Abstract
The crystal structures of three isomeric (E)-N0 -(chlorophenylmethylidene)-Nmethyl-2-(thiophen-2-yl)acetohydrazides (C14H13ClN2OS) are described, with
the Cl atom in ortho (I), meta (III) and para (IV) positions in the benzene ring.
The ortho-bromo derivative (II) (C14H13BrN2OS), which is isostructural with its
chloro congener (I), is also reported. Molecules (I)–(III) have similar conformations, which approximate to l-shapes, as indicated by their N—C—
C—Ct (t = thiophene) torsion angles of 90.1 (3), 91.44 (18) and 90.7 (9),
respectively. The conformation of (IV) is different, with an equivalent torsion
angle of 170.75 (11) corresponding to a more extended shape for the molecule. The thiophene ring in each structure features ‘flip’ rotational disorder.
The packing for (I) and (II) features inversion dimers, linked by pairs of C—HO interactions, which generate R22 (14) loops. In the crystal of (III), [010]C(8) chains arise, with adjacent molecules linked by pairs of C—HO hydrogen bonds. The packing for (IV) features unusually short C—HO interactions arising from an H atom attached to the benzene ring (HO = 2.18 A˚ ), which lead to C(9) [301] chains. Hirshfeld fingerprint percentage contact contributions are similar for the four title compounds.
the Cl atom in ortho (I), meta (III) and para (IV) positions in the benzene ring.
The ortho-bromo derivative (II) (C14H13BrN2OS), which is isostructural with its
chloro congener (I), is also reported. Molecules (I)–(III) have similar conformations, which approximate to l-shapes, as indicated by their N—C—
C—Ct (t = thiophene) torsion angles of 90.1 (3), 91.44 (18) and 90.7 (9),
respectively. The conformation of (IV) is different, with an equivalent torsion
angle of 170.75 (11) corresponding to a more extended shape for the molecule. The thiophene ring in each structure features ‘flip’ rotational disorder.
The packing for (I) and (II) features inversion dimers, linked by pairs of C—HO interactions, which generate R22 (14) loops. In the crystal of (III), [010]C(8) chains arise, with adjacent molecules linked by pairs of C—HO hydrogen bonds. The packing for (IV) features unusually short C—HO interactions arising from an H atom attached to the benzene ring (HO = 2.18 A˚ ), which lead to C(9) [301] chains. Hirshfeld fingerprint percentage contact contributions are similar for the four title compounds.
| Original language | English |
|---|---|
| Pages (from-to) | 313-318 |
| Number of pages | 6 |
| Journal | Acta Crystallographica Section E: Structure Reports Online |
| Volume | 74 |
| DOIs | |
| Publication status | Published - 2018 |
Bibliographical note
We thank the EPSRC National Crystallography Service (University of Southampton) for the X-ray data collectionsKeywords
- crystal structure
- carbohydrazide
- methylation
- weak hydrogen bonds