68 ( E)-Ethyl 4-chloro-3-- 2-(2-fluorophenyl)hydrazono buta

Journal of the Brazilian Chemical Society, 2016

The crystal structures of (Z)-1-phenyl-4-[((2-phenylhydrazono)methyl)]-1H-1,2,3-triazole, (Z)-4-[(2-(2,4-dimethylphenyl)hydrazono)methyl]-2-phenyl-2H-1,2,3-triazole, (E)-4-[(2-(2,4-dinitrophenyl)hydrazono)methyl]-2-phenyl-2H-1,2,3-triazole, and (E)-N '-((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)isonicotinohydrazide dihydrate are reported. The formations of (Z)-configurations about the C=N bonds in the first two compounds arise from the stabilizing presence of intramolecular N−H•••N hydrogen bonds, while in the third compound, the presence of intramolecular N−H•••O hydrogen bonds promotes an (E) geometry. The arrangement about the CONHC=N fragment in the hydrated acylhydrazone is E C(O)NH /E C=N. Also present in (E)-N '-((2phenyl-2H-1,2,3-triazol-4-yl)methylene)isonicotinohydrazide is an interesting R 4 4 (8) ring formed from hydrogen bonds generated from four water molecules.

The review surveys the present state of research on the conformation, isomerism, and intramolecular interactions of molecules of the immense class of organic compounds containing a hydrazone group. A list of 221 references is included.

Dyes and Pigments, 1996

The structural results clearly indicate that I-butyl-3-cyano-6-hydroxy-4methyl-5-(2-thiazolylazo)-2(IH)-pyridone, (Ct4HISNs0zS), exists primarily as the hydrazone tautomer in the solid state. The molecule is nearly planar not regarding the butyl group. Some of the bond lengths and angles are distorted due to n-electron delocalization and strain. A strong intramolecular N-H...0 hydrogen bond was found [N...O = 2.53(1)A]. The crystallographic parameters are as follows: triclinic Pi, a=5.972(4)A, b= 7.732(5)A,

Acta crystallographica. Section E, Crystallographic communications, 2015

The title compound, C12H10FN3, is approximately planar: the dihedral angles between the mean plane of the central N-N=C spacer unit and the fluoro-benzene and pyridine rings are 14.50 (13) and 4.85 (15)°, respectively, while the dihedral angle between the aromatic rings is 16.29 (6)°. The F atom lies at the same side of the mol-ecule as the N atom of the pyridine ring. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R 2 (2)(8) loops. Mol-ecules related by translation in the a direction are linked by two π-π stacking inter-actions involving pairs of benzene rings and pairs of pyridine rings. In each case, the ring-centroid separation is 3.8517 (9) Å. Two chains of this type pass through each unit cell, but there are no direction-specific inter-actions between adjacent chains.

The 2-(phenyl-hydrazono)-succinic acid dimethyl ester compound was synthesized by reacting phenylhydrazine with dimethylacetylene dicarboxylate at room temperature and characterized by elemental analysis, infrared, Raman, 1H and 13C NMR spectroscopies and mass spectrometry. Its solid state structure was determined by X-ray diffraction methods. The X-ray structure determination corroborates that the molecule is present in the crystal as the hydrazone tautomer, probably favored by a strong intramolecular N–H···O=C hydrogen bond occurring between the carbonyl (–C=O) and the hydrazone –C=N–NH– groups. A substantial fragment of the molecular skeleton is planar due to an extended -bonding delocalization. The topological analysis of the electron densities (Atom in Molecule, AIM) allows to characterize intramolecular N–H···O interaction, that can be classified as a resonant assisted hydrogen bond (RAHB). Moreover, the Natural Bond Orbital population analysis confirms that a strong hyperconjugative lpO1→ *(N2–H) remote interaction between the C2=O1 and N2–H groups takes place. Periodic system electron density and topological analysis have been applied to characterize the intermolecular interactions in the crystal. Weak intermolecular interactions determine the packing and the prevalence of non directional dispersive contributions are inferred on topological grounds. The IR spectrum of the crystalline compound was investigated by means of density functional theory calculations carried out with periodic boundary conditions on the crystal, showing excellent agreement between theory and the experiments. The vibrational assignment is complemented with the analysis of the Raman spectrum.

Chemical Data Collections, 2020

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Acta Crystallographica Section B Structural Science, 1994

The crystal and molecular structures of the following 1-ketone-2-arylhydrazones have been determined: (1) 4-(phenylhydrazono)-3-methyl-4H-isoxazol-5-one, C~oH9N302, Mr= 203.2, monoclinic, C2/c, a = 11.100 , b= 7.960(2), c= 21.744 (4)•, /3 = 95.82 (2) °, V = 1911.3 (8) A 3, Z = 8, Dx = 1.41 Mg m-3, A(Mo Ka) = 0.71069 .A,, /~ = 0.096 mm-I, F(000) = 848, T = 295 K, R = 0.040 for 1737 observed reflections;

Acta Crystallographica Section E Structure Reports Online, 2005

Ethyl 4-chloro-2-[2-(2-chlorophenyl)hydrazono]-3-oxobutanoate Crystal data

Acta Crystallographica Section E Structure Reports Online, 2014