Crystal structures of three N-acyl­hydrazone isomers

The crystal structures of three isomers of (E)-4-chloro-N-{2-[2-(chloro­benzyl­idene)hydrazin­yl]-2-oxoeth­yl}­benzene­sulfonamide, namely, (E)-4-chloro-N-{2-[2-(2-chloro­benzyl­idene)hydrazin­yl]-2-oxoeth­yl}­benzene­sulfonamide (I), (E)-4-chloro-N-{2-[2-(3-chloro­benzyl­idene)hydrazin­yl]-2-oxoeth­yl}­benzene­sul­fon­amide (II) and (E)-4-chloro-N-{2-[2-(4-chloro­benzyl­idene)hydrazin­yl]-2-oxo­eth­yl}­benzene­sulfonamide (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 benzyl­idene benzene ring. All the three isomeric compounds crystallize in the centrosymmetric triclinic P [Image: see text] space group with one mol­ecule each in the asymmetric unit and two mol­ecules 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 mol­ecule (–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 mol­ecules form inversion dimers with R (2) (2)(8) ring motifs, which are further augmented by C—H⋯O inter­actions.