Crystal structures of three N-acyl-hydrazone isomers.

The crystal structures of three isomers of (E)-4-chloro-N-{2-[2-(chloro-benzyl-idene)hydrazin-yl]-2-oxoeth-yl}-benzene-sulfonamide, namely, (E)-4-chloro-N-{2-[2-(2-chloro-benzyl-idene)hydrazin-yl]-2-oxoeth-yl}-benzene-sulfonamide (I), (E)-4-chloro-N-{2-[2-(3-chloro-benzyl-idene)hydrazin-yl]-2-oxoeth-yl}-benzene-sul-fon-amide (II) and (E)-4-chloro-N-{2-[2-(4-chloro-benzyl-idene)hydrazin-yl]-2-oxo-eth-yl}-benzene-sulfonamide (III), with the general formula C(15)H(13)Cl(2)N(3)O(3)S are described, with the chloro group in ortho, meta and para positions in the benzyl-idene benzene ring. All the three isomeric compounds crystallize in the centrosymmetric triclinic P space group with one mol-ecule each in the asymmetric unit and two mol-ecules in the unit cell. The dihedral angles between the two phenyl rings are 11.09†(14), 53.79†(18) and 72.37†(11)° in (I), (II) and (III), respectively. The central part of the mol-ecule (-C-N-N=C-) is almost linear with C-N-N-C torsion angles of 179.1†(2), -169.5†(3) and 178.5†(2)° for (I), (II) and (III), respectively. In all the three crystals, the mol-ecules form inversion dimers with R (2) (2)(8) ring motifs, which are further augmented by C-H⋯O inter-actions.