 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.151
S = 1.04
3292 reflections
181 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: CrysAlis PRO (Agilent Technologies, 2010 ▶); 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: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811009317/hg5008sup1.cif

e-67-0o955-sup1.cif^{(18.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811009317/hg5008Isup2.hkl

e-67-0o955-Isup2.hkl^{(161.4KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the pyridyl ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N3	0.87 (2)	2.16 (2)	2.592 (3)	111 (2)
N2—H2⋯S1ⁱ	0.88 (2)	2.73 (2)	3.610 (2)	174 (2)
C9—H9b⋯Cg1ⁱⁱ	0.96	2.89	3.776 (3)	155

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was supported financially by the Ministry of Science, Technology and Innovation (MOSTI) under research grant No. 06-01-09-SF0046. The authors thank Universiti Malaysia Sarawak (UNIMAS) for the facilities to carry out the research work. The authors also thank the University of Malaya for support of the crystallographic facility.

supplementary crystallographic information

Comment

In continuation of long-term structural investigations of thiourea derivatives (Tiekink, 1989; Lai & Tiekink, 2002; Muramulla et al., 2009), the title compound, (I), was investigated. The atoms comprising the thiosemicarbazone backbone of the molecules, i.e. S1,N1—N3,C1,C7—C10 are co-planar (r.m.s. = 0.0720 Å). While the pyridine residue is twisted out of this plane as seen in the value of the N3—C8—C10—N4 torsion angle of 164.7 (2) °, the cyclohexyl group is almost normal to the plane; C2—C1—N1—C7 is 87.7 (3) °. The amine-N—H1 and imine-N3 atoms are directed to the same side of the molecule enabling the formation of an intramolecular N—H···N hydrogen bond, Table 1. The pyridine-N atom is directed away from the rest of the molecule and is proximate to the methyl substituent which results in the formation of a C—H···N contact, Table 1.

The crystal packing is dominated by N—H···S hydrogen bonds that lead to centrosymmetric dimers, Table 1. Dimers aligned along the a axis are connected into a supramolecular chain via C—H···π interactions involving methyl-H and the pyridyl ring. There are no specific intermolecular interactions occurring between chains, Fig. 3.

Experimental

Cyclohexyl isothiocyanate (0.706 g, 5 mmol) and hydrazine hydrate (0.250 g, 5 mmol), each dissolved in 10 ml ethanol, were mixed with constant stirring. The stirring was continued for 30 min and the white product, N(4)-cyclohexylthiosemicarbazide formed was washed with ethanol and dried. A solution of the N(4)-cyclohexylthiosemicarbazide (0.51 g, 3 mmol) in 10 ml methanol was refluxed with a methanolic solution of 2-acetylpyridine (0.363 g, 3 mmol) for 5 h after adding 1–2 drops of acetic acid. A white powder separated on cooling the solution which was filtered and washed with methanol. This was recrystallized from methanol and dried in vacuo over silica gel. (M.pt. 453–455 K; Yield 0.682 g, 76%). Elemental analysis: Calc.: C, 60.83; H, 7.29; N, 11.60%. Found: C, 60.72; H, 7.25; N, 11.57%. FT—IR (KBr, cm^-1) ν_max: 3329 (s, NH), 2931, 2851 (s, cyclohexyl), 1580 (w, C═N—N═C), 980 (m, N—N), 1358, 835 (w, C═ S), 657 (m, pyridine in plane).