2-[(E)-3,4-Dimeth­oxy­benzyl­idene]hydrazinecarboxamide

In the title compound, C10H13N3O3, the 3,4-dimeth­oxy­benzyl­idene and hydrazinecarboxamide groups are oriented at a dihedral angle of 53.82 (6)° and an intra­molecular N—H⋯N hydrogen bond generates an S(5) ring motif. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds into sheets propagating in (-201), which feature R 1 2(5), R 2 2(8) and R 2 4(14) loops

5-[(E)-(2,6-Dichloro­benzyl­idene)amino]-2-hy­droxy­benzoic acid

There are two geometrically different mol­ecules in the asymmetric unit of the title compound, C14H9Cl2NO3. The 5-amino-2-hy­droxy­benzoic acid units [r.m.s. deviations of 0.0323 and 0.0414 Å] and 2,6-dichloro­benzaldehyde groups [r.m.s. deviations of 0.0285 and 0.0226 Å] are roughly planar and oriented at dihedral angles of 11.69 (13) and 83.12 (6)° in the two mol­ecules. An intra­molecular O—H⋯O hydrogen bond completes an S(6) ring motif in each mol­ecule. The two mol­ecules form dimers with each other through inter­molecular O—H⋯N and C—H⋯O hydrogen bonds, completing an R 2 2(8) ring motif. The dimers are inter­linked via inter­molecular O—H⋯N and C—H⋯O hydrogen bonds, forming polymeric sheets

2-Hy­droxy-5-[(E)-(1H-indol-3-yl­methyl­idene)aza­nium­yl]benzoate

The zwitterionic title compound, C16H12N2O3, was obtained as a result of the condensation of 5-amino­salicylic acid and 1H-indole-3-carbaldehyde. The whole mol­ecule is roughly planar: the 4-hy­droxy­anilinic group and the 1H-indole-3-carbaldehyde moieties are only slightly twisted, making a dihedral angle of 7.77 (11)°, whereas, the carboxyl­ate group makes a dihedral angle of 3.34 (45)° with the parent 4-hy­droxy­anilinic group. S(6) ring motifs are formed due to intra­molecular O—H⋯O hydrogen bonding. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds build up pseudo-rings with R 1 2(4), R 2 1(7) and R 2 2(14) ring motifs. These pseudo-dimers are further linked by N—H⋯O hydrogen bonds into a chain extending along [101]. C—H⋯π inter­actions also occur, along with offset π–π inter­actions between the anilinic phenyl and the heterocyclic five-membered rings with a centroid–centroid distance of 3.5716 (19) Å

(E)-1-(2-Nitro­benzyl­idene)-2-phenyl­hydrazine

The asymmetric unit of the title compound, C13H11N3O2, contains two mol­ecules with slightly different conformations: the dihedral angle between the aromatic rings is 13.01 (10)° in one mol­ecule and 14.05 (10)° in the other. Both mol­ecules feature short intra­molecular C—H⋯O contacts, which generate S(6) rings. In the crystal, both mol­ecules form inversion dimers linked by pairs of N—H⋯O hydrogen bonds, thereby generating R 2 2(16) rings

2-{[(E)-1,3-Benzodioxol-5-yl]methyl­idene­amino}­benzoic acid

In the title compound, C15H11NO4, the dihedral angle between the aromatic rings is 23.8 (2)° and an intra­molecular O—H⋯N hydrogen bond generates an S(6) ring. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network

N-[(E)-2,4-Dichloro­benzyl­idene]-4-methyl­aniline

In the title compound, C14H11Cl2N, the dihedral angle between the 4-methyl­anilinic and 2,4-dichloro­benzaldehyde moieties is 7.37 (8)°. In the crystal, C—H⋯π inter­actions between the terminal methyl group and a symmetry-related ring of the anilinic group help to establish the packing

N-{4-[(E)-(4-Methylphenyl)iminomethyl]phenyl}acetamide

There are two symmetry-independent molecules in the asymmetric unit of the title compound, C16H16N2O, that differ in conformation. The dihedral angles between the benzene rings in the two molecules are 44.35 (19) and 48.14 (17)°, but the rings twist in opposite directions. The acetamide groups make nearly equal dihedral angles of 25.4 (3) and 25.7 (3)° with the parent benzene rings. An S(6) ring motif is formed in each molecule by intramolecular C—H...O close contacts. In the crystal, strong N—H...O hydrogen bonds between acetamide groups generate a C(4) chain motif arranging the molecules into two symmetry-independent polymeric structures extending along [010]

Crystal structure of (E)-2-[(4-hydroxybenzylidene)azaniumyl]benzoate

The title Schiff base, C14H11NO3, crystallizes as a zwitterion (i.e. proton transfer from the carboxylic acid group to the imine N atom). The dihedral angle between the aromatic rings is 19.59 (6)° and an intramolecular N—H...O hydrogen bond closes an S(6) ring. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generate R24(24) loops. The dimers are linked by C—H...O interactions, generating (211) sheets