Crystal structures of three ortho-substituted N-acylhydrazone derivatives

To explore the effect of the nature of substitutions on the structural parameters and hydrogen-bond inter­actions in N-acyl­hydrazone derivatives, the crystal structures of three ortho-substituted N-acyl­hydrazone derivatives, namely (E)-N-{2-[2-(2-chloro­benzyl­idene)hydrazin­yl]-2-oxoeth­yl}-4-methyl­benzene­sulfon­amide, C16H16ClN3O3S (I), (E)-N-{2-[2-(2-methyl­benzyl­idene)hydrazin­yl]-2-oxoeth­yl}-4-methyl­benzene­sulfonamide, C17H19N3O3S (II), and (E)-N-{2-[2-(2-nitro­benzyl­idene)hydrazin­yl]-2-oxoeth­yl}-4-methyl­benzene­sulfonamide, C16H16N4O5S (III), have been determined. The structures of the three compounds display similar mol­ecular conformations and hydrogen-bond patterns. The hydrazone part of the mol­ecule, C—C—N—N=C, is almost planar in all the compounds, with the C—C—N—N and C—N—N=C torsion angles being 179.5 (3) and 177.1 (3)°, respectively, in (I), −179.4 (2) and −177.1 (3)° in (II) and −179.7 (2) and 173.4 (2)° in (III). The two phenyl rings on either side of the chain are approximately parallel to each other. In the crystal, the mol­ecules are linked to each other via N—H...O hydrogen bonds, forming ribbons with R22(8) and R22(10) ring motifs. The introduction of electron-withdrawing groups (by a chloro or nitro group) to produce compounds (I) or (III) results in C—H...O hydrogen-bonding inter­actions involving the sulfonyl O atoms of adjacent ribbons, forming layers parallel to the ab plane in (I) or a three-dimensional network in (III). In (III), one O atom of the nitro group is disordered over two orientations with refined occupancy ratio of 0.836 (12):0.164 (12)