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ABSTRACT: A Schiff base ligand containing thiocarbamide group of 4-phenyl-1-(4-methoxyl-1-phenylethylidene)thiosemicarbazide (HL) and
its three mononuclear metal complexes of ZnL2 (1), NiL2 (2), and CuL2 (3) have been synthesized. Elemental analysis, IR, and X-ray single crystal diffraction characterizations for the ligand and
the three complexes have been carried out. In the three complexes, the central metallic ions of Zn2+, Ni2+, and Cu2+ coordinate with two deprotonated ligands of L−, respectively. In 1, Zn2+ ion adopts a distorted tetrahedral geometry, while in 2 and 3, both the Ni2+ and Cu2+ ions possess distorted square planar configurations. For the four compounds, UV–Vis spectra have been measured and DFT calculations
at B3LYP/LANL2DZ level of theory prove that the electronic spectra of HL and 1 are corresponding with electronic transitions of n→π* and π→π* in the ligand itself and the electronic spectra of 2 and 3 are attributed to intraligand electronic transitions as well as d–d electronic transitions. Electrochemical investigations reveal that the different metal–ligand interactions have changed the
peak shapes and peak locations, which are corresponding with the DFT-B3LYP/LANL2DZ calculational results. Fluorescence spectra
measurements indicate that the ligand emits purple fluorescence and the complex 1 emits stronger blue fluorescence, while the complexes 2 and 3 quench fluorescence. The thermal analyses result show that the three complexes undergo two similar decomposition processes
because of their similar geometric configurations.
KeywordsSchiff base-Electronic spectra-Electrochemistry-Fluorescence-Thermal stability
Structural Chemistry 04/2012; 21(5):977-987. · 1.85 Impact Factor
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ABSTRACT: Two 2-pyrazoline derivatives of 1-phenyl-3-(4-chlorophenyl)-5-(2-chlorophenyl)-2-pyrazoline (1) and 1-phenyl-3-(4-methylphenyl)-5-(2-chlorophenyl)-2-pyrazoline (2) have been synthesized and characterized by elemental analysis, IR, UV–Vis, and fluorescence spectra. The crystal structure
of 2 has been determined by X-ray single crystal diffraction. For the two compounds, density functional theory (DFT) calculations
of the structures and natural population atomic charge analysis have been performed at B3LYP/6-311G** level of theory. By
using TD-DFT method, electron spectra of 1 and 2 have been predicted, which are in good agreement with the experimental ones. Comparative studies on 1 and 2 indicate that the change of substituted groups in 3-phenyl ring of pyrazoline ring will change the peak intensity and peak
locations both in electron spectra and fluorescence spectra.
Structural Chemistry 04/2012; 20(3):443-451. · 1.85 Impact Factor
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ABSTRACT: The title compound of 3-p-methylphenyl-4-amino-1, 2, 4-triazole-5-thione was synthesized and characterized by elemental analysis, IR, electronic spectra,
and X-ray single crystal diffraction. Quantum chemical calculations of the structure, natural bond orbital, and thermodynamic
functions of the title compound were performed by using B3LYP/6-311G** and HF-6-311G** methods. Both the methods can well
simulate the molecular structure. Vibrational frequencies were predicted, assigned and compared with the experimental values,
and B3LYP/6-311G** method is superior to HF/6-311G** method to predict the vibrational frequencies. Electronic absorption
spectra calculated by B3LYP/6-311G** method have some red shifts compared with the experimental ones and natural bond orbitals
analyses indicate that the two absorption bands are mainly derived from the contribution of n → π* and π→π* transitions. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures
have been calculated, revealing the correlations between C
0
p,m
, S
0
m
, H
0
m
, and temperatures.
Structural Chemistry 04/2012; 18(6):993-1000. · 1.85 Impact Factor
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ABSTRACT: The first lanthanide mixed sulfate-sulfite inorganic coordination polymer, poly[diaqua-μ(4)-sulfato-di-μ(4)-sulfito-didysprosium(III)], [Dy(2)(SO(3))(2)(SO(4))(H(2)O)(2)](n), has been obtained, in which both sulfate and sulfite groups originate from the disproportionation of S(2)O(3)(2-) under hydrothermal and weakly acidic conditions. The crystal structure of the title compound exhibits a three-dimensional framework. The Dy(III) ion is surrounded by eight O atoms from one water molecule and two sulfate and five sulfite groups. These DyO(8) polyhedra have two shared edges and form an infinite zigzag Dy-O chain. In the bc plane, neighbouring chains are integrated through SO(3) trigonal pyramids, forming a two-dimensional sheet. Along the a-axial direction, the sulfate group, with the central S atom lying on a twofold axis, links adjacent two-dimensional sheets via two S-O-Dy connections, thus generating the three-dimensional framework.
Acta crystallographica. Section C, Crystal structure communications 05/2011; 67(Pt 5):i27-9. · 0.78 Impact Factor
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ABSTRACT: In the title compound, C(25)H(20)Br(2)N(2) (2+)·2NO(3) (-), the cation lies on a twofold rotation axis which imposes disorder of the dibromo-fluorene unit. In addition, the unique nitrate anion is disordered over two general sites of equal occupancy. The crystal structure is stabilized by inter-molecular N-H⋯O hydrogen bonds.
Acta Crystallographica Section E Structure Reports Online 01/2010; 66(Pt 2):o251. · 0.35 Impact Factor
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ABSTRACT: p-Hydroxybenzoic acid (p-HOBA) was selected as the building block for self-assembly with five bases, i.e., diethylamine, tert-butylamine, cyclohexylamine, imidazole and piperazine, and generation of the corresponding acid–base complexes 1–5. Crystal structure analyses suggest that proton-transfer from the carboxyl hydrogen to the nitrogen atom of the bases can be observed in 1–4, while only in 5 does a solvent water molecule co-exist with p--HOBA and piperazine. With the presence of O–H···O hydrogen bonds in 1–4, the deprotonated p-hydroxybenzoate anions (p-HOBAA–) are simply connected each other in a head-to-tail motif to form one-dimensional (1D) arrays, which are further extended to distinct two-dimensional (2D) (for 1 and 4) and three-dimensional (3D) (for 2 and 3) networks via N–H···O interactions. While in 5, neutral acid and base are combined pair-wise by O–H···N and N–H···O bonds to form a 1D tape and then the 1D tapes are sequentially combined by water molecules to create a 3D network. Some interlayer or intralayer C–H···O, C–H···p and p×××p interactions help to stabilize the supramolecular buildings. Melting point determination analyses indicate that the five acid–base complexes are not the ordinary superposition of the reactants and they are more stable than the original reactants.
Journal of the Serbian Chemical Society. 01/2010;
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ABSTRACT: The main aim of this study was to investigate the relationship between mIn tA new Ni(II) complex of bisglycinato-bis[p-(hydroxylmethyl)py-ridine] was synthesized and characterized by elemental analysis, IR, UV–Vis spectroscopy and X-ray single crystal diffraction analysis. The thermal stability of the title complex was also determined. The complex adopts a distorted octahedral geometry and possesses inversion symmetry with the Ni(II) ion as the center of inversion. Density function theory (DFT) calculations of the structure, electronic absorption spectra, electron structure and natural population analysis (NPA) at the B3LYP/LANL2DZ level of theory were performed. The predicted geometric parameters and electronic spectra were compared with the experimental values and they supported each other. The NPA results indicate that the electronic transitions were mainly derived from the contribution of an intra-ligand (IL) transition, a ligand-to-metal charge transfer (LMCT) transition and a d-d transition. The electron structure calculations suggest that the central Ni(II) ion uses its 4s and 3d orbitals to form covalent bonds with coordinated N and O atoms. The calculated bond orders are also consistent with the thermal decomposition results. Based on vibrational analysis, the thermodynamic properties of the title complex were predicted and the correlative equations between these thermodynamic properties and temperature are also reported.
Journal of the Serbian Chemical Society. 01/2010;
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ABSTRACT: A dicycle pyrazoline derivative, 1-phenyl-5-(p-fluorophenyl)-3,4-(α-p-fluoro-tolylenecyclohexano) pyrazoline, was synthesized and characterized by elemental analysis, IR, UV-vis, fluorescence spectra and X-ray single crystal diffrac-tion. Density function theory (DFT) calculations were performed by using B3LYP method with 6-311G** basis set. The optimized geometry can well simulate the molecular structure. Vibrational frequencies were predicted, assigned and compared with the experimental values, which suggest that B3LYP/6-311G** method can well predict the IR spectra. Both the experimental electronic absorption spectra and the predicted ones by B3LYP/6-311G** method reveal three electron-transition bands, with the theoretical ones having some red shifts compared with the experimental data. Natural bond orbital analyses indicate that the absorption bands are mainly derived from the contribution of n → π* and π → π* transitions. Fluorescence spectra determination shows that the title compound can emit blue-light at about 478 nm. On the basis of vibrational analysis, the thermodynamic properties of title compound at different temperature have been cal-culated, revealing the correlations between C 0 p, m, S 0 m, H 0 m and temperature.
Korean Chem. Soc. 01/2010; 3131.
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ABSTRACT: 3-Phenylamino-4-phenyl-1,2,4-triazole-5-thione was synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction. Density functional theory calculations of the structure, natural bond orbitals, atomic charge distributions and thermodynamic functions of the title compound were performed at B3LYP/ 6-311G** and PBE1PBE/6-311G**levels of theory, respectively. NPA atomic charge distributions indicate that the title compound can be used as a potential multi-dentate ligand to coordinate with various metallic ions. Calculation of the second order optical nonlinearity was also carried out. The thermodynamic properties of C(0)(p,m), S(0)(m) and H(0)(m) were calculated and correlative equations between the thermodynamic properties and temperatures were also obtained.
Molecules 02/2009; 14(2):608-20. · 2.39 Impact Factor
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ABSTRACT: The title compound, C(16)H(13)FO(2), was prepared from 4-methoxy-hypnone and 4-fluoro-benzophenone by Claisen-Schmidt condensation. All the bond lengths and bond angles are in normal ranges. The dihedral angle formed by the two benzene rings is 33.49 (2)°. The crystal packing is stabilized by inter-molecular C-H⋯O hydrogen-bonding inter-actions.
Acta Crystallographica Section E Structure Reports Online 01/2009; 65(Pt 6):o1402. · 0.35 Impact Factor
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ABSTRACT: In the title compound, C(16)H(10)O(6), the complete mol-ecule is generated by a crystallographic centre of symmetry. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into (100) sheets and C-H⋯O links also occur.
Acta Crystallographica Section E Structure Reports Online 01/2009; 65(Pt 11):o2961. · 0.35 Impact Factor
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ABSTRACT: 1-Acetyl-3-(4-chlorophenyl)-5-(4-methylphenyl)-2-pyrazoline has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction. Density functional (DFT) calculations have been carried out for the title compound by using the B3LYP method at the 6-311G** basis set level. The calculated results show that the predicted geometry can reproduce well the structural parameters. Predicted vibrational frequencies have been assigned and compared with experimental IR spectra and they are supported each other. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between C(0)(p, m), S(0)(m), H(0)(m) and temperatures.
Molecules 02/2008; 13(9):2039-48. · 2.39 Impact Factor
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ABSTRACT: A hydrogen-bonded tetramer supramolecular motif of 2:2 benzimidazole (BIZ) and malonic acid (MLA) has been synthesized and characterized by elemental analysis, infrared (IR), and X-ray single crystal diffraction. Thermal stability analyses demonstrate that this supramolecular adduct is a new material and it is not the ordinary superposition of the original monomers. Density function theory (DFT) calculations for the models of dimers, trimers, and tetramer comprising BIZ and MLA have been carried out at B3LYP/6-31G* and PBE1PBE/6-31G* levels of theory, respectively. By comparing the calculated results with the experiments (single crystal structure, IR spectra, and thermal analysis) and based on the statistic thermodymnamic calculations, it is concluded that the dimers cannot exist at room temperature and the tetramer can simulate the title supramolecular complex better than the two trimers. Further studies on the model of tetramer indicate that the hydrogen bond of N···HO is stronger than that of O···HN. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
International Journal of Quantum Chemistry 09/2007; 108(3):521 - 531. · 1.36 Impact Factor
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ABSTRACT: The title compound of [Ni(H2O)6(NaSO4)2] has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallizes
in space group P21/c of the monoclinic system in a cell at 293.2K of a=6.1820(12)Å, b=12.316(3)Å, c=9.0890(18)Å, β=106.03(3)°, and V=665.1(2)Å3. In the title compound, each SO4 tetrahedron coordinates with three Na(I) ions and each Na(I) connects to three SO4 tetrahedrons. Such a coordinate model makes up a two-dimensional network having two different kinds of rings and, in the
bigger rings, the [Ni(H2O)6]2+ ions are located. In the solid state, some hydrogen bonds connect the title compound to form three-dimensional networks,
stabilizing the crystal structure. Thermogravimetric analysis shows that there are three steps of weight loss from the beginning
of 110°C and the residue may be the mixtures of NiO2 and Na2O.
Structural Chemistry 09/2006; 17(5):519-523. · 1.85 Impact Factor
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ABSTRACT: Ab initio calculations of the structure, atomic charges, natural bond orbital, and thermodynamic functions have been performed at HF/6-311G∗∗ and B3LYP/6-311G∗∗ levels of theory for the title compound of 4-phenyl-1-(propan-2-ylidene)thiosemicarbazide. The calculated results show that
the sulfur atom and all of the nitrogen atoms have bigger negative charges and they are the potential sites to react with
the metallic ions, which make the title compound become a multidentate ligand. The coordination ability of the sulfur atom
and the nitrogen atom of C=N double bond will increase with the increase of the polarity of the solvent. Electronic absorption
spectra have been calculated by time-dependent density functional theory (TD-DFT) method. The calculation of the second-order
optical nonlinearity also has been carried out, and the molecular hyperpolarizability is 3.068×10−30 esu.
Structural Chemistry 11/2005; 16(6):635-639. · 1.85 Impact Factor
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ABSTRACT: Isonicotinato cadmium(II) complex [Cd(C6H4NO2)2(H2O)4] has been synthesized by hydrothermal method and characterized by elemental analysis, electronic-spectra and thermogravimetric analysis. Density functional theory (DFT) method calculations of the structure, atomic charges distribution, electronic spectra, natural population analysis and the thermodynamic properties at different temperatures have been performed. The calculated results show the electronic transitions are mainly derived from the contribution of bands π → π* and the decomposition of the title compound should first occur at the bond of Cd—O, then at the bond of Cd—N, which agrees very well with the experimental data.
Structural Chemistry 09/2005; 16(5):529-533. · 1.85 Impact Factor
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ABSTRACT: The title compound, (p-methoxyphenyl)thiosemicarbazide, has been characterized by elemental analysis, IR, electronic spectroscopy, and single-crystal X-ray diffraction. Ab initio calculations of the structure, atomic charges, natural bond orbital, topological analysis, and thermodynamic functions of the title compound were performed at HF/6-311G** and B3LYP/6-311G** levels of theory. The calculated results show that the sulfur atom and nitrogen atoms have bigger negative charges, which result in that they are the potential sites to react with the metallic ions. Electronic absorption spectra were calculated by the time-dependent density functional theory (TD-DFT) and configuration interaction single-excitation (CIS) methods and they are corresponding to the experimental values. The calculation of the second-order optical nonlinearity was carried out, and the molecular hyperpolarizability was 2.59210−30 esu, indicating it is a potential candidate as second-order nonlinear optical material.
Structural Chemistry 01/2005; 16(4):361-367. · 1.85 Impact Factor
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ABSTRACT: The title compound, [Co2(H2PO4)4(C10H8N2)2], is dinuclear, centred on a symmetry centre of the P1 space group. Each Co atom has a distorted square-pyramidal coordination involving two N atoms from a bipyridine molecule and three O atoms from two bridging and one terminal dihydrogen orthophosphate anion. The molecular structure and packing are stabilized by intermolecular hydrogen-bond interactions.
Acta Crystallographica Section C Crystal Structure Communications 08/2004; 60(Pt 7):m348-9. · 0.52 Impact Factor
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Angewandte Chemie International Edition 01/2004; 42(46):5722-4. · 13.45 Impact Factor
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ABSTRACT: The title compound, 2,3-diketo-benzopiperazine, has been synthesized and characterized by elemental analysis, IR, electronic spectroscopy and single crystal X-ray diffraction. Ab initio calculations of the structure, natural bond orbital, topological analysis and thermodynamic functions of the title compound were performed at HF/6-311G** and B3LYP/6-311G** levels of theory. Vibrational frequencies were also predicted, assigned, compared with the experimental values, and they supported each other. Electronic absorption spectra were calculated by the time-dependent density functional theory, which indicates that the two absorption bands are mainly derived from the contribution of bands π→π*. The calculation of the second order optical non-linearity was carried out, and the molecular hyperpolarisability was 3.282×10−30 esu.
Journal of Molecular Structure. 705:133-139.
