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...

In the title compound, C(12)H(15)NO(3), all C, N and O atoms lie in a mirror plane. An intramolecular C-H⋯O hydrogen bond is present.

The title Schiff base compound, C(22)H(28)N(2)O(4), lies across a crystallographic inversion centre and adopts an E configuration with respect to the C=N bond. Pairs of weak inter-molecular C-H⋯O inter-actions link neighbouring mol-ecules into dimers with an R(2) (2)(28) ring motif. The crystal structure is stabilized by inter-molecular C-H⋯π inter-actions. An intramolecular O-H⋯N hydrogen bond...

Four new azo-dyes, 3-phenyl azopentane-2,4-dion (LA), 3-(4-nitro phenyl azo)-pentane-2,4-dion (LP), 3-(2-nitro phenyl azo)-pentane-2,4-dion (LO) and 4-(1-acetyle-2-oxo-propyl azo)-benzene sulfonate sodium (LS), were synthesized from, aniline, 4-nitroaniline, 2-nitroaniline and sulfanilic acid with acetylacetone, respectively. Reaction of these new dyes with acetate salts of copper(II), nickel(I...

In the crystal structure of the title compound, C(10)H(8)BrN(3)O, the dihedral angle between the two pyridine rings is 2.48 (2)°. A weak intramolecular N-H⋯O hydrogen bond is present.

In the title compound, C(21)H(16)N(2)O, the dihedral angle between the pendant aromatic rings is 74.2-(1)°.. The conformation is stabilized by an intramolecular O-H⋯N hydrogen bond.

The title compound, C(6)H(16)N(3) (+)·Br(-), is the bromide of the monoprotonated aza-macrocyclic triamine 1,4,7-triaza-cyclo-nonane (tacn). The threefold axis of the triamine is broken by the protonation of one of the three amine functions. The ammonium proton is bonded in an intra-molecular symmetrically bifurcated hydrogen bond to the two endodentate amine functions. Direct cation-anion cont...

molecular structure, isomerism, conformational stability and intramolecular hydrogen bonding (ihb) of cis-enol forms of 1-(n-pyridyl)butane-1,3-diones (npbd) (n = 2, 3, or 4) have been investigated by means of density functional theory (dft) calculations. energy differences for all possible npbd cis-enol forms of isomers with respect to the most stable form of the corresponding isomer have been...