Showing papers by "Hasan Tanak published in 2010"
TL;DR: Calculated results show that density functional theory (DFT) and HF can well reproduce the structure of the title compound.
Abstract: The Schiff base compound, 2-[(4-Fluorophenylimino)methyl]-3,5-dimethoxyphenol, has been synthesized and characterized by IR, electronic spectroscopy, and X-ray single-crystal determination. Molecular geometry from X-ray experiment of the title compound in the ground state have been compared using the Hartree-Fock (HF) and density functional method (B3LYP) with 6–31G(d) basis set. Calculated results show that density functional theory (DFT) and HF can well reproduce the structure of the title compound. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6–31G(d) basis set by applying the polarizable continuum model (PCM). The total energy of the title compound decrease with the increasing polarity of the solvent. By using TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental ones is determined. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), natural bond orbital (NBO), and thermodynamic properties were performed at B3LYP/6–31G(d) level of theory.
74 citations
TL;DR: The results reveal that the IPCM method yielded a more stable structure than Onsager's method, and the phenolate oxygen atom and all of the nitro group oxygen atoms have bigger negative charges.
Abstract: Density functional calculations of the structure, atomic charges, molecular electrostatic potential and thermodynamic functions have been performed at B3LYP/6-31G(d,p) level of theory for the title compound (E)-2-[(2-hydroxy-5-nitrophenyl)-iminiomethyl]-4-nitrophenolate. The results show that the phenolate oxygen atom and all of the nitro group oxygen atoms have bigger negative charges, and the coordination ability of these atoms differs in different solvents. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6-31G(d,p) basis set by applying the Onsager method and the isodensity polarized continuum model (IPCM). The results obtained with these methods reveal that the IPCM method yielded a more stable structure than Onsager’s method. In addition, natural bond orbital and frontier molecular orbital analysis of the title compound were performed using the B3LYP/6-31G(d,p) method.
65 citations
TL;DR: In this paper, the title compound of 2-methyl-6-[2-(trifluoromethyl)phenyliminomethymyl]phenol has been examined using B3LYP method with the 6-31G(d) basis set by applying the Onsager and the polarizable continuum model.
Abstract: Density functional calculations of the structure, molecular electrostatic potential and thermodynamic functions have been performed at B3LYP/6-31G(d) level of theory for the title compound of 2-methyl-6-[2-(trifluoromethyl)phenyliminomethyl]phenol. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6-31G(d) basis set by applying the Onsager and the polarizable continuum model. The results obtained with these methods reveal that the PCM method provided more stable structure than Onsager’s method. The predicted non-linear optical properties of the title compound are much greater than ones of urea. The changes of thermodynamic properties from the monomers to title compound with the temperature ranging from 200 K to 400 K have been obtained using the statistical thermodynamic method. At 298.15 K the change of Gibbs free energy for the formation reaction of the title compound is −0.709 kJ/mol. The title compound can be spontaneously produced from the isolated monomers at room temperature. In addition, natural bond orbital and frontier molecular orbital analysis of the title compound were performed using the B3LYP/6-31G(d) method.
60 citations
TL;DR: In this article, the triazole compound 4-(3-(1H-imidazol-1-yl)propyl)-5-methyl-2H-1,2,4-triazol 3(4H)-one monohydrate has been synthesized and characterised by 1H-NMR, 13C-NMRI, IR, and X-ray single-crystal determination.
Abstract: The triazole compound 4-(3-(1H-imidazol-1-yl)propyl)-5-methyl-2H-1,2,4-triazol-3(4H)-one monohydrate has been synthesised and characterised by 1H-NMR, 13C-NMR, IR, and X-ray single-crystal determination. The compound crystallizes in the triclinic space group with a = 9.0366(7) A, b = 11.5690(8) A, c = 12.0571(9) A, α = 110.733(6)°, β = 94.172(6)°, γ = 98.085(6)° and Z = 4. In addition to the molecular geometry from X-ray determination, the molecular geometry, vibrational frequencies and gauge, including atomic orbital (GIAO) 1H- and 13C-NMR chemical shift values of the title compound in the ground state, were calculated using the density functional method (B3LYP) with the 6-31G(d) basis set. The calculated results show that the optimised geometries can well reproduce the crystal structure, and the theoretical vibrational frequencies and chemical shift values show good agreement with experimental values. The energetic behaviour of the title compound in solvent media was examined using the B3LYP method with...
42 citations
TL;DR: In this paper, density functional calculations of the structure, molecular electrostatic potential and thermodynamic functions have been performed at B3LYP/6-31G(d) level of theory for the title compound of N -2-Methoxyphenyl-2-oxo-5-nitro-1-benzylidenemethylamine.
Abstract: Density functional calculations of the structure, molecular electrostatic potential and thermodynamic functions have been performed at B3LYP/6-31G(d) level of theory for the title compound of N -2-Methoxyphenyl-2-oxo-5-nitro-1-benzylidenemethylamine. To investigate the tautomeric stability, optimization calculations at B3LYP/6-31G(d) level were performed for the enol and keto forms of the title compound. Calculated results reveal that the enol form of the title compound is more stable than its keto form. The predicted non-linear optical properties of the title compound are much greater than ones of p-Nitroaniline. The changes of thermodynamic properties from the monomers to title compound with the temperature ranging from 200 K to 450 K have been obtained using the statistical thermodynamic method. At 298.15 K the change of Gibbs free energy for the formation reaction of the title compound is 30.654 kJ/mol. The title compound cannot be spontaneously produced from the isolated monomers at room temperature. The tautomeric equilibrium constant is computed as 0.0192 at 298.15 K for enol-imine ↔ keto-amine tautomerization of the title compound. In addition, natural bond orbital analysis of the title compound were performed using the B3LYP/6-31G(d) method.
42 citations
TL;DR: In this paper, the Schiff base compound 2-[(4-propylphenylimino)methyl]-4-nitrophenol has been synthesized and characterized by IR, UV-Vis, and X-ray single-crystal determination.
Abstract: The Schiff base compound 2-[(4-propylphenylimino)methyl]-4-nitrophenol has been synthesized and characterized by IR, UV–Vis, and X-ray single-crystal determination. The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree–Fock (HF) and density functional theory (DFT) with the 6-31G(d) basis set. The calculated results show that the DFT and HF can well reproduce the structure of the title compound. The energetic behaviour of the title compound in solvent media was examined using the B3LYP method with the 6-31G(d) basis set by applying the Onsager and the polarizable continuum model (PCM). The results obtained with these methods reveal that the PCM method provides a more stable structure than Onsager's method. Using the TD-DFT method, electronic absorption spectra of the title compound have been predicted and good agreement with the TD-DFT method and the experimental determination was found. The predicted nonlinear optical properties of th...
41 citations
TL;DR: In this article, the density functional theory (DFT) method with 6-31G(d) basis set was used to calculate the molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the title compound (3) in the ground state.
23 citations
TL;DR: The calculated results show that the optimized geometries can well reproduce the crystal structure and the theoretical vibrational frequencies and chemical shift values show good agreement with experimental ones.
Abstract: The triazole compound, 5-benzyl-4-(3,4-dimethoxyphenethyl)-2H-1,2,4-triazol-3(4H)-one, has been synthesized and characterized by 1H-NMR, 13C-NMR, IR, and X-ray single-crystal determination. The compound crystallizes in the monoclinic space group P21 with a = 11.8844(3) A, b = 17.5087(4) A, c = 17.3648(6) A, β = 99.990(2)˚ and Z = 8. In addition to the molecular geometry from X-ray experiment, the molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO) 1H- and 13C-NMR chemical shift values of the title compound in the ground state have been calculated using the density functional method (B3LYP) with 6-31G(d,p) basis set. The calculated results show that the optimized geometries can well reproduce the crystal structure and the theoretical vibrational frequencies and chemical shift values show good agreement with experimental ones. Besides, molecular electrostatic potential (MEP), natural bond orbital (NBO), and frontier molecular orbitals (FMO) analysis of the title compound were performed by the B3LYP/6-31G(d,p) method.
16 citations
TL;DR: In this paper, a series of new N′-3-(1H-imidazol-1-yl)propylcarbamoyl-4-halogenebenzo hydrazonate (3a-b) were obtained by reaction Ethyl 2-((4-Halogene phenyl) (ethoxy) methylene) hydrazinecarboxylate (1) and N-(3-aminopropyl)IMidazole (2) at 120-140 °C.
Abstract: A series of new N′-3-(1H-imidazol-1-yl)propylcarbamoyl-4-halogenebenzo hydrazonate (3a–b) were obtained by reaction Ethyl 2-((4-halogene phenyl) (ethoxy) methylene) hydrazinecarboxylate (1) and N-(3-aminopropyl)imidazole (2) at 120–140 °C. Compounds (4a–b) were obtained by the reaction compound 1 and N-(3-aminopropyl)imidazole (2) at 160–180 °C. The structures of compounds 3,4 have been inferred through UV–Vis, IR, 1H/13C NMR, mass spectrometry, elemental analyses, and X-ray crystallography. DFT level 6-31G (d) calculations provided structural information. The electronic structure of compound 3a has been studied by DFT level 6-31G (d) calculations using the X-ray data. The results are accordance with X-ray data.
15 citations
TL;DR: In the title compound, C13H15N3O3, the dihedral angle between the two aromatic ring is 51 (1)° and the crystal, molecules are connected by pairs of N—H⋯O hydrogen bonds into centrosymmetric dimers.
Abstract: In the title compound, C13H15N3O3, the dihedral angle between the two aromatic ring is 51.06 (1)°. In the crystal, molecules are connected by pairs of N—H⋯O hydrogen bonds into centrosymmetric dimers.
9 citations
TL;DR: In this paper, the Schiff base compound (E)-2-(1-(2-(4-methylphenylsulfonamido)ethyliminio)ethyl) phenolate has been synthesized and characterized by IR, UV-Vis, and X-ray single-crystal determination.
Abstract: The Schiff base compound (E)-2-(1-(2-(4-methylphenylsulfonamido)ethyliminio)ethyl) phenolate has been synthesised and characterized by IR, UV–Vis, and X-ray single-crystal determination. Ab initio calculations have been carried out for the title compound using the density functional theory (DFT) and Hartree–Fock (HF) methods at 6-31G(d) basis set. The calculated results show that the DFT/B3LYP and HF can well reproduce the structure of the title compound. Using the TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental ones is determined. Molecular orbital coefficient analyses reveal that the electronic transitions are mainly assigned to n → π* and π → π* electronic transitions. To investigate the tautomeric stability, optimization calculations at B3LYP/6-31G(d) level were performed for the NH and OH forms of the title compound. Calculated results reveal that the OH form is more stable than NH form. In addition, molecular electrostatic potential and NBO analysis of the title compound were performed at B3LYP/6-31G(d) level of theory.
TL;DR: In the zwitterionic title compound, C12H17NO4, an intramolecular N—H⋯O hydrogen bond generates a six-membered ring, producing an S(6) ring.
Abstract: In the zwitterionic title compound, C12H17NO4, an intramolecular N—H⋯O hydrogen bond generates a six-membered ring, producing an S(6) ring In the crystal structure, molecules are linked by intermolecular C—H⋯O and O—H⋯O interactions
TL;DR: The title compound, C6H6N2O3·H2O, crystallizes with two formula units in the asymmetric unit as mentioned in this paper, and is essentially planar with the nitro groups twisted slightly out of the ring planes [maximum deviations from the ring plane of 0.13
Abstract: The title compound, C6H6N2O3·H2O, crystallizes with two formula units in the asymmetric unit. The molecules are essentially planar with the nitro groups twisted slightly out of the ring planes [maximum deviations from the ring plane of 0.13 (2) and 0.22 (2) A in the two molecules]. The respective O—N—C—C torsion angles are 6.0 (4) and 12.5 (4)°. In the crystal structure, molecules are linked by intermolecular N—H⋯O, C—H⋯O, O—H⋯O and O—H⋯N interactions into a three-dimensional network.
TL;DR: In this article, one of the thio-phene rings is disordered [occupancy ratio 0.710/4:0.290/4] and the disorder is of the flip type.
Abstract: In the title compound, C20H16N4O2S2, one of the thiophene rings is disordered [occupancy ratio 0.710 (4):0.290 (4)] and the disorder is of the flip type. An intramolecular C—H⋯O hydrogen bond generates a six-membered ring with an S(6) motif.
TL;DR: The dihedral angle between the two rings in the title compound, C12H15N3O2, is 49.03 (1)°, and the crystal structure is stabilized by intermolecular N—H⋯O and C—H–O hydrogen bonds.
Abstract: The dihedral angle between the two rings in the title compound, C12H15N3O2, is 4903 (1)° The crystal structure is stabilized by intermolecular N—H⋯O and C—H⋯O hydrogen bonds and π–π stacking interactions between the triazole rings with a centroid–centroid distance of 3394 A