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Acta Crystallogr Sect E Struct Rep Online. 2010 November 1; 66(Pt 11): o2884.
Published online 2010 October 23. doi:  10.1107/S1600536810041632
PMCID: PMC3009173

N,N′-Bis[(E)-(3-methyl-2-thienyl)methyl­idene]ethane-1,2-diamine

Abstract

Two independent half-mol­ecules, each being completed by inversion symmetry, comprise the asymmetric unit of the title compound, C14H16N2S2. The major difference between the mol­ecules is found in the central C—C bond [the C—N—C—C torsion angles are 114.66 (18) and 128.94 (18)° in the two mol­ecules]. The thio­phene and imine groups are almost co-planar in each case [S—C—C—N torsion angles = −6.9 (2) and −3.6 (2)°]. In the crystal, the mol­ecules aggregate into supra­molecular chains via C—H(...)π inter­actions.

Related literature

For background to 2-substituted thio­phenes, see: Campaigne (1984 [triangle]); Kleemann et al. (2006 [triangle]). For related structures, see: Wang et al. (2007 [triangle]); Wardell et al. (2010 [triangle]).

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Object name is e-66-o2884-scheme1.jpg

Experimental

Crystal data

  • C14H16N2S2
  • M r = 276.41
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-o2884-efi1.jpg
  • a = 8.7610 (6) Å
  • b = 8.9502 (6) Å
  • c = 8.9853 (6) Å
  • α = 92.760 (1)°
  • β = 91.653 (1)°
  • γ = 106.066 (1)°
  • V = 675.61 (8) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.38 mm−1
  • T = 100 K
  • 0.30 × 0.30 × 0.10 mm

Data collection

  • Bruker SMART APEX diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.797, T max = 0.862
  • 6435 measured reflections
  • 3089 independent reflections
  • 2822 reflections with I > 2σ(I)
  • R int = 0.019

Refinement

  • R[F 2 > 2σ(F 2)] = 0.031
  • wR(F 2) = 0.100
  • S = 1.10
  • 3089 reflections
  • 165 parameters
  • H-atom parameters constrained
  • Δρmax = 0.45 e Å−3
  • Δρmin = −0.27 e Å−3

Data collection: APEX2 (Bruker, 2008 [triangle]); cell refinement: SAINT (Bruker, 2008 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]) and DIAMOND (Brandenburg, 2006 [triangle]); software used to prepare material for publication: publCIF (Westrip, 2010 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks general, I. DOI: 10.1107/S1600536810041632/pk2279sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810041632/pk2279Isup2.hkl

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

Acknowledgments

PB acknowledges the Department of Science and Technology (DST), India, for a research grant (SR/FTP/CS-57/2007). The authors are also grateful to the University of Malaya for support of the crystallographic facility.

supplementary crystallographic information

Comment

The title bifunctional Schiff base features 2-substituted thiophene rings (Campaigne, 1984; Kleemann et al., 2006) of interest owing to their putative biological activity (Wardell et al., 2010). The asymmetric unit comprises two half molecules of, as each of the two independent molecules, Figs 1 and 2, is located about crystallographic centres of inversion. The major difference between the molecules is found around the central C—C bond as manifested in the C2—N1—C1—C1i and C9—N2—C8—C8ii torsion angles of 114.66 (18)° and 128.94 (18)°, respectively [symmetry operation i: 1 - x, 2 - y, -z and ii: -x, 2 - y, 2 - z]. Further, the twist of the thiophene ring from the imine bond is more pronounced for the first independent molecule [the N1—C2—C3—S1 torsion angle = -6.9 (2)°] compared to that found in the second independent molecule [N2—C9—C10—S2 = -3.6 (2)°]. The conformation about each of the imine N1—C2 [1.274 (2) Å] and N2—C9 [1.272 (2) Å] bonds is E. The observed conformations match closely that found for the unsubstituted parent compound (Wang et al., 2007).

The most prominent feature of the crystal packing is the formation of supramolecular chains comprising both independent molecules, Fig. 3, that are sustained by C—H···π interactions, Table 1. The chains pack in layers parallel to (1 1 0), Fig. 4.

Experimental

A mixture of 3-methyl-2-thiophenecarboxaldehyde (0.43 ml, 0.004 M) and ethylenediamine (0.13 ml, 0.002 M) was stirred in dichloromethane for 3 h at room temperature. The solvent was removed under reduced pressure, and the resulting solid was dried and purified by column chromatography using a 1:3 mixture of ethyl acetate and hexane. Recrystallization was by slow evaporation of a dichloromethane solution which yielded colourless needles; yield: 81%. M. pt. 385–387 K.

Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 to 0.99 Å) and were included in the refinement in the riding model approximation, with Uiso(H) set to 1.2 to 1.5Uequiv(C).

Figures

Fig. 1.
Molecular structure of the first independent molecule showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level. Symmetry operation i: 1 - x, 2 - y, -z.
Fig. 2.
Molecular structure of the second independent molecule in showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level. Symmetry operation ii: -x, 2 - y, 2 - z.
Fig. 3.
Supramolecular chain sustained by C—H···π contacts (shown as purple dashed lines).
Fig. 4.
Unit-cell contents viewed in projection along the c axis. The C—H···π contacts are shown as purple dashed lines.

Crystal data

C14H16N2S2Z = 2
Mr = 276.41F(000) = 292
Triclinic, P1Dx = 1.359 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 8.7610 (6) ÅCell parameters from 4410 reflections
b = 8.9502 (6) Åθ = 4.3–28.3°
c = 8.9853 (6) ŵ = 0.38 mm1
α = 92.760 (1)°T = 100 K
β = 91.653 (1)°Prism, colourless
γ = 106.066 (1)°0.30 × 0.30 × 0.10 mm
V = 675.61 (8) Å3

Data collection

Bruker SMART APEX diffractometer3089 independent reflections
Radiation source: fine-focus sealed tube2822 reflections with I > 2σ(I)
graphiteRint = 0.019
ω scansθmax = 27.5°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)h = −11→11
Tmin = 0.797, Tmax = 0.862k = −11→10
6435 measured reflectionsl = −11→11

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.100H-atom parameters constrained
S = 1.10w = 1/[σ2(Fo2) + (0.0508P)2 + 0.4238P] where P = (Fo2 + 2Fc2)/3
3089 reflections(Δ/σ)max < 0.001
165 parametersΔρmax = 0.45 e Å3
0 restraintsΔρmin = −0.27 e Å3

Special details

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)

xyzUiso*/Ueq
S10.47805 (4)0.72178 (4)0.45069 (4)0.01583 (12)
N10.48699 (16)0.93243 (16)0.19349 (14)0.0171 (3)
C10.47949 (19)1.03494 (19)0.07326 (17)0.0170 (3)
H1A0.55541.13870.09680.020*
H1B0.37121.04830.06370.020*
C20.59455 (18)0.98652 (18)0.29593 (17)0.0151 (3)
H20.66411.08810.28900.018*
C30.61453 (18)0.89825 (18)0.42300 (17)0.0147 (3)
C40.73245 (18)0.93799 (18)0.53428 (17)0.0157 (3)
C50.7128 (2)0.82044 (19)0.63988 (17)0.0174 (3)
H50.78440.82640.72280.021*
C60.5808 (2)0.69924 (19)0.60906 (17)0.0180 (3)
H60.54930.61200.66860.022*
C70.8608 (2)1.0898 (2)0.5493 (2)0.0223 (3)
H7A0.82131.16820.60350.033*
H7B0.89131.12470.45000.033*
H7C0.95351.07560.60430.033*
S20.08033 (5)0.56857 (5)0.69562 (4)0.01757 (12)
N20.01928 (16)0.80946 (15)0.92178 (15)0.0166 (3)
C8−0.0229 (2)0.91842 (18)1.02823 (18)0.0179 (3)
H8A0.03280.91891.12570.021*
H8B−0.13880.88461.04270.021*
C90.09982 (18)0.72358 (18)0.97335 (17)0.0151 (3)
H90.13200.73691.07610.018*
C100.14457 (18)0.60595 (17)0.88127 (17)0.0138 (3)
C110.23606 (18)0.51136 (18)0.92386 (17)0.0147 (3)
C120.25375 (19)0.40900 (18)0.80306 (18)0.0177 (3)
H120.31340.33560.81160.021*
C130.1767 (2)0.42700 (19)0.67441 (19)0.0196 (3)
H130.17640.36800.58360.023*
C140.30760 (19)0.5131 (2)1.07776 (18)0.0191 (3)
H14A0.36630.62001.11080.029*
H14B0.38030.44731.07660.029*
H14C0.22290.47311.14640.029*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
S10.0184 (2)0.01340 (19)0.0147 (2)0.00282 (14)0.00089 (14)0.00138 (14)
N10.0216 (7)0.0169 (6)0.0123 (6)0.0044 (5)0.0017 (5)0.0028 (5)
C10.0196 (7)0.0176 (7)0.0136 (7)0.0046 (6)0.0003 (6)0.0034 (6)
C20.0176 (7)0.0133 (7)0.0152 (7)0.0054 (6)0.0039 (6)0.0008 (5)
C30.0172 (7)0.0130 (7)0.0142 (7)0.0045 (6)0.0029 (6)0.0009 (5)
C40.0185 (7)0.0146 (7)0.0149 (7)0.0061 (6)0.0014 (6)0.0001 (6)
C50.0229 (8)0.0178 (7)0.0133 (7)0.0090 (6)−0.0003 (6)0.0006 (6)
C60.0250 (8)0.0171 (7)0.0140 (7)0.0087 (6)0.0034 (6)0.0031 (6)
C70.0213 (8)0.0178 (8)0.0256 (8)0.0024 (6)−0.0047 (6)0.0022 (6)
S20.0210 (2)0.0169 (2)0.0142 (2)0.00442 (15)−0.00034 (14)0.00084 (14)
N20.0193 (6)0.0113 (6)0.0188 (6)0.0040 (5)−0.0001 (5)−0.0004 (5)
C80.0230 (8)0.0132 (8)0.0187 (7)0.0068 (6)0.0021 (6)0.0007 (6)
C90.0148 (7)0.0129 (7)0.0159 (7)0.0010 (5)0.0007 (5)0.0015 (6)
C100.0148 (7)0.0115 (7)0.0144 (7)0.0022 (5)0.0018 (5)0.0012 (5)
C110.0134 (7)0.0138 (7)0.0160 (7)0.0017 (5)0.0032 (5)0.0024 (6)
C120.0163 (7)0.0141 (7)0.0225 (8)0.0034 (6)0.0059 (6)0.0011 (6)
C130.0214 (8)0.0158 (7)0.0199 (8)0.0026 (6)0.0061 (6)−0.0026 (6)
C140.0171 (7)0.0228 (8)0.0186 (8)0.0069 (6)−0.0005 (6)0.0034 (6)

Geometric parameters (Å, °)

S1—C61.7119 (16)S2—C131.7125 (17)
S1—C31.7309 (16)S2—C101.7318 (16)
N1—C21.274 (2)N2—C91.272 (2)
N1—C11.4621 (19)N2—C81.460 (2)
C1—C1i1.525 (3)C8—C8ii1.520 (3)
C1—H1A0.9900C8—H8A0.9900
C1—H1B0.9900C8—H8B0.9900
C2—C31.453 (2)C9—C101.453 (2)
C2—H20.9500C9—H90.9500
C3—C41.377 (2)C10—C111.377 (2)
C4—C51.429 (2)C11—C121.426 (2)
C4—C71.502 (2)C11—C141.499 (2)
C5—C61.360 (2)C12—C131.361 (2)
C5—H50.9500C12—H120.9500
C6—H60.9500C13—H130.9500
C7—H7A0.9800C14—H14A0.9800
C7—H7B0.9800C14—H14B0.9800
C7—H7C0.9800C14—H14C0.9800
C6—S1—C391.47 (8)C13—S2—C1091.55 (8)
C2—N1—C1116.35 (13)C9—N2—C8116.78 (14)
N1—C1—C1i109.83 (16)N2—C8—C8ii110.34 (17)
N1—C1—H1A109.7N2—C8—H8A109.6
C1i—C1—H1A109.7C8ii—C8—H8A109.6
N1—C1—H1B109.7N2—C8—H8B109.6
C1i—C1—H1B109.7C8ii—C8—H8B109.6
H1A—C1—H1B108.2H8A—C8—H8B108.1
N1—C2—C3122.28 (14)N2—C9—C10122.61 (14)
N1—C2—H2118.9N2—C9—H9118.7
C3—C2—H2118.9C10—C9—H9118.7
C4—C3—C2127.93 (14)C11—C10—C9127.42 (14)
C4—C3—S1111.67 (12)C11—C10—S2111.68 (12)
C2—C3—S1120.39 (12)C9—C10—S2120.89 (11)
C3—C4—C5111.63 (14)C10—C11—C12111.52 (14)
C3—C4—C7124.67 (14)C10—C11—C14124.84 (14)
C5—C4—C7123.60 (14)C12—C11—C14123.64 (14)
C6—C5—C4112.87 (14)C13—C12—C11113.24 (14)
C6—C5—H5123.6C13—C12—H12123.4
C4—C5—H5123.6C11—C12—H12123.4
C5—C6—S1112.33 (12)C12—C13—S2112.00 (12)
C5—C6—H6123.8C12—C13—H13124.0
S1—C6—H6123.8S2—C13—H13124.0
C4—C7—H7A109.5C11—C14—H14A109.5
C4—C7—H7B109.5C11—C14—H14B109.5
H7A—C7—H7B109.5H14A—C14—H14B109.5
C4—C7—H7C109.5C11—C14—H14C109.5
H7A—C7—H7C109.5H14A—C14—H14C109.5
H7B—C7—H7C109.5H14B—C14—H14C109.5
C2—N1—C1—C1i114.66 (18)C9—N2—C8—C8ii128.94 (18)
C1—N1—C2—C3179.26 (14)C8—N2—C9—C10177.52 (14)
N1—C2—C3—C4174.57 (16)N2—C9—C10—C11177.29 (16)
N1—C2—C3—S1−6.9 (2)N2—C9—C10—S2−3.6 (2)
C6—S1—C3—C4−1.13 (13)C13—S2—C10—C11−0.31 (12)
C6—S1—C3—C2−179.90 (13)C13—S2—C10—C9−179.53 (13)
C2—C3—C4—C5−179.55 (15)C9—C10—C11—C12179.52 (15)
S1—C3—C4—C51.80 (17)S2—C10—C11—C120.36 (17)
C2—C3—C4—C73.9 (3)C9—C10—C11—C140.1 (3)
S1—C3—C4—C7−174.74 (13)S2—C10—C11—C14−179.05 (12)
C3—C4—C5—C6−1.7 (2)C10—C11—C12—C13−0.2 (2)
C7—C4—C5—C6174.86 (15)C14—C11—C12—C13179.18 (14)
C4—C5—C6—S10.86 (18)C11—C12—C13—S20.01 (18)
C3—S1—C6—C50.14 (13)C10—S2—C13—C120.17 (13)

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

Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the S1,C3–C6 ring.
D—H···AD—HH···AD···AD—H···A
C13—H13···Cg1iii0.952.893.6179 (19)134

Symmetry codes: (iii) −x+1, −y+1, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PK2279).

References

  • Brandenburg, K. (2006). DIAMOND Crystal Impact GbR, Bonn, Germany.
  • Bruker (2008). APEX2 and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Campaigne, E. (1984). Comprehensive Heterocyclic Chemistry, Vol. 4, edited by A. R. Katritzky & C. W. Rees, pp. 863–934. Oxford: Pergamon.
  • Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
  • Kleemann, A., Engel, J. B., Kutscher, B. & Reichert, D. (2006). Pharmaceutical Substances New York, Stuttgart: Georg Thieme Verlag.
  • Sheldrick, G. M. (1996). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Wang, D.-Q., Wang, Q. & Xiao, L.-J. (2007). Acta Cryst. E63, o4865.
  • Wardell, S. M. S. V., de Lima, G. M., Tiekink, E. R. T. & Wardell, J. L. (2010). Acta Cryst. E66, o271–o272. [PMC free article] [PubMed]
  • Westrip, S. P. (2010). J. Appl. Cryst.43, 920–925.

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