H. S. Naveenkumar

(E)-N′-[(E)-3-(4-Hydr­oxy-3-methoxy­phen­yl)allyl­idene]isonicotinohydrazide

In the title compound, C16H15N3O3, the dihedral angle between the pyridine and benzene rings is 7.66 (5)°. The crystal packing is consolidated by intermolecular C—H⋯O and O—H⋯N interactions, which link the molecules into zigzag chains propagating along [010]. The chains are further linked into a three-dimensional network by N—H⋯O, C—H⋯N, C—H⋯O and C—H⋯π interactions.

(E)-N'-(2,4,5-Trifluorobenzyl-idene)isonicotinohydrazide monohydrate.

In the Schiff base molecule of the title compound, C13H8F3N3O·H2O, the benzene ring and the pyridine ring are nearly coplanar, making a dihedral angle of 6.64 (7)°. The molecule exists in an E configuration with respect to the C=N double bond. In the crystal structure, molecules are linked via the water molecules into two-dimensional planes parallel to the ab plane through intermolecular N—H⋯O, O—H⋯O O—H⋯N and C—H⋯O hydrogen bonds.

(E)-N′-(2,4,5-Trimethoxy­benzyl­idene)isonicotinohydrazide dihydrate

The asymmetric unit of the title compound, C16H17N3O4·2H2O, contains one Schiff base molecule and two water molecules. The Schiff base molecule exists in an E configuration with respect to the C=N double bond and is essentially planar, the dihedral angle between the benzene and pyridine rings being 5.48 (8)°. The three methoxy groups are also coplanar with the benzene ring [C—O—C—C torsion angles = 3.9 (2), 178.51 (15) and 0.8 (2) Å]. In the crystal structure, the water molecules link the molecules into a three-dimensional network via intermolecular N—H⋯O, O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds.

(E)-N′-(2-Benzyl­oxybenzyl­idene)isonicotinohydrazide methanol solvate monohydrate

The title compound, C20H17N3O2·CH4O·H2O, was synthesized by the condensation reaction of 2-benzyloxybenzaldehyde with isoniazid (isonicotinic acid hydrazide). The tricyclic compound displays a trans configuration with respect to the C=N double bond. The central benzene ring makes dihedral angles of 8.83 (7) and 70.39 (8)° with the pyridine ring and the terminal benzene ring, respectively. The dihedral angle between the pyridine ring and the terminal benzene ring is 73.11 (8)°. In the crystal structure, molecules are connected by intermolecular N—H⋯O, O—H⋯O, O—H⋯(N,N) and C—H⋯O hydrogen bonds, forming a two-dimensional network perpendicular to the a axis.

Bis{(E)-N'-[2,4-bis(trifluoro-meth-yl)benzyl-idene]isonicotinohydrazide} monohydrate.

The asymmetric unit of the title compound, 2C15H9F6N3O·H2O, contains two independent Schiff base molecules and one water molecule. Both Schiff base molecules exist in an E configuration with respect to the C=N double bonds and the dihedral angles between the benzene and the pyridine rings in the two molecules are 17.53 (12) and 20.62 (12)°. In the crystal structure, molecules are linked by intermolecular N—H⋯O and C—H⋯O hydrogen bonds into infinite one-dimensional chains along the a axis. In addition, intermolecular O—H⋯N, O—H⋯F, C—H⋯F and C—H⋯O hydrogen bonds further link these chains into a three-dimensional network. Weak π–π interactions with centroid–centroid distances in the range 3.6495 (17)–3.7092 (16) Å are also observed.

(E)-N′-(2,4,6-Trihydroxy­benzyl­idene)isonicotinohydrazide sesquihydrate

In the title compound, C13H11N3O4·1.5H2O, the pyridine ring forms a dihedral angle of 1.50 (6)° with the benzene ring. An intramolecular O—H⋯N hydrogen bond forms a six-membered ring with an S(6) ring motif. In the crystal structure, one water molecule is disordered over two positions around an inversion centre with site-occupancy factors of 0.5. Intermolecular O—H⋯N, O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds consolidate the structure into a three dimensional network. A π–π stacking interaction with a centroid–centroid distance of 3.5949 (7) Å is also present.

(E)-N′-(2,4,6-Trimethyl­benzyl­idene)isonicotinohydrazide

The title isoniazid derivative, C(16)H(17)N(3)O, exists in an E configuration with respect to the Schiff base C=N bond. The pyridine ring is essentially planar [maximum deviation = 0.009 (3) Å]. The mean plane through the hydrazide unit forms dihedral angles of 38.38 (16) and 39.42 (16)°, respectively, with the pyridine and benzene rings. In the crystal structure, symmetry-related mol-ecules are linked via inter-molecular N-H⋯O hydrogen bonds into chains along [100]. The crystal structure is further stabilized by weak inter-molecular C-H⋯π inter-actions.

(E)-N′-[(E)-2-Methyl­pent-2-enyl­idene]isonicotinohydrazide

The asymmetric unit of the title Schiff base compound, C12H15N3O, contains two crystallographically independent molecules, with both existing in an E configuration with respect to the C=N double bonds. In the crystal structure, intermolecular N—H⋯N and C—H⋯O hydrogen bonds link the molecules into a three-dimensional network.

(E)-N′-(2,3,4-Trihy­droxy­benzyl­idene)­isonicotinohydrazide dihydrate

In the title isoniazid derivative, C13H11N3O4·2H2O, the Schiff base molecule exists in an E configuration with respect to the acyclic C=N bond. An intramolecular O—H⋯N hydrogen bond forms a six-membered ring, producing an S(6) ring motif. The essentially planar pyridine ring [maximum deviation = 0.0119 (8) Å] is inclined at a dihedral angle of 7.30 (4)° with respect to the benzene ring. In the crystal, intermolecular O—H⋯N, O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds link the molecules into two-dimensional arrays lying parallel to the (10) plane. These arrays are further interconnected into a three-dimensional extended network via O—H⋯O and C—H⋯O hydrogen bonds. A weak intermolecular π–π interaction [centroid-to-centroid distance = 3.5627 (5) Å] is also observed.

(E)-N’-(2,3,4-Trimethoxy­benzyl­idene)isonicotinohydrazide

In the title compound, C16H17N3O4, the molecule exists in an E configuration with respect to the C=N double bond. The molecule is not planar, the dihedral angle between the pyridine and benzene rings being 71.67 (8)°. In the crystal structure, molecules are linked into chains along the b axis by bifurcated N—H⋯O and C—H⋯O hydrogen bonds. These chains are linked into a three-dimensional network by C—H⋯O and C—H⋯π interactions.