The mol-ecule of the title compound, C(15)H(14)N(2)O(4), displays a trans configuration with respect to the hydrazide C=N bond. The dihedral angle between the two benzene rings is 15.0 (2)°. In the crystal structure, mol-ecules are linked through inter-molecular O-H⋯N and O-H⋯O hydrogen bonds, forming layers parallel to the ab plane; an intramolecular N-H⋯O hydrogen bond is also present.

In the title racemic compound, C(26)H(32)N(2)O(3), an intra-molecular O-H⋯N hydrogen bond is formed between the phenolic OH group and the tertiary amine N atom. Another O-H⋯N hydrogen bond that is formed between the OH group and the pyridine N atom links the mol-ecules into a polymeric chain extending along the a axis. The structure is further stabilized by intramolecular and intermolecular C-H...

The molecule of the title compound, C(15)H(16)N(2)O, is non-planar with a dihedral angle of 16.0 (1)° between the pyrrole and benzene rings. The ketone double-bond displays an s-cis conformation with an O=C-C=C torsion angle of 7.9 (3) and an intramolecular C-H⋯O hydrogen bond. In the crystal structure, adjacent mol-ecules are paired through N-H⋯O hydrogen bonds into centrosymmetric dimers.

The mol-ecule of the title compound, C(14)H(10)Cl(2)N(2)O(2), displays a trans configuration with respect to the C=N double bond and has an intramolecular O-H⋯N hydrogen bond. The dihedral angle between the two benzene rings is 1.4 (2)°. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains running along the a direction.

The title compound, C(10)H(12)N(2)O(4), adopts a trans configuration with respect to the C=N bond. The hydrazinecarboxyl-ate group is twisted from the benzene ring by 6.62 (5)° and an intramolecular O-H⋯O hydrogen bond occurs. In the crystal structure, mol-ecules are linked into a two-dimensional network parallel to (100) by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds. In addition, weak C-H⋯π inter-a...

3-Aminomethylation of salicylalkylamides afforded hybrids with a Mannich base. In addition, it triggered the rotation of the amide bond. The observed conformational switch is driven by strong intramolecular hydrogen bonding between the Mannich base and phenolic group. Crystal structure analysis reveals the stabilization of the hybrid molecules by double hydrogen bonding of the phenolic OH, whic...

have been structurally characterized, relatively few free Schiff bases have been similarly characterized.1 N-Substituted salicylaldimines show photochromism and thermochromism in the solid state. These effects are produced by intramolecular proton transfer associated with a change in the π-electron configuration.2 As part of a general study of tetradentate Schiff bases, we determined the struct...

The reliability of four force fields developed for 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids are compared to an ab inito molecular dynamics simulation regarding structural properties. Except the hydrogen bond structure between the most acidic hydrogen atom of the imidazolium ring and the nitrogen atom of the anion as well as the intramolecular potential surface...