N,N′-Bis[(E)-(5-chloro-2-thienyl)methyl­­idene]ethane-1,2-di­amine

The full mol­ecule of the title compound, C₁₂H₁₀Cl₂N₂S₂, is generated by the application of a centre of inversion. The thio­phene and imine residues are co-planar [the N—C—C—S torsion angle is −2.5 (4)°] and the conformation about the imine bond [1.268 (4) Å] is E. Supra­molecular arrays are formed in the bc plane via C—Cl⋯π inter­actions and these stack along the a axis.

Related literature

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

Experimental

Crystal data

• C₁₂H₁₀Cl₂N₂S₂

• M_r = 317.24

• Monoclinic, P 2₁ /c

• a = 14.682 (2) Å

• b = 4.7016 (7) Å

• c = 10.6607 (15) Å

• β = 109.439 (2)°

• V = 693.92 (17) ų

• Z = 2

• Mo Kα radiation

• μ = 0.75 mm⁻¹

• T = 100 K

• 0.25 × 0.15 × 0.05 mm

Data collection

• Bruker SMART APEX diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.835, T_max = 0.963

• 5721 measured reflections

• 1576 independent reflections

• 1270 reflections with I > 2σ(I)

• R_int = 0.058

Refinement

• R[F² > 2σ(F²)] = 0.038

• wR(F²) = 0.117

• S = 1.01

• 1576 reflections

• 82 parameters

• H-atom parameters constrained

• Δρ_max = 0.36 e Å⁻³

• Δρ_min = −0.48 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the S3,C3–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—Cl1⋯Cg1^i	1.71 (1)	3.52 (1)	3.994 (3)	93 (1)
Symmetry code: (i) x, y+1, z.

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; 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).

Supporting information

S1. Comment

Interest in their putative biological activity (Wardell et al., 2010) motivates studies of 2-substituted thiophene rings (Campaigne, 1984; Kleemann et al., 2006), including on-going crystallographic investigations (Wardell et al. 2010; Prasath et al., 2010).

The asymmetric unit of (I), Fig. 1, comprises half a molecule with the full molecule generated by a crystallographic centre of inversion. The thiophene residue is co-planar with the imine group as seen in the value of the N1—C2—C3—S1 torsion angle of -2.5 (4) °. The conformation about the imine N1—C2 [1.268 (4) Å] bond is E. The observed conformation matches closely those found for related compounds (Wang et al., 2007; Prasath et al., 2010).

The most prominent contacts in the crystal packing are of the type C—Cl···π, Table 1. These serve to connect molecules into a 2-D array in the bc plane, Fig. 2, which stack along the a axis, Fig. 3, with the chlorido atoms facing each other. Concerning the latter, the closest interlayer Cl···Cl contact is 3.3831 (11) Å [symmetry operation: 2 - x, -1/2 + y, 3/2 - z].

Related literature

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

S2. Experimental

A mixture of 5-chloro-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 from the reaction mixture was removed under reduced pressure. 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 of (I) which yielded colourless needles (yield: 73%). M. pt. 353–355 K.

S3. 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 U_iso(H) set to 1.2U_equiv(C). In the final refinement a low angle reflection evidently effected by the beam stop was omitted, i.e. (100).

Computing details

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); 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).

Figures

	Fig. 1. Molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level. Symmetry operation i: 1 - x, 1 - y, 1 - z.
	Fig. 2. A view of the supramolecular 2-D array in the bc plane mediated by C—Cl···π interactions (purple dashed lines).
	Fig. 3. Stacking of layers along the a axis in the crystal structure of (I). The C—Cl···π interactions are shown as purple dashed lines.

N,N'-Bis[(E)-(5-chloro-2-thienyl)methylidene]ethane- 1,2-diamine

Crystal data

C12H10Cl2N2S2	F(000) = 324
Mr = 317.24	Dx = 1.518 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2363 reflections
a = 14.682 (2) Å	θ = 3.0–28.0°
b = 4.7016 (7) Å	µ = 0.75 mm^−1
c = 10.6607 (15) Å	T = 100 K
β = 109.439 (2)°	Prism, colourless
V = 693.92 (17) Å^3	0.25 × 0.15 × 0.05 mm
Z = 2

Data collection

Bruker SMART APEX diffractometer	1576 independent reflections
Radiation source: fine-focus sealed tube	1270 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.058
ω scans	θmax = 27.5°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −18→18
Tmin = 0.835, Tmax = 0.963	k = −6→6
5721 measured reflections	l = −13→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0662P)^2 + 0.3727P] where P = (Fo^2 + 2Fc^2)/3
1576 reflections	(Δ/σ)max = 0.001
82 parameters	Δρmax = 0.36 e Å^−3
0 restraints	Δρmin = −0.48 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > σ(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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.94014 (5)	1.46904 (14)	0.80609 (6)	0.0258 (2)
S1	0.76180 (5)	1.12742 (14)	0.69149 (6)	0.0220 (2)
N1	0.58522 (16)	0.7601 (5)	0.6104 (2)	0.0286 (5)
C1	0.4988 (2)	0.5840 (6)	0.5603 (3)	0.0333 (7)
H1A	0.4406	0.7062	0.5355	0.040*
H1B	0.4955	0.4514	0.6308	0.040*
C2	0.63515 (19)	0.7367 (6)	0.7325 (3)	0.0267 (6)
H2	0.6151	0.6077	0.7868	0.032*
C3	0.72211 (19)	0.9026 (5)	0.7907 (3)	0.0238 (6)
C4	0.7822 (2)	0.9074 (6)	0.9193 (3)	0.0282 (6)
H4	0.7716	0.7970	0.9879	0.034*
C5	0.8620 (2)	1.0934 (6)	0.9411 (3)	0.0271 (6)
H5	0.9109	1.1220	1.0247	0.033*
C6	0.85924 (19)	1.2254 (6)	0.8263 (2)	0.0220 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0284 (4)	0.0242 (4)	0.0285 (3)	−0.0067 (2)	0.0141 (3)	−0.0066 (2)
S1	0.0249 (4)	0.0199 (4)	0.0230 (3)	−0.0031 (2)	0.0104 (3)	−0.0007 (2)
N1	0.0241 (12)	0.0212 (12)	0.0432 (14)	−0.0047 (9)	0.0149 (10)	−0.0032 (10)
C1	0.0288 (15)	0.0285 (15)	0.0463 (18)	−0.0089 (12)	0.0173 (13)	−0.0043 (13)
C2	0.0302 (14)	0.0184 (13)	0.0402 (16)	−0.0028 (11)	0.0232 (12)	−0.0029 (11)
C3	0.0287 (14)	0.0169 (13)	0.0323 (14)	−0.0025 (10)	0.0187 (12)	−0.0013 (10)
C4	0.0416 (17)	0.0220 (14)	0.0274 (13)	−0.0028 (12)	0.0202 (12)	0.0001 (10)
C5	0.0353 (15)	0.0261 (15)	0.0219 (12)	−0.0025 (11)	0.0122 (11)	−0.0033 (10)
C6	0.0259 (13)	0.0188 (13)	0.0241 (12)	−0.0002 (10)	0.0122 (10)	−0.0050 (9)

Geometric parameters (Å, º)

Cl1—C6	1.714 (3)	C2—C3	1.448 (4)
S1—C6	1.719 (3)	C2—H2	0.9500
S1—C3	1.728 (3)	C3—C4	1.362 (4)
N1—C2	1.268 (4)	C4—C5	1.419 (4)
N1—C1	1.459 (3)	C4—H4	0.9500
C1—C1^i	1.519 (6)	C5—C6	1.361 (4)
C1—H1A	0.9900	C5—H5	0.9500
C1—H1B	0.9900
C6—S1—C3	90.50 (13)	C4—C3—S1	111.7 (2)
C2—N1—C1	117.5 (2)	C2—C3—S1	119.7 (2)
N1—C1—C1^i	110.1 (3)	C3—C4—C5	113.4 (2)
N1—C1—H1A	109.6	C3—C4—H4	123.3
C1^i—C1—H1A	109.6	C5—C4—H4	123.3
N1—C1—H1B	109.6	C6—C5—C4	111.0 (3)
C1^i—C1—H1B	109.6	C6—C5—H5	124.5
H1A—C1—H1B	108.2	C4—C5—H5	124.5
N1—C2—C3	121.3 (2)	C5—C6—Cl1	127.1 (2)
N1—C2—H2	119.4	C5—C6—S1	113.4 (2)
C3—C2—H2	119.4	Cl1—C6—S1	119.53 (15)
C4—C3—C2	128.6 (2)
C2—N1—C1—C1^i	−126.6 (3)	S1—C3—C4—C5	0.0 (3)
C1—N1—C2—C3	179.9 (2)	C3—C4—C5—C6	0.2 (4)
N1—C2—C3—C4	178.4 (3)	C4—C5—C6—Cl1	179.4 (2)
N1—C2—C3—S1	−2.5 (4)	C4—C5—C6—S1	−0.3 (3)
C6—S1—C3—C4	−0.1 (2)	C3—S1—C6—C5	0.3 (2)
C6—S1—C3—C2	−179.4 (2)	C3—S1—C6—Cl1	−179.49 (17)
C2—C3—C4—C5	179.1 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the S3,C3–C6 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C6—Cl1···Cg1^ii	1.71 (1)	3.52 (1)	3.994 (3)	93 (1)

Symmetry code: (ii) x, y+1, z.

 

Footnotes

‡Additional correspondence author, e-mail: [e-mail].