Triazine-Based Hydrazone Derivatives; A Comparative Experimental-Theoretical Study (original) (raw)
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Molecules (Basel, Switzerland), 2015
We report here a comparative theoretical and experimental study of four triazine-based hydrazone derivatives. The hydrazones are synthesized by a three step process from commercially available benzil and thiosemicarbazide. The structures of all compounds were determined by using the UV-Vis., FT-IR, NMR (1H and 13C) spectroscopic techniques and finally confirmed unequivocally by single crystal X-ray diffraction analysis. Experimental geometric parameters and spectroscopic properties of the triazine based hydrazones are compared with those obtained from density functional theory (DFT) studies. The model developed here comprises of geometry optimization at B3LYP/6-31G (d, p) level of DFT. Optimized geometric parameters of all four compounds showed excellent correlations with the results obtained from X-ray diffraction studies. The vibrational spectra show nice correlations with the experimental IR spectra. Moreover, the simulated absorption spectra also agree well with experimental res...
ACS Omega
Herein, halo-functionalized hydrazone derivatives "2-[(6′-chloroazin-2′-yl)oxy]-N′-(2-fluorobenzylidene) acetohydrazone (CPFH), 2-[(6′-chloroazin-2′-yl)oxy]-N′-(2-chlorobenzylidene) aceto-hydrazones (CCPH), 2-[(6′-chloroazin-2′yl)oxy]-N′-(2-bromobenzylidene) aceto-hydrazones (BCPH)" were synthesized and structurally characterized using FTIR, 1 H-NMR, 13 C-NMR, and UV−vis spectroscopic techniques. Computational studies using density functional theory (DFT) and time dependent DFT at CAM-B3LYP/6-311G (d,p) level of theory were performed for comparison with spectroscopic data (FT-IR, UV−vis) and for elucidation of the structural parameters, natural bond orbitals (NBOs), natural population analysis, frontier molecular orbital (FMO) analysis and nonlinear optical (NLO) properties of hydrazones derivatives (CPFH, CCPH, and BCPH). Consequently, an excellent complement between the experimental data and the DFT-based results was achieved. The NBO analysis confirmed that the presence of hyper conjugative interactions was pivotal cause for stability of the investigated compounds. The energy gaps in CPFH, CCPH, and BCPH were found as 7.278, 7.241, and 7.229 eV, respectively. Furthermore, global reactivity descriptors were calculated using the FMO energies in which global hardness revealed that CPFH was more stable and less reactive as compared to BCPH and CCPH. NLO findings disclosed that CPFH, CCPH, and BCPH have superior properties as compared to the prototype standard compound, which unveiled their potential applications for optoelectronic technology.
Letters in Organic Chemistry, 2012
A series of novel symmetric triazine hydrazones [N 3 C 3 (-OC 6 H 4-p-C(CH 3)=N-NH-C(O)-C 6 H 4-p-X) 3 ] (X = H, Br, Cl, F, OH, OCH 3 , CH 3 , NO 2 , NH 2) were prepared in excellent yields by a threefold condensation reaction of 2,4,6tris(4-acetylphenoxy)-1,3,5-triazine with p-substituted benzoic acid hydrazides [NH 2-NH-C(O)-C 6 H 4-p-X]. The structures were confirmed by FT-IR, 1 H, 13 C, 2D-HMQC NMR and mass spectrometry (MALDI-TOF).
A three series of p-substituted aromatic hydrazones have been synthesized by condensation of benzhydrazide/p-substituted benzhydrazides (CH 3 , OCH 3 , Cl and OH) with benzaldehyde/p-substituted benzaldehydes ( OCH 3 and NO 2). Initially, p-substituted esters were prepared from benzoic acid, p-substituted benzoic acid and methanol. In the second step, p-substituted hydrazides were prepared from the previously synthesized esters and hydrazine hydrate. Finally, p-substituted aromatic hydrazones were obtained from hydrazides and benzaldehyde or p-substituted benzaldehyde. The identity of the synthesized hydrazones was confirmed by the following techniques: 1 H NMR, 13 C NMR, IR and UV spectroscopy and element analysis (CNH). The proposed method of synthesis resulted in excellent yield and purity of the prepared hydrazones. Using three conventional LFER models based on mono and the dual substituent parameters, quantitative assessment of the substituent effects on the substituent chemical shifts (SCS) was made. In order to obtain the correlation models for investigated series the IR (
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013
A new 1,2,4-triazole-based Schiff base hydrazone with N, O, S donor set of atoms, H 4 L, has been prepared by condensation reaction of N,N'-bis(3-formyl-5methylsalicylidene)ethane-1,2-diamine, H 2 L, with 4-amino-3-(4-pyridyl)-5-mercapto-1,2,4triazole. The structure of H 4 L was characterized by using FT-IR, UV-Vis and 1 H NMR spectroscopic methods as well as elemental analysis data. The formation constants of copper(II), cadmium(II), mercury(II) and silver(I) complexes of H 4 L in DMSO were calculated using a hard model chemometrics method applying the spectrophotometric data. The protonation constants of H 4 L were also measured in DMSO-water (1:10) mixture. Furthermore, 1 H chemical shifts of H 4 L were studied by the gauge independent atomic orbital (GIAO) and continuous set of gauge transformations (CSGT) methods at the level of density functional theory using B3LYP/6-311++G* basis sets in gas phase. The computed chemical shifts are in reasonably good agreement with the experimental data.
Synthesis and characterization of new p-substituted aromatic hydrazones
Organic Chemistry: An Indian Journal, 2012
A three series of p-substituted aromatic hydrazones have been synthesized by condensation of benzhydrazide/p-substituted benzhydrazides (CH3, OCH3, Cl and OH) with benzaldehyde/p-substituted benzaldehydes (OCH3 and NO2). Initially, p-substituted esters were prepared from benzoic acid, p-substituted benzoic acid and ethanol. In the second step, p-substituted hydrazides were prepared from the previously synthesized esters and hydrazine hydrate. Finally, p-substituted aromatic hydrazones were obtained from hydrazides and benzaldehyde or p-substituted benzaldehyde. The identity of the synthesized hydrazones was confirmed by the following techniques: 1H NMR, 13C NMR, IR and UV spectroscopy and element analysis (CNH). The proposed method of synthesis resulted in excellent yield and purity of the prepared hydrazones. Using three conventional LFER models based on mono and the dual substituent parameters, quantitative assessment of the substituent effects on the substituent chemical shifts (SCS) was made. In order to obtain the correlation models for investigated series the IR (C=O, C=N and NHC=O), 1HNH, 1H=CH, 13C=CH- and 13C C=O peaks were used.
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.
Theoretical Studies of Structure, Spectroscopy, and Properties of a New Hydrazine Derivative
Journal of Chemistry, 2013
We will report a combined experimental and theoretical study on molecular structure, vibrational spectra, and energies of (E)-1-(2,4-dinitrophenyl)-2-[(4-methylphenyl)methylidene]hydrazine (1). The molecular geometry and vibrational frequencies and energies in the ground state are calculated by using HF and DFT levels of theory with 6-311G basis sets. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The harmonic vibrational frequencies were calculated, and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed bar-type spectrograms.
Theoretical and Vibrational Analysis of Substituted Hydrazones: Valence Force Field
2022
The vibrational spectroscopic and theoretical investigation of some diketo hydrazones derivatives; (2Z)-2-[2-(4-methylphenyl)hydrazinylidene]-1-(naphthalen-2yl)butane-1,3-dione(NBTMH), (2Z)-2-[2-(4bromophenyl)hydrazinylidene]-1-(naphthalen-2-yl)butane-1,3-dione (NBTBH), and (2Z)-2-[2,4-(phenyl)hydrazinylidene]-1-(naphthalen-2-yl) butane-1,3-dione (NBTBFH) were made in this study. Theoretical investigations of these compounds includes conformational, NBO and vibrational analyses to see the most stable structure, possible hydrogen bondings and chemical bond diversities of the compounds, respectively. The potential energy surfaces of the compounds were obtained by DFT method regarding the selected degree of torsional freedom, which was varied from 0 o to 360 o in 18 o steps. The geometries of the compounds were optimized through conformational analysis followed by the minimum energy conformer. Possible hydrogen bonds were searched by NBO analysis. The vibrational frequencies were calculated using the optimized geometry (bond lengths, bond angles), the atomic masses, and the force constants as the input. The atomic radii and the electronegativities of the compounds were also used as the input to calculate IR and RAMAN activities. Wilson's GF Matrix method was used for the calculation of vibrational frequencies and the activities. The experimentally measured vibrational spectra were elucidated through theoretical calculations.
Egyptian Journal of Chemistry, 2018
T HE OBJECTIVE of this study is synthesizing of binary and mixed ligands complexes by reacting Co(II), Ni(II), Cu(II) ions with (E)-3-(2-(5,6-diphenyl-1,2,4-triazin-3-yl) hydrazono) butan-2-one oxime (H 2 L) in presence and in absence of 8-Hydroxyquinoline ligand. The characterization of complexes is performed by analytical, spectral (IR, mass, UV-Vis, 1 H NMR and ESR), magnetic susceptibility, molar conductivity measurements and thermal gravimetric analysis techniques. The scanning electron microscopy is used for detection of the morphology of the ligand and some complexes. The analytical data, spectral studies and magnetic moments established octahedral geometries for all complexes. The ligand behaves as monobasic tridentate (C=N azomethine , C=N triazine and OH) for binary complexes. On other hands, The ligand acts as monobasic bidentate (C=N azomethine and OH), for mixed ligands complexes. and mixed ligands complexes, respectively. The optimized structures of the triazine ligand and its complexes theoretically have been done. The structural parameters were correlated with the experimental data. The activity of the triazine ligand and its complexes against Hepatocellular carcinoma, fungi and bacteria have been examined using the diffusion method. The Cu complexes have best activity than the ligand, Co(II) and Ni(II) complexes.