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Robabeh Alizadeh

Assistant Professor of Inorganic Chemistry

  • TEL: +98-23-3522-0095
  • Selected Publications

    Alizadeh, R., Amani, V., Seyfi, S., Alemohammad, A., Zarepoor, F., Harms, K. Synthesis, characterization, crystal structure determination and luminescence study of new linear coordination polymers based on Mercury(II), Cadmium(II) and 4,7-phenanthroline ligand (2019) Journal of Molecular Structure, 1175, pp. 450-457.

    DOI: 10.1016/j.molstruc.2018.08.005

    Three novel coordination polymers containing Hg(II) and/or Cd(II) with 4,7-phenanthroline ligand (4,7-phen) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Complexes [Hg(η2-4,7-phen)Br2]n (1), [Hg(η2-4,7-phen)I2]n (2) and [Cd(η2-4,7-phen)I2]n (3) were prepared from the reaction of one equivalent of 4,7-phenanthroline ligand with one equivalent of HgBr2 (1), HgI2 (2) and CdI2 (3), in methanol, respectively. Suitable crystals of title compounds were obtained for X-ray diffraction measurement by methanol diffusion into a DMSO solution. All compounds have linear polymeric structures which extend parallel to the c axis and contain Hg(II) and Cd(II) centers coordinated by two bridging 4,7-phenanthroline ligands, and two coordinated halogen molecules, completing the Hg(II) and Cd(II) coordination spheres, and resulting in a distorted tetrahedral geometry. Furthermore, π-π (in 1–3) and M-I⋯π (in 2 and 3) interactions play crucial role on stabilization of the crystal packing. The luminescence properties of the free ligand as well as the complexes 1–3 were investigated in solution. Thermal stabilities of these complexes were also studied by TGA/DTA analyses. © 2018 Elsevier B.V.

    AUTHOR KEYWORDS: 4,7-Phenanthroline; Cd(II); Coordination polymer; Crystal structure; Hg(II); Luminescence; TGA/DTA analyses
    INDEX KEYWORDS: Bromine compounds; Cadmium compounds; Chelation; Crystal structure; Ligands; Luminescence; Methanol; Polymers; Single crystals; X ray diffraction, 4,7-Phenanthroline; Cd(II); Coordination Polymers; Crystal structure determination; Distorted tetrahedral geometries; Single crystal x-ray diffraction; TGA/DTA analysis; X-ray diffraction measurements, Mercury compounds
    PUBLISHER: Elsevier B.V.

    Seyfi, S., Alizadeh, R., Darvish Ganji, M., Amani, V. Synthesis, spectral and luminescence study, crystal structure determination and DFT calculation of binuclear palladium(II) complexes (2018) Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 190, pp. 298-311.

    DOI: 10.1016/j.saa.2017.09.024

    Binuclear palladium(II) complexes with metal–metal (d8–d8) bonding interaction were synthesized by reactions of the 1-methyl-1H-1,2,3,4-tetrazole-5-thiol (Hmtzt) or a mixture of Hmtzt and 1,3-propanediamine (1,3-pda) ligands. Complex [Pd2(μ-mtzt)4]·2CH3CN (1) was synthesized by the reaction of Pd(OAc)2 with Hmtzt dissolved in acetonitrile and complex [Pd2(μ-mtzt)2(mtzt)2(1,3-pda)] (2) was synthesized by reaction of a mixture of Hmtzt and 1,3-propanediamine (dissolved in methanol) with PdCl2 (dissolved in acetonitrile) and were identified through elemental analysis, IR, UV–Vis, 1H NMR, luminescence spectroscopy as well as single-crystal X-ray diffraction method. A single-crystal of complex 1 shows that two Pd(II) centers are linked together by four bridging tetrazole ligands providing a paddle wheel-like arrangement. Also a crystal structure of complex 2 shows that this complex possesses a symmetric structure in which one Pd atom is tetra-coordinated by four sulfur atoms to forms PdS4 and other Pd atom is tetra-coordinated by four nitrogen to forms PdN4 coordination sphere. Density functional theory (DFT) was performed in this study for the Hmtzt ligand and binuclear palladium(II) complexes (1) and (2). The DFT calculation shows PdII–PdII bond lengths of 2.831 and 3.086 Å in complex 1 and 2, respectively which are close to the observed bond lengths of 2.802(11) and 3.0911(17) Å from single-crystal X-ray structure. The optimized geometry of the complexes is shown good agreement by X-ray data. Structural properties and molecular descriptors including bond lengths, bond angles, chemical hardness, dipole moment, HOMO-LUMO energy levels, electron transfer were analyzed. The IR spectroscopy was performed using VEDA4 software and UV–Vis spectra were analyzed using time-dependent density functional theory (TD-DFT) method. The theoretical and experimental data were also compared with each other. © 2017 Elsevier B.V.

    AUTHOR KEYWORDS: Complex; Crystal structure; DFT; Pd(II); TD-DFT; Tetrazole
    INDEX KEYWORDS: Acetonitrile; Atoms; Bins; Bond length; Chemical analysis; Chemical bonds; Coordination reactions; Crystal atomic structure; Crystal structure; Density functional theory; Dissolution; Geometry; Ligands; Luminescence; Mixtures; Palladium; Single crystals; Synthesis (chemical); X ray diffraction, Complex; Crystal structure determination; Luminescence spectroscopy; Single crystal X-ray diffraction method; Single crystal x-ray structures; TD-DFT; Tetrazoles; Time dependent density functional theory, Palladium compounds
    PUBLISHER: Elsevier B.V.

    Seyfi, S., Alizadeh, R., Ganji, M.D., Amani, V. Palladium(II) complexes with 1,2,4-triazole derivative & ethylene diamine as ligands, synthesis, characterization, luminesence study & crystal structure determination (2017) Polyhedron, 134, pp. 302-315.

    DOI: 10.1016/j.poly.2017.06.034

    Complexes [Pd(aemptrz)Cl2] (1) and [Pd2(μ-mptrz)2(mptrz)2(en)]·CH3OH (2) (where aemptrz is 1‐(1‐(λ2‐azanyl)ethyl)‐4‐methyl‐5‐(λ1‐sulfanyl)‐4H‐1λ4,2,4‐triazole, mptrz is 4-methyl-4H-1,2,4-triazole-3-thiolato and en is ethylene diamine) were synthesized by the reaction of 4-methyl-4H-1,2,4-triazole-3-thiol (Hmptrz) (1) or a mixture of (Hmptrz) and ethylene diamine (2) with PdCl2. Complexes [Pd2(μ-mptrz)4] (3) and [Pd2(μ-mptrz)2(mptrz)2(en)] (4) were obtained by similar methods, but using Pd(OAc)2 instead of PdCl2. The four complexes were thoroughly characterized by elemental analysis, IR, UV–Vis, 1H NMR, luminescence spectroscopy as well as single-crystal X-ray diffraction method. Central Pd(II) ions in 1 are tetra-coordinated by two chloride atom in the cis-positions, one sulfur atom and one nitrogen atom to form PdNSCl2 coordination sphere, presenting slightly distorted square planar geometry around Pd atom. In complex 2, the Pd1 atoms are coordinated to four triazole units via four Pd–S bond (PdS4 square-plane) and the Pd2 atoms are coordinated to two of these triazole units together with the two N atoms of ethylene diamine ligand (PdN4 square-plane). In complex 3 the two Pd(II) centers are connected together by four bridging triazole ligands providing a paddle wheel-like arrangement. The Pd1 atom in complex 4 has a square-planar coordination involving the S atoms from four mptrz− ligands (two terminals and two bridged triazole) and the Pd2 atom is coordinated by two nitrogens of ethylene diamine and two nitrogens of the two bridged triazole ligand. Complex 1 has τ4 value (the geometric parameter) of 0.043, which fits with a slightly distorted square planar geometry. Considering the Pd⋯Pd contact, the stereochemistry of the palladium(II) ion in 2, 3 and 4 suggest a distorted square pyramid with a geometrical factor τ5 = 0.042, 0.013 and 0.040, respectively. The luminescence properties of the free ligand as well as the complexes 1–4 were investigated in solution. © 2017 Elsevier Ltd

    AUTHOR KEYWORDS: 4-Methyl-4H-1,2,4-triazole-3-thiolato; Coordination compound; Crystal structure; Luminescence; Palladium
    PUBLISHER: Elsevier Ltd

    Amani, V., Alizadeh, R., Alavije, H.S., Heydari, S.F., Abafat, M. Mononuclear mercury(II) complexes containing bipyridine derivatives and thiocyanate ligands: Synthesis, characterization, crystal structure determination, and luminescent properties (2017) Journal of Molecular Structure, 1142, pp. 92-101.

    DOI: 10.1016/j.molstruc.2017.04.034

    A series of mercury(II) complexes, [Hg(N[sbnd]N)(SCN)2] (N[sbnd]N is 4,4′-dimethyl-2,2′-bipyridine in 1, 5,5′-dimethyl-2,2′-bipyridine in 2, 6,6′-dimethyl-2,2′-bipyridine in 3 and 6-methyl-2,2′-bipyridine in 4), were prepared from the reactions of Hg(SCN)2 with mentioned ligands in methanol. Suitable crystals of these complexes were obtained for X-ray diffraction measurement by methanol diffusion into a DMSO solution. The four complexes were thoroughly characterized by spectral methods (IR, UV–Vis, 13C{1H}NMR, 1H NMR and luminescence), elemental analysis (CHNS) and single crystal X-ray diffraction. The X-ray structural analysis indicated that in the structures of these complexes, the mercury(II) cation is four-coordinated in a distorted tetrahedral configuration by two S atoms from two thiocyanate anions and two N atoms from one chelating 2,2′-bipyridine derivative ligand. Also, in these complexes intermolecular interactions, for example C[sbnd]H⋯N hydrogen bonds (in 1–4), C[sbnd]H⋯S hydrogen bonds (in 1, 2 and 4), π … π interactions (in 2–4), Hg⋯N interactions (in 2) and S⋯S interactions (in 4), are effective in the stabilization of the crystal structures and the formation of the 3D supramolecular complexes. Furthermore, the luminescence spectra of the title complexes show that the intensity of their emission bands are stronger than the emission bands for the free bipyridine derivative ligands. © 2017 Elsevier B.V.


    AUTHOR KEYWORDS: Bipyridine derivative ligands; Crystal structure; Luminescence spectroscopy; Mercury(II) complexes
    INDEX KEYWORDS: Chelation; Complexation; Coordination reactions; Crystal structure; Hydrogen bonds; Ligands; Luminescence; Mercury (metal); Methanol; Single crystals; Spectroscopy; Synthesis (chemical); X ray diffraction, Bipyridines; Crystal structure determination; Intermolecular interactions; Luminescence spectroscopy; Mercury complex; Single crystal x-ray diffraction; Tetrahedral configurations; X-ray diffraction measurements, Crystal atomic structure
    PUBLISHER: Elsevier B.V.

    Seyfi, S., Alizadeh, R., Ganji, M.D., Amani, V. Molecular, electronic structure and spectroscopic properties of 6,6′-dimethyl-2,2′-bipyridine and HgI2 complex: Experimental and DFT investigations (2017) Vacuum, 139, pp. 9-22.

    DOI: 10.1016/j.vacuum.2017.02.002

    Transition metal–bipyridine complexes have been considered for use in various applications including catalysis, luminescent sensors, artificial photosynthesis, electrochemistry, nonlinear optical materials and organic light emitting diodes. Bipyridine derivative complexes have been studied from both experimental and theoretical point of views. In this study, we have carried out density functional theory (DFT) calculations for geometry optimization, charge distribution, molecular orbital description, energy gap, chemical hardness η and vibrational frequencies (IR) were performed at B3LYP level of theory for synthesized [HgI2(dmbpy)] (dmbpy is 6,6′-dimethyl-2,2′-bipyridine) complex. The calculated vibrational frequencies were found to be in reasonable to good agreement with experimental values. The vibrational modes obtained from solid-phase FT–IR spectra could be assigned based on our theoretical calculations. Using time-dependent DFT (TD-DFT) calculations the UV-Vis and electronic spectra of [HgI2(dmbpy)] were predicted to be in agreement with experimental data. Based on the description of the frontier molecular orbitals and the shifts in electron density during complexation, bonding characteristics in the complex were determined. Furthermore the π-π stacking interactions between the pyridine rings of adjacent molecules were investigated. Our DFT calculations show that van der Waals forces play an important role in the π-π stacking interactions for the [HgI2(dmbpy)] complex. © 2017 Elsevier Ltd

    AUTHOR KEYWORDS: DFT; Electronics structure; IR spectra; Structural properties; UV-Vis spectra; [HgI2(dmbpy)]
    INDEX KEYWORDS: Chemical bonds; Electronic structure; Light emitting diodes; Molecular orbitals; Optical materials; Organic light emitting diodes (OLED); Structural properties; Transition metals; Van der Waals forces, Artificial photosynthesis; Bonding characteristics; Frontier molecular orbitals; IR spectrum; Non-linear optical material; Theoretical calculations; UV-vis spectra; [HgI2(dmbpy)], Density functional theory
    PUBLISHER: Elsevier Ltd

    Alizadeh, R., Amani, V. Syntheses, crystal structures, and photoluminescence of three cadmium(II) coordination complexes based on bipyridine ligands with different positioned methyl substituents (2016) Inorganica Chimica Acta, 443, pp. 151-159.

    DOI: 10.1016/j.ica.2015.12.034

    Three new cadmium(II) complexes, [Cd(5,5′-dmbipy)2(η2-NO3)2] (1), [Cd(6-mbipy)2(η2-NO3)(η-NO3)] (2) and [Cd(6,6′-dmbipy)2(η2-NO3)][Cd(6,6′-dmbipy)(η2-NO3)3] (3) were prepared from the reaction of Cd(NO3)2·4H2O with 5,5′-dmbipy (5,5′-dimethyl-2,2′-bipyridine), 6-mbipy (6-methyl-2,2′-bipyridine) and 6,6′-dmbipy (6,6′-dimethyl-2,2′-bipyridine) ligands in a mixture of CH3CN and CH3OH (1:1) at 40 °C, respectively. The three complexes were thoroughly characterized by elemental analysis, IR, UV-Vis, 1H and 13C{1H}NMR spectroscopy and their structures were studied by the single-crystal diffraction method. We are interested in influencing the structure, as well as the optical properties of the complexes by means of changing the position of the methyl substituent on the bipyridine (bipy) ring, which is to be determined using X-ray crystal structure determination and luminescence studies. These studies revealed that upon coordination to Cd(II) the luminescent intensity is enhanced in comparison with the related unbound ligands. Furthermore, through intermolecular weak interactions, for example, C-H-O hydrogen bonding (1-3), π-π stacking (1-2) and C-H-π interaction (1-2), 3D supramolecular structures are assembled in these compounds. © 2015 Elsevier Ltd. All rights reserved.

    AUTHOR KEYWORDS: Cadmium(II); Complex; Crystal structure; Luminescent properties; Methyl-substituted 2,2′-bipyridine ligands; π-Stacking
    PUBLISHER: Elsevier S.A.

    Alizadeh, R., Hafezeffati, S., Amani, V., Khavasi, H.R., Harms, K. Synthesis, characterization, crystal structure determination, and luminescence properties of two new gold(III) complexes with phenanthridine ligand (2015) Monatshefte fur Chemie, 146 (4), pp. 581-589.

    DOI: 10.1007/s00706-014-1348-9

    Two new gold(III) complexes of phenanthridine (phend) ligand, gold(III) trichlorophenanthridine ([Au(phend)Cl3]) and gold(III) tribromophenanthridine ([Au(phend)Br3]), have been synthesized from the reaction of HAuCl4•3H2O and AuBr3 with phend, respectively, and characterized by elemental analysis, luminescence, IR, 1H and 13C NMR spectroscopy, and their structures were studied by the single-crystal diffraction method. [Au(phend)Cl3] crystallizes in the space group P21/n of the monoclinic system with a = 7.6661(7) Å, b = 20.816(2) Å, c = 17.4906(16) Å, β = 98.500(7)°, and Z = 8. [Au(phend)Br3] crystallizes in the space group Pi¯ of the triclinic system with a = 10.2137(4) Å, b = 11.1191(4) Å, c = 14.6540(6) Å, α = 68.631(3), β = 71.706(3), γ = 66.098(3)°, and Z = 4. There are two molecules of the complex in the asymmetric units and in both molecules, the geometry at the gold(III) centers is square planar, formed by one nitrogen atom of phend and three chloride or bromide ions. Weak hydrogen bonding, π-π interaction, together with interhalogen contact, may play an important role in determining the structure of both complexes. © 2014 Springer-Verlag Wien.


    AUTHOR KEYWORDS: Crystal structure; Fluorescence; Gold(III); Phenanthridine
    PUBLISHER: Springer-Verlag Wien

    Darvish Ganji, M., Shokri, M., Alizadeh, R., Khademaboulfazli, M. Structural and electronic properties of supramolecular C60:RU(II)(bipy)3:C60 triad: Ab initio van der Waals calculations (2015) Physica E: Low-Dimensional Systems and Nanostructures, 69, pp. 384-393.

    DOI: 10.1016/j.physe.2015.02.012

    We have investigated the influence of non-local dispersion interactions and temperature on the structure and electronic properties of Ru(bipy)3-(C60)2 triad using the ab initio van der Waals density functional (vdW-DF) calculations. It was found that non-local dispersion interactions affects slightly on the structural geometry and charge transfer property of the system under study. Therefore, it's not necessary to consider dispersion interactions which are computationally more expensive than the conventional DFT calculations for the presented supramolecules. The obtained results from the ab initio MD simulations indicated that structural property of respected molecule varies at various temperatures. The Mulliken charge analyses show a remarkable charge transfer about 0.64 electrons between Ru (bipy)3-bridges as donors and fullerenes as acceptors entities in the isolated molecule by increasing the temperature, the charge transfer was also increased. Our first-principles results for the isolated complex showed that the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) states were located on the fullerene spheroid and thus the charge separation (orbital localization) is not desirable. However, increasing of temperature causes the LUMO's to localize on the acceptor moieties (fullerenes) and the HOMO's on the donor moieties (Ru(bipy)3). From the results obtained for the molecular orbitals we found that the best distribution is occurred at ambient condition (300 K). © 2015 Elsevier B.V.All rights reserved.
    AUTHOR KEYWORDS: ab initio MD simulations; DFT; Fullerenes; Solar cells; Supramolecule; van der Waals forces

    INDEX KEYWORDS: Calculations; Charge transfer; Dispersions; Electromagnetic dispersion; Electronic properties; Fullerenes; Molecular orbitals; Molecules; Ruthenium alloys; Solar cells; Van der Waals forces, Charge transfer properties; DFT; Dispersion interaction; Highest occupied molecular orbital; Lowest unoccupied molecular orbital; MD simulation; Structural and electronic properties; Supramolecules, Structural properties
    PUBLISHER: Elsevier

    Zarei, K., Alinejad, M., Alizadeh, R. Simultaneous voltammetric determination of Mo(VI) and W(VI) by adsorptive differential pulse stripping method using adaptive neuro-fuzzy inference system (2013) Journal of Analytical Chemistry, 68 (10), pp. 885-890.

    DOI: 10.1134/S1061934813100134

    An adsorptive differential pulse stripping method is proposed for the simultaneous determination of molybdenum and tungsten based on the formation of their complexes with a novel proton transfer compound, [phenH] +[pyzdc]-, containing both pyrazine-2,3-dicarboxylic acid and 1,10-phenanthroline. The optimum experimental conditions were obtained using 0.052 mM [phenH]+[pyzdc]- ligand, pH 3.3, accumulation potential of -0.1 V versus Ag/AgCl, accumulation time of 60 s and scan rate of 33.3 mV/s. An adaptive neuro-fuzzy inference system (ANFIS) was utilized for the analysis of the voltammogram data. The detection limits were 4.0 ng/mL for Mo(VI) and 3.0 ng/mL for W(VI). The influence of potential interfering ions on the determination of molybdenum and tungsten was studied. The procedure was applied to the simultaneous determination of molybdenum and tungsten in some water samples. © 2013 Pleiades Publishing, Ltd.

    AUTHOR KEYWORDS: 1,10-phenanthroline; adaptive neuro-fuzzy inference system; molybdenum; pyrazine-2,3-dicarboxylic acid; simultaneous voltammetric determination; tungsten
    INDEX KEYWORDS: 1 ,10-phenanthroline; Adaptive neuro-fuzzy inference system; Determination of molybdenum; Differential pulse; Experimental conditions; Proton-transfer compounds; Simultaneous determinations; Voltammetric determination, Molybdenum; Tracking (position); Tungsten, Fuzzy systems

    Moradi, S., Ajloo, D., Lashkarbolouki, T., Alizadeh, R., Saboury, A.A. Physicochemical studies on the interaction of gold(III) trichlorophenanthridine complex with calf thymus DNA (2013) Monatshefte fur Chemie, 144 (10), pp. 1499-1505.

    DOI: 10.1007/s00706-013-1032-5

    The interaction of gold(III) trichlorophenanthridine complex, [Au(phend)Cl3], with calf thymus DNA was investigated by UV-Vis absorption, circular dichroism, and fluorescence spectrophotometery as well as viscometry, cyclic voltammetry (CV), and molecular docking. The values of binding constants K b (obtained by UV-Vis) and K f (obtained by fluorescence) are 3 × 104 and 7.68 × 10 5 M-1, respectively. Evidence for intercalation comprised a hyperchromic effect at 210 nm and a hypochromic effect at 250 nm caused by the ligand, increasing the T m of DNA, increasing of viscosity, increasing the intensity of the positive peak, decreasing the intensity of the negative peak, and the positive shift of the cathodic peak potential in CV. © 2013 Springer-Verlag Wien.

    AUTHOR KEYWORDS: DNA; Fluorescence spectroscopy; Gold complex; Intercalation compounds; Ligand docking

    Zakavi, S., Rahiminezhad, H., Ghanbelanie Mojarrad, A., Mokary Yazdeli, T., Alizadeh, R. Effects of core and/or peripheral protonation of meso -tetra(2-, 3-, and 4-pyridyl)porphyrin and meso -tetra(3-methylpyridyl)porphyrin on their UV-vis spectra (2013) Journal of Spectroscopy, 1 (1), art. no. 713745, .

    DOI: 10.1155/2013/713745

    Core and/or peripheral protonation of meso-tetra(pyridyl)porphyrins, H 2(py)P, with weak and strong acids have been studied by UV-vis spectroscopy. The results support the proposal that the position of the Soret as well as the Q(0,0) bands of the dications is influenced by π donation from the meso substituents to the porphyrin core. The red shift of the Q(0,0) band of H2t(py)P dications with 2-, 3-, and 4-pyridyl substituents does not correlate with the order of π electron donor ability of the meso groups. The decreased electron donation from the central nitrogen atoms to the acids on going from 3-pyridyl group to 4- and 2-pyridyl ones has been used to explain this observation. In spite of the negative effect of N-methylation of pyridyl substituents on the basicity of the central nitrogen atoms of meso-tetra(3-methylpyridyl)porphyrin, H2t(3-Mepy)P, protonation of H2t(3-Mepy)P occurs with weak and strong acids. The blue shift of the Q(0,0) bands upon protonation of H2t(3-Mepy)P with weak and strong acids clearly shows the importance of resonance interactions between the π-systems of porphyrin and the aryl substituents on the position of the band. © 2013 Saeed Zakavi et al.

    INDEX KEYWORDS: Aryl substituents; Electron donation; Electron donors; N-methylation; Nitrogen atom; Resonance interaction; UV-vis spectra; UV-vis spectroscopy, Alkylation; Nitrogen; Protonation; Substitution reactions; Ultraviolet visible spectroscopy, Porphyrins, acid; nitrogen; porphyrin, article; electron; methylation; proton transport; ultraviolet spectroscopy

    Shahabadi, N., Mohammadi, S., Alizadeh, R. DNA interaction studies of a new platinum(II) complex containing different aromatic dinitrogen ligands (2011) Bioinorganic Chemistry and Applications, 2011, art. no. 429241, .

    DOI: 10.1155/2011/429241

    A new mononuclear Pt(II) complex, [Pt(DMP)(DIP)]Cl 2.H 2O, in which DMP is 4,4-dimethyl-2,2-bipyridine and DIP is 4,7-diphenyl-1,10-phenantroline, has been synthesized and characterized by physicochemical and spectroscopic methods. The binding interaction of this complex with calf thymus DNA (CT-DNA) was investigated using fluorimetry, spectrophotometry, circular dichroism, viscosimetry and cyclic voltametry (CV). UV-VIS spectrum showed 4nm bathochromic shift of the absorption band at 280nm along with significant hypochromicity for the absorption band of the complex. The intrnisic binding constant (K b = 2 × 10 4 M -1) is more in keeping with intercalators and suggests this binding mode. The viscosity measurements showed that the complex-DNA interaction can be hydrophobic and confirm intercalation. Moreover, the complex induced detectable changes in the CD spectrum of CT-DNA. The fluorescence studies revealed that the probable quenching mechanism of fluorescence of the complex by CT-DNA is static quenching. The thermodynamic parameters (ΔH>0 and ΔS>0) showed that main interaction with hydrogenic forces occurred that is intercalation mode. Also, CV results confirm this mode because, with increasing the CT-DNA concentration, shift to higher potential was observed. Copyright © 2011 Nahid Shahabadi et al.

    Alizadeh, R., Amani, V. Two new lead(II) coordination polymer and discrete complex containing bipyridine ligands with different positioned methyl substituents: Synthesis, characterization, crystal structure determination, and luminescent properties (2011) Structural Chemistry, 22 (5), pp. 1153-1163.

    DOI: 10.1007/s11224-011-9809-9

    Lead(ll) coordination polymer [Pb(5,5′-dmbpy) (μ-NO 3)2],n (1) and mononuclear complex [Pb(6,6′-dmbpy) (NO3)2] (2) (where 5,5′-dmbpy is 5,5′-dimethyl-2,2′- bipyridine and 6,6′-dmbpy is 6,6′-dimethyl-2,2′-bipyridine) were synthesized from reaction of lead(II) nitrate with 5,5′-dmbpy and 6,6′-dmbpy, respectively. Both complexes were thoroughly characterized by elemental analysis, infrared, 'H and '3C NMR, UV-Vis, emission spectroscopy, as well as single-crystal X-ray diffraction. Polymer 1 possesses one-dimensional (ID) chain structure, whilst complex 2 exhibits a discrete complex which provide an extended chain parallel to the [001] direction via weak intermolecular C-H-0 hydrogen bonding. Coordination number of Pb2+ in 1 and 2 are 8 and 6, respectively, with the stereochemically active lone pair, resulting in the hemidirected geometry for both complexes. The nitrate anions exhibit a tridentate chelating/bridging mode in 1, and a bi-chelating mode in 2. The supramolecular features in these complexes are guided/influenced by weak directional intermolecular C-H-0 hydrogen bonding (1 and 2) together with π- π and C-H-π (1) interactions. The luminescence studies of 1 and 2 confirmed that the position of methyl substituent on 2,2′-bipyridine rings has a profound effect on the fluorescence emissions. © Springer Science+Business Media, LLC 2011.

    AUTHOR KEYWORDS: Coordination polymer; Crystal structure; Lead(II); Luminescent properties; Methyl-substituted 2'20-bipyridine ligands

    Alizadeh, R., Seifi, S., Amani, V. (6,6′-Dimethyl-2,2′-bipyridine-κ2 N,N′)diiodidomercury(II) (2011) Acta Crystallographica Section E: Structure Reports Online, 67 (3), pp. m305.

    DOI: 10.1107/S1600536811004041

    In the title complex, [HgI2(C12H12N 2)], the HgII atom has a distorted tetrahedral coordination formed by two N atoms of the 6,6′-dimethyl-2,2′- bipyridine ligand and two terminal I atoms [N - Hg - N = 70.1 (2) and I - Hg - I = 130.59 (3)°]. The crystal packing features π-π contacts between the pyridine rings of adjacent molecules [centroid-centroid distance = 3.773 (5) Å] and also between a pyridine ring of one molecule and the five-membered chelate ring of an adjacent molecule [centroid-centroid distance = 3.668 (4) Å].

    Zakavi, S., Rahiminezhad, H., Alizadeh, R. Hydrogen bond controlled adduct formation of meso-tetra(4-sulfonatophenyl) porphyrin with protic acids: A UV-vis spectroscopic study (2010) Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 77 (5), pp. 994-997.

    DOI: 10.1016/j.saa.2010.08.036

    Interaction of meso-tetra(4-sulfonatophenyl)porphyrin (H 2tppS 4) with weak and strong protic acid have been studied by UV-vis spectroscopy in water, dichloromethane and methanol. Different shifts of the Soret and Q(0,0) bands in the three solvents, the aggregation of diprotonated species and the stability of porphyrin-acid adducts in the solution, may be explained by the inter- and intramolecular hydrogen bonds. Whilst, the addition of excess amounts of tetra-n-butylammonium chloride to H 2tppS 4(Cl) 2 in dichloromethane has little to no effect on the UV-vis spectrum of the dication, gradual addition of tetra-n-butylammonium hydrogen sulfate to the dichloromethane solution of H 2tppS 4(H 2SO 4) 2 leads to the degradation of adducts and the release of porphryin. The results of this study clearly show the crucial role played by hydrogen bonds between the porphyrin diprotonated species and the counter ion in the stability of porphyrin diacids in solution. © 2010 Elsevier B.V. All rights reserved.

    AUTHOR KEYWORDS: Hydrogen bond; meso-Tetraarylporphyrins; Porphyrin dication; Q(0,0) band; Saddling; Soret band; Water soluble porphyrin
    INDEX KEYWORDS: meso-Tetraarylporphyrins; Q(0,0) band; Saddling; Soret bands; Water soluble porphyrin, Acids; Dichloromethane; Hydrogen; Methanol; Porphyrins; Protonation; Spectroscopic analysis; Ultraviolet spectroscopy, Hydrogen bonds, acid; cation; dichloromethane; inorganic salt; porphyrin; proton; quaternary ammonium derivative; solvent; tetra n butylammonium chloride; tetra-n-butylammonium chloride; tetraphenylporphine sulfonate; water, article; biological model; chemistry; conformation; drug effect; hydrogen bond; macromolecule; metabolism; methodology; ultraviolet spectrophotometry, Acids; Cations; Hydrogen Bonding; Macromolecular Substances; Methylene Chloride; Models, Biological; Molecular Conformation; Porphyrins; Protons; Quaternary Ammonium Compounds; Salts; Solvents; Spectrophotometry, Ultraviolet; Water

    Alizadeh, R., Mohammadi Eshlaghi, P., Amani, V. Dichlorido(6,6′-dimethyl-2,2′-bipyridine-κ2N, N′)cadmium(II) (2010) Acta Crystallographica Section E: Structure Reports Online, 66 (8), pp. m1024.

    DOI: 10.1107/S1600536810029399

    In the title compound, [CdCl2(C12H12N 2)], the CdII atom is four-coordinated in a distorted tetra-hedral geometry by two N atoms from a 6,6′-dimethyl-2,2′- bipyridine ligand and two terminal Cl atoms. Inter-molecular C - H⋯Cl hydrogen bonds and π-π stacking inter-actions between the pyridyl rings [centroid-centroid distance = 3.7337 (18) Å] are present in the crystal structure.

    INDEX KEYWORDS: Tetra

    Alizadeh, R., Mohammadi Eshlaghi, P., Amani, V. Dibromido(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)zinc(II) (2010) Acta Crystallographica Section E: Structure Reports Online, 66 (8), pp. m996.
    https://www.scopus.com/inward/record.uri?eid=2-s2.0-77956842285&doi=10.1107%2fS1600536810028692&partnerID=40&md5=882469e1a2e803c503524e0c72a7b156

    DOI: 10.1107/S1600536810028692

    The asymmetric unit of the title compound, [ZnBr2(C 12H12N2)], contains two half-molecules; both are completed by crystallographic twofold axes running through the Zn II atoms which are coordinated by an N,N′-bidentate 4,4′-dimethyl-2,2′-bipyridine ligand and two Br- ions, resulting in distorted ZnN2Br2 tetrahedral coordination geometries. In the crystal, C - H⋯Br interactions link the molecules.

    Alizadeh, R., Amani, V., Akbar Farshady, A., Reza Khavasi, H. Synthesis, characterization, and crystal structure determination of two mercury(II) dimer complexes with 4,7-diphenyl-1,10-phenanthroline, 5,5'-dimethyl-2,2'-bipyridine and bromide (2010) Journal of Coordination Chemistry, 63 (12), pp. 2122-2131.

    DOI: 10.1080/00958972.2010.496128

    Mercury(II) complexes, {[Hg(Ph2phen)(-Br)]2Br 2} CH3CN (1) and {[Hg(dmbpy)(-Br)]2Br 2}(2) (where Ph2phen is 4,7-diphenyl-1,10-phenanthroline and dmbpy is 5,5'-dimethyl-2,2'-bipyridine), were synthesized from reaction of HgBr2 with Ph2phen and dmbpy in CH3CN and CH3OH. Both complexes were thoroughly characterized by elemental analysis, infrared, 1H and 13C NMR spectroscopy and single-crystal X-ray diffraction. Complexes 1 and 2 crystallize in the space group P21/n of the monoclinic and P1 of the triclinic systems and contain four and one molecules per unit cell, respectively. The unit cell dimensions for 1 are: a = 20.422(4)Å , b = 11.384(2)Å, c = 20.665(4)Å, and ß= 109.94(3)° and for 2 are: a = 8.7470(17)Å , b = 8.8328(18)Å, c = 9.4950(19)Å and α= 75.47(3)°, ß= 82.21(3)°, y= 85.56(3)°. According to X-ray structure determination both complexes are five coordinate with three bromides and one bidentate ligand; one bromide is set at a semi-bridging position. © 2010 Taylor & Francis.

    AUTHOR KEYWORDS: 4,7-diphenyl-1,10-phenanthroline; 5,5'-dimethyl-2,2'-bipyridine; Crystal structure; Mercury(II)

    Alizadeh, R., Kalateh, K., Khoshtarkib, Z., Ahmadi, R., Amani, V. (6,6′-Dimethyl-2,2′-bipyridine-κ2 N,N′)diiodidozinc(II) (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (11), pp. m1439-m1440.

    DOI: 10.1107/S1600536809043049

    The complete mol-ecule of the title compound, [ZnI2(C12H 12N2)], is generated by crystallograpic twofold symmetry, with the ZnII atom lying on the rotation axis. The ZnII atom is coordinated by the N,N-bidentate 6,6′-dimethyl-2,2′- bipyridine ligand and two iodide ions, resulting in a distorted ZnN 2I2 tetra-hedral geometry for the metal. In the crystal, there are weak π-π contacts between the pyridine rings [centroid-centroid distance = 3.978 (3) Å].

    INDEX KEYWORDS: Tetra

    Alizadeh, R., Khoshtarkib, Z., Chegeni, K., Ebadi, A., Amani, V. Dibromido(6,6′-dimethyl-2,2′-bipyridine-κ2 N,N′)zinc(II) (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (11), pp. m1311.

    DOI: 10.1107/S1600536809039610

    In the title compound, [ZnBr2(C12H12N 2)], the ZnII atom is four-coordinated in a distorted tetra-hedral arrangement by an N,N′-bidentate 6,6′-dimethyl-2, 2′-bipyridine ligand and two bromide ions. In the crystal, there are aromatic π-π contacts between the pyridine rings [centroid-centroid distances = 3.818 (3) and 3.728 (4) Å].

    INDEX KEYWORDS: Tetra

    Ahmadi, R., Kalateh, K., Alizadeh, R., Khoshtarkib, Z., Amani, V. Tetra-kis(6-methyl-2,2′-bipyridine)-12 N,N′2 2 N,N′32 N,N′42 N,N′-tetra- nitrato-1:22 O:O′2:33 O:O′,O′′2: 33 O,O′:O′′3:42 O:O′-tetra- nitrato-14 O,O′42 O,O′-tetra-lead(II) (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (10), pp. m1169-m1170.

    DOI: 10.1107/S160053680903459X

    In the tetranuclear centrosymmetric title compound, [Pb4(NO 3)8(C11H10N2)4], irregular PbN2O5 and PbN2O4 coordination polyhedra occur. The hepta-coordinated lead(II) ion is bonded to two bidentate and one monodentate nitrate ion and one bidentate 6-methyl-2,2′-bipyridine (mbpy) ligand. The six-coordinate lead(II) ion is bonded to one bidentate and two monodentate nitrate anions and one mbpy ligand. In the crystal, bridging nitrate anions lead to infinite chains propagating in [111]. A number of C- H⋯O hydrogen bonds may stabilize the structure.

    INDEX KEYWORDS: Tetra

    Alizadeh, R., Kalateh, K., Ebadi, A., Ahmadi, R., Amani, V. Dichlorido(6,6′-dimethyl-2,2′-bipyridine-2 N,N′)zinc(II) (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (10), pp. m1250.

    DOI: 10.1107/S1600536809038215

    In the title compound, [ZnCl2(C12H12N2)], the complete mol-ecule is generated by crystallographic mirror symmetry, with the Zn atom and both chloride ions lying on the reflecting plane, yielding a distorted ZnN 2Cl2 tetra-hedral coordination for the metal ion. In the crystal, there are π-π contacts between the pyridine rings [centroid-centroid distance = 3.7857 (17) Å].

    INDEX KEYWORDS: Tetra

    Ahmadi, R., Kalateh, K., Alizadeh, R., Khoshtarkib, Z., Amani, V. Dichlorido(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline-2 N,N′)mercury(II) acetonitrile hemisolvate (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (8), pp. m848-m849.

    DOI: 10.1107/S1600536809024180

    The asymmetric unit of the title compound, [HgCl2(C 26H20N2)]·0.5CH3CN, contains two crystallographic-ally independent [HgCl2(C26H 20N2)] molecules and one acetonitrile solvent molecule. The HgII atoms are four-coordin-ated in distorted tetra-hedral configurations by two N atoms from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline ligands and two Cl atoms. The ligand ring systems are not planar. The phenyl rings are oriented at dihedral angles of 74.61 (3) and 66.00 (3)° in the two molecules. In the crystal structure, π-π contacts between phenanthroline rings [centroid-centroid distances = 3.809 (1), 3.686 (1), 3.986 (1), 3.877 (1), 3.697 (1), 3.789 (1), 3.745 (1), 3.797 (1) and 3.638 (1) Å] may stabilize the structure. © 2009 Ahmadi et al.

    INDEX KEYWORDS: Tetra

    Alizadeh, R. (2,9-Dimethyl-4,7-diphenyl-1,10-phen-anthroline-κ2 N,N′)bis-(thiocyanato-κS)mercury(II) (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (7), pp. m817-m818.

    DOI: 10.1107/S1600536809023228

    In the mol-ecule of the title compound, [Hg(NCS)2(C 26H20N2)], the HgII atom is four-coordinated in a distorted tetra-hedral configuration by two N atoms from a chelating 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline ligand and by two S atoms from two thio-cyanate anions. The ligand ring system is not planar. The dihedral angle between the phenyl rings is 53.20 (3)°. In the crystal structure, π-π contacts between phenanthroline rings [centroid-centroid distance = 3.981 (1) Å] may stabilize the structure.

    INDEX KEYWORDS: Tetra

    Khoshtarkib, Z., Ebadi, A., Ahmadi, R., Alizadeh, R. 5,5′-Dimethyl-2,2′-bipyridine (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (7), pp. o1586.

    DOI: 10.1107/S1600536809019151

    The asymmetric unit of the title compound, C12H 12N2, contains two half-molecules related by an inversion center, the planes of their pyridine rings being oriented at a dihedral angle of 69.62 (4)°. In the crystal structure, a π-π contact between the pyridine rings [centroid-centroid distance = 3.895 (3) Å] may stabilize the structure. A weak C-H⋯π inter-action is also found.

    Khoshtarkib, Z., Ebadi, A., Alizadeh, R., Ahmadi, R., Amani, V. Dichloridobis(phenanthridine-κN)zinc(II) (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (7), pp. m739-m740.
    https://www.scopus.com/inward/record.uri?eid=2-s2.0-67650832290&doi=10.1107%2fS160053680901959X&partnerID=40&md5=2505bda834d88649cde0fd86c317ed74

    DOI: 10.1107/S160053680901959X

    In the mol-ecule of the title compound, [ZnCl2(C 13H9N)2], the ZnII atom is four-coordinated in a distorted tetra-hedral configuration by two N atoms from two phenanthridine ligands and by two terminal Cl atoms. The dihedral angle between the planes of the phenanthridine ring systems is 69.92 (3)°. An intra-molecular C - H⋯Cl inter-action results in the formation of a planar five-membered ring, which is oriented at a dihedral angle of 8.32 (3)° with respect to the adjacent phenanthridine ring system. In the crystal structure, π-π contacts between the phenanthridine systems [centroid-centroid distances = 3.839 (2), 3.617 (1) and 3.682 (1) Å] may stabilize the structure. Two weak C - H⋯π inter-actions are also found.

    INDEX KEYWORDS: Tetra

    Alizadeh, R., Heidari, A., Ahmadi, R., Amani, V. Dibromido(2,9-dimethyl-1,10-phenanthroline-κ2 N,N′)mercury(II) (2009) Acta Crystallographica Section E: Structure Reports Online, 65 (5), pp. m483-m484.

    DOI: 10.1107/S1600536809009994

    In the mol-ecule of the title compound, [HgBr2(C14H12N2)], the Hg II atom is four-coordinated in a distorted tetra-hedral configuration by two N atoms from a 2,9-dimethyl-1,10-phenanthroline ligand and by two Br atoms. In the crystal structure, weak inter-molecular C - H⋯Br hydrogen bonds link the mol-ecules into chains along the b axis. There are π-π contacts between the phenanthroline rings [centroid-centroid distances = 3.806 (4), 3.819 (4), 3.739 (3), 3.690 (3), 3.619 (4) and 3.674 (3) Å].

    INDEX KEYWORDS: Tetra

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