Benzyl 2-methyl-3-[(E)-(thio­phen-2-yl)methyl­idene]dithio­carbazate

Saroj K S Hazari; B K Dey; Tapashi G Roy; B Ganguly; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812012652

. 2012 Mar 28;68(Pt 4):o1216. doi: 10.1107/S1600536812012652

Benzyl 2-methyl-3-[(E)-(thiophen-2-yl)methylidene]dithiocarbazate

Saroj K S Hazari ^a, B K Dey ^a, Tapashi G Roy ^a,^‡, B Ganguly ^a, Seik Weng Ng ^b,^c, Edward R T Tiekink ^b,^*

PMCID: PMC3344150 PMID: 22606153

Abstract

In the title compound, C₁₄H₁₄N₂S₃, the thione S atom and methyl group are syn, as are the two thioether S atoms. The molecule is twisted, the dihedral angles between the central (C₂N₂S₂) residue and the pendent 2-thienyl and phenyl rings being 21.57 (6) and 77.54 (3)°, respectively. In the crystal, molecules assemble into a three-dimensional architecture via C—H⋯π interactions, involving both the five- and six-membered rings as acceptors, as well as S⋯S interactions [3.3406 (5) Å] between centrosymmetrically related 2-thienyl rings.

Related literature

For the biological activity of related Schiff base compounds, see: Hazari et al. (2002 ▶). For a related structure, see: Scovill & Silverton (1980 ▶).

Experimental

Crystal data

C₁₄H₁₄N₂S₃
M _r = 306.45
Monoclinic,
a = 6.0585 (1) Å
b = 19.3774 (5) Å
c = 12.5769 (3) Å
β = 103.200 (2)°
V = 1437.49 (6) Å³
Z = 4
Cu Kα radiation
μ = 4.60 mm⁻¹
T = 100 K
0.15 × 0.15 × 0.15 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.871, T _max = 1.000
5742 measured reflections
2958 independent reflections
2746 reflections with I > 2σ(I)
R _int = 0.017

Refinement

R[F ² > 2σ(F ²)] = 0.029
wR(F ²) = 0.080
S = 1.04
2958 reflections
173 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); 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 datablock(s) global, I. DOI: 10.1107/S1600536812012652/hg5198sup1.cif

e-68-o1216-sup1.cif^{(17.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812012652/hg5198Isup2.hkl

e-68-o1216-Isup2.hkl^{(145.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812012652/hg5198Isup3.cml

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

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

Cg1 and Cg2 are the centroids of the S1,C1–C4 and C9–C14 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6A⋯Cg1ⁱ	0.98	2.85	3.4021 (17)	117
C8—H8A⋯Cg2ⁱⁱ	0.99	2.80	3.4795 (15)	127

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

Acknowledgments

The University Grants Commission, Bangladesh, is thanked for a fellowship to BG. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

As a continuation of systematic studies into the synthesis, characterization and biological activities of substituted Schiff base ligands and their metal complexes (Hazari et al., 2002), crystals of the title compound, (I), were isolated and characterized crystallographically.

In (I), Fig. 1, the conformation about the imine N1═C5 bond [1.2876 (18) Å] is E. The six atoms of the central residue (S2,S3,N1,N2,C6 & C7) are co-planar having a r.m.s. deviation for the fitted atoms of 0.0395 Å. The maximum deviations from this plane are 0.0478 (7) Å for the S2 atom and -0.0557 (7) Å for the N1 atom. The 2-thienyl and phenyl rings form dihedral angles of 21.57 (6) and 77.54 (3)°, respectively, with the central plane, indicating a twisted molecule. In a rare example of a closely related compound, an S-methyl ester, the extreme ends of the molecule are both co-planar with the central residue (Scovill & Silverton, 1980). In (I), the thione-S and methyl group are syn, as are the two thioether-S atoms.

Molecules are consolidated into a three-dimensional architecture by C—H···π interactions, involving both the five- and six-membered rings as acceptors, Table 1, as well as S1···S1ⁱ interactions [distance = 3.3406 (5) Å for symmetry operation i: 1 - x, 1 - y, -z] between centrosymmetrically related 2-thienyl rings, Fig. 2.

Experimental

The title compound was isolated after a four step synthetic procedure. Synthesis of N-methyl-S-benzyldithiocarbazate: Potassium hydroxide (11.5 g), was dissolved in 90% ethanol (60 ml) and the mixture was cooled down to 273 K in an ice-bath. To this, methyl hydrazine (11.1 ml) was added slowly with mechanical stirring. A solution of carbondisulfide (12 ml) was added drop-wise from a burette with constant stirring over a period of 1 h. During this addition, the temperature of the reaction mixture was not to allowed to rise above 279 K. A yellow solution was obtained. Benzyl chloride (25 mL) was then added drop-wise with vigorous mechanical stirring. After the complete addition, the mixture was stirred for further 15 min, whereupon well formed crystals appeared. The product was separated by filtration and washed with water and recrystallized from ethanol and dried in a vacuum desiccator over silica gel. Yield: 15.75 g. M.pt: 373–375 K.

Synthesis of (I): A hot solution thiophene-2-carboxaldehyde (1.05 ml, 10 mmol) in absolute ethanol (40 ml) was mixed with a hot solution of N-methyl-S-benzyldithiocarbazate (2.12 g, 10 mmol) in the same solvent (40 ml). The mixture was refluxed for 6 h. on a water bath. After reducing a pale-red product appeared which was filtered off. This product was washed with ethanol several times (3 × 2 ml) and dried in a vacuum desiccator over silica gel. Yield: 1.55 g. M.pt: 433–435 K.

Attempted preparation of the dioxomolybdenum(VI) complex with (I): [MoO₂(acac)₂] (10 mmol) was dissolved in dry ethanol (40 ml) to which a hot solution of L (10 mmol) in dry ethanol (40 ml) was added. The mixture was refluxed for 6 h. on a water bath. After reducing the volume and standing overnight a light-blue product appeared, which was washed with ethanol for several times and dried in a vacuum desiccator over silica gel. M. pt: of product was > 493 K. Crystallization: The product was dissolved in ethanol to which half volume of petroleum ether was added (10/5 ml v/v). The solution was left for several days after which the title compound, (I), was deposited as crystals.