(E)-N′-(3-Bromobenzylidene)isonicotinohydrazide

Abstract

The title compound, C13H10BrN3O, is roughly planar and displays a trans configuration with respect to the C=N double bond. The dihedral angle between the benzene and pyridine rings is 4.2 (3)°. The crystal structure is stabilized by intermolecular N—H...N hydrogen bonds.

N′-[1-(5-Chloro-2-hydroxyphenyl)methylidene]isonicotinohydrazide

“…In (I) ( Fig. 1), all the bond lengths are within normal ranges (Allen et al, 1987), and comparable to those of the similar compounds (Qian et al, 2006;Qiu, Xu et al, 2006;Qiu, Fang, Yang et al, 2006). The C7-N1 bond length of 1.267 (2) Å conforms to the value for a double bond.…”

N′-(4-Bromobenzylidene)propanohydrazide

“…C7=N1 bond length of 1.279 (4) Å conforms to the value for a double bond and similar to the distance reported by Qiu et al, 2006. The bond length of 1.346 (4) Å is greater than the value for a double bond, and less than the value for a single bond, because of conjugation effects in the molecule.…”

Supramolecular structures in N-isonicotinoyl arylaldehydehydrazones: multiple hydrogen-bonding modes in series of geometric isomers

“…In each such case, the unit-cell parameters, space groups and the atomic coordinates indicate that the same phase was studied at ambient temperatures and 120 K. However, without exception, these previous reports provide extremely brief structure descriptions, with no analysis of the supramolecular aggregation. In a report on the 3-bromophenyl compound (IX), the authors stated that the structure 'is stabilized by intermolecular N-HÁ Á ÁN hydrogen bonds' (Qiu, Fang et al 2006), but the nature of the supramolecular structure was not further discussed. Similarly, in a report on the 2-methoxyphenyl derivative (XI), the authors stated only that the structure 'is stabilized by intermolecular N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds' (Yang et al, 2006).…”

“…The earlier of these (Shanmuga Sundara Raj et al, 1999) stated only that 'the water and hydroxyl group are involved in a variety of N-HÁ Á ÁO and O-HÁ Á ÁN hydrogen bonds', even though no hydroxyl group is present; while the more recent report (Jing et al, 2005), which did not mention the earlier one, identified O-HÁ Á ÁO, O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds, all involving the water molecule, but did not analyse or describe the structural consequences of these hydrogen bonds. Whenever these reports provided a depiction of the crystal structure (Jing et al, 2005;Qiu, Fang et al, 2006;Yang et al, 2006), neither the illustration itself nor the accompanying caption was really informative. In the course of the present study, we have now redetermined these structures from diffraction data Stereoviews of parts of the crystal structure of (I) showing (a) the combination of the two motifs parallel to [010] forming a sheet parallel to (001), and (b) the ladder parallel to [100] which links adjacent (001) sheets.…”