Synthesis, spectral analysis, structural elucidation and quantum chemical studies of (E)-methyl-4-[(2-phenylhydrazono)methyl]benzoate.

The title compound, (E)-methyl-4-[(2-phenylhydrazono)methyl]benzoate, (I), (C15H14N2O2), has been synthesized by condensation reaction of methyl-4-formylbenzoate and phenylhydrazine. The compound has been characterized by elemental analysis, IR, (1)H NMR, (13)C NMR, UV-Vis spectroscopies and single crystal X-ray diffraction techniques. Optimized molecular structure, harmonic vibrational frequencies, (1)H and (13)C NMR chemical shifts have been investigated by B3LYP/6-31G(d,p) method using density functional theory (DFT). Global chemical reactivity descriptors, natural population analysis (NPA), thermodynamic and non-linear optical (NLO) properties have also been studied. The energetic behavior of the compound has been examined in solvent media using the integral equation formalism polarizable continuum model (IEF-PCM).

Comparative experimental and theoretical studies of N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine novel Schiff base.

In this work, N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine, C15H14N2O2, Schiff base molecule has been synthesized and characterized by elemental analyses, UV-Vis and IR spectroscopy and single crystal X-ray determination. The molecule of the title compound adopt an E configuration about the azomethine CN double bond. The benzene and phenyl rings are planar and the dihedral angle between the planes is 7.2(2)°. The crystal structure is stabilized by intermolecular OH⋯O and intramoleculer NH⋯O hydrogen bonding interactions. X-ray diffraction analyses show that, N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine Schiff base molecule crystallizes in the monoclinic system, P21/c space group, a=4.392(5)Å, b=22.340(5)Å, c=13.528(5)Å, ß=92.882(5)°, V=1325.7(16)Å(3), Z=4. The conformational analysis of N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine was performed by the density functional theory (DFT) B3LYP method using the 6-311++G(d,p) basis set. Also, theoretical values of FTIR and UV-Vis were performed by the same method. The calculated geometry parameters, IR and UV-Vis results were compared with experimental results.

Synthesis, spectroscopy, and quantum-chemical calculations on 1-substituted phenyl-3,5-diphenylformazans.

In this study 1-substituted phenyl-3,5-diphenylformazans were synthesized from benzaldehyde-N-phenylhydrazone and appropriate phenyldiazonium salts having CH(3), Br, and Cl at the o-, m-, and p-positions of 1-phenyl ring. Their structures were determined by infrared and ultraviolet-visible spectra. Bathochromic effect in accordance with the electron-donating effect of CH(3), Br, and Cl group and its magnitude were dependent upon type and position of substituent on the ring. The ground-state geometries and absorption wavelengths for 1-phenyl substituted formazans were studied with density functional theory and time-dependent density functional theory. The calculations were carried out by using PBE1PBE functional with 6-311G(2d,2p) basis set for lambda(max) of the UV-vis spectra for the studied formazans. A good agreement was obtained between the experimental and computed values.

Electrochemical and Spectroscopic Behaviors of 1-(o-, m-, p- Cl, or Br) Substituted Phenyl-3, 5-diphenylformazans in Dimethyl Sulfoxide.

1-(o-, m-, p-Cl, -Br) substituted phenyl-3, 5-diphenylformazans were synthesized. Their structures were elucidated and spectral behaviours were investigated by elemental analysis, FT-IR, UV-vis spectral data. The electrochemical properties such as number of electrons transferred (n), diffusion coefficient (D) and heterogeneous rate constant (ks) were determined and possible mechanisms were proposed using platinum and ultramicro platinum electrodes, cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The oxidations were carried out at different electrochemical steps that were dependent upon the structure of formazans. The relation between their absorption properties with electrochemical properties was investigated. A suitable correlation was obtained between the absorption λmax with electrochemical properties, and between the oxidation peak potentials Eox1 with ks values of formazans.

Synthesis, spectroscopic and electrochemical studies on bis-[1,3-substituted (Cl, Br) phenyl-5-phenyl formazanato]nickel(II) complexes.

In this study, new 1:2 Ni complexes of 1,3-substituted phenyl-5-phenylformazans were synthesized with -Cl, -Br substituents in the o-, m-, p-positions of the 1-phenyl ring and -NO2 group in the m-position of the 3-phenyl ring. Their structures were elucidated and spectral behaviors were investigated with the use of elemental analysis, GC-Mass, 1H NMR, 13C NMR, FTIR, UV-vis spectra. Furthermore electrochemical properties such as number of electrons transferred (n), diffusion coefficients (D) and possible reaction mechanism of the compounds were determined with the use of cyclic voltammetry, ultramicrodisc electrode and chronoamperometry. The relation between their absorption properties and electrochemical properties was examined. A linear correlation was obtained between Hammett substituent coefficients with lambda(max) values.

Synthesis and spectral properties of some bis-substituted formazans.

Novel, 1,4-bis-[3,3'-phenyl-5,5'-(o-carboxyphenyl)-formaz-1-yl]-benzene-o-sulphonic acid and its derivatives contained OH group at the o-, m-, p-positions of the 3-phenyl ring were synthesized. The structures of the formazans were confirmed by elemental analyses, GC-mass, IR, (1)H NMR, UV-vis spectra. Their absorption properties were investigated. It was seen that lambda(max) values shifted towards shorter wave lengths by 130nm in CSPF relative to 1,3,5-triphenylformazan (TPF) due to the fact that the structure of CSPF contained electron withdrawing COOH and SO(3)H groups (hypsochromic effect). With binding of OH group to 3-phenyl ring of CSPF, it was observed a small bathochromic effect in accordance to the electron donating effect of OH group.

Electrochemical investigation of 1,3,5-triphenylformazan and its nitro derivatives in dimethyl sulfoxide.

Cyclic voltammetric (CV) and chronoamperometric (CA) behaviors of 1,3,5-triphenylformazan (TPF), 3-(p-nitrophenyl)-1,5-diphenylformazan (PNF) and 3-(m-nitrophenyl)-1,5-diphenylformazan (MNF) were studied in dimethyl sulfoxide medium. TPF was found to give a single sharp cathodic CV peak corresponding to a gain of one-electron per molecule. The diffusion coefficient and the number of electrons transferred were calculated using the Baranski equation with the CV-data obtained by an ultramicroelectrode. Standard rate constants for the reduction were calculated by the Klingler-Kochi technique. The electrochemical data obtained support the mechanism proposed by Umemoto.

N-(4-nitrobenzylidene)-N'-phenylhydrazine.

Molecules of the title compound (alternative name: p-nitrobenzaldehyde phenylhydrazone), C(13)H(11)N(3)O(2), adopt an E configuration about the azomethine C=N double bond. Molecules are approximately planar and the dihedral angle between the planes of the phenyl rings is 11.62 (9) degrees. Hydrogen bonding links molecules related by 4(2) screw axes to form helices with a pitch of 7.7186 (8) A.

Crystal structure of 2,3-diaza-1,3-diphenylpropene.

The title compound crystallizes in monoclinic space group P2(1)/c. There are two molecules in the asymmetric unit. While one of these molecules is in a general position, the other is in disordered position. The angle between the directions of the molecules in the asymmetric unit is 87.5(1) degrees.

N-(4-Methoxybenzylidene)-N'-(2-pyridyl)hydrazine.

Molecules of the title compound (alternative name p-methoxybenzaldehyde 2-pyridylhydrazone), C(13)H(13)N(3)O, adopt an E configuration about the azomethine C=N double bond. Molecules are almost planar, the dihedral angle between the pyridine and methoxyphenyl rings being only 6.19 (12) degrees. Pairwise N-H.N hydrogen bonds [R(2)(2)(8) in graph-set notation] link centrosymmetrically related molecules into discrete pairs.