4-Cyano­benzaldehyde thio­semi­carbazone

De-Hong Wu; You-Hong Zhang; Zhu-Feng Li; Yong-Hua Li

doi:10.1107/S1600536808041792

. 2008 Dec 13;65(Pt 1):o107. doi: 10.1107/S1600536808041792

4-Cyanobenzaldehyde thiosemicarbazone

De-Hong Wu ^a,^*, You-Hong Zhang ^a, Zhu-Feng Li ^a, Yong-Hua Li ^a

PMCID: PMC2968031 PMID: 21581570

Abstract

The molecule of the title compound, C₉H₈N₄S, adopts an E configuration about both the C=N and C—NH bonds. In the crystal structure, adjacent molecules are linked by intermolecular N—H⋯S hydrogen-bonding interactions, forming chains running parallel to the b axis.

Related literature

For a general background to thiosemicarbazone compounds, see: Casas et al. (2000 ▶); Tarafder et al. (2000 ▶); Deschamps et al. (2003 ▶); Liu et al. (1999 ▶); Wu et al. (2000 ▶). For reference structural data, see: Sutton (1965 ▶).

Experimental

Crystal data

C₉H₈N₄S
M _r = 204.26
Monoclinic,
a = 12.284 (6) Å
b = 8.209 (4) Å
c = 10.058 (3) Å
β = 92.20 (3)°
V = 1013.5 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.28 mm⁻¹
T = 291 (2) K
0.25 × 0.17 × 0.15 mm

Data collection

Rigaku Mercury2 diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.94, T _max = 0.96
10019 measured reflections
2309 independent reflections
1596 reflections with I > 2σ(I)
R _int = 0.055

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.109
S = 1.01
2309 reflections
127 parameters
H-atom parameters constrained
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808041792/rz2264sup1.cif

e-65-0o107-sup1.cif^{(14.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808041792/rz2264Isup2.hkl

e-65-0o107-Isup2.hkl^{(113.5KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯S1ⁱ	0.86	2.50	3.355 (2)	171
N1—H1B⋯S1ⁱⁱ	0.86	2.63	3.399 (3)	150

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

Acknowledgments

The authors thank the Start-up Projects for Postdoctoral Research Funds of Southeast University (grant No. 1112000048).

supplementary crystallographic information

Comment

Thiosemicarbazones constitute an important class of N,S donors due to their propensity to react with a wide range of metals (Casas et al., 2000). Schiff bases show potential as antimicrobial and anticancer agents (Tarafder et al., 2000; Deschamps et al., 2003) and so have biochemical and pharmacological applications. It has been postulated that extensive electron delocalization in the thiosemicarbazone moiety helps the free thiosemicarbazone ligands and their metal complexes to exhibit SHG (second harmonic generation) efficiency (Liu et al., 1999; Wu et al., 2000). As part of a research on non-linear optical materials, specifically thiosemicarbazones and their metal complexes, we report here the crystal structure of a new Schiff base compound derived from thiosemicarbazide and 4-cyanobenzaldehyde.

In the title compound (Fig. 1), the thiosemicarbazone moiety is nearly planar (maximum deviation 0.113 (2) Å for atom N2) and shows an E configuration about both the C1═N2 and C2═N3 bonds. The molecule is not strictly planar, the dihedral angle between the thiosemicarbazone moiety and the phenyl ring being 15.8 (6)°. The C—S bond distance of 1.689 (2) Å agrees well with similar bonds in related compounds, being intermediate between the value of 1.82Å for a C—S single bond and 1.56 Å for a C═S double bond (Sutton, 1965). The C1—N2 bond distance (1.344 (3)Å) is indicative of some double-bond character, suggesting extensive electron delocalization in the whole molecule. The C1—N1 bond distance of 1.316 (3)Å is also indicative of some double-bond character. All the bond distances except for the C6—C9 bond length (1.447 (3) Å) fall within the normal range. In the crystal packing, adjacent molecules are linked by N—H···S hydrogen bonds (Table 1) to form chains running parallel to the b axis.

Experimental

The title compound was synthesized by refluxing 4-cyanobenzaldehyde (1.05 g, 8 mmol) and thiosemicarbazide (0.73 g, 8 mmol) in absolute ethanol (40 ml) for 6 h. After cooling to room temperature, the white solid formed was isolated and dried under vacuum (1.47 g, yield 90%). Single crystals suitable for X-ray structure analysis were obtained by slow evaporation of a methanol solution.