(E)-Methyl N′-[1-(4-methoxy­phen­yl)ethyl­idene]hydrazinecarboxyl­ate

The mol­ecule of the title compound, C11H14N2O3, adopts a trans configuration with respect to the C=N bond. The dihedral angle between the benzene ring and the hydrazinecarboxyl­ate plane is 12.06 (9)°. Mol­ecules are linked into a one-dimensional network by N—H⋯O hydrogen bonds and C—H⋯π inter­actions. The benzene rings of inversion-related mol­ecules are stacked with their centroids separated by 3.777 (1) Å, indicating π–π inter­actions

(E)-Ethyl N′-(3-hy­droxy­benzyl­idene)hydrazinecarboxyl­ate dihydrate

The asymmetric unit of the title compound, C10H12N2O3·2H2O, contains two organic mol­ecules with similar conformations and four water mol­ecules. Each organic mol­ecule is close to planar (r.m.s. deviations = 0.035 and 0.108 Å) and adopts a trans conformation with respect to its C=N bond. In the crystal, the components are linked into a three-dimensional network by N—H⋯O, O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds, some of which are bifurcated. An R 2 2(8) loop occurs between adjacent organic mol­ecules

N′-(2-Meth­oxy­benzyl­idene)aceto­hydrazide

In the title mol­ecule, C10H12N2O2, the acetohydrazide group is almost planar [within 0.0306 (12) Å] and forms a dihedral angle of 12.15 (14)° with the benzene ring. The meth­oxy group deviates from the attached benzene ring with a C—O—C—C torsion angle of 4.2 (4)°·The mol­ecule adopts a trans configuration with respect to the C=N bond. In the crystal, mol­ecules are linked into centrosymmetric dimers by pairs of N—H⋯O hydrogen bonds and intermolecular C—H⋯O interactions further stabilize the structure

(E)-Methyl N′-[(1H-indol-3-yl)methyl­idene]hydrazinecarboxyl­ate 0.25-hydrate

The asymmetric unit of the title compound, C11H11N3O2·0.25H2O, contains two independent organic mol­ecules and a water mol­ecule, which lies on a twofold rotation axis. The side chains of the two mol­ecules have slightly different orientations, the C=N—N—C torsion angle being −163.03 (15)° in one and −177.52 (14)° in the other, with each adopting a trans configuration with respect to the C=N bond. In the crystal, mol­ecules are linked into chains extending along b by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds and in addition, four inter­molecular C—H⋯π inter­actions are present

(E)-Methyl N′-[1-(4-methyl­phen­yl)ethyl­idene]hydrazinecarboxyl­ate

The title mol­ecule, C11H14N2O2, adopts a trans configuration with respect to the C=N bond. The dihedral angle between the benzene ring and the hydrazinecarboxyl­ate plane is 7.61 (16)°. In the crystal structure, mol­ecules are linked into centrosymmetric dimers by N—H⋯O hydrogen bonds and the dimers are linked together by C—H⋯π inter­actions

N′-(4-Hydr­oxy-3-methoxy­benzyl­idene)acetohydrazide monohydrate

In the title compound, C10H12N2O3·H2O, the Schiff base mol­ecule is approximately planar [within 0.189 (1) Å]. The inter­planar angle between the benzene and acetohydrazide planes is 8.50 (10)°. In the crystal, mol­ecules are linked into a three-dimensional network by strong and weak O—H⋯O and strong N—H⋯O hydrogen bonds. The hydr­oxy H atom deviates from the 4-hydr­oxy-3-methoxy­phenyl mean plane by 0.319 (2) Å, probably due to the involvement of this H atom in the O—H⋯O hydrogen bond. The weak O—H⋯O hydrogen bond is involved in a bifurcated hydrogen bond with R 1 2(4) motif. A weak C—H⋯π inter­action is also present

(E)-Ethyl N′-[1-(4-methoxy­phen­yl)ethyl­idene]hydrazinecarboxyl­ate

The mol­ecule of the title compound, C12H16N2O3, adopts a trans configuration with respect to the C=N bond. The dihedral angle between the benzene ring and the hydrazinecarboxyl­ate plane is 13.82 (6)°. In the crystal structure, mol­ecules are linked into centrosymmetric dimers by N—H⋯O and C—H⋯O hydrogen bonds, and the dimers are linked together by C—H⋯π inter­actions

(E)-Methyl N′-(2-furylmethyl­ene)­hydrazinecarboxyl­ate

The title compound, C7H8N2O3, crystallizes with two independent but essentially identical mol­ecules in the asymmetric unit. Each mol­ecule adopts a trans configuration with respect to the C=N bond. The hydrazinecarboxyl­ate group is twisted from the furan ring by 7.78 (13)° in one mol­ecule and by 7.01 (17)° in the other. In the crystal structure, mol­ecules are linked into chains running along [010] by bifurcated N—H⋯(N,O) and N—H⋯O hydrogen bonds. In addition, weak C—H⋯O inter­actions and an O⋯C short contact [2.896 (3) Å] are observed

N′-[4-(Dimethyl­amino)benzyl­idene]acetohydrazide

The title compound, C11H15N3O, crystallizes with two independent mol­ecules per asymmetric unit which differ slightly in their side-chain orientations: the C=N—N—C torsion angle is −176.2 (3)° in one of the mol­ecules and −179.83 (3)° in the other. Each independent mol­ecule adopts a trans configuration with respect to the C=N bond. The two independent mol­ecules are related by a pseudo-inversion center and they exist as a N—H⋯O hydrogen-bonded dimer. The dimers are linked into zigzag chains along [100] by C—H⋯O hydrogen bonds