Crystal structures of 4-[(4-methylbenzyl)oxy]-benzohydrazide and its N^́-[(thiophen-2-yl)methylidene]- derivative

The molecular and crystal structures of a benzoylhydrazine bearing an ether group, 4-[(4-methylbenzyl)oxy]benzohydrazide, C₁₅H₁₆N₂O₂, (I), and of the corresponding N^́-[(thiophen-2-yl)methylidene]- derivative, 4-[(4-methylbenz-yl)oxy]-N^́-[(thiophen-2-yl)methylidene]benzohydrazide, C₂₀H₁₈N₂O₂S, (II), are described. The supramolecular structures of both compounds are governed by N—H. . .N and N—H. . .O hydrogen-bonding interactions. The hydrazine compound (I) shows a crystal packing with a more complex hydrogen-bonding scheme because of the NH—NH₂ entity, forming a di-periodic supramolecular structure extending parallel to (100). Hydrazone molecules in (II) are hydrogen-bonded through N—H. . .O interactions, giving rise to the formation of ribbons parallel to [010]. Molecules of (I) and (II) show a different orientation of the carbohydrazide moiety likely to favor the crystal packing and thus hydrogen-bonding interactions.