1-Benzothio-phene-2-carbaldehyde 4-ethylthiosemicarbazone

The title compound, C₁₃H₁₅N₃S₂, crystallizes with two unique mol-ecules, A and B, in the asymmetric unit. These differ principally in that the methyl group of the 4-ethyl-thio-semicarbazone moiety is ordered in mol-ecule A but disordered over two positions with equal occupancies in mol-ecule B. The benzothio-phene group and the semicarbazone unit are inclined at dihedral angles of 11.78 (8)° for mol-ecule A and 8.18 (13)° for mol-ecule B. Weak intra-molecular N - H⋯N inter-actions contribute to the planarity of the semicarbazone units in both mol-ecules and each mol-ecule adopts an E configuration with respect to the C=N bonds. In the crystal structure, mol-ecules form centrosymmetric dimers as a result of N - H⋯S hydrogen bonds, augmented by C - H⋯S inter-actions for mol-ecule A and C - H⋯S inter-actions for mol-ecule B. Weak C - H⋯π inter-actions stack the dimers of both mol-ecules into columns down the a axis.