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.

The full molecule of the title compound, C 12 H 10 Cl 2 N 2 S 2 , 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 À2.5 (4) ] and the conformation about the imine bond [1.268 (4) Å ] is E. Supramolecular arrays are formed in the bc plane via C-ClÁ Á Á interactions and these stack along the a axis.
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.

Structure Reports Online
ISSN 1600-5368 ‡ Additional correspondence author, e-mail: juliebhavana@gmail.com. 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.

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.

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). 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.