WorldWideScience

Sample records for bipyridines

  1. Synthesis and complexation characteristics of phenanthroline and bipyridine diols

    NARCIS (Netherlands)

    Koning, B.; Boer, J.W. de; Meetsma, A.; Kellogg, R.M.

    2004-01-01

    Neocuproine (2,9-dimethyl-1,10-phenanthroline) 1 was converted to achiral and chiral tetradentate phenanthroline diols 3a-c by addition to benzophenone, adamantanone and camphor, respectively. Analogously 6,6'-dimethyl-2,2'-bipyridine 2 was converted to diol 7a on base-induced addition to benzopheno

  2. Forces and conductances in a single-molecule bipyridine junction

    DEFF Research Database (Denmark)

    Stadler, Robert; Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

    2005-01-01

    Inspired by recent measurements of forces and conductances of bipyridine nanojunctions, we have performed density functional theory calculations of structure and electron transport in a bipyridine molecule attached between gold electrodes for seven different contact geometries. The calculations...... show that both the bonding force and the conductance are sensitive to the surface structure, and that both properties are in good agreement with experiment for contact geometries characterized by intermediate coordination of the metal atoms corresponding to a stepped surface. The conductance...... is mediated by the lowest unoccupied molecular orbital, which can be illustrated by a quantitative comparison with a one-level model. Implications for the interpretation of the experimentally determined force and conductance distributions are discussed....

  3. Crystal structure of bis(2,2′-bipyridine-κ2N,N′)bis(thiocyanato-κN)manganese(II) 2,2′-bipyridine monosolvate

    OpenAIRE

    Stefan Suckert; Inke Jess; Christian Näther

    2015-01-01

    In the crystal structure of the mononuclear title compound, [Mn(NCS)2(C10H8N2)2]·C10H8N2, the MnII cation is coordinated in an all-cis configuration by two N-bound thiocyanate anions and two 2,2′-bipyridine ligands within a slightly distorted octahedral environment. The asymmetric unit consists of one MnII cation, two thiocyanate anions and two 2,2′-bipyridine ligands, as well as two non-coordinating 2,2′-bipyridine ligands that are each located on centres of inversion. In the crystal structu...

  4. The adsorption of bipyridine molecules on Au(110) as measured by reflection anisotropy spectroscopy

    International Nuclear Information System (INIS)

    The reflection anisotropy spectra of 2, 2'-bipyridine and 4, 4'-bipyridine adsorbed onto an Au(110) surface in an electrochemical cell demonstrate that both systems form ordered structures. It is shown that reflection anisotropy spectroscopy can be used to distinguish between structural isomers adsorbed on the Au(110) surface

  5. Evaluation of Tris-Bipyridine Chromium Complexes for Flow Battery Applications: Impact of Bipyridine Ligand Structure on Solubility and Electrochemistry.

    Science.gov (United States)

    Cabrera, Pablo J; Yang, Xingyi; Suttil, James A; Brooner, Rachel E M; Thompson, Levi T; Sanford, Melanie S

    2015-11-01

    This report describes the design, synthesis, solubility, and electrochemistry of a series of tris-bipyridine chromium complexes that exhibit up to six reversible redox couples as well as solubilities approaching 1 M in acetonitrile. We have systematically modified both the ligand structure and the oxidation state of these complexes to gain insights into the factors that impact solubility and electrochemistry. The results provide a set of structure-solubility-electrochemistry relationships to guide the future development of electrolytes for nonaqueous flow batteries. In addition, we have identified a promising candidate from the series of chromium complexes for further electrochemical and battery assessment. PMID:26468668

  6. 4,4’-Bis(4-octylphenoxy-2,2’-bipyridine

    Directory of Open Access Journals (Sweden)

    Zhen-Ting Du

    2009-12-01

    Full Text Available 4,4’-Bis(4-octylphenoxy-2,2’-bipyridine which can be used in complexes of ruthenium was synthesized. This ligand bears a long chain for the purpose of increasing the solubility of the final complex. The synthesis was achieved through a nucleophilic aromatic substitution reaction of 4,4’-bromo-2,2’-bipyridine and 4-octylphenol.

  7. 4,4’-Bis(4-octylphenoxy)-2,2’-bipyridine

    OpenAIRE

    Zhen-Ting Du; Jun-Ru Wang; Ru Liu; Yan Xu

    2009-01-01

    4,4’-Bis(4-octylphenoxy)-2,2’-bipyridine which can be used in complexes of ruthenium was synthesized. This ligand bears a long chain for the purpose of increasing the solubility of the final complex. The synthesis was achieved through a nucleophilic aromatic substitution reaction of 4,4’-bromo-2,2’-bipyridine and 4-octylphenol.

  8. Planar geometry of 4-substituted-2,2'-bipyridines synthesized by Sonogashira and Suzuki cross-coupling reactions

    Energy Technology Data Exchange (ETDEWEB)

    Luong Thi, T. T., E-mail: thuyltt@hnue.edu.vn; Nguyen Bich, N.; Nguyen, H. [Hanoi National University of Education, Chemistry Department (Viet Nam); Van Meervelt, L., E-mail: luc.vanmeervelt@chem.kuleuven.be [KU Leuven, Chemistry Department (Belgium)

    2015-12-15

    Two 4-substituted 2,2'-bipyridines, namely 4-(ferrocenylethynyl)-2,2'-bipyridine (I) and 4-ferrocenyl-2,2'-bipyridine (II) have been synthesized and fully characterized via single-crystal X-ray diffraction and {sup 1}H and {sup 13}C NMR analyses. The π-conjugated system designed from 2,2'-bipyridine modified with the ferrocenylethynyl and ferrocenyl groups shows the desired planarity. In the crystal packing of I and II, the molecules arrange themselves in head-to-tail and head-to-head motifs, respectively, resulting in consecutive layers of ferrocene and pyridine moieties.

  9. Crystal structure of bis(2,2′-bipyridine-κ2N,N′bis(thiocyanato-κNmanganese(II 2,2′-bipyridine monosolvate

    Directory of Open Access Journals (Sweden)

    Stefan Suckert

    2015-01-01

    Full Text Available In the crystal structure of the mononuclear title compound, [Mn(NCS2(C10H8N22]·C10H8N2, the MnII cation is coordinated in an all-cis configuration by two N-bound thiocyanate anions and two 2,2′-bipyridine ligands within a slightly distorted octahedral environment. The asymmetric unit consists of one MnII cation, two thiocyanate anions and two 2,2′-bipyridine ligands, as well as two non-coordinating 2,2′-bipyridine ligands that are each located on centres of inversion. In the crystal structure, the discrete [Mn(NCS2(C10H8N22] complex molecules are arranged in such a way that cavities are formed, in which the solvent 2,2′-bipyridine molecules are located. Apart from van der Waals forces, there are no remarkable intermolecular interactions present in the crystal structure.

  10. Peculiarities of the SEHRS and SERS Spectra of - Bipyridine Molecule

    CERN Document Server

    Chelibanov, Vladimir P; Polubotko, Aleksey M

    2016-01-01

    The SEHRS and SERS spactra of 4,4 - Bipyridine are analyzed on the base of the Dipole-Quadrupole theory for two possible geometries of the molecule. It is demonstrated that there appear strong lines caused by vibrations transforming after a unit irreducible representation both for the geometry with D2 and D2h symmetry groups, which may probably describe the symmetry properties of the molecule. Appearance of these lines is associated with a strong quadrupole light-molecule interaction, which arises in nano size rregions of sharp roughness of the metal. In addition, there are the lines caused by contributions from both the vibrations transforming after the unit irredicible representations A or Ag and the representations B1 or B1u, respectively, which describe transformational properties of the Ez component of the dipole moment, which is perpendicular to the surface for both geometries. This result is associated with a specific geometry of the molecule, when the indicated vibrations can be nearly degenerated and...

  11. Crystal structure of poly[[(2,2′-bipyridine)manganese(II)]-di-μ-thiocyanato

    OpenAIRE

    Stefan Suckert; Susanne Wöhlert; Inke Jess; Christian Näther

    2014-01-01

    In the crystal structure of the polymeric title compound, [Mn(NCS)2(C10H8N2)]n, the MnII cations are coordinated by one chelating 2,2′-bipyridine ligand and four thiocyanate anions (two N- and two S-coordinating), forming a distorted [MnN4S2] octahedron. The asymmetric unit consists of one manganese cation located on a twofold rotation axis and half of a 2,2′-bipyridine ligand, the other half being generated by the same twofold rotation axis, as well as one thiocyanate anion in a general posi...

  12. 2,3,4,5-Tetrafluorobenzoic acid–4,4′-bipyridine (2/1

    Directory of Open Access Journals (Sweden)

    Xiaohui Zhu

    2009-08-01

    Full Text Available The asymmetric unit of the title compound, 2C7H2F4O2·C10H8N2, contains one molecule of 2,3,4,5-tetrafluorobenzoic acid (tfb and half of a centrosymmetric 4,4′-bipyridine molecule. Intermolecular O—H...N hydrogen bonds link two tfb molecules and one 4,4′-bipyridine molecule into a trimer. Weak intermolecular C—H...F interactions assemble these trimers into a three-dimensional network structure.

  13. 2,3,4,5-Tetrafluorobenzoic acid–4,4′-bipyridine (2/1)

    OpenAIRE

    Xiaohui Zhu

    2009-01-01

    The asymmetric unit of the title compound, 2C7H2F4O2·C10H8N2, contains one molecule of 2,3,4,5-tetrafluorobenzoic acid (tfb) and half of a centrosymmetric 4,4′-bipyridine molecule. Intermolecular O—H...N hydrogen bonds link two tfb molecules and one 4,4′-bipyridine molecule into a trimer. Weak intermolecular C—H...F interactions assemble these trimers into a three-dimensional network structure.

  14. Versatile ruthenium complexes based on 2,2'-bipyridine modified peptoids.

    Science.gov (United States)

    Baskin, Maria; Panz, Larisa; Maayan, Galia

    2016-08-16

    Helical peptoids bearing 2,2'-bipyridine form ruthenium complexes via intermolecular binding to linear peptoid strands or intramolecular binding to a cyclic scaffold. Ru(ii) binding promoted changes in the conformational order of the peptoids, and chiral induction from the peptoids to their metal center was observed. PMID:27349289

  15. The intercalation reaction of 2,2'-bipyridine with layered compound MnPS3

    International Nuclear Information System (INIS)

    The intercalation process of 2,2'-bipyridine into layered MnPS3 is studied with powder X-ray powder diffraction (XRD) technology as the monitoring tool. From the XRD results, it is found that the absence or presence of acid greatly influences the existing form and the arranged orientation of the guest. Two series of the reactions are carried out. In Series A, only MnPS3 and 2,2'-bipyridine are present. While in Series B, a variety of acetic acid is added. During the intercalation of Series A, there coexist four phases: the 0 0 l phase (with lattice spacing of 6.47 A) is pristine MnPS3; the 0 0 l' phase (with lattice spacing of 9.81 A), indicating the parallel orientation of the 2,2'-bipyridine molecular ring to the layer; the 0 0 l'' phase (with lattice spacing of 12.20 A), indicating the perpendicular orientation of the 2,2'-bipyridine molecular ring to the layer of the host, which is only an intermediate phase for the formation of the 0 0 l''' phase; the 0 0 l''' phase (with the lattice spacing of 15.33 A), indicating the existence of the complex cation [Mn(bipy)3]2+ coming from the in situ coordination of the inserted guest with intralayered Mn2+ ions between the interlayer space of host. As the intercalation proceeds, the 0 0 l, 0 0 l' and 0 0 l'' phases finally disappear, and 0 0 l''' phase is intensified and a complete intercalate is obtained. In Series B, due to the presence of the acid, the formation of the complex cation [Mn(bipy)3]2+ is inhibited, and the amount of the acid in the intercalation plays a key role in the formation of the guest. With the increase of the acid, the protonated bipyridine becomes the main existing form of the guest, which is arranged in the perpendicular orientation of molecular ring to the layer. From the experimental evidences, the possible intercalation mechanisms are proposed and the novel intercalation phenomenon of in situ coordination of the inserted 2,2'-bipyridine with Mn2+ of the host is elucidated

  16. Density Functional Theory Study of Hydrogen Bonds of Bipyridine with 1,3,5-Benzenetricarboxylic Acid

    Institute of Scientific and Technical Information of China (English)

    LI Quan; ZHAO Keqing

    2009-01-01

    The hydrogen-bonded dimer and trimer formed between 1,3,5-benzenetricarboxylic acid and bipyridine have been investigated using a density functional theory(DFT)method and 6-31++G** basis set.The interaction enerstretching modes in the dimer and trimer red-shifted relative to those of the 1,3,5-benzenetricarhoxylic acid monomer.The natural bond orbit analysis shows that the inter-molecular charge transfers are 0.60475e and 1.20225e for the dimer and trimer,respectively.Thermodynamic analysis indicates that the formation of trimer is an exothermic H-O intermolecular hydrogen bonds between bipyridine and 1,3,5-benzenetricarboxylic acid,which is in good agreement with the experimental results.

  17. Structural, Electronic, and Computational Studies of Heteroleptic Cu(I) Complexes of 6,6'-Dimesityl-2,2'-bipyridine with Ferrocene-Appended Ethynyl-2,2'-bipyridine Ligands.

    Science.gov (United States)

    Barnsley, Jonathan E; Scottwell, Synøve Ø; Elliott, Anastasia B S; Gordon, Keith C; Crowley, James D

    2016-08-15

    Optical characterization and computational modeling of three ferrocene-appended ethynyl-2,2'-bipyridine ligands and the associated heteroleptic copper(I) complexes of 6,6'-dimesityl-2,2'-bipyridine are reported. These dyes have been studied using electrochemical analysis, electronic absorption, and Raman and resonance Raman spectroscopies, coupled with density functional theoretical approaches. For the complexes, optical spectra are dominated by a low energy copper(I) centered metal to ligand charge transfer (MLCT) transition; this is modulated by the presence of pendant ferrocene units and the extent of conjugation of the ferrocenyl bipyridine backbone. Electronic tuning due to ferrocene is shown to result in a redshift of the MCLT transition of up to ∼0.2 eV, while an elongation of conjugation appears to result in an increased MLCT intensity of around 50%. PMID:27459334

  18. Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations

    Science.gov (United States)

    Hommes, Paul

    2016-01-01

    Summary The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a–e, the corresponding β-ketoenamines 2a–e were converted into different β-ketoenamides 3a–g by N-acylation with 2-pyridinecarboxylic acid derivatives. These β-ketoenamides were treated with a mixture of TMSOTf and Hünig’s base to promote the cyclocondensation to 4-hydroxypyridine derivatives. Their immediate O-nonaflation employing nonafluorobutanesulfonyl fluoride provided the expected 4-nonafloxy-substituted bipyridine derivatives 5a–g in moderate to good overall yields. The bipyridyl nonaflates are excellent precursors for palladium-catalyzed reactions as demonstrated by representative Suzuki and Sonogashira couplings. Thus, a library of specifically substituted bipyridine derivatives was generated, showing the versatility of the simple 1,3-diketone-based approach to this important class of ligands. PMID:27559368

  19. Dibromido(6-methyl-2,2′-bipyridine-κ2N,N′zinc(II

    Directory of Open Access Journals (Sweden)

    Vahid Amani

    2010-10-01

    Full Text Available In the title compound, [ZnBr2(C11H10N2], the ZnII atom is four-coordinated in a distorted tetrahedral configuration by two N atoms from a 6-methyl-2,2′-bipyridine ligand and two terminal Br atoms. Weak intermolecular C—H...Br hydrogen bonds and π–π stacking interactions between the pyridine rings [centroid–centroid distances = 3.763 (5 and 3.835 (6 Å] contribute to crystal-packing effects.

  20. Polymorphism of felodipine co-crystals with 4,4'-bipyridine

    DEFF Research Database (Denmark)

    Surov, Artem Olegovich; Solanko, Katarzyna A.; Bond, Andrew;

    2014-01-01

    The calcium-channel blocking agent felodipine (Fel) forms co-crystals with 4,4′-bipyridine (BP) with 1:1 and 2:1 molar ratios. The [Fel + BP] (1:1) co-crystal exists in two polymorphic forms. Differential scanning calorimetry and solution calorimetry show that form I of the [Fel + BP] (1:1) co......-crystal is the most thermodynamically stable phase. The difference in the crystal lattice energies between different polymorphs of the co-crystal is found to be comparable with that between the polymorphic forms of pure felodipine. The enthalpies of formation of the co-crystals are small, which indicates...

  1. The electronic spectrum of cryogenic ruthenium-tris-bipyridine dications in vacuo

    Science.gov (United States)

    Xu, Shuang; Smith, James E. T.; Weber, J. Mathias

    2016-07-01

    We report the electronic spectrum of the prototypical ruthenium coordination complex Ru(bpy)32+ (bpy = 2, 2'-bipyridine) by messenger tagging with N2 in a cryogenic ion trap and photodissociation spectroscopy of mass selected Ru(bpy)32+ ṡ N2 ions. We observe individual electronic bands and groups of bands with unprecedented detail, particularly in the usually unresolved metal-to-ligand charge transfer region of the spectrum. By comparing our experimental results with time-dependent density functional theory, both with and without spin-orbit interaction [Heully et al., J. Chem. Phys. 131, 184308 (2009)], we are able to assign the spectrum of the isolated ion.

  2. Synthesis of modified pyridine and bipyridine substituted coumarins as potent antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Lad Hemali B.

    2015-01-01

    Full Text Available In search for new antimicrobial agents a series of new modified pyridine and bipyridine substituted coumarins 5a-y was designed and synthesized by adopting molecular hybridization strategy. All the synthesized compounds were evaluated for their in vitro antimicrobial activity using broth dilution method against selected bacterial (Gram-positive and Gram-negative and fungal strains. Compounds 5a, 5f, 5g, 5n, 5r, 5t, 5w, 5x and 5y demonstrated promising antibacterial activity while other derivatives showed comparable activity to standard drugs used as reference.

  3. Reactivity descriptors and electron density analysis for ligand chemistry: A case study of 2,2'-bipyridine and its analogues

    Indian Academy of Sciences (India)

    Bhakti S Kulkarni; Akhilesh Tanwar; Sourav Pal

    2007-09-01

    In this paper, we study the reactivity of diimines like 2,2'-bipyridine and its analogues using reactivity descriptors. We discuss evaluation of local descriptors using relaxed as well as frozen approximation and characterize the / acceptance/donor characteristics of the above ligands. The intermolecular reactivity sequence for the same systems is examined by the global and local philicity index. In addition, electron density analysis has been carried out to highlight the possible strengths of interaction of the bipyridine and its analogues with metal ions.

  4. Crystal structure, physical, and photophysical properties of a ruthenium(II) bipyridine diazafluorenone complex

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Jackman, D.C.; Rillema, D.P. [Univ. of North Carolina, Charlotte, NC (United States)] [and others

    1995-09-01

    The complex [Ru(bpy){sub 2}(dafo)](PF{sub 6}){sub 2}, where bpy is 2,2{prime}-bipyridine and dafo is diazafluorenone crystallizes in the space group P2{sub 1}/n with a = 9.5059(3){angstrom}, b = 14.002(2){angstrom} and c = 25.783(8){angstrom}. The coordination geometry of the Ru atom is that of a distorted octahedron with a RuN{sub 6} core. The two Ru-N bond distances to the dafo ligand are 2.13(1) and 2.15(1) {angstrom}; the four Ru-N bond distances to the bipyridine ligands are 2.03(1), 2.05(1), 2.06(1), and 2.07(1) {angstrom}. The three shortest Ru-N distances are trans to the three longest Ru-N distances. The complex is oxidized and reduced reversibly at 1.41 and -0.65 V vs. SSCE, respectively. It displays absorptions at 438 nm (1.6 x 10{sup 4}), 285 nm (6.2 x 10{sup 4}), and 240 nm (4.1 x 10{sup 4}) and a broad emission centered at 626 nm in water at room temperature. The emission lifetime is 420 ns and the emission quantum yield is 5.3 x 10{sup -4}.

  5. Intermediate-Valence Tautomerism in Decamethylytterbocene Complexes of Methyl-Substituted Bipyridines

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Corwin H.; Kazhdan, Daniel; Werkema, Evan L.; Walter, Marc D.; Lukens, Wayne W.; Bauer, Eric D.; Hu, Yung-Jin; Maron, Laurent; Eisenstein, Odile; Head-Gordon, Martin; Andersen, Richard A.

    2011-01-25

    Multiconfigurational, intermediate valent ground states are established in several methyl-substituted bipyridine complexes of bispentamethylcyclopentadienylytterbium, Cp*{sub 2} Yb(Me{sub x}-bipy). In contrast to Cp*{sub 2} Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state are altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings. In particular, certain substitutions result in multiconfigurational, intermediate valent open-shell singlet states in both the ground state and the first excited state. These conclusions are reached after consideration of single-crystal x-ray diffraction (XRD), the temperature dependence of x-ray absorption near-edge structure (XANES), extended x-ray absorption fine-structure (EXAFS), and magnetic susceptibility data, and are supported by CASSCF-MP2 calculations. These results place the various Cp*{sub 2}Yb(bipy) complexes in a new tautomeric class, that is, intermediate-valence tautomers.

  6. Decamethylytterbocene Complexes of Bipyridines and Diazabutadienes: Multiconfigurational Ground States and Open-Shell Singlet Formation

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Corwin H.; Walter, Marc D.; Kazhdan, Daniel; Hu, Yung-Jin; Lukens, Wayne W.; Bauer, Eric D.; Maron, Laurent; Eisenstein, Odile; Andersen, Richard A.

    2009-04-22

    Partial ytterbium f-orbital occupancy (i.e., intermediate valence) and open-shell singlet formation are established for a variety of bipyridine and diazabutadiene adducts with decamethylytterbocene, (C5Me5)2Yb, abbreviated as Cp*2Yb. Data used to support this claim include ytterbium valence measurements using Yb LIII-edge X-ray absorption near-edge structure spectroscopy, magnetic susceptibility, and complete active space self-consistent field (CASSCF) multiconfigurational calculations, as well as structural measurements compared to density functional theory calculations. The CASSCF calculations indicate that the intermediate valence is the result of a multiconfigurational ground-state wave function that has both an open-shell singlet f13(?*)1, where pi* is the lowest unoccupied molecular orbital of the bipyridine or dpiazabutadiene ligands, and a closed-shell singlet f14 component. A number of other competing theories for the unusual magnetism in these materials are ruled out by the lack of temperature dependence of the measured intermediate valence. These results have implications for understanding chemical bonding not only in organolanthanide complexes but also for f-element chemistry in general, as well as understanding magnetic interactions in nanoparticles and devices.

  7. Decamethylytterbocene Complexes of Bipyridines and Diazabutadienes: Multiconfigurational Ground States and Open-Shell Singlet Formation

    International Nuclear Information System (INIS)

    Partial ytterbium f-orbital occupancy (i.e., intermediate valence) and open-shell singlet formation are established for a variety of bipyridine and diazabutadiene adducts with decamethylytterbocene, (C5Me5)2Yb, abbreviated as Cp*2Yb. Data used to support this claim include ytterbium valence measurements using Yb LIII-edge X-ray absorption near-edge structure spectroscopy, magnetic susceptibility, and complete active space self-consistent field (CASSCF) multiconfigurational calculations, as well as structural measurements compared to density functional theory calculations. The CASSCF calculations indicate that the intermediate valence is the result of a multiconfigurational ground-state wave function that has both an open-shell singlet f13(π*)1, where π* is the lowest unoccupied molecular orbital of the bipyridine or dpiazabutadiene ligands, and a closed-shell singlet f14 component. A number of other competing theories for the unusual magnetism in these materials are ruled out by the lack of temperature dependence of the measured intermediate valence. These results have implications for understanding chemical bonding not only in organolanthanide complexes but also for f-element chemistry in general, as well as understanding magnetic interactions in nanoparticles and devices

  8. Synthesis, Characterization and Crystal Structure of (2, 2'-Bipyridine) (μ-maleato) copper (Ⅱ) Dihydrate

    Institute of Scientific and Technical Information of China (English)

    LI,Zhen-Yu(李震宇); XU,Duan-Jun(徐端钧); SHI,Wei-Liang(史卫良); CHEN,De-Yu(陈德余); WU,Jing-Yun(吴景云); CHIANG,Michael Y.(蒋燕南)

    2002-01-01

    The title polymeric aomplex [Cu(C4H2O4)(C10H8N2)]n@2nH2O was prepared and its crystal structure was determined by X-ray diffraction methods. The crystal belongs to space group P2 1/ c with cell dimensions of α= 1.0104(1), b =1.9952(2), c=0.7357(2) nm, β=98.38(2)° and Z =4. The complex forms zig-zag chains along crystallographic axis c via Cu-O (carboxyl) bond in the apical direction. Each repeated unit consists of a square pyramidal Cu(H) centre with one maleate dianion and one 2,2'-bipyridine forming a basal plane. Adjacent chains link to each other by H-bonding between carboxyl groups and crystalline water. The distance of 0.3482 nm between parallel bipyridine rings shows a π-π stacking interaction. The title complex was also characterized by IR, UV and ESR spectra.

  9. Diazonium salt derivatives of osmium bipyridine complexes: Electrochemical grafting and characterisation of modified surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, David J. [MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Jenkins, Peter [School of Chemistry, National University of Ireland, Galway (Ireland); Polson, Matthew I.J. [Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Leech, Donal [School of Chemistry, National University of Ireland, Galway (Ireland); Baronian, Keith H.R. [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Downard, Alison J., E-mail: alison.downard@canterbury.ac.n [MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand)

    2011-02-01

    Osmium bipyridine complexes were directly grafted to carbon electrodes through electroreduction of the diazonium salts [Os(bpy-ph-N{sub 2}{sup +}){sub 3}](PF{sub 6}){sub 5} (1) and [Os(bpy-ph-N{sub 2}{sup +}){sub 2}Cl{sub 2}](PF{sub 6}){sub 2} (2). Growth of the films was not self-limiting as is usually found for grafting from diazonium salts. It appears that electron hopping through the bipyridine ligands of the immobilised complexes enables film growth to continue at a constant rate during grafting by potential cycling. The surface concentrations of deposited films were measured electrochemically and the film thicknesses were measured by depth-profiling using the atomic force microscope. Films up to 42 nm thick were prepared with no evidence for slowing of film growth. The grafted films exhibited high stability when repetitively cycled through the Os{sup 2+/3+} couple and electron transfer rate constants of 11.4 s{sup -1} and 35.4 s{sup -1} were measured in ACN and PBS, respectively, for the Os{sup 2+/3+} couple of the film grafted from 1.

  10. Diazonium salt derivatives of osmium bipyridine complexes: Electrochemical grafting and characterisation of modified surfaces

    International Nuclear Information System (INIS)

    Osmium bipyridine complexes were directly grafted to carbon electrodes through electroreduction of the diazonium salts [Os(bpy-ph-N2+)3](PF6)5 (1) and [Os(bpy-ph-N2+)2Cl2](PF6)2 (2). Growth of the films was not self-limiting as is usually found for grafting from diazonium salts. It appears that electron hopping through the bipyridine ligands of the immobilised complexes enables film growth to continue at a constant rate during grafting by potential cycling. The surface concentrations of deposited films were measured electrochemically and the film thicknesses were measured by depth-profiling using the atomic force microscope. Films up to 42 nm thick were prepared with no evidence for slowing of film growth. The grafted films exhibited high stability when repetitively cycled through the Os2+/3+ couple and electron transfer rate constants of 11.4 s-1 and 35.4 s-1 were measured in ACN and PBS, respectively, for the Os2+/3+ couple of the film grafted from 1.

  11. Fluorescence property of tris (2, 2'-bipyridine) ruthenium (Ⅱ) dichloride immobilized in the gallery of γ-zirconium phosphates

    Institute of Scientific and Technical Information of China (English)

    Ming Hui Xiang; Xian Bo Shi; Na Li; Ke An Li

    2007-01-01

    Tris (2, 2'-bipyridine) ruthenium (Ⅱ) (Ru(bpy)32+) dichloride was successfully immobilized into the galleria of layered gamma zirconium phosphate (γ-ZrP) preintercalated by butyl amine(BA). The compounds showed extended luminescence lifetime of about four times of unimmobilized metal complex.

  12. Solvation structure around ruthenium(II tris(bipyridine in lithium halide solutions

    Directory of Open Access Journals (Sweden)

    Ida Josefsson

    2016-03-01

    Full Text Available The solvation of the ruthenium(II tris(bipyridine ion ([Ru(bpy3]2+ is investigated with molecular dynamics simulations of lithium halide solutions in polar solvents. The anion distribution around the [Ru(bpy3]2+ complex exhibits a strong solvent dependence. In aqueous solution, the iodide ion forms a solvent shared complex with [Ru(bpy3]2+, but not in the other solvents. Between Cl– and [Ru(bpy3]2+, the strong hydration of the chloride ion results in a solvent separated complex where more than one solvent molecule separates the anion from the metal center. Hence, tailored solvation properties in electrolytes is a route to influence ion-ion interactions and related electron transfer processes.

  13. Solvation structure around ruthenium(II) tris(bipyridine) in lithium halide solutions

    Science.gov (United States)

    Josefsson, Ida; Eriksson, Susanna K.; Rensmo, Håkan; Odelius, Michael

    2016-01-01

    The solvation of the ruthenium(II) tris(bipyridine) ion ([Ru(bpy)3]2+) is investigated with molecular dynamics simulations of lithium halide solutions in polar solvents. The anion distribution around the [Ru(bpy)3]2+ complex exhibits a strong solvent dependence. In aqueous solution, the iodide ion forms a solvent shared complex with [Ru(bpy)3]2+, but not in the other solvents. Between Cl– and [Ru(bpy)3]2+, the strong hydration of the chloride ion results in a solvent separated complex where more than one solvent molecule separates the anion from the metal center. Hence, tailored solvation properties in electrolytes is a route to influence ion-ion interactions and related electron transfer processes. PMID:26798838

  14. Heterogeneous Catalysis for Water Oxidation by an Iridium Complex Immobilized on Bipyridine-Periodic Mesoporous Organosilica.

    Science.gov (United States)

    Liu, Xiao; Maegawa, Yoshifumi; Goto, Yasutomo; Hara, Kenji; Inagaki, Shinji

    2016-07-01

    Heterogenization of metal-complex catalysts for water oxidation without loss of their catalytic activity is important for the development of devices simulating photosynthesis. In this study, efficient heterogeneous iridium complexes for water oxidation were prepared using bipyridine-bridged periodic mesoporous organosilica (BPy-PMO) as a solid chelating ligand. The BPy-PMO-based iridium catalysts (Ir-BPy-PMO) were prepared by postsynthetic metalation of BPy-PMO and characterized through physicochemical analyses. The Ir-BPy-PMOs showed high catalytic activity for water oxidation. The turnover frequency (TOF) values for Ir-BPy-PMOs were one order of magnitude higher than those of conventional heterogeneous iridium catalysts. The reusability and stability of Ir-BPy-PMO were also examined, and detailed characterization was conducted using powder X-ray diffraction, nitrogen adsorption, (13) C DD MAS NMR spectroscopy, TEM, and XAFS methods. PMID:27168492

  15. Gold nanoparticles-decorated silver-bipyridine nanobelts for the construction of mediatorless hydrogen peroxide biosensor.

    Science.gov (United States)

    Boujakhrout, Abderrahmane; Díez, Paula; Sánchez, Alfredo; Martínez-Ruíz, Paloma; Pingarrón, José M; Villalonga, Reynaldo

    2016-11-15

    Au nanoparticles modified with 4-mercaptopyridine and 6-mercapto-1-hexanol were used as coordination agents to prepare a novel hybrid nanomaterial with Ag:4,4'-bipyridine nanobelts. This nanohybrid was employed to modify glassy carbon electrodes and to construct a horseradish peroxidase-based mediatorless amperometric biosensor for H2O2. The electrode, poised at -100mV, exhibited a rapid response within 4s and a linear calibration range from 90pM to 6.5nM H2O2. The biosensor showed a high sensitivity of 283A/Mcm(2) and a very low detection limit of 45pM at a signal-to-noise ratio of 3. The enzyme biosensor showed high stability when stored at 4°C under dry conditions, retaining over 96% and 78% of its initial activity after 15 and 30days of storage at 4°C, respectively. PMID:27497231

  16. Luminescent lanthanide complexes of a bis-bipyridine-phosphine-oxide ligand as tools for anion detection.

    Science.gov (United States)

    Charbonnière, Loïc J; Ziessel, Raymond; Montalti, Marco; Prodi, Luca; Zaccheroni, Nelsi; Boehme, Christian; Wipff, Georges

    2002-07-01

    The Gd(3+), Tb(3+), and Eu(3+) complexes of a bis-bipyridine-phenylphosphine oxide ligand PhP(O)(bipy)(2) 1 (bipy for 6-methylene-6'-methyl-2,2'-bipyridine) have been synthesized. In acetonitrile solutions at room temperature, the Tb(3+) and Eu(3+) complexes show a metal-centered luminescence, indicative of an efficient energy transfer from the two bipy subunits to the Ln center. The photophysical properties drastically depend on the nature of the anions present in solution. In particular, addition of 2 equiv of nitrate anions to a solution containing the [Ln.1](OTf-)(3) leads to an 11-fold increase of the luminescence intensity for the Eu(3+) and a 7-fold increase for the Tb(3+) complexes. Similar effects are provided with Cl-, F-, and CH(3)COO- anions. UV-vis titration experiments were used to determine association constants for binding of, respectively, one, two, and three anions. Stepwise anion addition has also been investigated on the molecular level using quantum mechanical (QM) calculations for the Eu complexes. These calculations reproduce the experimental findings, especially if solvent molecule addition is taken into account. The X-ray crystal structure of the nitrate salt of the Tb complex, as well as QM calculation of a similar Eu complex, demonstrates the coordination of three nitrate anions in a bidentate mode and the step-by-step relegation of the bipy subunits in the second coordination sphere. These features give valuable insights into the mechanism of the overall light amplification process. PMID:12083932

  17. Crystal structure of Cr (III) complex containing nitrilotriacetic acid and 4, 4'-bipyridine

    International Nuclear Information System (INIS)

    The title compound (C10H9N2)[Cr(C6H7NO6)2](C10H8N2).2H2O or (4,4'-bipy H)[Cr(nta H)2](4,4'-bipy). 2H2O (ntaH3 is nitrilotriacetic acid) was synthesized by reaction of Cr(NO3)3.9H2O with 4,4'-bipyridine, and nitrilotriacetic acid with 4:2:1 molar ratio in aqueous solution. The crystal structure of this complex was identified using X-ray crystallography. The unit cell parameters are as follows: a= 9.8501(3) Angstrom, b = 13.157(2) Angstrom, c = 26.842(4) Angstrom, β = 104.807(7)degree. The final R value is 0.041 for 7747 independent reflections. The title compound crystallized in monoclinic system and belongs to P21/c space group. The central CrIII atom is coordinated by two tridentaid (ntaH2) ligands and the resulted CrO4N2 set can be described as distorted octahedral geometry. The asymmetric unit contains two half of anionic complex, one 4, 4'-bipyridinium ion, (4, 4'-bipy H)+, one neutral 4, 4'-bipyridine molecule and two non-coordinated water molecules. Intramolecular hydrogen bonds, π-π [centroid -centroid distances of 3.674 A], C-H...π, O-H...π and N-H...π stacking interactions [with distance of 3.714, 3.736 and 3.270 A respectively], connect the various components into a supramolecular structures.

  18. Determination of Silver(I) by Differential Pulse Voltammetry Using a Glassy Carbon Electrode Modified with Synthesized N-(2-Aminoethyl)-4,4′-Bipyridine

    OpenAIRE

    Gabriel Lucian Radu; Bogdan Bucur; Madalina Petruta Bucur; Medeea Radulescu; Maria-Cristina Radulescu; Ana Chira

    2010-01-01

    A new modified glassy carbon electrode (GCE) based on a synthesized N-(2-aminoethyl)-4,4'-bipyridine (ABP) was developed for the determination of Ag(I) by differential pulse voltammetry (DPV). ABP was covalently immobilized on GC electrodes surface using 4-nitrobenzendiazonium (4-NBD) and glutaraldehyde (GA). The Ag(I) ions were preconcentrated by chemical interaction with bipyridine under a negative potential (−0.6 V); then the reduced ions were oxidized by differential pulse voltammetry and...

  19. μ-4,4′-Bipyridine-κ2N:N′-bis[aqua(4,4′-bipyridine-κN(l-valinato-κ2N,Ocopper(II] dinitrate dihydrate

    Directory of Open Access Journals (Sweden)

    Mao-Chun Hong

    2008-02-01

    Full Text Available In the title dinuclear complex, [Cu2(C5H10NO22(C10H8N23(H2O2](NO32·2H2O, each of the two l-valinate anions chelates a CuII center through the amino N and carboxylate O atom, forming a five-membered ring. A 4,4′-bipyridine molecule bridges two water-coordinated Cu atoms, each of which is connected to another 4,4′-bipyridine, giving rise to a square-pyramidal coordination geometry for the CuII centers. The dinuclear dications, nitrate anions and uncoordinated water molecules are linked into a two-dimensional structure.

  20. Coordination polymers and metal-organic frameworks derived from 4,4'-dicarboxy-2,2'-bipyridine and 4,4',6,6'-tetracarboxy-2,2'-bipyridine ligands: a personal perspective.

    Science.gov (United States)

    Kruger, Paul E

    2013-01-01

    Presented herein is a personal overview of some of the contributions we have made over recent years to coordination polymer chemistry employing 2,2'-bipyridine-polycarboxylic acid ligands in conjunction with first row transition, main group or lanthanide metal ions. Primarily the discussion is centred upon the two ligands with which we have enjoyed the most success: 4,4'-dicarboxy-2,2'-bipyridine (4,4'-H2dcbp) and 4,4',6,6'-tetracarboxy-2,2'-bipyridine (4,4',6,6'-H4tcbp). Initial discussion is focused upon the synthetic aspects of ligand formation and their structural characterisation and then moves on to the synthesis of metal complexes incorporating these ligands and the coordination polymers they form. Where possible the discussion is presented from a synthetic and structural perspective with highlight given to the pertinent properties of the coordination polymers formed e.g. thermal behaviour, magnetic, luminescent or small molecule sorption properties. We end the review with some conclusions and highlight some current work with a view to future research.

  1. Crystal Structure and Luminescence Property of Lanthanide Complexes with 2-Fluorobenzoic Acid and 2,2'-Bipyridine

    Institute of Scientific and Technical Information of China (English)

    Li Xia; Zhang Zhuoyong; Song Haibin

    2005-01-01

    The two compounds of [Ln(2-FBA)3·2,2'-bpy]2 (2-FBA=2-fluorobenzoato, 2,2'-bpy=2,2'-bipyridine, Ln=Eu(1), Dy(2)) were synthesized and their structures were determined by X-ray diffraction method. Crystallized complexes 1 and 2 are isomorphous, monoclinic system with P21/n space group. The two complexes are binuclear molecule with an inversion center. The two lanthanide ions are linked by four bridged 2-FBA ligands and each lanthanide ion is further bonded to one chelated bidentate 2-FBA ligand and one 2,2'-bipyridine molecule. The coordination number of metal ion is eight. The europium complex exhibits strong red fluorescence. 5D0→7Fj (j= 1~4) transition emission of Eu3+ ion was observed.

  2. Modulation of the conductance of a 2,2'-bipyridine-functionalized peptidic ion channel by Ni2+.

    Science.gov (United States)

    Pilz, Claudia S; Steinem, Claudia

    2008-07-01

    An alpha-helical amphipathic peptide with the sequence H2N-(LSSLLSL)3-CONH2 was obtained by solid phase synthesis and a 2,2'-bipyridine was coupled to its N-terminus, which allows complexation of Ni2+. Complexation of the 2,2'-bipyridine residues was proven by UV/Vis spectroscopy. The peptide helices were inserted into lipid bilayers (nano black lipid membranes, nano-BLMs) that suspend the pores of porous alumina substrates with a pore diameter of 60 nm by applying a potential difference. From single channel recordings, we were able to distinguish four distinct conductance states, which we attribute to an increasing number of peptide helices participating in the conducting helix bundle. Addition of Ni2+ in micromolar concentrations altered the conductance behaviour of the formed ion channels in nano-BLMs considerably. The first two conductance states appear much more prominent demonstrating that the complexation of bipyridine by Ni2+ results in a considerable confinement of the observed multiple conductance states. However, the conductance levels were independent of the presence of Ni2+. Moreover, from a detailed analysis of the open lifetimes of the channels, we conclude that the complexation of Ni2+ diminishes the frequency of channel events with larger open times.

  3. 3-Aminobenzoic acid–4,4′-bipyridine (2/3

    Directory of Open Access Journals (Sweden)

    Pornsuda Lhengwan

    2012-08-01

    Full Text Available The asymmetric unit of the title compound, 3C10H8N2·2C7H7NO2, consists of three molecules of 4,4′-bipyridine (bpy and two molecules of 3-aminobenzoic acid (bza. Two molecules of bza and two molecules of bpy are connected via O—H...N, N—H...N and N—H...O hydrogen bonds, forming forming infinite double-stranded zigzag chains along the c axis. The third molecule of bpy is linked to the chain by weak C—H...O interactions. Adjacent chains are linked via π–π interactions [centroid–centroid distances = 3.759 (3–3.928 (3 Å] involving the pyridine rings of bpy molecules, resulting in a sheet-like structure parallel to (100. These sheets are stacked via C—H...π interactions, resulting finally in the formation of a three-dimensional supramolecular structure.

  4. Decamethylytterbocene complexes of bipyridines and diazabutadines: multiconfigurational ground states and open-shell singlet formation

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Eric D [Los Alamos National Laboratory; Booth, C H [LBNL; Walter, M D [LBNL; Kazhdan, D [LBNL; Hu, Y - J [LBNL; Lukens, Wayne [LBNL; Maron, Laurent [INSA TOULOUSE; Eisentein, Odile [UNIV MONTPELLIER 2; Anderson, Richard [LBNL

    2009-01-01

    Partial ytterbium f-orbital occupancy (i.e. intermediate valence) and open-shell singlet Draft 12/formation are established for a variety of bipyridine and diazabutadiene adducts to decamethylytterbocene, (C{sub 5}Me{sub 5}){sub 2}Yb or Cp*{sub 2}Yb. Data used to support this claim includes ytterbium valence measurements using Yb Lm-edge x-ray absorption near-edge structure (XANES) spectroscopy, magnetic susceptibility and Complete Active Space Self-Consistent Field (CASSCF) multi configurational calculations, as well as structural measurements compared to density-functional theory (DFT) calculations. The CASSCF calculations indicate that the intermediate valence is the result of a multiconfigurational ground state wave function that has both an open-shell singlet f{sup 13} and a closed-shell singlet f{sup 14} component. A number of other competing theories for the unusual magnetism in these materials are ruled out by the presence of intermediate valence and its lack of any significant temperature dependence. These results have implications for understanding chemical bonding not only in organolanthanide complexes, but also for organometallic chemistry in general, as well as understanding magnetic interactions in nanopartic1es and devices.

  5. Study of ruthenium complexation by 22' bipyridine in nitric aqueous solutions

    International Nuclear Information System (INIS)

    Substitution of the NO3-, NO+ ions of RuNO(NO3)x.yH2Osup((3-x)+) complexes by 22'bipyridine (bipy) in nitric aqueous solution was studied by spectrophotometry. In the absence of reducing agent we observe the species RuNO(bipy)(NO3)sub(z)sup((3-z)+) and RuNO(bipy)2NO32+. Most reducing agents give rise to the RuNO(bipy)2NO32+ + e → RuNO(bipy)2NO3+ reaction. The oxydation potential of the reversible couple RuNO(bipy)2NO32+/RuNO(bipy)2NO3+ was measured by cyclic voltamperometry at the platinum electrode. Its value is + 1.02 V/NHE. Substitution of NO+ ions by a (bipy) molecule is only possible in the presence of reducing agents of apparent formal potential below + 0.5 V/NHE, and anti-nitrite agents are also needed; these two functions can be fulfilled by hydrazine and ascorbic acid. The presence of HSO3 NH2 was necessary to obtain the substitution of NO+ and NO3- by bipy during electrochemical reductions. The intermediate complexes RuNO(bipy)2NO32+ and RuNO(bipy)2NO3+ probably include two bipy molecules in the trans position whereas RuNO(bipy)22+ complexes, where the sixth coordination position is occupied by π donors stronger than NO3-, have two bipy molecules in the cis position

  6. Quantum processes in 8-Oxo-Guanine-Ru(bipyridine)32+ photosynthetic systems of artificial minimal cells

    Science.gov (United States)

    Tamulis, Arvydas; Grigalavicius, Mantas; Krisciukaitis, Sarunas; Medzevicius, Giedrius

    2011-06-01

    Density functional theory methods were used to investigate various self-assembled photoactive bioorganic systems of interest for artificial minimal cells. The cell systems studied are based on nucleotides or their compounds and consisted of up to 123 atoms (not including the associated water or methanol solvent shells) and are up to 2.5 nm in diameter. The electron correlation interactions responsible for the weak hydrogen and Van derWaals chemical bonds increase due to the addition of a polar solvent (water or methanol). The precursor fatty acid molecules of the system also play a critical role in the quantum mechanical interaction based self-assembly of the photosynthetic center and the functioning of the photosynthetic processes of the artificial minimal cells. The distances between the separated sensitizer, fatty acid precursor, and methanol molecules are comparable to Van derWaals and hydrogen bonding radii. As a result the associated electron correlation interactions compress the overall system, resulting in an even smaller gap between the highest occupied molecular orbital (HOMO), and lowest unoccupied molecular orbital (LUMO) electron energy levels and photoexcited electron tunnelling occurs from the sensitizer (either Ru(bpy)32+ or [Ru(bpy)2(4-Bu-4'-Me-2,2'-bpy)]2++ derivatives) to the precursor fatty acid molecules (notation used: Me = methyl; Bu = butyl; bpy = bipyridine). The shift of the absorption spectrum to the red for the artificial protocell photosynthetic centers might be considered as the measure of the complexity of these systems.

  7. Iridium-bipyridine periodic mesoporous organosilica catalyzed direct C-H borylation using a pinacolborane.

    Science.gov (United States)

    Maegawa, Yoshifumi; Inagaki, Shinji

    2015-08-01

    Heterogeneous catalysis for direct C-H borylation of arenes and heteroarenes in the combination of iridium (Ir) complex fixed on periodic mesoporous organosilica containing bipyridine ligands within the framework (Ir-BPy-PMO) and pinacolborane (HBpin) is reported. Ir-BPy-PMO showed higher catalytic activity toward the borylation of benzene with inexpensive HBpin compared to expensive bis(pinacolato)diboron (B2pin2). The precatalyst could be handled without the use of a glove box. The catalyst was easily recovered from reaction mixtures by simple filtration under air. The recovered catalyst still showed good catalytic activity for at least three more times for the borylation of benzene. A variety of arenes and heteroarenes were successfully borylated with high boron efficiency by Ir-BPy-PMO using HBpin, whereas almost no activity was observed for borylation of some heteroarenes with B2pin2. The system using Ir-BPy-PMO and HBpin was also utilized in syntheses of multi-boronated thiophene-based building blocks containing ladder-, acenefused-, and fused-thiophene skeletons. The combination of a stable and reusable solid catalyst and inexpensive HBpin is expected to be superior to conventional approaches for the development of industrial applications. PMID:25748945

  8. Photoluminescent multilayer film based on polyoxometalate and tris(2,2-bipyridine)ruthenium

    International Nuclear Information System (INIS)

    A photoluminescent multilayer film based on Keggin-type polyoxometalate PMo12O403- (PMo12) and transition metal complex tris(2,2-bipyridine) ruthenium [Ru(bpy)3]2+ (Ru(bpy)) was prepared by using layer-by-layer assembly(LBL). The formation of multilayer film was monitored by ultraviolet absorption spectra. The absorption intensity of characteristic peaks increase with a four-layer cycle, indicating that the LBL assembly film grow linearly and reproducibly from layer to layer. The composition of the film was measured by X-ray photoelectron spectrum (XPS). The data of XPS confirmed the presence of the expected elements. The film exhibited photoluminescence arising from π*-t2g ligand-to-metal transition of Ru(bpy) and redox activity attributing to molybdenum-centered redox processes of PMo12. The surface morphology of multilayer film was characterized by atomic force microscopy (AFM). The result shows that the film had a smooth surface with root-mean-square (rms) roughness ca. 1.363 nm for {PEI/(PSS/PEI/PMo12/Ru(bpy))3}. The grains are homogeneously dispersed in the substrate and have a rather narrow diameter size distribution

  9. Bis(4,4′-bipyridinium dodecatungstosilicate 4,4′-bipyridine hexahydrate

    Directory of Open Access Journals (Sweden)

    Quan Zhao

    2008-10-01

    Full Text Available The title compound, (C10H10N22[SiW12O40]·C10H8N2·6H2O or (4,4′-bipyH22[SiW12O40].(4,4′-bipy·6H2O (4,4′-bipy is 4,4′-bipyridine, was prepared under hydrothermal conditions. The asymmetric unit contains a discrete Keggin-type [SiW12O40]4− anion (located on a twofold axis, one 4,4′-bipy (located on a twofold axis, two (4,4′-bipyH22+ cations and six uncoordinated water molecules. The polyoxoanion is constructed from a central SiO4 tetrahedron which shares its O atoms with four trinuclear W3O13 groups, each of which is made up of three edge-sharing WO6 octahedra. The water molecules and [SiW12O40]4− anions are linked through hydrogen bonds.

  10. Electronic properties and reactivity of vanadium complexes of bipyridine and cyanometallates

    International Nuclear Information System (INIS)

    This work deals with the chemistry of two types of vanadium compounds. The first one consists of polymeric pigments containing vanadium (III) ions and hexacyanoferrate (II) or substituted pentacyanoferrate (II) complexes. A series of 14 complexes were isolated in solid state, exhibiting the following composition V sub(4) [ Fe (CN) sub(4) ]. 16H sub(2)O or V [ Fe (CN) sub(5) L ]. 4H sub(2)O (L imidazole, pyridine and pyrazine derivatives). These complexes exhibit strong absorption bands in the visible-uv region, ascribed to intervalence transfer transitions. The infrared spectra were assigned, showing a linear correlation of the CN stretching frequencies with the sup(13)C NMR chemical shifts of the cyanide ligands in the complexes. The second system which has been investigated consists of a series of substituted species with vanadium (II) and (III) ions with 2,2 bypyridine ligands, formulated as [V (bipy) 3 - n (H sub(2)O) 6-2n ] sup(2+) and [ Cl (bipy)nVOV(bipy)nCl] sup(4)+ (n= 1-3) respectively. The electronic spectra of these complexes were assigned in parallel with magnetic and vibrational studies. Resonance Raman spectra of the vanadium (II) complexes exhibited strong enhancement of the bipyridine vibrational modes. In contrast, the vibrational modes of the V (III)-O-V(III) chromophore were preferentialy enhanced in the dimeric species. (author)

  11. Mn(II) complexes with bipyridine, phenanthroline and benzoic acid: Biological and catalase-like activity

    Indian Academy of Sciences (India)

    Ibrahim Kani; Özlem Atlier; Kiymet Güven

    2016-04-01

    Five mononuclear Mn(II) complexes, [Mn(phen)2(ClO4)2] (1), [Mn(phen)3](ClO4)2(H2CO3)2(2), [Mn(bipy)2(ClO4)2] (3), [Mn(bipy)3](ClO4)2) (4), and Mn(phen)2(ba)(H2O)](ClO4)(CH3OH) (5), where bipy = 2,2’-bipyridine, phen = 1,10-phenanthroline, and ba = benzoic acid were prepared and characterized by Xray, IR and UV-Vis spectroscopies, and their catalase-like and biological activities were studied. The presence of two different types and the number of chelating NN-donor neutral ligands allowed for analysis of their effects on the catalase and biological activities. It was observed that the presence and number of phen ligands improved the activity more than the bipy ligand. Complexes 1 and 2, which contain more basic phen ligands, disproportionate H2O2 faster than complexes 3 and 4, which contain less basic bipy ligands. The in vitro antimicrobial activities of all the complexes were also tested against seven bacterial strains by microdilution tests. All the bacterial isolates demonstrated sensitivity to the complexes and the antifungal (anticandidal) activities of the Mn(II) complexes were remarkably higher than the reference drug ketoconazole.

  12. Synthesis and characterization of new dn metal complexes with 4,4'-bipyridine and formates

    International Nuclear Information System (INIS)

    New mixed-ligand complexes of the stoichiometric formulae: Mn(4-bpy)2(HCOO)2·2H2O, Co(4-bpy)2(HCOO)2·H2O, Ni(4-bpy)2(HCOO)2·4H2O, Cu(4-bpy)2(HCOO)2·H2O, Zn2(4-bpy)3(HCOO)4, Cd(4-bpy)3(HCOO)2 (where 4-bpy = 4,4'-bipyridine) have been isolated in pure state. The IR and VIS spectra (for compounds Co(II), Ni(II), Cu(II)), molar conductivity measurements and other physical properties of these compounds are discussed. Thermal behaviour of all compounds was studied by means of DTA, DTG, TG techniques under static conditions in air. The resultant final products were the metal oxide in all cases. A coupled TG-MS system was used to analysis of principal volatile thermal decomposition (or fragmentation) products of Co(II) and Ni(II) complexes. The principal volatile mass fragments correspond to: C+, OH+, H2O+, NO+, CO2+ and other. (author)

  13. Synthesis and Properties of Novel Luminescent Compounds Containing Triphenylamine and Bipyridine Units

    Institute of Scientific and Technical Information of China (English)

    L(U) Hai-jun; LI Xiang-gao; WANG Shi-rong; GAO Wen-zheng; WANG Sha-sha

    2012-01-01

    Blue luminescent compounds T1-T4 containing triphenylamine donors,bipyridine acceptors and olefinic linkers were synthesized and characterized by 1H NMR,13C NMR and high resolution mass spectrometry(HRMS).Four compounds T1-T4 exhibit excellent solubility in common solvents and good film forming properties.Quantum chemical calculations show that compounds T1-T4 have asymmetric linear structures and the proper highest occupied molecular orbital(HOMO)levels.The UV-Vis absorption and fluorescence emission spectra of the four compounds in dilute chloroform solutions and on the solid films were measured.It reveals that compounds T1-T4 exhibit similar spectral behavior,suggesting that these compounds can form amorphous state in solid films.The calculated absorption and emission spectra of compounds T1-T4 are in good agreement with experimentally determined ones.Compounds T1-T4 have absolute fluorescence quantum yield above 17% in dilute chloroform solutions.Four compounds possess high glass-transition temperature(Tg)exceeding 97 ℃ and the maximum Tg is 155.28 ℃ for compound T3.Cyclic voltammetry measurements show that these compounds have proper HOMO levels in a range of-5.01—-5.13 eV for hole injection.The properties of compounds T1—T4 indicate that these compounds are candidates for the application in organic light-emitting devices(OLEDs)as hole-transporting materials(HTMs).

  14. (2,2′-Bipyridine(2-formyl-6-methoxyphenolatonickel(II perchlorate

    Directory of Open Access Journals (Sweden)

    Cui-Juan Wang

    2009-01-01

    Full Text Available In the title compound, [Ni(C8H7O3(C10H8N2]ClO4, the NiII atom is in a slightly distorted square-planar coordination by two N atoms from the 2,2′-bipyridine (bipy ligand and two O atoms from the deprotonated 2-formyl-6-methoxyphenolate (mbd ligand. The bipy ligand is nearly coplanar with the NiII square plane, the Ni atom being only 0.042 (2 Å from the mean plane, whereas the benzaldehyde plane is folded with respect to the square plane, making a dihedral angle of 19.17 (8°. One of the O atoms of the perchlorate anion is involved in a weak interaction with the Ni atom, with an Ni—O distance of 2.5732 (18 Å. The packing is stabilized by weak C—H...O interactions.

  15. Vanadium methyl-bipyridine organoligand and its influence on energy balance and organs mass.

    Science.gov (United States)

    Krośniak, Mirosław; Francik, Renata; Wojtanowska-Krośniak, Agnieszka; Tedeschi, Cinzia; Krasoń-Nowak, Małgorzata; Chłopicka, Joanna; Gryboś, Ryszard

    2014-09-01

    In the treatment of lifestyle diseases, including metabolic syndrome and type 2 diabetes, it is important to lower body mass and fat tissue, and consequently, to increase insulin-sensitivity. Unfortunately, it often happens that low-energy diet which would lower overweight is not observed and, thus, it does not bring the expected effects. This paper discusses the influence of three diets-control, high-fructose, and high-fatty diet-on absorption of energy from food in order to transform it into body mass. The kJ/g ratio which describes this process has been calculated. In the tested diets, the addition of fructose (79.13 ± 2.47 kJ/g) or fat (82.48 ± 2.28 kJ/g) results in higher transformation of energy into body mass than in the case of control diet (89.60 ± 1.86 kJ/g). The addition of Na[VO(O2)2(4,4′-Me2-2,2′-bpy)]•8H2O (where 4,4′-Me2-2,2′-bpy = 4,4′-dimethyl-2,2′-bipyridine) results in statistical increase of that ratio: fructose diet (86.88 ± 0.44 kJ/g), fat diet (104.68 ± 3.01 kJ/g), and control diet (115.98 ± 0.56 kJ/g), respectively. Fat diet statistically influences the decrease of kidney mass in comparison to the other diets. The application of the tested vanadium compound results also in the statistical decrease of the fatty liver caused by fructose and fat diet.

  16. One-dimensional Polymers Constructed with Binuclear Copper(Ⅱ) α,β-Unsaturated Carboxylates Bridged by 4,4'-Bipyridine

    Institute of Scientific and Technical Information of China (English)

    刘萍; 王尧宇; 李东升; 栾新军; 高松; 史启祯

    2005-01-01

    A methanol solution of 4,4'-bipyridine reacts with Cu2A4(H2O)2 to yield coordination polymers of general formula: [Cu2A4(bipy)]n [A: CH2=C(Me)CO2- (1), CH2=CHCO2- (2); bipy: 4,4'-bipyridine]. They were characterized by elemental analyses, IR spectra and thermal analyses. The X-ray structure analyses of 1 show a one-dimensional chain structure where the binuclear structural units Cu2[CH2=C(Me)CO2]4 are bridged by 4,4'-bipyridine molecules. Furthermore, the binuclear units between adjacent layers can form micropores. The temperature-dependent magnetic susceptibility of 1 indicates that the strong antiferromagnetic interaction exists between copper(Ⅱ) atoms in the binuclear units.

  17. Crystal structures of bis- and hexakis[(6,6'-di-hydroxy-bipyridine)copper(II)] nitrate coordination complexes.

    Science.gov (United States)

    Gerlach, Deidra L; Nieto, Ismael; Herbst-Gervasoni, Corey J; Ferrence, Gregory M; Zeller, Matthias; Papish, Elizabeth T

    2015-12-01

    Two multinuclear complexes synthesized from Cu(NO3)2 and 6,6'-di-hydroxy-bipyridine (dhbp) exhibit bridging nitrate and hydroxide ligands. The dinuclear complex (6,6'-di-hydroxy-bipyridine-2κ(2) N,N')[μ-6-(6-hy-droxy-pyridin-2-yl)pyridin-2-olato-1:2κ(3) N,N':O (2)](μ-hydroxido-1:2κ(2) O:O')(μ-nitrato-1:2κ(2) O:O')(nitrato-1κO)dicopper(II), [Cu2(C10H7N2O2)(OH)(NO3)2(C10H8N2O2)] or [Cu(6-OH-6'-O-bpy)(NO3)(μ-OH)(μ-NO3)Cu(6,6'-dhbp)], (I), with a 2:1 ratio of nitrate to hydroxide anions and one partially deprotonated dhbp ligand, forms from a water-ethanol mixture at neutral pH. The hexa-nuclear complex bis-(μ3-bi-pyridine-2,2'-diolato-κ(3) O:N,N':O')tetra-kis-(6,6'-di-hydroxy-bipyridine-κ(2) N,N')tetra-kis-(μ-hydroxido-κ(2) O:O')bis-(methanol-κO)tetra-kis-(μ-nitrato-κ(2) O:O')hexa-copper(II), [Cu6(C10H6N2O2)2(CH4O)2(OH)4(NO3)4(C10H8N2O2)4] or [Cu(6,6'-dhbp)(μ-NO3)2(μ-OH)Cu(6,6'-O-bpy)(μ-OH)Cu(6,6'dhbp)(CH3OH)]2, (II), with a 1:1 NO3-OH ratio and two fully protonated and fully deprotonated dhbp ligands, was obtained by methanol recrystallization of material obtained at pH 3. Complex (II) lies across an inversion center. Complexes (I) and (II) both display intra-molecular O-H⋯O hydrogen bonding. Inter-molecular O-H⋯O hydrogen bonding links symmetry-related mol-ecules forming chains along [100] for complex (I) with π-stacking along [010] and [001]. Complex (II) forms inter-molecular O-H⋯O hydrogen-bonded chains along [010] with π-stacking along [100] and [001]. PMID:26870402

  18. cis-Bis(acetonitrile-κNbis(2,2′-bipyridine-κ2N,N′ruthenium(II tetrafluoridoborate

    Directory of Open Access Journals (Sweden)

    Ying Wang

    2012-01-01

    Full Text Available In the cation of the title compound, [Ru(CH3CN2(C10H8N22](BF42, the RuII atom is six-coordinated in a distorted octahedral geometry by the N atoms of the two 2,2′-bipyridine (bpy ligands and two cis-arranged acetonitrile molecules. The dihedral angles formed by the pyridine rings of the bpy ligands are 8.86 (12 and 10.12 (14°. In the crystal, the cations and anions are linked by C—H...F hydrogen bonds into a three-dimensional network.

  19. Crystal structures of bis- and hexakis[(6,6'-di-hydroxy-bipyridine)copper(II)] nitrate coordination complexes.

    Science.gov (United States)

    Gerlach, Deidra L; Nieto, Ismael; Herbst-Gervasoni, Corey J; Ferrence, Gregory M; Zeller, Matthias; Papish, Elizabeth T

    2015-12-01

    Two multinuclear complexes synthesized from Cu(NO3)2 and 6,6'-di-hydroxy-bipyridine (dhbp) exhibit bridging nitrate and hydroxide ligands. The dinuclear complex (6,6'-di-hydroxy-bipyridine-2κ(2) N,N')[μ-6-(6-hy-droxy-pyridin-2-yl)pyridin-2-olato-1:2κ(3) N,N':O (2)](μ-hydroxido-1:2κ(2) O:O')(μ-nitrato-1:2κ(2) O:O')(nitrato-1κO)dicopper(II), [Cu2(C10H7N2O2)(OH)(NO3)2(C10H8N2O2)] or [Cu(6-OH-6'-O-bpy)(NO3)(μ-OH)(μ-NO3)Cu(6,6'-dhbp)], (I), with a 2:1 ratio of nitrate to hydroxide anions and one partially deprotonated dhbp ligand, forms from a water-ethanol mixture at neutral pH. The hexa-nuclear complex bis-(μ3-bi-pyridine-2,2'-diolato-κ(3) O:N,N':O')tetra-kis-(6,6'-di-hydroxy-bipyridine-κ(2) N,N')tetra-kis-(μ-hydroxido-κ(2) O:O')bis-(methanol-κO)tetra-kis-(μ-nitrato-κ(2) O:O')hexa-copper(II), [Cu6(C10H6N2O2)2(CH4O)2(OH)4(NO3)4(C10H8N2O2)4] or [Cu(6,6'-dhbp)(μ-NO3)2(μ-OH)Cu(6,6'-O-bpy)(μ-OH)Cu(6,6'dhbp)(CH3OH)]2, (II), with a 1:1 NO3-OH ratio and two fully protonated and fully deprotonated dhbp ligands, was obtained by methanol recrystallization of material obtained at pH 3. Complex (II) lies across an inversion center. Complexes (I) and (II) both display intra-molecular O-H⋯O hydrogen bonding. Inter-molecular O-H⋯O hydrogen bonding links symmetry-related mol-ecules forming chains along [100] for complex (I) with π-stacking along [010] and [001]. Complex (II) forms inter-molecular O-H⋯O hydrogen-bonded chains along [010] with π-stacking along [100] and [001].

  20. Bis(2,2′-bipyridine(2-hydroxy-2,2-diphenylacetatocopper(II nitrate dihydrate

    Directory of Open Access Journals (Sweden)

    Xuan Xu

    2010-10-01

    Full Text Available In the title complex, [Cu(C14H11O3(C10H8N22]NO3·2H2O, the CuII atom is coordinated by four N atoms from two 2,2′-bipyridine ligands and two O atoms from one benzilate ligand in a distorted octahedral geometry. A supramolecular network is formed via intermolecular O—H...O and C—H...O hydrogen-bonding interactions. π–π stacking interactions between neighboring pyridine rings are also present, the centroid—centroid distance being 3.808 (2 Å.

  1. Preparation and Spectroscopic Properties of Tris(2,2′-bipyridine)ruthenium(Ⅱ) Loaded in Siliceous Mesoporous MCM-41

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    [Ru(bpy)3]2+/MCM-41 composite material obtained by loading tris(2,2′-bipyridine)ruthenium(Ⅱ)([Ru(bpy)3]2+) in siliceous mesoporous MCM-41 was characterized by X-ray powder diffraction, UV-Vis absorption and emission spectroscopies. The absorption spectrum of [Ru(bpy)3]2+/MCM-41 is similar to that of [Ru(bpy)3]2+ aqueous solution, whereas its emission spectrum exhibits hypsochromic shift compared to the solution spectrum. On the other hand, the peak position of the emission spectrum of [Ru(bpy)3]2+/MCM-41 shifts towards longer wavelength when the loading amount increases.

  2. Synthesis, Spectroscopic and Antibacterial Properties of Some Metal (II) Mixed Ligand Complexes of Riboflavin and 2,2'-Bipyridine.

    OpenAIRE

    Aderoju A Osowole; Anthony C. Ekennia; Austin E Osukwe

    2014-01-01

    Mixed ligand complexes of Riboflavin (L) and 2,2’ - Bipyridine (L1) wit h Mn(II), Fe(II), Co(II) , Ni(II), Cu(II) a nd Zn(II) ions were synthesized and characterized by , infrared and electronic spectroscopies, room temperature magnetic moments, melting points and conductance measurements . The % me tal analysis confirmed that the complexes analyzed as [ MX 2 (L)(L 1 )] where X = Cl /(CH 3 C O 2 )/SO 4 . Infrared spectra data confirmed that coordination is via the imine nitrog...

  3. (η6-Benzene)(2,2′-bipyridine-κ2 N,N′)chloridoruthenium(II) chloride methanol sesquisolvate

    OpenAIRE

    Polson, Matthew I. J.

    2007-01-01

    In the title compound, [RuCl(C6H6)(C10H8N2)]Cl·1.5CH4O, the RuII atom is in a distorted octahedral environment coordinated by an η6-benzene ring, a chelating 2,2′-bipyridine ligand and a chloride ion. The asymmetric unit is completed by a chloride anion and two methanol molecules, one of which is disordered about a centre of inversion with an occupancy of 0.5. It is an example of a ruthenium complex with a less sterically congested environment than in similar derivatives. In t...

  4. 4-{Phenyl[4-(6-phenyl-2,2′-bipyridin-4-ylphenyl]amino}benzaldehyde

    Directory of Open Access Journals (Sweden)

    Yu-yang Zhang

    2014-08-01

    Full Text Available The title molecule, C35H25N3O, is a triphenylamine derivative with the 4-position substituted by an aldehyde group, and the 4′-position substituted by a 6-phenyl-2,2′-bipyridine group. The whole molecule is non-planar and the dihedral angle between the core benzene and pyridine rings is 36.96 (5°. The dihedral angle between the phenyl and benzaldehyde groups bonded to the amine N atom is 70.86 (5°.

  5. trans-cis photoisomerization of azobenzene-conjugated dithiolato-bipyridine platinum(II) complexes: extension of photoresponse to longer wavelengths and photocontrollable tristability.

    Science.gov (United States)

    Sakamoto, Ryota; Kume, Shoko; Sugimoto, Manabu; Nishihara, Hiroshi

    2009-01-01

    Azobenzene derivatives modified with dithiolato-bipyridine platinum(II) complexes were synthesized, revealing their highly extended photoresponses to the long wavelength region as well as unique photocontrollable tristability. The absorptions of trans-1 and trans-2 with one azobenzene group on the dithiolene and bipyridine ligands, respectively, cover the range from 300 to 700 nm. These absorptions are ascribed, by means of time-dependent (TD)DFT calculations, to transitions from dithiolene(pi) to bipyridine(pi*), namely, interligand charge transfer (CT), pi-pi*, and n-pi* transitions of the azobenzene unit, and pi-pi* transitions of the bipyridine ligand. In addition, only trans-1 shows distinctive electronic bands, assignable to transitions from the dithiolene(pi) to azobenzene(pi*), defined as intraligand CT. Complex 1 shows photoisomerization behavior opposite to that of azobenzene: trans-to-cis and cis-to-trans conversions proceed with 405 and 312 nm irradiation, which correspond to excitation with the intraligand CT, and pi-pi* bands of the azobenzene and bipyridine units, respectively. In contrast, complex 2 shows photoisomerization similar to that of azobenzene: trans-to-cis and cis-to-trans transformations occur with 365 and 405 nm irradiation, respectively. Irradiation at 578 nm, corresponding to excitation of the interligand CT transitions, results in cis-to-trans conversion of both 1 and 2, which is the longest wavelength ever reported to effect the photoisomerization of the azobenzene group. The absorption and photochromism of 4, which has azobenzene groups on both the dithiolato and bipyridine ligands, have characteristics quite similar to those of 1 and 2, which furnishes 4 with photocontrollable tristability in a single molecule using light at 365, 405, and 578 nm. We also clarified that 1 and 2 have high photoisomerization efficiencies, and good thermal stability of the cis forms. Complexes 3 and 5 have almost the identical photoresponse to those

  6. Coordination chemistry for antibacterial materials: a monolayer of a Cu(2+) 2,2'-bipyridine complex grafted on a glass surface.

    Science.gov (United States)

    Pallavicini, Piersandro; Dacarro, Giacomo; Grisoli, Pietro; Mangano, Carlo; Patrini, Maddalena; Rigoni, Federica; Sangaletti, Luigi; Taglietti, Angelo

    2013-04-01

    A propyltrimethoxysilane-modified 2,2'-bipyridine ligand is synthesized and its acetonitrile solutions are used to prepare monolayers of the molecule on glass surfaces. Absorption and X-ray photoelectron spectroscopy demonstrate that the modified glass surfaces bind Cu(2+) with a 1:1 ratio with respect to the 2,2'-bipyridine moieties under the chosen preparative conditions, producing materials bearing 0.016 μg cm(-2) of copper. Although in trace amounts, the bound Cu(2+) cations exert a significant microbicidal effect against Escherichia coli and Staphylococcus aureus.

  7. π-Stacking and hydrogen bonding in catena-poly[[4,4 '-bipyridine-κN)-dioxouranium(VI)]-di-μ-hydroxo

    International Nuclear Information System (INIS)

    The title compound, [UO2(OH)2(C10H8N2)]n, was obtained under hydrothermal conditions. The U atom is seven-coordinated and its environment is pentagonal bipyramidal, with the oxo atoms in axial positions, and one N atom and four hydroxide groups in the equatorial plane. The hydroxide ions are bridging, which results in the formation of infinite chains with the bipyridine molecules alternately located on either side. Neighbouring chains interpenetrate so that each bipyridine ligand is involved both in hydrogen bonds with two hydroxide ions and in π-stacking with its two neighbours from the next chain. (authors)

  8. Tetrakis[μ-3-(3-hydroxyphenylpropenoato]bis{aqua(2,2′-bipyridine[3-(3-hydroxyphenylpropenoato]neodymium(III} 2,2′-bipyridine disolvate dihydrate

    Directory of Open Access Journals (Sweden)

    Jing-Ke Guo

    2011-12-01

    Full Text Available The dinuclear title compound, [Nd2(C9H7O36(C10H8N22]·2C10H8N2·2H2O, was synthesized under hydrothermal conditions. The centrosymmetric complex consists of two nine-coordinated Nd3+ cations, six 3-hydroxycinnamate anions and two chelating 2,2′-bipyridine molecules. The coordination geometry around the cations can be best described as distorted tricapped trigonal-prismatic. The carboxylate groups show different coordination and bridging modes. Two of them chelate to one Nd3+ cation, two bridge the two cations in a bis-monodentate fashion, and two chelate to one and bridge monodentately to the symmetry-related Nd3+ cation. The dinuclear molecule is surrounded by two 2,2′-bipyridine solvent and two water molecules. Extensive O—H...O and O—H...N hydrogen-bonding interactions between the components lead to the formation of a three-dimensional network.

  9. Interaction of 2-mercaptopyrimidine and 4,4'-bipyridine and competition experiments between bipyridines and 1,10'-phenanthroline for the thiol layer on Au(1 1 1) by STM

    Science.gov (United States)

    Pinheiro, L. S.; Temperini, M. L. A.

    2001-02-01

    STM was employed to study the coadsorption of 4,4'-bipyridine (4bipy) and 2-mercaptopyrimidine (2MPy) on Au(1 1 1). The adsorption of 4bipy as a single layer was also analyzed. For the single layer STM reveals a molecular structure made of parallel periodic chains with a repeat distance of 11.5-11.7 Å. The mixed layer is formed with a ratio of two molecules of 2MPy to one of 4bipy. 4bipy assumes two different positions in relation to the 2MPy dimer. Competition between 4bipy, 2,2'-bipyridine and 1,10'-phenanthroline was investigated to obtain a qualitative view of the preference of the 2MPy assembly for these molecules. The mixed layers were grown on Au(1 1 1) from ternary molecular solutions containing either 2MPy+4bipy+2bipy or 2MPy+4bipy+phen. STM shows that the resulting layers are made of the 2MPy dimeric assembly plus one of the oligopyridines. A split of the 2MPy dimer or the formation of mixed domains with the three molecules present in the stock solution was not found.

  10. XPS study of ruthenium tris-bipyridine electrografted from diazonium salt derivative on microcrystalline boron doped diamond.

    Science.gov (United States)

    Agnès, Charles; Arnault, Jean-Charles; Omnès, Franck; Jousselme, Bruno; Billon, Martial; Bidan, Gérard; Mailley, Pascal

    2009-12-28

    Boron doped diamond (BDD) functionalization has received an increasing interest during the last few years. Such an infatuation comes from the original properties of BDD, including chemical stability or an electrochemical window, that opens the way for the design of (bio)sensors or smart interfaces. In such a context, diazonium salts appear to be well suited for BDD functionalization as they enable covalent immobilization of functional entities such as enzymes or DNA. In this study we report microcrystalline BDD functionalization with a metallic complex, ruthenium tris(bipyridine), using the p-(tris(bipyridine)Ru(2+))phenyl diazonium salt. Electrografting using cyclic voltammetry (CV) allowed the formation of a ruthenium complex film that was finely characterized using electrochemistry and X-ray photoelectron spectroscopy (XPS). Moreover, we showed that chronopotentiometry (CP) is a convenient tool to monitor Ru complex film deposition through the control of the electrochemical pulse parameters (i.e. current density and pulse duration). Finally, such a control was demonstrated through the correlation between electrochemical and XPS characterizations. PMID:20024438

  11. Quantum conductance of 4,4-bipyridine molecular junctions: Role of electrode work function and local d band

    DEFF Research Database (Denmark)

    Rauba, J.M.C.; Strange, Mikkel; Thygesen, Kristian Sommer

    2008-01-01

    We present density-functional theory calculations for the geometry and conductance of 4,4-bipyridine (BPD) nanojunctions with Au and Pt electrodes. The fact that transport takes place via bipyridine's lowest unoccupied molecular orbital (LUMO) suggests that the Au-BPD junction should have larger.......02G(0) for the Au and Pt contacts, respectively (G(0)=2e(2)/h is the conductance quantum). The effect of coupling to the electrodes is investigated by means of the group orbital which makes precise the concept of the local band. The construction allows us to explain and rationalize the first...... conductance than the Pt-BPD junction due to the smaller work function of Au as compared to Pt. On the other hand, coupling to the local d band is stronger in the case of Pt and this broadens the LUMO resonance. We find that these effects largely outbalance each other leading to conductances of 0.01G(0) and 0...

  12. Metal dependent motif transition in a self-assembled monolayer of bipyridine derivatives via coordination: An STM study

    Science.gov (United States)

    Wang, Yi; Yuan, Qunhui; Xu, Hongbo; Zhu, Xuefeng; Gan, Wei

    2016-07-01

    Low-dimensional molecular motifs with diversity developed via the on-surface chemistry are attracting growing interest for their potential in advanced nanofabrication. In this work, scanning tunneling microscopy was employed to investigate the in situ and ex situ metal coordinations between 4,4'-ditetradecyl-2,2'-bipyridine (bpy) and Zn(ii) or Cu(ii) ions at a highly oriented pyrolytic graphite (HOPG)/1-phenyloctane interface under ambient conditions. The results demonstrate that the bpy adopts a flat-lying orientation with its substituted alkyl chains in a tail-to-tail arrangement in a bpy monolayer. For the in situ coordination, the bpy/Zn(ii) and bpy/Cu(ii) complexes are aligned in edge-on fashions, wherein the bpy stands vertically on the HOPG surface and interdigitates at the alkyl chains. In the two-dimensional arrays of ex situ coordinated complexes, metal dependent motifs have been observed with Zn(ii) and Cu(ii), wherein the bipyridine moieties are parallel to the graphite surface. These results suggest that the desired on-surface coordination architectures may be achieved by the intentional selection of the metal centers.

  13. Time-dependent SERS spectra monitoring the dynamic adsorption behavior of bipyridine isomerides combined with bianalyte method.

    Science.gov (United States)

    Yan, Xiunan; Li, Pan; Yang, Liangbao; Liu, Jinhuai

    2016-08-15

    Based on the bianalyte method, time-dependent surface-enhanced Raman spectrosopy (SERS) spectra were applied to observe and study the competitive adsorption of bipyridine isomerides 2,2'-bpy and 4,4'-bpy. These time-dependent SERS spectra offer a significant advantage for observing the continuous SERS spectra of analyte with 2 s resolution, letting one monitor real-time competitive adsorption and corresponding SERS signal intensity for mixed or pure analyte type events under different concentrations. In this study, we report experimental evidence of competitive adsorption of two bipyridine isomerides using SERS mapping and independent spectra in chronological order. On the one hand, the time-dependent SERS spectra of 2,2'-bpy were prior dominated in the early stage either in high concentration or in low concentration. On the other hand, pure type 2,2'-bpy or 4,4'-bpy events only occurred for strong intensity, whereas weak intensity events exhibited more mixed analytes in low concentration, showing a great difference from those at the higher concentration. In addition, we believe that these results and this evidence can motivate the use of time-dependent SERS spectra for distinguishing the fingerprint information of several molecules from similar isomeride molecules in chemical and biological systems. PMID:27181986

  14. Aqua(2,2′-bipyridine-κ2N,N′bis(thiophene-2-carboxylato-κOcopper(II

    Directory of Open Access Journals (Sweden)

    Christoph Janiak

    2009-08-01

    Full Text Available In the title complex, [Cu(C5H3O2S2(C10H8N2(H2O], the CuII atom is in a distorted square-pyramidal environment, with an Addison τ parameter of 0.07. The coordination geometry is defined by two nitrogen donors from the 2,2′-bipyridine ligand, two O atoms from two monodentate thiophene-2-carboxylate ligands and one O atom from the aqua ligand. The latter occupies the elongated apical position. This is different from the related structure of aqua(1,10-phenanthrolinebis(thiophene-2-carboxylatocopper(II where a carboxylate O atom is in the apical position [Feng et al. (2005. Z. Kristallogr. New Cryst. Struct. 220, 429–430]. The uncoordinated carboxylate O atoms form intra- and intermolecular hydrogen bonds to the aqua ligand. Two neighbouring 2,2′-bipyridine ligands form a π-stack, with a centroid–centroid distance of 3.683 (2 Å.

  15. Design and Synthesis of 4,4'-Disubstituted-[2,2']-Bipyridines for Catalyzing CO/Styrene Copolymerization with Palladium(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    郭锦棠; 郁培云; 王海霞; 赵海洋

    2015-01-01

    A series of 4,4'-disubstituted-[2,2']-bipyridines, featuring electron withdrawing/donating functional groups such as amino, chloro, nitro, ethoxycarbonyl, carboxy, methyl, methoxy and hydroxymethyl, have been syn-thesized and employed in the copolymerization of carbon monoxide(CO)and styrene. The available bipyridine and its derivatives were coordinated with palladium(Ⅱ)acetate for catalyzing the copolymerization of CO and styrene, and the concomitant polyketone was characterized by means of 13C NMR, FTIR, differential scanning calo-rimetry(DSC)and element analysis techniques concerning its structure and thermal performance. The effect of dif-ferent electron-donating and electron-withdrawing groups on catalyst performance and molecular weight of co-polymer was studied under certain experimental condition. It has been proved that the enhancement of electron donating and conjugative effects on bipyridine ligand will not only improve the catalytic activity of the composi-tion, but also increase the molecular weight of the as-prepared polyketone. The catalytic activity is the highest in hydroxymethyl substituted 2,2'-bipyridine ligand(1 356 gSTCO/(gPd · h)), when the molecular weight and polydispersity index of the polyketone are Mn=8 502,Mw=1 3440 and Mw/Mn=1.581, respectively.

  16. Polymer Acceptor Based on Double B←N Bridged Bipyridine (BNBP) Unit for High-Efficiency All-Polymer Solar Cells.

    Science.gov (United States)

    Long, Xiaojing; Ding, Zicheng; Dou, Chuandong; Zhang, Jidong; Liu, Jun; Wang, Lixiang

    2016-08-01

    A novel polymer acceptor based on the double B←N bridged bipyridine building block is reported. All-polymer solar cells based on the new polymer acceptor show a power conversion efficiency of as high as 6.26% at a photon energy loss of only 0.51 eV. PMID:27167123

  17. A Selective Chemosensor for Mercuric Ions Based on 4-Aminothiophenol-Ruthenium(II Bis(bipyridine Complex

    Directory of Open Access Journals (Sweden)

    Amer A. G. Al Abdel Hamid

    2011-01-01

    Full Text Available A new ruthenium(II complex (cis-ruthenium-bis[2,2′-bipyridine]-bis[4-aminothiophenol]-bis[hexafluorophosphate] has been synthesized and characterized using standard analytical and spectroscopic techniques, FTIR, 1H and 13C-NMR, UV/vis, elemental analysis, conductivity measurements, and potentiometric titration. Investigation of the synthesized complex with metal ions showed that this complex has photochemical properties that are selective and sensitive toward the presence of mercuric ion in aqueous solution. The detection limit for mercuric ions using UV/vis spectroscopy was estimated to be ~ 0.4 ppm. The results presented herein may have an important implication in the development of a spectroscopic selective detection for mercuric ions in aqueous solution.

  18. Establishment of structure-conductivity relationship for tris(2,2'-bipyridine) ruthenium ionic C(60) salts.

    Science.gov (United States)

    Hong, Jie; Shores, Matthew P; Elliott, C Michael

    2010-12-20

    Three ionic C(60) salts with [Ru(bpy)(3)](m+) (bpy = 2,2'-bipyridine) as cations were synthesized. The UV-vis-NIR spectra, XPS spectra, and elemental analysis have demonstrated their compositions: [Ru(bpy)(3)](2)(C(60)) (1), [Ru(bpy)(3)](C(60)) (2), and [Ru(bpy)(3)](C(60))(2) (3). Single crystals of polycrystalline compounds 1 and 2 were obtained as solvates. At room temperature, all three salts are semiconducting with the highest four-probe conductivity observed for compound 1 at ∼10 S m(-1). The electronic conduction mechanisms can be described appropriately by an electron hopping model in this immobilized polyvalent redox system. PMID:21070047

  19. Analysis of Peculiarities of the SEHRS Spectrum of - Bipyridine Molecule on the Base of the Dipole-Quadrupole Theory

    CERN Document Server

    Chelibanov, V P; Polubotko, A M

    2015-01-01

    The SEHRS spectrum of 4,4' Bipyridine is analyzed on the base of the Dipole Quadrupole theory. It is demonstrated that there appear strong lines caused by vibrations transforming after a unit irreducible representation of the D2 symmetry group. which is most probably describes the symmetry properties of the molecule. These lines are nearly forbidden for the molecule, adsorbed on rough metal surface. Appearance of these lines is associated with a strong quadrupole light molecule interaction, which exists in this system. In addition, there are lines, caused by contributions from both the vibrations transforming after the unit irreducible representation A and the representation B1, which describes transformational properties of the dz component of the dipole moment, which is perpendicular to the surface. This result is associated with the specific geometry of the molecule, when the indicated vibrations can be nearly degenerated and cannot be resolved by the SEHRS spectra analysis. Analysis of the SEHRS spectra f...

  20. Synthesis and Crystal Structure of Palladium(Ⅱ) Complex with 2,2'-Bipyridine-3,3'-dicarboxylic Acid

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The title complex Pd(H2BDA)Cl2(2DMSO (C16H14Cl2N2O6PdS2, H2BDA = 2,2'- bipyridine-3,3'-dicarboxylic acid) has been synthesized and characterized by IR spectra, elemental analysis and 1H NMR spectra. Its structure was determined by single-crystal X-ray diffraction analysis. The complex crystallizes in the monoclinic system, space group P21/c with a = 1.3604(6), b = 1.2606(6), c = 1.3521(6) nm, β = 103.677(7)°, V = 2.2530(17) nm3, Mr = 571.75, Z = 4, Dc = 1.686 g/cm3, μ = 1.280 mm-1, F(000) = 1136, R = 0.0405 and wR = 0.0908. The complex presents a planar quadrangle arrangement and is assembled via hydrogen bonds.

  1. (2,2′-Bipyridine-κ2N,N′dichloridopalladium(II 1,4-dioxane hemisolvate

    Directory of Open Access Journals (Sweden)

    Ricardo Alfredo Gutiérrez Márquez

    2014-06-01

    Full Text Available The asymmetric unit of the title compound, [PdCl2(C10H8N2]·0.5C4H8O2, consists of one PdII complex molecule and a half-molecule of 1,4-dioxane, the complete molecule being generated by inversion symmetry. The PdII atom has an almost square-planar coordination formed by the 2,2′-bipyridine ligand and two chloride ligands. Two intramolecular C—H...Cl hydrogen bonds occur. In the crystal, the PdII complex and 1,4-dioxane molecules are connected by C—H...O hydrogen bonds, forming a layer parallel to (10-1. Within the layer, weak π–π interactions [centroid–centroid distance = 3.817 (4 Å] are observed between the pyridine rings.

  2. Characterization of multi-walled carbon nanotube electrodes functionalized by electropolymerized tris(pyrrole-ether bipyridine) ruthenium (II)

    Energy Technology Data Exchange (ETDEWEB)

    Le Goff, Alan; Holzinger, Michael [Departement de Chimie Moleculaire UMR-5250, ICMG FR-2607, CNRS Universite Joseph Fourier, BP-53, 38041 Grenoble (France); Cosnier, Serge, E-mail: Serge.Cosnier@ujf-grenoble.f [Departement de Chimie Moleculaire UMR-5250, ICMG FR-2607, CNRS Universite Joseph Fourier, BP-53, 38041 Grenoble (France)

    2011-04-01

    We synthesized new electropolymerizable [Ru(bpy){sub n}L{sub m}](PF{sub 6}){sub 2} (L = 4,4 bis(3-pyrrol-1-ylpropyloxy)bipyridyl) derivatives. The introduction of electron donating ether groups in the bipyridine ligand induced a negative shift of the Ru(III)/(II) redox couple. The electrochemical behavior of complex Ru1 (n = 2, m = 1) and complex Ru2 (n = 0, m = 3) were compared using platinum and Multi-Walled Carbon Nanotube (MWCNT) electrode. Higher polymerization yields and surface concentrations were obtained at MWCNT electrodes. Furthermore, MWCNT electrodes increase polymer permeability and decrease the charge trapping phenomenon involved in the oxidation and reduction of the polypyrrolic skeleton of the Ru(II) functionalized polymers.

  3. Host–guest complexes of mixed glycol-bipyridine cryptands: prediction of ion selectivity by quantum chemical calculations, part V

    Directory of Open Access Journals (Sweden)

    Svetlana Begel

    2013-06-01

    Full Text Available The selectivity of the cryptands [2.2.bpy] and [2.bpy.bpy] for the endohedral complexation of alkali, alkaline-earth and earth metal ions was predicted on the basis of the DFT (B3LYP/LANL2DZp calculated structures and complex-formation energies. The cavity size in both cryptands lay between that for [2.2.2] and [bpy.bpy.bpy], such that the complexation of K+, Sr2+ and Tl3+ is most favorable. While the [2.2.bpy] is moderately larger, preferring Rb+ complexation and demonstrating equal priority for Sr2+ and Ba2+, the slightly smaller [2.bpy.bpy] yields more stable cryptates with Na+ and Ca2+. Although the CH2-units containing molecular bars fixed at the bridgehead nitrogen atoms determine the flexibility of the cryptands, the twist angles associated with the bipyridine and glycol building blocks also contribute considerably.

  4. Liquid chromatography of antihistamines using post-column tris(2,2'-bipyridine) ruthenium(III) chemiluminescence detection.

    Science.gov (United States)

    Holeman, J A; Danielson, N D

    1994-09-23

    The separation and detection of five antihistamine drugs commonly found within over-the-counter allergy and cold pharmaceutical products was performed by HPLC with chemiluminescence (CL) detection. Comparable detection limits at 5-10 pmol were found for the antihistamines by both UV at 214 nm and tris(2,2'-bipyridine) ruthenium(III) CL. However, urine samples were found not to generate as large an unretained peak by CL detection as compared to those peaks by UV detection at 214 and 254 nm. For example, the pheniramine peak representing 0.15 microgram/ml was almost totally obscured at 214 nm. Quantitative results received for three antihistamine commercial samples ranged from 4 to 8% error in accuracy when an internal standard was used to compensate for short term detector drift.

  5. Mn(II) complexes containing the polypyridylic chiral ligand (-)-pinene[5,6]bipyridine. Catalysts for oxidation reactions.

    Science.gov (United States)

    Rich, Jordi; Rodríguez, Montserrat; Romero, Isabel; Vaquer, Lydia; Sala, Xavier; Llobet, Antoni; Corbella, Montserrat; Collomb, Marie-Noëlle; Fontrodona, Xavier

    2009-10-14

    A series of mononuclear and dinuclear chiral manganese(II) complexes containing the neutral bidentate chiral nitrogen ligand (-)-pinene[5,6]bipyridine, (-)-L, were prepared from different manganese salts. The chirality in these complexes arises from the pinene ring that has been fused to the 5,6 positions of one pyridine group of the bipyridine ligand. These complexes have been characterized through analytical, spectroscopic (IR, UV/Vis, ESI-MS) and electrochemical techniques (cyclic voltammetry). Single X-ray structure analysis revealed a five-coordinated Mn(II) ion in [{MnCl((-)-L)}2(mu-Cl)2] (2), [{Mn((-)-L)}2(mu-OAc)3](PF6) (3) and [MnCl2(H2O)((-)-L)] (4) and a six-coordinated one in [MnCl2((-)-L)2] (5), [Mn(CF3SO3)2((-)-L)2] (6) and [Mn(NO3)(H2O)((-)-L)2)](NO3) (7). The magnetic properties of the binuclear compounds 2 and 3 have been studied. Both compounds show a weak antiferromagnetic coupling (2, J = -0.22 cm(-1); 3, J = -0.85 cm(-1)). The catalytic activity of the whole set of complexes has been tested with regard to the epoxidation of aromatic alkenes with peracetic acid. In the particular case of styrene, good selectivities and moderate enantioselectivities were obtained. Furthermore, total retention of the initial cis configuration was achieved when epoxidizing cis-beta-methylstyrene with the chloride complexes. In general, the epoxidation activity of these manganese complexes is strongly dependent on the steric encumbrance of the substrates employed.

  6. Copper (II and 2,2'-bipyridine complexation improves chemopreventive effects of naringenin against breast tumor cells.

    Directory of Open Access Journals (Sweden)

    Júlio César Conceição Filho

    Full Text Available Cancer is the second leading cause of death worldwide and there is epidemiological evidence that demonstrates this tendency is emerging. Naringenin (NGEN is a trihydroxyflavanone that shows various biological effects such as antioxidant, anticancer, anti-inflammatory, and antiviral activities. It belongs to flavanone class, which represents flavonoids with a C6-C3-C6 skeleton. Flavonoids do not exhibit sufficient activity to be used for chemotherapy, however they can be chemically modified by complexation with metals such as copper (Cu (II for instance, in order to be applied for adjuvant therapy. This study investigated the effects of Cu(II and 2,2'-bipyridine complexation with naringenin on MDA-MB-231 cells. We demonstrated that naringenin complexed with Cu(II and 2,2'-bipyridine (NGENCuB was more efficient inhibiting colony formation, proliferation and migration of MDA-MB-231 tumor cells, than naringenin (NGEN itself. Furthermore, we verified that NGENCuB was more effective than NGEN inhibiting pro-MMP9 activity by zymography assays. Finally, through flow cytometry, we showed that NGENCuB is more efficient than NGEN inducing apoptosis in MDA-MB-231 cells. These results were confirmed by gene expression analysis in real time PCR. We observed that NGENCuB upregulated the expression of pro-apoptotic gene caspase-9, but did not change the expression of caspase-8 or anti-apoptotic gene Bcl-2. There are only few works investigating the effects of Cu(II complexation with naringenin on tumor cells. To the best of our knowledge, this is the first work describing the effects of Cu(II complexation of a flavonoid on MDA-MB-231 breast tumor cells.

  7. Disposable biosensor based on cathodic electrochemiluminescence of tris(2,2-bipyridine)ruthenium(II) for uric acid determination

    Energy Technology Data Exchange (ETDEWEB)

    Ballesta-Claver, J.; Rodríguez-Gómez, R. [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain); Capitán-Vallvey, L.F., E-mail: lcapitan@ugr.es [ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada (Spain)

    2013-04-03

    Highlights: ► Cathodic ECL offers conventional and non-aggressive analysis conditions. ► The ECL hydrogen peroxide/ruthenium complex system for uric acid determination is novel. ► The ruthenium complex is electrochemically immobilized on graphite screen-printed electrodes. ► The quantification of the uric acid is based on a Stern–Volmer type equation. ► The use of the cathodic ECL working methodology reduces interferences during analysis. -- Abstract: A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)–uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy){sub 3}{sup 2+} in the presence of uricase. The use of a −1.1 V pulse for 1 s with a dwelling time of 10 s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern–Volmer type calibration function shows a dynamic range from 1.0 × 10{sup −5} to 1.0 × 10{sup −3} M with a limit of detection of 3.1 × 10{sup −6} M and an accuracy of 13.6% (1.0 × 10{sup −4} M, n = 5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination.

  8. 2,3,4,5-Tetra­fluoro­benzoic acid–4,4′-bipyridine (2/1)

    OpenAIRE

    Zhu, Xiaohui

    2009-01-01

    The asymmetric unit of the title compound, 2C7H2F4O2·C10H8N2, contains one mol­ecule of 2,3,4,5-tetra­fluoro­benzoic acid (tfb) and half of a centrosymmetric 4,4′-bipyridine mol­ecule. Inter­molecular O—H⋯N hydrogen bonds link two tfb mol­ecules and one 4,4′-bipyridine mol­ecule into a trimer. Weak inter­molecular C—H⋯F inter­actions assemble these trimers into a three-dimensional network structure.

  9. catena-Poly[[[tetraaquacobalt(II]-μ-4,4′-bipyridine-κ2N:N′] 2-[4-(2-carboxylatoethylphenoxy]acetate

    Directory of Open Access Journals (Sweden)

    Xi-Fang Wang

    2009-07-01

    Full Text Available In the title complex, {[Co(C10H8N2(H2O4](C11H10O5}n, the unique CoII ion lies on an inversion center and is coordinated by two N atoms from two 4,4′-bipyridine ligands and four O atoms from four water molecules in a slightly distorted octahedral coordination geometry. The 4,4′-bipyridine ligands bridge CoII ions into a one-dimensional chain structure. In the crystal structure, intermolecular O—H...O hydrogen bonds link cations and anions into a three-dimensional network. The dianions are completely disordered about an inversion center.

  10. Coordination polymers with the chiral ligand N-p-tolylsulfonyl-L-glutamic acid: Influence of metal ions and different bipyridine ligands on structural chirality

    International Nuclear Information System (INIS)

    Four new polymers, namely [Ni(-tsgluO)(2,4'-bipy)2(H2O)2]n.5nH2O (1), [Co(-tsgluO)(2,4'-bipy)2(H2O)2]n.5nH2O (2), [Ni(-tsgluO)(4,4'-bipy)]n.0.5nH2O (3), and [Co(-tsgluO)(4,4'-bipy)]n.0.5nH2O (4), where tsgluO2-=(+)-N-p-tolylsulfonyl-L-glutamate dianion, 2,4'-bipy=2,4'-bipyridine, and 4,4'-bipy=4,4'-bipyridine, have been prepared and structurally characterized. Compounds 1 and 2 are isostructural and mononuclear, and crystallize in the acentric monoclinic space group Cc, forming 1D chain structures. Compound 3 is also mononuclear, but crystallizes in the chiral space group P21, forming a homochiral 2D architecture. In contrast to the other complexes, compound 4 crystallizes in the space group P-1 and is composed of binuclear [Co2O6N2]n4- units, which give rise to a 2D bilayer framework. Moreover, compounds 1, 2, and 4 self-assemble to form 3D supramolecular structures through π-π stacking and hydrogen-bonding interactions, while compound 3 is further hydrogen-bonded to form 3D frameworks. We have demonstrated the influence of the central metal and bipyridine ligands on the framework chirality of the coordination complexes. - Graphical abstract: Four novel polymers based on a chiral ligand were prepared and structurally characterized; it represents the first series of investigations about the effect of central metals and bipyridine ligands on framework chirality.

  11. Luminescent Ruthenium(II) Complex Bearing Bipyridine and N-Heterocyclic Carbene-based C∧N∧C Pincer Ligand for Live-Cell Imaging of Endocytosis

    Science.gov (United States)

    Tsui, Wai-Kuen; Chung, Lai-Hon; Wong, Matthew Man-Kin; Tsang, Wai-Him; Lo, Hoi-Shing; Liu, Yaxiang; Leung, Chung-Hang; Ma, Dik-Lung; Chiu, Sung-Kay; Wong, Chun-Yuen

    2015-03-01

    Luminescent ruthenium(II)-cyanide complex with N-heterocyclic carbene pincer ligand C∧N∧C = 2,6-bis(1-butylimidazol-2-ylidene)pyridine and 2,2'-bipyridine (bpy) shows minimal cytotoxicity to both human breast carcinoma cell (MCF-7) and human retinal pigmented epithelium cell (RPE) in a wide range of concentration (0.1-500 μM), and can be used for the luminescent imaging of endocytosis of the complex in these cells.

  12. Synthesis and Photochemical Properties of a New Substituted Phenol Covalently Linked to Ruthenium (Ⅱ) Tris-bipyridine Containing Four Ester Groups as Sensitizer

    Institute of Scientific and Technical Information of China (English)

    Feng SHI; Hong Yang LI; Xiao Jun PENG; Rong ZHANG; Xiao Qiang CHEN; Jiang Li FAN; Li Cheng SUN

    2004-01-01

    As photosensitizer for solar cell, a new ruthenium (Ⅱ) complex with four ester groups had been synthesized, in which a phenol substituted by {[(2-hydroxy-5-tert-butylbenzyl)(pyridyl2-methyl)amino]methyl} is covalently linked to ruthenium (Ⅱ) tris-bipyridine. The structures of the new compounds were confirmed by NMR and ESI-MS spectra. The electrochemical and photochemical properties were also studied.

  13. Crystal structure of catena-poly[[[triaqua(4-cyanobenzoato-κOnickel(II]-μ-4,4′-bipyridine-κ2N:N′] 4-cyanobenzoate

    Directory of Open Access Journals (Sweden)

    Alfredo A. Morales-Tapia

    2015-11-01

    Full Text Available In the title polymeric complex salt, {[Ni(C8H4NO2(C10H8N2(H2O3](C8H4NO2}n, the NiII cation is coordinated by a 4-cyanobenzoate anion, two 4,4′-bipyridine ligands and three water molecules in a distorted N2O4 octahedral geometry. The 4,4′-bipyridine ligands bridge the NiII cations to form polymeric chains of the title complex cations, propagating along the c-axis direction. The dihedral angle between the pyridine rings of the 4,4′-bipyridine ligand is 24.9 (6°. In the crystal, the uncoordinating 4-cyanobenzoate anions link with the complex cations via O—H...O hydrogen bonds into a three-dimensional supramolecular architecture. Weak C—H...O, C—H...N interactions and π–π stacking [centroid-to-centroid distances = 3.566 (4 and 3.885 (4 Å] are also observed in the crystal.

  14. Synthesis and characterization of 6,6’-bis(2-hydroxyphenyl)-2,2’-bipyridine ligand and its interaction with ct-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Selamat, Norhidayah; Heng, Lee Yook; Hassan, Nurul Izzaty; Karim, Nurul Huda Abd [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43650 Bangi, Selangor (Malaysia)

    2015-09-25

    The tetradentate ligand with four donor atoms OONN was synthesized. Bis(phenoxy)bipyridine ligand was prepared by Suzuki coupling reaction between 6,6’-dibromo-2,2’-bipyridyl and 2-hydroxyphenylboronic acid with presence of palladium (II) acetate. Bis(phenoxy)bipyridine ligand was also synthesized by demethylating of 6,6’-bis(2-methoxyphenyl)-2,2’-bipyridyl ligand through solvent free reaction using pyridine hydrocloride. The formation of both phenoxy and methoxy ligands was confirmed by {sup 1}H, 2D cosy and {sup 13}C NMR spectroscopy, ESI-MS spectrometry, FTIR spectroscopy. The purity of the ligand was confirmed by melting point. Binding studies of small molecules with DNA are useful to understand the reaction mechanism and to provide guidance for the application and design of new and more efficient drugs targeted to DNA. In this study, the binding interaction between the synthesized ligand with calf thymus-DNA (ct-DNA) has been investigated by UV/Vis DNA titration study. From the UV/Vis DNA study, it shows that bis(phenoxy)bipyridine ligand bind with ct-DNA via outside binding with binding contant K{sub b} = 1.19 × 10{sup 3} ± 0.08 M{sup −1}.

  15. Synthesis and characterization of 6,6’-bis(2-hydroxyphenyl)-2,2’-bipyridine ligand and its interaction with ct-DNA

    International Nuclear Information System (INIS)

    The tetradentate ligand with four donor atoms OONN was synthesized. Bis(phenoxy)bipyridine ligand was prepared by Suzuki coupling reaction between 6,6’-dibromo-2,2’-bipyridyl and 2-hydroxyphenylboronic acid with presence of palladium (II) acetate. Bis(phenoxy)bipyridine ligand was also synthesized by demethylating of 6,6’-bis(2-methoxyphenyl)-2,2’-bipyridyl ligand through solvent free reaction using pyridine hydrocloride. The formation of both phenoxy and methoxy ligands was confirmed by 1H, 2D cosy and 13C NMR spectroscopy, ESI-MS spectrometry, FTIR spectroscopy. The purity of the ligand was confirmed by melting point. Binding studies of small molecules with DNA are useful to understand the reaction mechanism and to provide guidance for the application and design of new and more efficient drugs targeted to DNA. In this study, the binding interaction between the synthesized ligand with calf thymus-DNA (ct-DNA) has been investigated by UV/Vis DNA titration study. From the UV/Vis DNA study, it shows that bis(phenoxy)bipyridine ligand bind with ct-DNA via outside binding with binding contant Kb = 1.19 × 103 ± 0.08 M−1

  16. A novel bis tridentate bipyridine carboxamide ligand and its complexation to copper(II): synthesis, structure, and magnetism.

    Science.gov (United States)

    Wang, Jian; Djukic, Brandon; Cao, Jingyi; Alberola, Antonio; Razavi, Fereidoon S; Pilkington, Melanie

    2007-10-15

    A new bis tridentate ligand 2,2'-bipyridine-3,3'-[2-pyridinecarboxamide] H(2)L(1) which can bind transition metal ions has been synthesized via the condensation of 3,3'-diamino-2,2'-bipyridine together with 2-pyridine carbonyl chloride. Two copper(II) coordination compounds have been prepared and characterized: [Cu(2)(L(1))(hfac)(2)].3CH(3)CN.H(2)O (1) and [Cu(2)(L(1))Cl(2)].CH(3)CN (2). The single-crystal X-ray structures reveal that complex 1 crystallizes in the triclinic space group P1, with the unit cell parameters a = 12.7185(6) A, b = 17.3792(9) A, c = 19.4696(8) A, alpha = 110.827(2) degrees, beta = 99.890(3) degrees, gamma = 97.966(3) degrees, V = 3868.3(3) A3, Z = 4, R = 0.0321 and R(w) = 0.0826. Complex 2 crystallizes in the monoclinic space group P2(1)/n with the unit cell parameters a = 12.8622(12) A, b = 9.6100(10) A, c = 19.897(2) A, beta = 102.027(3) degrees, V = 2405.3(4) A(3), Z = 4, R = 0.0409 and R(w) = 0.1005. In both complexes the ligand is in the dianionic form and coordinates the divalent Cu(II) ions via one amido and two pyridine nitrogen donor atoms. In 1, the coordination geometry around both Cu(II) ions is best described as distorted trigonal bipyramidal where the remaining two coordination sites are satisfied by hexafluoroacetylacetonate counterions. In 2 both Cu(II )ions adopt a (4 + 1) distorted square pyramidal geometry. One copper forms a longer apical bond to an adjacent carbonyl oxygen atom, whereas the second copper is chelated to a neighboring Cu-Cl chloride ion to afford a mu-Cl-bridged dimerized [Cu(2)(L(1))Cl(2)](2) complex. The magnetic susceptibility data for 1 (2 -270 K), reveal the occurrence of weak antiferromagnetic interactions between the Cu(II) ions. In contrast, variable-temperature magnetic susceptibility measurements for 2 reveal more complex magnetic properties, with the presence of a weak antiferromagnetic exchange (J = -10.1 K) between the copper ions in each dinuclear copper complex and a stronger ferromagnetic

  17. Multispectroscopic DNA-binding studies of a terbium(III) complex containing 2,2'-bipyridine ligand.

    Science.gov (United States)

    Aramesh-Boroujeni, Zahra; Khorasani-Motlagh, Mozhgan; Noroozifar, Meissam

    2016-01-01

    Agarose gel electrophoresis, absorption, fluorescence, viscosity, and circular dichroism (CD) have been used in exploring the interaction of terbium(III) complex, [Tb(bpy)2Cl3(OH2)] where bipy is 2,2'-bipyridine, with Fish salmon DNA. Agarose gel electrophoresis assay, along with absorption and fluorescence studies, reveal interaction between the corresponding complex and FS-DNA. Also, the binding constants (Kb) and the Stern-Volmer quenching constants (Ksv) of Tb(III) complex with FS-DNA were determined. The calculated thermodynamic parameters suggested that the binding of mentioned complex to FS-DNA was driven mainly by hydrophobic interactions. A comparative study of this complex with respect to the effect of iodide-induced quenching, ionic strength effect, and ethidium bromide exclusion assay reflects binding of explicit to the FS-DNA primarily in a groove fashion. CD and viscosity data also support the groove binding mode. Furthermore, Tb(III) complex have been simultaneously screened for their antibacterial and antifungal activities.

  18. Synthesis and spectral characterization of ternary complexes of oxovanadium(IV) containing some acid hydrazones and 2,2?-bipyridine

    Science.gov (United States)

    Sreeja, P. B.; Kurup, M. R. Prathapachandra

    2005-01-01

    An interesting series of heterocyclic base adducts of oxovanadium(IV) complexes have been synthesized by the reaction of vanadium(IV) oxide acetylacetonate with some hydrazones (H 2L) in the presence of a heterocyclic base 2,2'-bipyridine. The compounds were characterized by analytical and different physico-chemical techniques like IR, electron paramagnetic resonance (EPR) and UV-Vis spectral studies and magnetic studies. The EPR spectra indicate that the free electron is in the d xy orbital. The coordination geometry around oxovanadium(IV) in all complexes is octahedral, with one dibasic tridentate ligand L 2-, and one bidentate heterocyclic base. The IR spectra suggest that coordination takes place through azomethine nitrogen and enolate oxygen from the hydrazide moiety and phenolate oxygen. The pyridyl nitrogens of the hydrazones, H 2L 2 and H 2L 4 are not involved in the coordination. The molar conductivities show that all the complexes are non-electrolytes. All electronic transitions were assigned. All the compounds are paramagnetic. EPR studies of all compounds suggest axial symmetry. The calculated bonding parameters indicate that in-plane σ bonding is more covalent than in-plane π bonding.

  19. Synthesis and spectral characterization of ternary complexes of oxovanadium(IV) containing some acid hydrazones and 2,2'-bipyridine.

    Science.gov (United States)

    Sreeja, P B; Kurup, M R Prathapachandra

    2005-01-01

    An interesting series of heterocyclic base adducts of oxovanadium(IV) complexes have been synthesized by the reaction of vanadium(IV) oxide acetylacetonate with some hydrazones (H(2)L) in the presence of a heterocyclic base 2,2'-bipyridine. The compounds were characterized by analytical and different physico-chemical techniques like IR, electron paramagnetic resonance (EPR) and UV-Vis spectral studies and magnetic studies. The EPR spectra indicate that the free electron is in the d(xy) orbital. The coordination geometry around oxovanadium(IV) in all complexes is octahedral, with one dibasic tridentate ligand L(2-), and one bidentate heterocyclic base. The IR spectra suggest that coordination takes place through azomethine nitrogen and enolate oxygen from the hydrazide moiety and phenolate oxygen. The pyridyl nitrogens of the hydrazones, H(2)L(2) and H(2)L(4) are not involved in the coordination. The molar conductivities show that all the complexes are non-electrolytes. All electronic transitions were assigned. All the compounds are paramagnetic. EPR studies of all compounds suggest axial symmetry. The calculated bonding parameters indicate that in-plane sigma bonding is more covalent than in-plane pi bonding. PMID:15556457

  20. Redetermination of (2,2′-bipyridine-κ2N,N′dichloridopalladium(II dichloromethane solvate

    Directory of Open Access Journals (Sweden)

    Nam-Ho Kim

    2009-06-01

    Full Text Available In the title compound, [PdCl2(C10H8N2]·CH2Cl2, the Pd2+ ion is four-coordinated in a slightly distorted square-planar environment by two N atoms of the 2,2′-bipyridine (bipy ligand and two chloride ions. The compound displays intramolecular C—H...Cl hydrogen bonds and pairs of complex molecules are connected by intermolecular C—H...Cl hydrogen bonds. Intermolecular π–π interactions are present between the pyridine rings of the ligand, the shortest centroid–centroid distance being 4.096 (3 Å. As a result of the electronic nature of the chelate ring, it is possible to create π–π interactions to its symmetry-related counterpart [3.720 (2 Å] and also with a pyridine ring [3.570 (3 Å] of the bipy unit. The present structure is a redetermination of a previous structure [Vicente et al. (1997. Private communication (refcode PYCXMN02. CCDC, Cambridge, England]. In the new structure refinement all H atoms were located in a difference Fourier synthesis. Their coordinates were refined freely, together with isotropic displacement parameters.

  1. Redetermination of (2,2'-bipyridine-κN,N')dichlorido-palladium(II) dichloro-methane solvate.

    Science.gov (United States)

    Kim, Nam-Ho; Hwang, In-Chul; Ha, Kwang

    2009-05-07

    In the title compound, [PdCl(2)(C(10)H(8)N(2))]·CH(2)Cl(2), the Pd(2+) ion is four-coordinated in a slightly distorted square-planar environment by two N atoms of the 2,2'-bipyridine (bipy) ligand and two chloride ions. The compound displays intra-molecular C-H⋯Cl hydrogen bonds and pairs of complex mol-ecules are connected by inter-molecular C-H⋯Cl hydrogen bonds. Inter-molecular π-π inter-actions are present between the pyridine rings of the ligand, the shortest centroid-centroid distance being 4.096 (3) Å. As a result of the electronic nature of the chelate ring, it is possible to create π-π inter-actions to its symmetry-related counterpart [3.720 (2) Å] and also with a pyridine ring [3.570 (3) Å] of the bipy unit. The present structure is a redetermination of a previous structure [Vicente et al. (1997 ▶). Private communication (refcode PYCXMN02). CCDC, Cambridge, England]. In the new structure refinement all H atoms were located in a difference Fourier synthesis. Their coordinates were refined freely, together with isotropic displacement parameters.

  2. Crystal structure of 4,4′-(disulfanediyldibutanoic acid–4,4′-bipyridine (1/1

    Directory of Open Access Journals (Sweden)

    Ana María Atria

    2014-09-01

    Full Text Available 4,4′-(Disulfanediyldibutanoic acid (dtba and 4,4′-bipyridine (4,4′-bpy crystallize in an 1:1 ratio, leading to the title co-crystal with composition C8H14O4S2·C10H8N2. A distinctive feature of the crystal structure is the geometry of the dtba moiety, which appears to be stretched [with a 9.98 (1 Å span between outermost carbons] and acts as an hydrogen-bonding connector, forming linear chains along [-211] with the 4,4′-bpy moiety by way of O—H...N hydrogen bonds and C—H...O interactions. The influence of the molecular shape on the hydrogen-bonding pattern is analysed by comparing the title compound and two other 4,4′-bpy co-crystals with closely related molecules of similar formulation but different geometry, showing the way in which this correlates with the packing arrangement.

  3. Quantum processes in 8-Oxo-Guanine-Ru(bipyridine){3/2+} photosynthetic systems of artificial minimal cells

    Science.gov (United States)

    Tamulis, Arvydas; Grigalavicius, Mantas; Krisciukaitis, Sarunas; Medzevicius, Giedrius

    2011-06-01

    Density functional theory methods were used to investigate various self-assembled photoactive bioorganic systems of interest for artificial minimal cells. The cell systems studied are based on nucleotides or their compounds and consisted of up to 123 atoms (not including the associated water or methanol solvent shells) and are up to 2.5 nm in diameter. The electron correlation interactions responsible for the weak hydrogen and Van derWaals chemical bonds increase due to the addition of a polar solvent (water or methanol). The precursor fatty acid molecules of the system also play a critical role in the quantum mechanical interaction based self-assembly of the photosynthetic center and the functioning of the photosynthetic processes of the artificial minimal cells. The distances between the separated sensitizer, fatty acid precursor, and methanol molecules are comparable to Van derWaals and hydrogen bonding radii. As a result the associated electron correlation interactions compress the overall system, resulting in an even smaller gap between the highest occupied molecular orbital (HOMO), and lowest unoccupied molecular orbital (LUMO) electron energy levels and photoexcited electron tunnelling occurs from the sensitizer (either Ru(bpy){3/2+} or [Ru(bpy)2(4-Bu-4'-Me-2,2'-bpy)]2++ derivatives) to the precursor fatty acid molecules (notation used: Me = methyl; Bu = butyl; bpy = bipyridine). The shift of the absorption spectrum to the red for the artificial protocell photosynthetic centers might be considered as the measure of the complexity of these systems.

  4. Supramolecular Assemblies of(±)-2,2'-Dihydroxy-1,1'-binaphthyl with 2,2'-Bipyridine and Naphthodiazine

    Institute of Scientific and Technical Information of China (English)

    JI Bao-Ming吉保明; CHEN Hua-Ting陈花婷; DU Chen-Xia杜晨霞; DING Kui-Ling丁奎岭

    2004-01-01

    Supramolecular assemblies of (±)-2,2'-dihydroxy-l,l'-binaphthyl (BINOL, A), with aza donor molecules including 2,2'-bipyridine (B) and naphthodiazine (C), have been synthesized and characterized by single-crystal X-ray diffraction methods. Two inclusion complexes crystallize in the triclinic system with P-1 space group. In the inclusion complex between A and B, two molecules of A and two molecules of B are linked each other by intermolecular hydrogen bonds with two molecules of water as the bridges, forming a centrosymmetric dimer with formula of A2(H2O)2B2; while in the inclusion complex between A and C, the molecule C virtually acts as a bridge to link molecules A through intermolecular O-H...N hydrogen bonds, forming a short-chain supramolecular block with interactions also play an important role in the solid-state packing of these two inclusion complexes. The structural information disclosed on the complex between dihydroxy compound and aza hydrogen bond acceptors in this work would be particularly important for the rational design of supramolecular organic functional materials.

  5. A second monoclinic polymorph of bis(2,2′-bipyridine-κ2N,N′diiodidomanganese(II

    Directory of Open Access Journals (Sweden)

    Kwang Ha

    2011-10-01

    Full Text Available The MnII ion in the title complex, [MnI2(C10H8N22], is six-coordinated in a distorted cis-N4I2Mn octahedral environment by four N atoms of the two chelating 2,2′-bipyridine ligands and two iodide anions. As a result of the different trans effects of the N and I atoms, the Mn—N bonds trans to the I atom are slightly longer than the Mn—N bonds trans to the N atom. The dihedral angle between the approximately planar ligands [maximum deviation = 0.064 (7 Å] is 75.0 (1°. Numerous inter- and intramolecular π–π interactions between the pyridyl rings are present, the shortest centroid–centroid distance being 3.905 (5 Å. The structure reported herein represents a new monoclinic polymorph of the previously reported monoclinic (P21/c form [Ha (2011. Z. Kristallogr. New Cryst. Struct. 226, 187–188].

  6. Synthesis and biological evaluation of 4-(2-fluorophenoxy)-3,3'-bipyridine derivatives as potential c-met inhibitors.

    Science.gov (United States)

    Zhao, Sijia; Zhang, Yu; Zhou, Hongyang; Xi, Shuancheng; Zou, Bin; Bao, Guanglong; Wang, Limei; Wang, Jiao; Zeng, Tianfang; Gong, Ping; Zhai, Xin

    2016-09-14

    Six series of novel 4-(2-fluorophenoxy)-3,3'-bipyridine derivatives conjugated with aza-aryl formamide/amine scaffords were designed and synthesized through a structure-based molecular hybridization approach. The target compounds were evaluated for c-Met kinase inhibitory activities and cytotoxicity against four cancer cell lines (HT-29, A549, MKN-45 and MDA-MB-231) in vitro. Most compounds exhibited moderate to excellent potency, and the most promising candidate 26c (c-Met kinase IC50 = 8.2 nM) showed a 4.7-fold increase in cytotoxicity against c-Met-addicted MKN-45 cell line in vitro (IC50 = 3 nM), superior to that of Foretinib (IC50 = 23 nM). The preliminary structure-activity relationship indicated that a 1H-benzo [e] [1,3,4]thiadiazine-3-carboxamide-4,4-dioxide moiety as linker contributed to the antitumor potency. PMID:27187857

  7. Microbore liquid chromatography of tertiary amine anticholinergic pharmaceuticals with tris(2,2'-bipyridine)ruthenium(III) chemiluminescence detection.

    Science.gov (United States)

    Holeman, J A; Danielson, N D

    1995-06-01

    The post-column chemiluminescent reaction of six anticholinergic alkaloid compounds with tris(2,2'-bipyridine)ruthenium(III) (Ru(bpy)3(3+)) is applied to microbore high-performance liquid chromatography (HPLC). At flow rates less than 200 microL/min, the capillary mixing cell in which Ru(bpy)3(3+) and the analyte are mixed directly allows for good light detection. In contrast, a diminished signal occurs at these low flow rates with conventional post-column mixing in a tee. Optimal chemiluminescent pH conditions for atropine, scopolamine, dicyclomine, cyclopentolate, cyclobenzaprine, and procyclidine are determined at moderately basic conditions (pH 7 to 9). 2-Butanone is found to be compatible with the chemiluminescent reaction, whereas tetrahydrofuran and propionitrile cause an increase in background noise and a chemiluminescent signal loss. As 2-butanone is more nonpolar than acetonitrile, it assists in the elution of these hydrophobic anticholinergic compounds. Five anticholinergic compounds are resolved successfully with a PRP-1 polymeric column and a slightly basic mobile phase, but a C8 silica column is better suited for the more hydrophobic compounds (cyclobenzaprine, procyclidine, and dicyclomine).

  8. Redetermination of (2,2'-bipyridine-κN,N')dichlorido-palladium(II) dichloro-methane solvate.

    Science.gov (United States)

    Kim, Nam-Ho; Hwang, In-Chul; Ha, Kwang

    2009-01-01

    In the title compound, [PdCl(2)(C(10)H(8)N(2))]·CH(2)Cl(2), the Pd(2+) ion is four-coordinated in a slightly distorted square-planar environment by two N atoms of the 2,2'-bipyridine (bipy) ligand and two chloride ions. The compound displays intra-molecular C-H⋯Cl hydrogen bonds and pairs of complex mol-ecules are connected by inter-molecular C-H⋯Cl hydrogen bonds. Inter-molecular π-π inter-actions are present between the pyridine rings of the ligand, the shortest centroid-centroid distance being 4.096 (3) Å. As a result of the electronic nature of the chelate ring, it is possible to create π-π inter-actions to its symmetry-related counterpart [3.720 (2) Å] and also with a pyridine ring [3.570 (3) Å] of the bipy unit. The present structure is a redetermination of a previous structure [Vicente et al. (1997 ▶). Private communication (refcode PYCXMN02). CCDC, Cambridge, England]. In the new structure refinement all H atoms were located in a difference Fourier synthesis. Their coordinates were refined freely, together with isotropic displacement parameters. PMID:21582986

  9. Reaction of tris(bipyridine)ruthenium(III) with hydroxide and its application in a solar energy storage system.

    Science.gov (United States)

    Creutz, C; Sutin, N

    1975-08-01

    Irradiation of Ru(bipy)(3) (2+) (bipy = 2,2'-bipyridine) with light below 560 nm results in the formation of a charge-transfer excited state potentially capable of reducing water to dihydrogen with concomitant production of Ru(bipy)(3) (3+). The latter may be reduced by hydroxide [Formula: see text] to form dioxygen and regenerate the starting complex. The use of these reactions in a cell designed to bring about the photochemical decomposition of water is proposed.The stoichiometry, kinetics, and mechanism of the Ru(bipy)(3) (3+)-hydroxide reaction have been investigated by conventional and stopped-flow spectrophotometry. The dioxygen yield is a sharp function of pH, attaining its maximum value (about 80%) at pH 9. At low pH (3 and 4.8) the production of ruthenium(II) is first order with k(obsd) = (1.41 +/- 0.04) x 10(-4) sec(-1) (25 degrees , ionic strength mu = 1.00 M with sodium sulfate). In the intermediate pH range (7.9-10.0) complex kinetics are observed. In the hydroxide range 0.01-0.50 M, ruthenium(II) production is predominantly first order with k(obsd) = k(a)[OH(-)] + k(b)[OH(-)](2) sec(-1); k(a) = 148 M(-1) sec(-1) and k(b) = 138 M(-2) sec(-1) (25 degrees , mu = 1.00 M, sodium sulfate). For the k(a) term, the activation parameters are DeltaH(double dagger) = 15.3 +/- 1.0 kcal mol(-1) and DeltaS(double dagger) = 7 +/- 3 cal deg(-1) mol(-1) (1 cal = 4.184 J). An intermediate species (lambda(max) 800 nm) forms at the same rate as ruthenium(II) in this hydroxide range. It disappears with k(obsd) = 1.2 + 1.1 x 10(2) [OH(-)] sec(-1) at 25 degrees . Similarly absorbing (lambda(max) 750 to 800 nm) species are generated by the addition of hydroxyl radical to M(bipy)(3) (2+/3+) [M = Fe(II), Os(II), Ru(II), Cr(III), Ru(III)] in pulse radiolysis experiments. The kinetics above pH 7 are described in terms of rate-determining nucleophilic attack by hydroxide on the bound bipyridine ring. The hydroxide adduct so generated is tentatively identified with that observed in

  10. The excited triplet (T{sub 1}) state structure and vibrational properties of 2,2'-bipyridine

    Energy Technology Data Exchange (ETDEWEB)

    Lapouge, C.; Buntinx, G. [Laboratoire de Spectrochimie Infrarouge et Raman, UMR 8516 de l' Universite et du CNRS, Centre d' Etudes et de Recherches Lasers et Applications (FR 2416 du CNRS), Bat. C5, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq (France); Poizat, O. [Laboratoire de Spectrochimie Infrarouge et Raman, UMR 8516 de l' Universite et du CNRS, Centre d' Etudes et de Recherches Lasers et Applications (FR 2416 du CNRS), Bat. C5, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq (France)], E-mail: olivier.poizat@univ-lille1.fr

    2008-06-02

    The geometry of the lowest lying excited triplet state (T{sub 1}) of 2,2'-bipyridine (22BPY) was optimized by using the time-dependent density functional theory (TD-DFT) with the B3LYP functional and the SVP basis set. The T{sub 1} state is of {sup 3}B{sub u} symmetry and results from a nearly one-electron {pi}{pi}* transition from the 3b{sub g} HOMO to the 4a{sub u} LUMO. Its geometry is trans-planar and essentially characterized by a reinforcement of the interring CC bond and a quinoidal distortion of the rings. This calculated triplet structure is firmly validated by an unequivocal agreement, for four 22BPY isotopomers, between the derived theoretical vibrational frequencies and previously reported experimental time-resolved resonance Raman (TR3) spectra. Moreover, vertical transitions to the 10 lowest energy triplet states T{sub n} were calculated and the corresponding T{sub 1} state resonance Raman intensities estimated, in the short-time dynamics approximation of the Franck-Condon scattering mechanism, from the gradient of the T{sub n} potential surfaces at the T{sub 1} geometry along the totally symmetric modes. Excellent agreement with the experimental resonance Raman intensities was observed for a 4a{sub u} (LUMO) {yields} 5b{sub g} (LUMO + 3) T{sub 1} {yields} T{sub n} transition. This analysis provides a further support of the TD-DFT optimized T{sub 1} state structure of 22BPY.

  11. CuCl-Catalyzed Aerobic Oxidation of Allylic and Propargylic Alcohols to Aldehydes or Ketones with 1 : 1 Combination of Phenanthroline and Bipyridine as the Ligandst%CuCl-Catalyzed Aerobic Oxidation of Allylic and Propargylic Alcohols to Aldehydes or Ketones with 1 : 1 Combination of Phenanthroline and Bipyridine as the Ligandst

    Institute of Scientific and Technical Information of China (English)

    刘宇; 麻生明

    2012-01-01

    We developed a modified protocol for the oxidation of 2,3-allenyl alcohols using CuCI with l : 1 combination of phenanthroline and bipyridine as the catalyst. To further investigate the applicability of this system, other types of alcohols such as allylic and propargylic alcohols have been tested: we found that both allylic and propargylic alcohols may be oxidized to the corresponding aldehydes or ketones using molecular oxygen in air as the oxidant with moderate to excellent yields.

  12. Investigation of torsional potentials, molecular structure, vibrational properties, molecular characteristics and NBO analysis of some bipyridines using experimental and theoretical tools

    Science.gov (United States)

    Prashanth, J.; Reddy, B. Venkatram; Rao, G. Ramana

    2016-08-01

    The Fourier Transform Infrared (FTIR) and Fourier Transform Raman (FT-Raman) spectra of 2,2‧-bipyridine (2BPE); 4,4‧-bipyridine (4BPE); and 2,4‧-bipyridine (24BPE) were measured in the range 4000-450 cm-1 and 4000-50 cm-1, respectively. Torsional potentials were evaluated at various angles of rotation around the C-C inter-ring bond for the three molecules in order to arrive at the molecular conformation of lowest energy. This conformation was further optimized to get ground state geometry. Vibrational frequencies along with infrared and Raman intensities were computed. In the above calculations, DFT employing B3LYP functional with 6311++G(d,p) basis set was used. The rms error between observed and calculated frequencies was 10.0, 10.9 and 10.2 cm-1 for 2BPE, 4BPE and 24BPE, respectively. A 54-parameter modified valence force field was derived by solving inverse vibrational problem using Wilson's GF matrix method. The force constants were refined using 117 experimental frequencies of the three molecules in overlay least-squares technique. The average error between observed and computed frequencies was 12.44 cm-1. PED and eigen vectors calculated in the process were used to make unambiguous vibrational assignments of all the fundamental vibrations. The values of dipole moment, polarizability and hyperpolarizability were computed to determine the NLO behaviour of these molecules. The HOMO and LUMO energies, thermodynamic parameters and molecular electrostatic surface potentials (MESP) were also evaluated. Stability of the molecules arising from hyper conjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis.

  13. “Covalent Hydration” Reactions in Model Monomeric Ru 2,2'-Bipyridine Complexes: Thermodynamic Favorability as a Function of Metal Oxidation and Overall Spin States

    Energy Technology Data Exchange (ETDEWEB)

    Ozkanlar, Abdullah; Cape, Jonathan L.; Hurst, James K.; Clark, Aurora E.

    2011-09-05

    Density functional theory (DFT) has been used to investigate the plausibility of water addition to the simple mononuclear ruthenium complexes, [(NH{sub 3}){sub 3}(bpy)Ru=O]{sup 2+}/{sup 3+} and [(NH{sub 3}){sub 3}(bpy)RuOH]{sup 3+}, in which the OH fragment adds to the 2,2{prime}-bipyridine (bpy) ligand. Activation of bpy toward water addition has frequently been postulated within the literature, although there exists little definitive experimental evidence for this type of 'covalent hydration'. In this study, we examine the energetic dependence of the reaction upon metal oxidation state, overall spin state of the complex, as well as selectivity for various positions on the bipyridine ring. The thermodynamic favorability is found to be highly dependent upon all three parameters, with free energies of reaction that span favorable and unfavorable regimes. Aqueous addition to [(NH{sub 3}){sub 3}(bpy)Ru=O]{sup 3+} was found to be highly favorable for the S = 1/2 state, while reduction of the formal oxidation state on the metal center makes the reaction highly unfavorable. Examination of both facial and meridional isomers reveals that when bipyridine occupies the position trans to the ruthenyl oxo atom, reactivity toward OH addition decreases and the site preferences are altered. The electronic structure and spectroscopic signatures (EPR parameters and simulated spectra) have been determined to aid in recognition of 'covalent hydration' in experimental systems. EPR parameters are found to uniquely characterize the position of the OH addition to the bpy as well as the overall spin state of the system.

  14. Poly[μ-4,4′-bipyridine-κ2N:N′-μ-thiocyanato-κ2N:S-copper(I)

    OpenAIRE

    Mario Wriedt; Sina Sellmer; Christian Näther

    2008-01-01

    In the crystal structure of the title compound, [Cu(NCS)(C10H8N2)]n, the CuI atom is coordinated by two N atoms from two symmetry-related 4,4′-bipyridine (bipy) ligands and one N and one S atom from two symmetry-related thiocyanate ligands in a distorted tetrahedral environment. The thiocyanate ligands bridge the CuI atoms into a zigzag [CuSCN]n chain running parallel to the a axis. These chains are further connected through two bipy ligands that bridge the CuI centers to generate a two...

  15. catena-Poly[[(5-phenyl-2,2′-bipyridine-κ2N,N′copper(I]-μ-thiocyanido-κ2N:S

    Directory of Open Access Journals (Sweden)

    Shuxin Cui

    2012-02-01

    Full Text Available The title compound, [Cu(NCS(C16H12N2]n, was synthesised under hydrothermal conditions. The CuI ion shows distorted tetrahedral geometry being coordinated by two N atoms from a 5-phenyl-2,2′-bipyridine ligand and by the N and S atoms from two different thiocyanate anions. The CuI ions are bridged by thiocyanide groups, forming a one-dimensional coordination polymer along the b axis. The crystal packing is through van der Waals contacts and C—H...π interactions.

  16. CuCl-catalyzed aerobic oxidation of 2,3-allenols to 1,2-allenic ketones with 1:1 combination of phenanthroline and bipyridine as ligands

    Directory of Open Access Journals (Sweden)

    Shengming Ma

    2011-04-01

    Full Text Available A protocol has been developed to prepare 1,2-allenyl ketones using molecular oxygen in air or pure oxygen as the oxidant from 2,3-allenylic alcohols with moderate to good yields under mild conditions. In this reaction CuCl (20 mol % with 1,10-phenanthroline (10 mol % and bipyridine (10 mol % was used as the catalyst. It is interesting to observe that the use of the mixed ligands is important for the higher yields of this transformation: With the monoligand approach developed by Markó et al., the yields are relatively lower.

  17. Study on the Interaction of Ternary Complex Pd(Ⅱ)-2,2'-bipyridine-L-asparagic acid with DNA

    Institute of Scientific and Technical Information of China (English)

    高恩君; 赵淑敏; 张丹; 刘祁涛

    2005-01-01

    The ternary complex Pd(Ⅱ)-2,2'-bipyridine-L-asparagic acid was synthesized and characterized by elemental analysis, IR-spectra and molar conductance. The formula of the complex is Pd(bipy)(L-asp). The interaction of the complex with DNA has been studied by UV-spectra, fluorescence spectra, CD-spectra and gel electrophoresis. The results showed that the interaction of the complex with DNA performed mainly in intercalative mode and the extent of interaction was dependent on the concentration of the complex.

  18. catena-Poly[[[tetraaquazinc(II]-μ-4,4′-bipyridine-κ2N:N′] benzene-1,4-dicarboxylate

    Directory of Open Access Journals (Sweden)

    Ming-Bo Ruan

    2009-07-01

    Full Text Available In the title compound, {[Zn(C10H8N2(H2O4](C8H4O4}n, the ZnII atoms, lying on a twofold rotation axis, are bridged by 4,4′-bipyridine ligands, resulting in a linear chain along the b axis. In the chain, the ZnII atom adopts a slightly distorted octahedral coordination geometry involving four water molecules at the equatorial positions. The noncoordinated benzene-1,4-dicarboxylate anion, which is also located on a twofold rotation axis, bridges adjacent chains through O—H...O hydrogen bonds, forming a three-dimensional supramolecular network.

  19. (2,2′-Bipyridine-κ2N,N′)[2-tert-butylanilinato(2−)]dichloridooxidomolybdenum(VI) dichloromethane hemisolvate

    OpenAIRE

    Alastair J. Nielson; Waters, Joyce M.

    2010-01-01

    The MoVI atom in the title structure, [Mo(C10H13N)Cl2O(C10H8N2)]·0.5CH2Cl2, has a distorted octahedral coordination sphere with cis-orientated oxide and imide ligands, trans-chloride ligands and the 2,2′-bipyridine (bipy) ligand N atoms lying trans to the oxide and imide ligands. An imide-ligand tert-butyl-methyl-group H atom makes a close approach with the oxide ligand (distance = 2.53 Å) and the imide-ligand N atom (distance = 2.41 Å)...

  20. Synthesis, structure and photoluminescence of (PLAGH)2[ZnCl4] and comparative analysis of photoluminescence properties with tris(2,2′-bipyridine)ruthenium(II)

    International Nuclear Information System (INIS)

    Highlights: • New zinc(II) complex with pyridoxalaminoguanidine was synthesized. • The enhancement of the photoluminescence due to the compound formation was achieved. • Very high photoluminescence of Zn(II) compound was noticed. • Comparative analysis of photoluminescence with tris(2,2′-bipyridine) ruthenium(II) was provided. - Abstract: The first compound of zinc(II) containing pyridoxalaminoguanidine has been synthesized and characterized by elemental analysis, infrared spectra, conductometric measurements and X-ray crystallography. Single crystals of the compound were obtained in the reaction of methanolic solution of zinc(II) chloride and pyridoxalaminoguanidine hydrochloride. In this compound the coordination of chelate ligand is absent and tetrachlorido complex of zinc(II) with pyridoxalaminuguanidinium cation as contraion is obtained. Photoluminescence spectra were measured. Lorentzian multipeak technique was used to determine peak wavelengths and their intensities. Photoluminescence spectroscopy upon 325, 488 and 514 nm laser excitation light was used to obtain results. This novel compound of zinc(II) was compared to the well-known organic light emitting diode material—ruthenium(II) complex with bypiridine i.e., tris(2,2′-bipyridine)ruthenium(II), under the same circumstances and the identical experimental setup. A scheme of energy levels and transitions is proposed to explain the obtained experimental results

  1. Luminescent cyclometalated alkynylgold(III) complexes with 6-phenyl-2,2'-bipyridine derivatives: synthesis, characterization, electrochemistry, photophysics, and computational studies.

    Science.gov (United States)

    Au, Vonika Ka-Man; Lam, Wai Han; Wong, Wing-Tak; Yam, Vivian Wing-Wah

    2012-07-16

    A novel class of luminescent gold(III) complexes containing various tridentate cyclometalating ligands derived from 6-phenyl-2,2'-bipyridine and alkynyl ligands, [Au(RC^N^N)(C≡C-R')]PF(6), has been successfully synthesized and characterized. One of the complexes has also been determined by X-ray crystallography. Electrochemical studies show a ligand-centered reduction originated from the cyclometalating RC^N^N ligands as well as an alkynyl-centered oxidation. The electronic absorption and photoluminescence properties of the complexes have also been investigated. In acetonitrile at room temperature, the complexes show intense absorption at higher energy region with wavelength shorter than 320 nm, and a moderately intense broad absorption band at 374-406 nm, assigned as the metal-perturbed intraligand π-π* transition of the cyclometalating RC(∧)N(∧)N ligand, with some charge transfer character from the aryl ring to the bipyridine moiety. Most of the complexes have been observed to show vibronic-structured emission bands at 469-550 nm in butyronitile glass at 77 K, assigned to an intraligand excited state of the RC^N^N ligand, with some charge transfer character from the aryl to the bipyridyine moiety. Insights into the origin of the absorption and emission have also been provided by density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations. PMID:22731665

  2. A Novel 3D Supramolecular Network Constructed from [Cu(4,4'-bipyridine)(O2CMe)2]2 Molecular Ladders by Hydrogen Bonding

    Institute of Scientific and Technical Information of China (English)

    YANG E; WANG Xiao-Qin; QIN Ye-Yan

    2006-01-01

    The title complex, {[Cu2(4,4'-bipyridine)2(μ-O2CMe)2(O2CMe)2](H2O}n 1, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in monoclinic, space group C2/c with a = 13.4474(5), b = 11.7566(2), c = 19.5380(6) (A), β = 92.930(2)°, V = 3084.84(16) (A)3, Z = 4, Cu2C28N4O9H30, Mr = 693.64, Dc = 1.494 g/cm3, F(000) = 1424 and μ(MoKa) = 1.436 mm-1. With the use of 2062 observed reflections (Ⅰ>2σ(Ⅰ)), the structure was refined to R = 0.0769 and wR = 0.2154. In complex 1, the dimeric copper acetate units are linked through 4,4'-bipyridine to yield 1D molecular ladders. These ladders are connected via O-H···O hydrogen bonds to generate 2D layers, which are further linked through C-H···O hydrogen bonds to give a 3D supramolecular network.

  3. Crystal Structure and Magnetic Property of a Two-dimensional Manganese Compound [Mn(PhCOO)2(4,4'-bipyridine)]n

    Institute of Scientific and Technical Information of China (English)

    CHEN Hui; WANG Wen-Guo; MA Cheng-Bing; CHEN Chang-Neng; LIU Qiu-Tian; LIAO Dai-Zheng; LI Li-Cun

    2007-01-01

    A new two-dimensional polymeric manganese compound [Mn(PhCOO)2(4,4'-bipyridine)]n 1 has been prepared and structurally characterized by X-ray diffraction. The complex crystallizes in space group Pbcn with a = 18.7158(2), b = 11.6919(3), c = 9.4799(2)(A), V = 2074.42(7)(A)3, Z = 4, Mr = 453.34, Dc = 1.452 g/cm3, μ = 0.670 mm-1 and F(000) = 932. The final refinement gave R = 0.0458 and wR = 0.1439 for 1358 observed reflections with Ⅰ> 2σ(Ⅰ). The complex consists of repeating units of Mn(PhCOO)2(4,4'-bipyridine). Each Mn center is sixcoordinated by four carboxylate O atoms of four benzoate anions and two pyridyl N atoms from bipy ligands to furnish a slightly distorted octahedral geometry. The two adjacent Mn atoms are connected by a pair of μ1,3-carboxylate groups to form infinite chains, which are further interlinked by bipy to complete a 2D grid network. The magnetic property of the polymeric complex has also been investigated.

  4. Crystal Structure and Catalytic Behavior in Olefin Epoxidation of a One-Dimensional Tungsten Oxide/Bipyridine Hybrid.

    Science.gov (United States)

    Amarante, Tatiana R; Antunes, Margarida M; Valente, Anabela A; Paz, Filipe A Almeida; Pillinger, Martyn; Gonçalves, Isabel S

    2015-10-19

    The tungsten oxide/2,2'-bipyridine hybrid material [WO3(2,2'-bpy)]·nH2O (n = 1-2) (1) has been prepared in near quantitative yield by the reaction of H2WO4, 2,2'-bpy, and H2O in the mole ratio of ca. 1:2:700 at 160 °C for 98 h in a rotating Teflon-lined digestion bomb. The solid-state structure of 1 was solved and refined through Rietveld analysis of high-resolution synchrotron X-ray diffraction data collected for the microcrystalline powder. The material, crystallizing in the orthorhombic space group Iba2, is composed of a one-dimensional organic-inorganic hybrid polymer, ∞(1)[WO3(2,2'-bpy)], topologically identical to that found in the previously reported anhydrous phases [MO3(2,2'-bpy)] (M = Mo, W). While in the latter the N,N'-chelated 2,2'-bpy ligands of adjacent corner-shared {MO4N2} octahedra are positioned on the same side of the 1D chain, in 1 the 2,2'-bpy ligands alternate above and below the chain. The catalytic behavior of compound 1 for the epoxidation of cis-cyclooctene was compared with that for several other tungsten- or molybdenum-based (pre)catalysts, including the hybrid polymer [MoO3(2,2'-bpy)]. While the latter exhibits superior performance when tert-butyl hydroperoxide (TBHP) is used as the oxidant, compound 1 is superior when aqueous hydrogen peroxide is used, allowing near-quantitative conversion of the olefin to the epoxide. With H2O2, compounds 1 and [MoO3(2,2'-bpy)] act as sources of soluble active species, namely, the oxodiperoxo complex [MO(O2)2(2,2'-bpy)], which is formed in situ. Compounds 1 and [WO(O2)2(2,2'-bpy)] (2) were further tested in the epoxidation of cyclododecene, trans-2-octene, 1-octene, (R)-limonene, and styrene. The structure of 2 was determined by single-crystal X-ray diffraction and found to be isotypical with the molybdenum analogue.

  5. Tris(2,2'-bipyridine)ruthenium Derivatives with Multiple Viologen Acceptors: Quadratic Dependence of Photocatalytic H2 Evolution Rate on the Local Concentration of the Acceptor Site.

    Science.gov (United States)

    Kitamoto, Kyoji; Sakai, Ken

    2016-08-22

    Three Ru(bpy)3 (2+) derivatives tethered to multiple viologen acceptors, [Ru(bpy)2 (4,4'-MV2)](6+) , [Ru(bpy)2 (4,4'-MV4)](10+) , and [Ru(bpy)(4,4'-MV4)2 ](18+) [bpy=2,2'-bipyridine, 4,4'-MV2=4-ethoxycarbonyl-4'-(N-G1 -carbamoyl)-2,2'-bipyridine, and 4,4'-MV4=4,4'-bis(N-G1 -carbamoyl)-2,2'-bipyridine, where G1 =Asp(NHG2 )-NHG2 and G2 =-(CH2 )2 -N(+) C5 H4 -C5 H4 N(+) -CH3 ] were prepared as "photo-charge separators (PCSs)". Photoirradiation of these complexes in the presence of a sacrificial electron donor (EDTA) results in storage of electrons per PCS values of 1.3, 2.7, and 4.6, respectively. Their applications in the photochemical H2 evolution from water in the presence of a colloidal Pt H2 -evolving catalyst were investigated, and are discussed along with those reported for [Ru(bpy)2 (5,5'-MV4)](10+) , [Ru(4,4'-MV4)3 ](26+) , and [Ru(5,5'-MV4)3 ](26+) (Inorg. Chem. Front. 2016, 3, 671-680). The PCSs with high dimerization constants (Kd =10(5) -10(6)  m(-1) ) are superior in driving H2 evolution at pH 5.0, whereas those with lower Kd values (10(3) -10(4)  m(-1) ) are superior at pH 7.0, where Kd =[(MV(+) )2 ]/[MV(+) (.) ](2) . The (MV(+) )2 site can drive H2 evolution only at pH 5.0 as a result of its 0.15 eV lower driving force for H2 evolution relative to MV(+) (.) , whereas the PCSs with lower Kd values exhibit higher performance at pH 7.0 owing to the higher population of free MV(+) (.) . Importantly, the rate of electron charging over the PCSs is linear to the apparent H2 evolution rate, and shows an intriguing quadratic dependence on the number of MV(2+) units per PCS. PMID:27434613

  6. ITO电极上催化伏安法测定锇联吡啶的研究%Determination of Osmium Bipyridine at ITO Electrode by Catalytic Voltammetry

    Institute of Scientific and Technical Information of China (English)

    邹蕊

    2012-01-01

    An electron transfer mediator osmium bipyridine was synthesized. The electrochemical behaviors of osmi- um bipyridine at ITO electrode were studied and the catalytic reaction kinetics of it in system of glucose/glucose ox- idase was measured. The homogeneous reaction rate constant (Ks ) is 2.07 ×10^-2cm/s, and the first- order reac- tion rate constant (Kf) and second -order reaction rate constant (Kmed) in catalyzed reaction are 1.05 × 10^-3s-1 and 1.57× 10^4 L/( mol. s), respectively. The detection limited is 0. 016 μmol/L. Therefore, as an electrochemical label, osmium bipyridine can be used to construct biosensor for the catalyzed signal amplification.%合成了电子转移介体锇联吡啶Os(bpy)3,采用催化伏安法研究了Os(bpy)3在ITO电极上的电化学行为,并对Os(bpy)3在葡萄糖一葡萄糖氧化酶体系中的催化反应动力学常数进行了测定。Os(bpy)3的均相反应速率常数Ks为2.07×10^-2cm/s,催化反应中一级反应速率常Kf为1.05×10^-3s^-1,二级反应速率常数kmed为1.57×10^4L/(mol.s)。并采用催化伏安法测定Os(bpy)3的检出限为为0.016μmol/L。因此,Os(bpy)3作为电化学标记物,能够用于生物传感器的构建。

  7. Poly[μ-4,4′-bipyridine-κ2N:N′-μ-thiocyanato-κ2N:S-copper(I

    Directory of Open Access Journals (Sweden)

    Mario Wriedt

    2008-11-01

    Full Text Available In the crystal structure of the title compound, [Cu(NCS(C10H8N2]n, the CuI atom is coordinated by two N atoms from two symmetry-related 4,4′-bipyridine (bipy ligands and one N and one S atom from two symmetry-related thiocyanate ligands in a distorted tetrahedral environment. The thiocyanate ligands bridge the CuI atoms into a zigzag [CuSCN]n chain running parallel to the a axis. These chains are further connected through two bipy ligands that bridge the CuI centers to generate a two-dimensional brick-like network. The pyridyl planes of the ligands exhibit a dihedral angle of 37.35 (12°.

  8. 4-(2,4-Dichlorophenyl-6-(1H-indol-3-yl-2,2′-bipyridine-5-carbonitrile

    Directory of Open Access Journals (Sweden)

    M. N. Ponnuswamy

    2009-05-01

    Full Text Available The title compound, C25H14Cl2N4, crystallizes with two independent molecules in the asymmetric unit. The two pyridine rings are almost coplanar, making dihedral angles of 3.2 (1 and 8.6 (1° in the two independent molecules. The dichlorophenyl and indole rings are twisted away from the bipyridine ring by 64.32 (5 and 18.46 (4°, respectively in the first molecule and by 51.0 (1 and 27.99 (5°, respectively in the second molecule. The crystal packing is stabilized by C—H...N, C—H...Cl, N—H...N and C—H...π interactions.

  9. (2,2′-Bipyridine-κ2N,N′bromido(1,4,7-trithiacyclononane-κ3S,S′,S′′ruthenium(II hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    José A. Fernandes

    2011-02-01

    Full Text Available The title compound, [RuBr(C10H8N2(C6H12S3]PF6 or [RuBr(bpy([9]aneS3]PF6 ([9]aneS3 is 1,4,7-trithiacyclononane and bpy is 2,2′-bipyridine, exhibits a very similar octahedral coordination geometry for the Ru2+ atom to that of its [RuCl(bpy([9]aneS3]+ analogue, with only the chloride ligand being substituted by a bromide ligand. The presence of a PF6− anion (alongside with the coordinated bromide ligand promotes the existence of an extensive network of weak C—H...X (X = F, Br interactions.

  10. (4,4')-Bipyridine in Vacuo and in Solvents: A Quantum Chemical Study of a Prototypical Floppy Molecule From a Molecular Transport Perspective

    CERN Document Server

    Bâldea, Ioan; Wenzel, Wonfgang

    2015-01-01

    We report results of quantum chemical calculations for the neutral and anionic species of (4,4{'})-bipyridine (44BPY), a prototypical molecule with a floppy degree of freedom, placed in vacuo and in solvents. In addition to equilibrium geometries and vibrational frequencies and spectra, we present adiabatic energy curves for the vibrational modes with significant intramolecular reorganization upon charge transfer. Special attention is paid to the floppy strongly anharmonic degree of freedom of 44BPY, which is related to the most salient structural feature, namely the twist angle $\\theta$ between the two pyridine rings. The relevance of the present results for molecular transport will be emphasized. We show that the solvent acts as an effective gate electrode and propose a scissor operator to account for solvent effects on molecular transport. Our result on the conductance $G$ vs. $\\cos^2\\theta$ is consistent with a significant transmission in perpendicular conformation indicated by previous microscopic analys...

  11. Cyanoacetanilides intermediates in heterocyclic synthesis. Part 6: Preparation of some hitherto unknown 2-oxopyridine, bipyridine, isoquinoline and chromeno[3,4-c]pyridine containing sulfonamide moiety

    Directory of Open Access Journals (Sweden)

    Yousry A. Ammar

    2014-11-01

    Full Text Available Treatment of cyanoacetanilide derivative 1 with tetracyanoethylene (2 in dioxane/triethylamine furnished 2-pyridone derivative 6. Aminopyridine 9 was obtained by cyclization of compound 1 with ketene dithioacetal 7/EtONa. Cyclocondensation of 1 with malononitrile and/or acetylacetone (1:1 M ratio gave pyridine derivatives 11 and 13. Ternary condensation of compound 1, aliphatic aldehydes and malononitrile (1:1:1 M ratio yielded the 2-pyridones 20a and b. Bipyridines 22a–c were prepared by refluxing of compound 21 with active methylene reagents. Cyclization of chromene derivatives 24 and 28 with malononitrile produced the novel chromeno[3,4-c]pyridine 26 and pyrano[3′,2′:6,7]chromeno[3,4-c]pyridine 29.

  12. (Bipyridine-κ2N,N′chlorido[N-(2-hydroxyethyl-N-isopropyldithiocarbamato-κ2S,S′]zinc(II

    Directory of Open Access Journals (Sweden)

    Fatin Allia Mohamad

    2012-07-01

    Full Text Available The ZnII atom in the title compound, [Zn(C6H12NOS2Cl(C10H8N2], is coordinated by a chelating N-2-hydroxyethyl-N-isopropyldithiocarbamate ligand, a 2,2′-bipyridine ligand and a Cl atom. The resulting ClN2S2 donor set defines a distorted square-pyramidal coordination geometry. Helical supramolecular chains sustained by O—H...S hydrogen bonds and propagating along the b axis feature in the crystal packing. A three-dimensional architecture is stabilized by C—H...O, C—H...S and C—H...Cl interactions.

  13. Synthesis, Characterization Studies and Bond Valence Sum (BVS) analysis on 2:1 Adducts involving Zinc(II)dithiocarbamates and 4,4’-Bipyridine

    OpenAIRE

    Arumugam Manohar; Kuppukannu Ramalingam; Kottamalai Karpagavel

    2015-01-01

    2:1 adducts involving [Zn(dtc)2]2 (dtc- = pipdtc-, H10C5NCS-2; dnpdtc-, (H3CCH2CH2)2NCS-2; dedtc-, (H5C2)2NCS-2; dmdtc-, (H3C)2NCS-2; nmedtc-, HOCH2CH2(CH)3NCS-2; deadtc-, (HOCH2CH2)2NCS-2) and 4,4' – bipyridine were prepared and characterized by elemental analyses, IR, UV-Visible, Cyclic voltammetric and thermal studies. IR spectra of the complexes show the reduction in the thioureide stretching frequency due to the increase in coordination around the zinc ion and the resultant increase in e...

  14. cis-Bis(2,2'-bipyridine-κN,N')bis-(dimethyl sulfoxide-κO)zinc bis-(tetra-phenyl-borate) dimethyl sulfoxide monosolvate.

    Science.gov (United States)

    Tomyn, Stefania; Gumienna-Kontecka, Elżbieta; Usenko, Natalia I; Iskenderov, Turganbay S; Prisyazhnaya, Elena V

    2011-12-01

    In the mononuclear title complex, [Zn(C(10)H(8)N(2))(2)(C(2)H(6)OS)(2)](C(24)H(20)B)(2)·C(2)H(6)OS, the Zn(II) ion is coordinated by four N atoms of two bidentate 2,2'-bipyridine mol-ecules and by the O atoms of two cis-disposed dimethyl sulfoxide mol-ecules in a distorted octa-hedral geometry. The S atom and the methyl groups of one of the coordinated dimethyl sulfoxide mol-ecules are disordered in a 0.509 (2):0.491 (2) ratio. The crystal packing is stabilized by C-H⋯O hydrogen bonds between the dimethyl sulfoxide solvent mol-ecules and tetra-phenyl-borate anions. PMID:22199567

  15. Electrogenerated chemiluminescence of tris(2,2' bipyridine)ruthenium(II) using common biological buffers as co-reactant, pH buffer and supporting electrolyte.

    Science.gov (United States)

    Kebede, Noah; Francis, Paul S; Barbante, Gregory J; Hogan, Conor F

    2015-11-01

    A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3](2+)). These were found to be very attractive as "multi-tasking" reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)3](2+) in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications. PMID:26347905

  16. Synthesis and fluorescence properties of Eu(Ⅲ), Tb(Ⅲ) and Sm(Ⅲ) with β-diketone and 2,2'- bipyridine

    Institute of Scientific and Technical Information of China (English)

    LIU Xingwang; JIANG Jiadong; YONG Shengli; GUO Yuwei; YANG Kun; WANG Li

    2012-01-01

    Three new rare earth ternary complexes,RE(PPP)3bpy (RE=Sm3+,Eu3+,Tb3+),were synthcsized by the reaction of 1-phenyl-3-(p-phenylethynylphenyl)-1,3-propanedione (HPPP) and 2,2'-bipyridine(bpy) with rare earth chloride RECl3,respectively,in alcohol solution.The compositions were characterized by means of infrared (IR) spectra,chemical analysis,elemental analysis,and thermodynamic analysis.Luminescent properties of the three complexes were studied.At room temperature,under UV light excitation,the Sm3+,Eu3+ and Tb3+ complexes exhibited characteristic emission of the central ions.The fluorescence spectra showed that the fluorescence emission intensity of Eu3+ complex was the strongest.The narrow strongest emission band of Eu3+ complex was considered to be a valuable material with bright red fluorescence.

  17. Electrogenerated chemiluminescence of tris(2,2' bipyridine)ruthenium(II) using common biological buffers as co-reactant, pH buffer and supporting electrolyte.

    Science.gov (United States)

    Kebede, Noah; Francis, Paul S; Barbante, Gregory J; Hogan, Conor F

    2015-11-01

    A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3](2+)). These were found to be very attractive as "multi-tasking" reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)3](2+) in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications.

  18. One novel multidimensional organic-inorganic hybrid based on polyoxometalates and copper chlorine coordination polymers with 4,4′-bipyridine ligands

    Institute of Scientific and Technical Information of China (English)

    Li Chun Xuan; Qing Jiang Pan

    2012-01-01

    One novel organic-inorganic hybrid materials with 4,4′-bipy ligands and copper chlorine coordination polymers as linkers,with new topology,{[CuI(4,4′-bipy)]10Cl2(SiW12O40)2}·6H2O (1) (4,4′-bipy =4,4′-bipyridine),has been hydrothermally synthesized.The single crystal X-ray structural analysis reveals that the structure of 1 is constructed from classical Keggin anions and [CuI(4,4′-bipy)] cations into a novel,three-dimensional (3D) polyoxometalates (POMs)based network.From the topological view,compound 1 is a novel (3.44.52.63)(32.44.56.69) topology.The electrochemical and photocatalysis properties of 1 have been investigated in details.

  19. Electrogenerated chemiluminescence quenching of Ru(bpy)32+ (bpy=2,2′-bipyridine) in the presence of acetaminophen, salicylic acid and their metabolites

    International Nuclear Information System (INIS)

    Quenching of Ru(bpy) 32+ (bpy=2,2′-bipyridine) coreactant electrogenerated chemiluminescence (ECL) has been observed in the presence of acetaminophen, salicylic acid and related complexes. However, no quenching is observed with the acetylsalicylic acid. In most instances, quenching is observed with 100-fold excess of quencher (compared to ECL luminophore) with complete quenching observed between 10,000 and 100,000 fold excess. Fluorescence and UV–vis experiments coupled with bulk electrolysis support the formation of benzoquinone products upon electrochemical oxidation. The mechanism of quenching may involve the interaction of the electrochemically generated benzoquinone species with (i) the ⁎Ru(bpy)32+ excited state or (ii) highly energetic coreactant radicals. - Highlights: ▶ Efficient quenching of the electrogenerated chemiluminescence is observed. ▶ Acetaminophen, salicylic acid and related compounds can be detected. ▶ The mechanism of quenching involves benzoquinones formed upon electrolysis.

  20. Metal-organic framework based on copper(I) sulfate and 4,4‧-bipyridine catalyzes the cyclopropanation of styrene

    Science.gov (United States)

    Shi, Fa-Nian; Silva, Ana Rosa; Rocha, João

    2011-08-01

    The hydrothermal synthesis of a new metal-organic framework (MOF) formulated as Cu 2(4,4'-bpy) 2SO 4·6(H 2O), [abbreviation: (1); bpy or 4,4'-bpy=4,4'-bipyridine; SO 42-=sulfate group] has been reported. The structure of this MOF consists of Cu + nodes connected via 4,4'-bpy to form infinite chains, with two neighboring chains further bridged on the nodes by SO 42-, resulting in a 1-D double chain network. Guest water molecules reside in between the chains and are hydrogen-bonded to the O and S atoms from the nearest sulfate groups, leading to the formation of a 3-D supramolecular framework. This MOF is good heterogeneous catalyst for the cyclopropanation of styrene, with high trans cyclopropane diastereoselectivity and was recycled and reused for three consecutive cycles without a significant loss of catalytic activity.

  1. Coordination Complexes of Decamethylytterbocene with4,4'-Disubstituted Bipyridines: An Experimental Study of Spin Coupling inLanthanide Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Marc D.; Berg, David J.; Andersen, Richard A.

    2005-12-08

    The paramagnetic 1:1 coordination complexes of (C5Me5)2Ybwith a series of 4,4'-disubstituted bipyridines, bipy-X, where X is Me,tert-Bu, OMe, Ph, CO2Me, and CO2Et have been prepared. All of thecomplexes are paramagnetic and the values of the magnetic susceptibilityas a function of temperature show that these values are less thanexpected for the cation, [(C5Me5)2Yb(III)(bipy-X)]+, which have beenisolated as the cation-anion ion-pairs[(C5Me5)2Yb(III)(bipy-X)]+[(C5Me5)2YbI2]f fnfn where X is CO2Et, OMe andMe. The 1H NMR chemical shifts (293 K) for the methine resonances locatedat the 6,6' site in the bipy-X ring show a linear relationship with thevalues of chiT (300 K) for the neutral complexes which illustrates thatthe molecular behavior does not depend upon the phase with one exception,viz., (C5Me5)2Yb(bipy-Me). Single crystals of the 4,4'-dimethylbipyridinecomplex undergo an irreversible, abrupt first order phase change at 228 Kthat shatters the single crystals. The magnetic susceptibility,represented in a delta vs. T plot, on this complex, in polycrystallineform undergoes reversible abrupt changes in the temperature regime 205 -212 K, which is suggested to be due to the way the individual molec ularunits pack in the unit cell. A qualitative model is proposed thataccounts for the sub-normal magnetic moments in theseytterbocene-bipyridine complexes.

  2. Crystal structures of [Ln(NO33(μ2-bpydo2], where Ln = Ce, Pr or Nd, and bpydo = 4,4′-bipyridine N,N′-dioxide: layered coordination networks containing 44 grids

    Directory of Open Access Journals (Sweden)

    Michael L. Stromyer

    2016-01-01

    Full Text Available Three isostructural coordination networks of Ce, Pr, and Nd nitrate with 4,4′-bipyridine N,N′-dioxide (bpydo are reported, namely poly[[tris(nitrato-κ2O,O′cerium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Ce(NO33(C10H8N2O22], poly[[tris(nitrato-κ2O,O′praeseodymium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Pr(NO33(C10H8N2O22], and poly[[tris(nitrato-κ2O,O′neodymium(III]-bis(μ2-4,4′-bipyridine N,N′-dioxide-κ2N:N′], [Nd(NO33(C10H8N2O22]. All three compounds are isostructural to the previously reported La analogue. The asymmetric unit of [Ln(NO33(μ2-bpydo2] contains one lanthanide cation, two bpydo ligands, and three nitrate anions. Both bpydo ligands act as end-to-end μ2-bridges and display nearly ideal cis and gauche conformations, respectively. The bpydo ligands link the ten-coordinate LnIII cations, forming interdigitating 44 grid-like layers extending parallel to (-101, where interdigitation of layers is promoted by C—H...O interactions between nitrate anions and bpydo ligands. The interdigitated layers are linked to sets of neighboring layers via further C—H...O and π–π interactions.

  3. Ion-pair triple helicates and mesocates self-assembled from ditopic 2,2 -bipyridine-bis(urea) ligands and Ni(II) and Fe(II) sulfate salts

    Energy Technology Data Exchange (ETDEWEB)

    Custelcean, Radu [ORNL; Bonnesen, Peter V [ORNL; Roach, Benjamin D [ORNL; Duncan, Nathan C [ORNL

    2012-01-01

    NiSO{sub 4} and FeSO{sub 4} self-assemble with heteroditopic ligands (L) comprising 2,2{prime}-bipyridine and o-phenylene-(bis)urea cation- and anion-binding sites, respectively, into [ML{sub 3}SO{sub 4}] (M = Ni{sup 2+}, Fe{sup 2+}) triple-stranded ion-pair helicates and mesocates.

  4. Oxovanadium(IV) Compounds of cis-[VOCl(N-N)2]+ (N-N = 4,4'- and 5,5'-dimethyl-2,2'-bipyridine); Crystal Structure and Biological Activity

    International Nuclear Information System (INIS)

    Vanadium(IV) complexes in a general formula of cis-[VOX(N-N)2]0/+1, (X=Cl., OH., SO4-2 and N-N = phen, bipy) have been reported. We considered the methyl-substituted bipyridine analogues, 4,4'-dimethyl-2,2'-bipyridine (4dmbpy) and 5,5'-dimethyl-2,2'-bipyridine (5dmbpy) as ligands since our last studies on cytotoxicity of oxovanadium(IV) exhibited that introduction of a methyl group into N-N ligands causes further enhanced cytotoxicity of the related complex. Totally, two new oxovanadium(IV), [VOCl(4dmbpy)2]·Cl·H2O·C2H5OH (1) and [VOCl(5dmbpy)2]·Cl·H2O·CH3OH (2) were synthesized, proposing anticancer activity of the cationic part of the complexes, as ionic vanadium compounds show to increase membrane permeability with a potential for dose reduction.4 Both complexes were fully characterized by means of elemental analysis, IR and UV-Vis. spectroscopy as well as the X-ray diffraction method. Furthermore their cytotoxicity were assayed in three cell cultures, colorectal adenocarcinoma (Caco-2), colon carcinoma (HT-29) and breast ductal carcinoma (T47D) by means of MTT assay (MTT=3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide) and the results were compared with cisplatin, an anticancer drugs which shows limited activity on colon and breast cancers

  5. Bis(2,2′-bipyridine-κ2N,N′bis(1H-indole-2-carboxylato-κ2O,O′cadmium–2,2′-bipyridine–water (1/0.5/2

    Directory of Open Access Journals (Sweden)

    Yun-Xia Li

    2011-07-01

    Full Text Available The asymmetric unit of title compound, [Cd(C9H6NO22(C10H8N22]·0.5C10H8N2·2H2O, consists of one complex molecule, one half of an uncoordinated 2,2′-bipyridine molecule and two solvent water molecules. The uncoordinated 2,2′-bipyridine molecule is located on a center of symmetry. Within the complex molecule, the CdII atom is coordinated by four N atoms from two 2,2′-bipyridine ligands and three O atoms from two 1H-indole-2-carboxylate anion ligands, completing a distorted CdN4O3 pentagonal bipyramid. The molecules are assembled into one-dimensional chains along the [100] direction through classical hydrogen bonds (O—H...N, N—H...O and O—H...O. The resulting chains are further connected into two-dimensional supramolecular layers parallel to the (110 direction by intermolecular classical hydrogen bonds (N—H...O and O—H...O from adjacent chains. A three-dimensional supramolecular network is formed via interlayer and O—H...O hydrogen bonds.

  6. Crystal structures of 2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-ethoxyprop-2-en-1-ide and bis(2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-(dicyanomethylenepropane-1,3-diide

    Directory of Open Access Journals (Sweden)

    Zouaoui Setifi

    2015-05-01

    Full Text Available In 2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-ethoxyprop-2-en-1-ide, C10H9N2+·C9H5N4O−, (I, the ethyl group in the anion is disordered over two sets of atomic sites with occupancies 0.634 (9 and 0.366 (9, and the dihedral angle between the ring planes in the cation is 2.11 (7°. The two independent C(CN2 groups in the anion make dihedral angles of 10.60 (6 and 12.44 (4° with the central propenide unit, and the bond distances in the anion provide evidence for extensive electronic delocalization. In bis(2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-(dicyanomethylenepropane-1,3-diide [alternative name bis(2,2′-bipyridin-1-ium tris(dicyanomethylenemethanediide], 2C10H9N2+·C10N62− (II, the dihedral angles between the ring planes in the two independent cations are 7.7 (2 and 10.92 (17°. The anion exhibits approximate C3 symmetry, consistent with extensive electronic delocalization, and the three independent C(CN2 groups make dihedral angles of 23.8 (2, 27.0 (3 and 27.4 (2° with the central plane. The ions in (I are linked by an N—H...N hydrogen bond and the resulting ion pairs are linked by two independent C—H...N hydrogen bonds, forming a ribbon containing alternating R44(18 and R44(26 rings, where both ring types are centrosymmetric. The ions in (II are linked by two independent N—H...N hydrogen bonds and the resulting ion triplets are linked by a C—H...N hydrogen bond, forming a C21(7 chain containing anions and only one type of cation, with the other cation linked to the chain by a further C—H...N hydrogen bond.

  7. SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES ON MIXED LIGAND COMPLEXES OF CO (II, NI (II AND CU (II WITH ISOXAZOLE SCHIFF BASE AND 1, 10-PHENANTHROLINE/ 2, 2' -BIPYRIDINE LIGANDS Synthese, Charakterisierung und antimikrobiellen STUDIES ON MIXED Ligand-Komplexe von Co (II, Ni (II und Cu (II MIT Isoxazol SCHIFF BASE AND 1, 10-Phenanthrolin / 2, 2 '-Bipyridin-Liganden

    Directory of Open Access Journals (Sweden)

    R.Shakru, N.J.P.Subhashini, Shivaraj

    2011-08-01

    Full Text Available Synthesis, Characterization and antimicrobial studies of Cobalt (II, Nickel (II and Copper (II ternary complexes of mixed ligands with Schiff base derived from 3-amino 5-methyl isoxazole with 2-hydroxy 1-naphthaldehyde and 1, 10-phenanthroline/ 2, 2' bipyridine. The micro analytical, magnetic moment, IR and electronic spectral data analysis have been used to confirm the structure of these complexes, their lower electrical conductance values indicates that all the complexes are non- electrolytes. The magnetic moment values and electronics spectral data of the Co (II and Ni (II complexes further indicates the octahedral geometry and Cu (II complexes are tetragonal geometry. The synthesized compounds have been tested against microorganisms such as (bacillus and pseudomonas bacteria and (R.Saloni and A. niger fungi. A comparative study of the MIC (minimum inhibitory concentration values of the ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligand and control.

  8. Ruthenium-bipyridine complexes bearing fullerene or carbon nanotubes: synthesis and impact of different carbon-based ligands on the resulting products.

    Science.gov (United States)

    Wu, Zhen-yi; Huang, Rong-bin; Xie, Su-yuan; Zheng, Lan-sun

    2011-09-01

    This paper discusses the synthesis of two carbon-based pyridine ligands of fullerene pyrrolidine pyridine (C(60)-py) and multi-walled carbon nanotube pyrrolidine pyridine (MWCNT-py) via 1,3-dipolar cycloaddition. The two complexes, C(60)-Ru and MWCNT-Ru, were synthesized by ligand substitution in the presence of NH(4)PF(6), and Ru(II)(bpy)(2)Cl(2) was used as a reaction precursor. Both complexes were characterized by mass spectroscopy (MS), elemental analysis, nuclear magnetic resonance (NMR) spectroscopy, infrared spectroscopy (IR), ultraviolet/visible spectroscopy (UV-VIS) spectrometry, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and cyclic voltammetry (CV). The results showed that the substitution way of C(60)-py is different from that of MWCNT-py. The C(60)-py and a NH(3) replaced a Cl(-) and a bipyridine in Ru(II)(bpy)(2)Cl(2) to produce a five-coordinate complex of [Ru(bpy)(NH(3))(C(60)-py)Cl]PF(6), whereas MWCNT-py replaced a Cl(-) to generate a six-coordinate complex of [Ru(bpy)(2)(MWCNT-py)Cl]PF(6). The cyclic voltammetry study showed that the electron-withdrawing ability was different for C(60) and MWCNT. The C(60) showed a relatively stronger electron-withdrawing effect with respect to MWCNT. PMID:21769337

  9. Complexation of different transition metals with 4,4'-dimethyl-2,2'-bipyridine: Crystal structure, UV spectra and Hirshfeld surfaces.

    Science.gov (United States)

    Yang, Li-Jing; Liu, Qing-Ling; Wang, Ming-Xin; Gu, Lian-Shuai; Luo, Yang-Hui; Sun, Bai-Wang

    2016-09-01

    Four new complexes, [Co(dmbpy)2(dca)2]·CH3OH (1), [Ni(dmbpy)2(dca)2]·CH3OH (2), [Zn(dmbpy)2(dca)2]·(3) and [Cu(dmbpy)2(OH)2]·5H2O (4) (dca=dicyanamide), derived from 4,4'-dimethyl-2,2'-bipyridine (dmbpy) have been synthesized and characterized by elemental analysis, TGA and single-crystal X-ray diffraction. Crystal structures and Hirshfeld surfaces analysis revealed that the complexes 1-3 were mainly supported by OH⋯N, CH⋯N and π⋯π intermolecular interactions, and for complex 4, the uncoordinated water molecules play a key role in the construction of the 3D stacking motif. UV spectrum measurements demonstrate that all of the complexes show typical metal to ligand charge transfer (MLCT) absorption bands between 301 and 306nm. Moreover, after complexation, the absorption maximum bands about intraligand π→π* transitions similarly show slightly red shift compared to dmbpy ligand, consisting with the DFT calculations. PMID:27176132

  10. A Microcalorimetry and Spectroscopy Study on the Interaction of BSA with 2,2′-Bipyridine Octylglycinato Palladium(II) Nitrate

    Institute of Scientific and Technical Information of China (English)

    MANSOORI-TORSHIZI Hassan; ISLAMI-MOGHADDAM Mahbobe; SABOURY Ali Akbar

    2003-01-01

    The interaction of bovine serum albumin (BSA) with a new palladium(II) complex [Pd(bpy)(Oct-Gly)]NO3 (bpy, 2,2′-bipyridine; Oct-Gly, octyl-glycine) was studied by isothermal titration UV-visible spectrophotometry and microcalorimetry in 30 mmol/L Tris buffer, pH 7.0. There is a set of 18 binding sites for this complex on BSA at 300 and 310 K with positive cooperativity in the binding process. The Hill coefficients at 300 and 310 K are 2.2 and 2.4, respectively. The binding of this palladium complex on BSA is endothermic with mean association binding constant of 21.0 and 16.4 (mmol/L)-1 at 300 and 310 K, respectively. The complex can denature the protein as surfactants. The stability of BSA in the interaction study with the complex is 84 and 58 kJ/mol at 300 and 310 K, respectively. Also, the enthalpy of BSA denaturation due to the interaction with the complex is 842 kJ/mol.

  11. Three silver-based complexes constructed from organic carboxylic acid and 4,4‧-bipyridine-like ligands: Syntheses, structures and photocatalytic properties

    Science.gov (United States)

    Wang, Chong-chen; Jing, Huan-ping; Wang, Peng

    2014-09-01

    The reactions of AgNO3 with combinations of 4,4‧-bipyridine (bpy)/1,2-di(4-pyridyl)ethylene (dpe), and 5-aminophthalic acid (H2ap)/2,6-Naphthalenedicarboxylic acid (H2npdc)/4,4‧-stilbenedicarboxylic acid (H2sbdc) in aqueous alcohol/ammonia at room temperature produce crystals of [Ag4(bpy)4](ap)2·11H2O (1), [Ag2(bpy)2](npdc)·2H2O (2) and [Ag2(dpe)1.5(sbdc)0.5](sbdc)0.5·7H2O (3). All complexes 1, 2 and 3 consist of 1D infinite silver-ligand cationic chains, interspersed with organic carboxylate anions that provide charge compensation in the crystal structures. The lattice water molecules are situated among the framework of the crystal structure and show rich hydrogen-bonding interactions, which serve to orientate of the organic carboxylate anions in the crystal packing, while the presence of Ag⋯N and Ag⋯Ag contacts strengthens the frameworks. In addition, complexes 1-3 exhibit good photocatalytic activities for dye decolorization under UV light.

  12. Electrochemiluminescent determination of methamphetamine based on tris(2,2'-bipyridine)ruthenium(II) ion-association in organically modified silicate films

    Energy Technology Data Exchange (ETDEWEB)

    Yi Changqing [Key Laboratory of Analytical Sciences of Ministry of Education, Department of Chemistry, Xiamen University, Xiamen 361005 (China); Tao Yin [Key Laboratory of Analytical Sciences of Ministry of Education, Department of Chemistry, Xiamen University, Xiamen 361005 (China); Wang Bo [Institute of Criminal Science and Technology of Xiamen, Xiamen 361005 (China); Chen Xi [Key Laboratory of Analytical Sciences of Ministry of Education, Department of Chemistry, Xiamen University, Xiamen 361005 (China)]. E-mail: xichen@xmu.edu.cn

    2005-06-13

    Tetramethoxysilane (TMOS) and dimethyldimethoxysilane (DiMe-DiMOS) were used as co-precursor to immobilize poly(p-styrenesulfonate) (PSS), then tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy){sub 3} {sup 2+}) was successfully immobilized on a glass carbon electrode via ion-association. The immobilized Ru(bpy){sub 3} {sup 2+} shows good electrochemical and photochemical activities. Electrochemical and electrochemiluminescence (ECL) characterizations of the organically modified silicates (ORMOSILs) modified film electrodes were made by means of cyclic voltammetry and chronocoulometry. The ORMOSIL films were investigated by atomic force microscopy, scanning electrochemical microscope, tunnelling electrochemical microscope, X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy and fluorescence spectroscopy. XPS in-depth profiles revealed a homogeneous distribution of Ru(bpy){sub 3} {sup 2+} inside the silica thin layers. The modified electrode was used for the ECL determination of methamphetamine (METH) and showed high sensitivity. Detection limit was 2.0 x 10{sup -7} mol l{sup -1} for METH (S/N = 3) with a linear range from 5.0 x 10{sup -7} to 1.0 x 10{sup -3} mol l{sup -1} (R = 0.986). The relative standard deviation (n = 6) was 1.1% for the determination of 1.0 x 10{sup -5} mol l{sup -1} METH. Furthermore, the Ru(bpy){sub 3} {sup 2+} immobilized modified electrode was applied in the ECL determination of methamphetamine (METH) in scout cases.

  13. Spectrophotometric Determination of Iron(II after Solid Phase Extraction of Its 2,2′ Bipyridine Complex on Silica Gel-Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    Nahid Pourreza

    2013-01-01

    Full Text Available A new solid phase extraction procedure was developed for preconcentration of iron(II using silica gel-polyethylene glycol (silica-PEG as an adsorbent. The method is based on retention of iron(II as 2,2′ bipyridine complex on silica-PEG. The retained complex is eluted by 1.0 mol L−1 of sulfuric acid-acetone mixture (1:2 and its absorbance is measured at 518 nm, spectrophotometrically. The effects of different parameters such as pH, concentration of the reagent, eluting reagent, sample volume, amount of adsorbent, and interfering ions were investigated. The calibration graph was linear in the range of 1–60 ng mL−1 of iron(II. The limit of detection based on 3Sb was 0.57 ng mL−1 and relative standard deviations (R.S.D for ten replicate measurements of 12 and 42 ng mL−1 of iron(II were 2.4 and 1.7%, respectively. The method was applied to the determination of of iron(II in water, multivitamin tablet, and spinach samples.

  14. Synthesis and Crystal Structure of a Novel Layered Lead(Ⅱ) Carboxylate-sulfonate Compound Templated by 4,4'-Bipyridine

    Institute of Scientific and Technical Information of China (English)

    YING Shao-Ming; LUO Qiu-Yan; XU Ya-Ping; LIN Jun-Yue; HUANG Gan-Sheng

    2007-01-01

    A new lead(Ⅱ) carboxylate-sulfonate has been hydrothermally synthesized and characterized by X-ray single-crystal and elemental analyses. It crystallizes in triclinic, space group P,(1) with a=8.1573(6), b=9.4663(7), c=12.7488(9) (A), α=89.2320(10), β=80.7380(10), γ=77.9760(10)°, Z=2, V=950.10(12) (A)3, Mr=599.57, Dc=2.096 g/cm3, μ=9.032 mm-1, F(000)=572, the final R=0.0412 and wR=0.1035. It has a 1D chain structure, and the Pb(Ⅱ) is six-coordinated. Two PbO6 polyhedra are interconnected via edge-sharing into a two-core unit. Such units are further interconnected by 3-sulfonato-benzoic acids into 1D chains which are linked by hydrogen bonds into a layer structure. The 4,4'-bipyridines are located at the interlayer space and link the layers into a supramolecular structure by π-π stacking interactions.

  15. Redetermined structure of 4,4'-bi-pyridine-1,4-phenyl-enedi-acetic acid (1/1) co-crystal.

    Science.gov (United States)

    Paul, Rima; Bora, Sanchay Jyoti

    2015-10-01

    The asymmetric unit of the title 1:1 co-crystal, C10H8N2·C10H10O4, consists of one half-mol-ecule each of 4,4'-bi-pyridine and 1,4-phenyl-enedi-acetic acid: the complete mol-ecules are generated by crystallographic inversion centres. The dihedral angle between the -CO2H group and the benzene ring in the diacid is 73.02 (7)°. In the crystal, the components are linked by O-H⋯N hydrogen bonds, generating [1-2-1] chains of alternating amine and carb-oxy-lic acid mol-ecules. The chains are cross-linked by C-H⋯O inter-actions. This structure was previously incorrectly described as a (C10H10N2)(2+)·(C10H8O4)(2-) mol-ecular salt [Jia et al. (2009 ▸). Acta Cryst. E65, o2490-o2490]. PMID:26594486

  16. Synthesis, Characterization Studies and Bond Valence Sum (BVS analysis on 2:1 Adducts involving Zinc(IIdithiocarbamates and 4,4’-Bipyridine

    Directory of Open Access Journals (Sweden)

    Arumugam Manohar

    2015-06-01

    Full Text Available 2:1 adducts involving [Zn(dtc2]2 (dtc- = pipdtc-, H10C5NCS-2; dnpdtc-, (H3CCH2CH22NCS-2; dedtc-, (H5C22NCS-2; dmdtc-, (H3C2NCS-2; nmedtc-, HOCH2CH2(CH3NCS-2; deadtc-, (HOCH2CH22NCS-2 and 4,4' – bipyridine were prepared and characterized by elemental analyses, IR, UV-Visible, Cyclic voltammetric and thermal studies. IR spectra of the complexes show the reduction in the thioureide stretching frequency due to the increase in coordination around the zinc ion and the resultant increase in electron density. The charge transfer transitions are observed in the region 260 – 320 nm by electronic spectra. Thermal studies show a single stage weight loss. The cyclic voltammetric study on the complexes show an increase of electron density on zinc in the adducts compared to [Zn(dtc2]2. The bond valence sum(BVS analysis shows the values to be close to '2', which is equivalent to the formal oxidation state of zinc in the zinc complexes.

  17. The kinetics of substitution reaction of oxydiacetate and thiodiacetate copper(II) complexes with 1,10-phenanthroline and 2,2’-bipyridine

    Indian Academy of Sciences (India)

    Joanna Pranczk; Dagmara Jacewicz; Dariusz Wyrzykowski; Aleksandra Tesmar; Lech Chmurzyński

    2015-10-01

    The kinetics of substitution reactions of the CuODA and CuTDA binary complexes (ODA = oxydiacetate, TDA = thiodiacetate) with 1,10-phenanthroline (phen) and 2,2’-bipyridine (bipy) were studied in aqueous and DMSO solutions. These reactions were monitored spectrometrically using the stopped-flow method in the UV range. The studies were carried out at three temperatures - 298.15, 303.15 and 308.15 K. The concentrations of the binary complexes were kept within the range of 0.2–0.5 mmol L−1, whereas the concentration of phen or bipy was constant = 0.05 mmol L−1. The values of the reaction rate constants were calculated based on the A → B reaction model. A linear relationship of the rate of the substitution reaction versus the concentration of the binary complex as well as temperature was observed. The impact of the type of the primary (ODA and TDA) and auxiliary ligands (phen and bipy) as well as the effect of solvent on the rate of substitution reaction have been discussed.

  18. Preparation, physicochemical analysis and molecular modeling investigation of 2,2‧-Bipyridine: β-Cyclodextrin inclusion complex in solution and solid state

    Science.gov (United States)

    Periasamy, R.; Kothainayaki, S.; Sivakumar, K.

    2015-11-01

    Supramolecular interaction between 2,2‧-Bipyridine (BPY) and β-Cyclodextrin (β-CD) has been investigated in solution and solid state. Non-covalent interaction between BPY and β-CD was studied in solution using absorption and fluorescence spectroscopy. Inclusion complex of BPY and β-CD was prepared in solid state by co-precipitation method and it was characterized using Fourier Transform Infra-red spectroscopy (FT-IR), Thermal analysis, Scanning Electron Microscopy (SEM), Powder X-ray diffractometry (XRD) and Atomic Force Microscopy (AFM). Binding constant values and 1:1 stoichiometry of the inclusion complex were calculated using Benesi-Hildebrand plots at 303 K. Using continuous variation method the 1:1 stoichiometry has been confirmed for BPY: β-CD complex. Thermodynamic parameter, ΔG of inclusion complex formation was determined and the negative value indicated that the inclusion process was an exergonic and spontaneous process. The most probable model of BPY: β-CD inclusion complex suggested by molecular docking studies was in good agreement with the results obtained by experimental methods.

  19. Synthesis, crystal structure and photoelectric property of two new coordination polymers constructed by longer-spanning suberic acid and 4,4'-bipyridine ligands.

    Science.gov (United States)

    Xie, Yan; Bai, Feng Ying; Li, Jing; Xing, Yong Heng; Wang, Zhuo; Zhao, Hai Yan; Pu, Zhi Feng; Ge, Mao Fa; Shi, Zhan

    2010-11-01

    Two-dimensional coordination polymers, [M(C₈H₁₂O₄)(C₁₀H₈N₂)]·H₂O [M=Co (1), Cd (2); C₁₀H₈N₂ = 4,4-bipyridine, C₈H₁₄O₄=subaric acid] were obtained from the reaction of the metal salts, bipy and subaric acid at 180°C and characterized by elemental analysis, infrared spectrum, and single-crystal X-ray diffraction and surface photovoltage spectrum (SPS). The single-crystal X-ray diffraction showed that the subaric ligand in the two complexes exhibits two types of modes coordinating to transition metal ions, resulting in the formation of a 1D infinite chain along the c-axis. In addition, the results of SPS for complexes 1 and 2 indicate that these two complexes exhibit positive surface photovoltage responses in the range of 300-800 nm, which can be assigned to LMCT and MLCT, respectively. And the SPS of complex 1 also can be assigned to the d→d* electronic transition. The SPS spectra of the two complexes are consistent with their UV-vis spectra.

  20. Catena-dichloro(4,4?-dimethyl-2,2?-bipyridine) Cadmium(II), a New One-dimensional Chain with Blue Fluorescent Emission

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gui-Ling; LI Yan-Tuan; LUO Xu-Qiang; WU Zhi-Yong

    2008-01-01

    A new μ-chloro-bridged one-dimensional coordination polymer [Cd(dmbpy)Cl2]n (dmbpy = 4,4?-dimethyl-2,2?-bipyridine) has been synthesized and structurally characterized by elemental analyses, IR, UV spectra and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group C2/c with a = 17.745(4), b = 10.326(2), c = 7.3382(15) ?, β = 106.85(3)o, V = 1286.9(4) ?3, Z = 4, C12H12N2Cl2Cd, Mr = 367.54, Dc = 1.897 g/cm3, F(000) = 720, λ(MoK() = 0.71073 ?, ( = 2.089 mm-1, R = 0.0368 and wR = 0.1048 for 1041 observed reflections (I > 2σ(I)). Cadmium(II) adopts a distorted octahedral coordination geometry and adjacent coordination chains are intercalated in a zipper-like fashion into 2D layers through the π-π stacking interactions between dmbpy. Fluorescent analyses show that it exhibits intense blue photoluminescence in both DMF and DMSO solutions at room temperature.

  1. Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc(II) Coordination Polymer Assembled by Phthalate and 4,4'-Bipyridine

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-Mei; WANG Qing-Wei; CUI Yun-Cheng; LI Chuan-Bi; WANG Ren-Zhang; LIU Bo

    2006-01-01

    A metal-organic coordination polymer {[Zn(Pht)(4,4′-bipy)(H2O)2]·2H2O}n (Pht = phthalate, 4,4′-bipy = 4,4′-bipyridine) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in the monoclinic system, space group P2/n, a = 7.6346(14), b = 11.316(2), c = 10.8133(19) (A), β = 92.444(3)o, V = 933.3(3)(A)3, C18H20N2O8Zn, Mr = 457.73, Dc = 1.629 g/cm3, F(000) = 472, Z = 2, μ(MoKα) = 1.367 mm-1, the final R = 0.0323 and wR = 0.0821 for 1859 observed reflections (I > 2σ(I)). The structure of 1 exhibits a two-dimensional bilayer framework formed by hydrogen bonding interactions. Furthermore, 1 shows yellow photoluminescent pro- perty at room temperature.

  2. Crystal structure of [tris(4,4′-bipyridine]diium bis(1,1,3,3-tetracyano-2-ethoxypropenide trihydrate

    Directory of Open Access Journals (Sweden)

    Fatima Setifi

    2016-09-01

    Full Text Available The title hydrated salt, C30H26N62+·2C9H5N4O−·3H2O, was obtained as an unexpected product from the hydrothermal reaction between potassium 1,1,3,3-tetracyano-2-ethoxypropenide, 4,4′-bipyridine and iron(II sulfate heptahydrate. The cation lies across a twofold rotation axis in the space group I2/a with the other components all in general positions. In the cation, the H atom linking the pyridine units is disordered over two adjacent sites having occupancies of 0.66 (4 and 0.36 (4, i.e. as N—H...N and N...H—N. The water molecules of crystallization are each disordered over two sets of atomic sites, having occupancies of 0.522 (6 and 0.478 (6 for one, and 0.34 (3 and 0.16 (3 for the other, and it was not possible to reliably locate the H atoms associated with these partial-occupancy sites. In the crystal, four independent C—H...N hydrogen bonds link the ionic components into a three-dimensional network.

  3. Hydrothermal Synthesis, Crystal Structure and Magnetic Properties of a Cobalt(Ⅱ) Coordination Polymer Assembled by 4-Sulfophthalate and 4,4'-Bipyridine

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-Wei; LI Xiu-Mei; HAN Jing

    2006-01-01

    A novel metal-organic coordination polymer {[Co2(4-sphth)2(4,4'-bpy)4(H2O)4]- [Co(4,4'-bpy)2(H2O)4]}n (4-sphth = 4-sulfophthalic acid, 4,4'-bpy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and magnetic susceptibility measurements. The complex crystallizes in monoclinic, space group C2/c with a = 18.893(6), b = 23.080(7), c = 22.473(7) (A), β = 107.311(4)o, V = 9356(5) (A)3, C76H70Co3N12O22S2, Mr = 1744.35, Dc = 1.238 g/cm3, μ(MoKα) = 0.640 mm(1, F(000) = 3596, Z = 4, the final R = 0.0444 and wR = 0.0846 for 9178 observed reflections (Ⅰ>2б(Ⅰ)). It exhibits a novel three-dimensional supramolecular network formed by hydrogen-bonding and π-π interactions. Variable-temperature magnetic measure shows an overall anti-ferromagnetic behavior for compound 1.

  4. μ-Oxido-bis-[chlorido(4,4'-di-tert-butyl-2,2'-bipyridine-κN,N')dioxido-molybdenum(VI)] 0.2-hydrate.

    Science.gov (United States)

    Gomes, Ana C; Fernandes, José A; Gamelas, Carla A; Gonçalves, Isabel S; Almeida Paz, Filipe A

    2011-12-01

    The title hydrate, [Mo(2)Cl(2)O(5)(C(18)H(24)N(2))(2)]·0.2H(2)O, has been isolated as the oxidation product of [Mo(η(3)-C(3)H(5))Cl(CO)(2)(di-t-Bu-bipy)] (where di-t-Bu-bipy is 4,4'-di-tert-butyl-2,2'-bipyridine). A μ-oxide ligand bridges two similar MoCl(di-t-Bu-bipy)O(2) units, having the terminal oxide ligands mutually cis, and the chloride and μ-oxide trans to each other. In the binuclear complex, the coordination geometries of the metal atoms can be described as highly distorted octa-hedra. Individual complexes co-crystallize with a partially occupied water mol-ecule of crystallization (occupancy factor = 0.20; H atoms not located), with the crystal packing being mediated by the need to effectively fill the available space. A number of weak C-H⋯O and C-H⋯Cl inter-actions are present. PMID:22199539

  5. (2,2′-Bipyridine-κ2N,N′[2-tert-butylanilinato(2−]dichloridooxidomolybdenum(VI dichloromethane hemisolvate

    Directory of Open Access Journals (Sweden)

    Alastair J. Nielson

    2010-12-01

    Full Text Available The MoVI atom in the title structure, [Mo(C10H13NCl2O(C10H8N2]·0.5CH2Cl2, has a distorted octahedral coordination sphere with cis-orientated oxide and imide ligands, trans-chloride ligands and the 2,2′-bipyridine (bipy ligand N atoms lying trans to the oxide and imide ligands. An imide-ligand tert-butyl-methyl-group H atom makes a close approach with the oxide ligand (distance = 2.53 Å and the imide-ligand N atom (distance = 2.41 Å. Another imide-ligand tert-butyl-methyl-group H atom makes a close approach to a chloride ligand (distance = 2.82 Å. One bipy-ligand α-H atom makes a close approach to the oxide ligand (distance = 2.4 Å and the other α-H atom makes a close approach to the imide-ligand phenyl-ring ortho-H atom (distance = 2.52 Å. These close approaches suggest the presence of weak intramolecular hydrogen bonds. The solvent molecule has been modelled under consideration of half-occupancy.

  6. Tris(bipyridineMetal(II-Templated Assemblies of 3D Alkali-Ruthenium Oxalate Coordination Frameworks: Crystal Structures, Characterization and Photocatalytic Activity in Water Reduction

    Directory of Open Access Journals (Sweden)

    Alla Dikhtiarenko

    2016-02-01

    Full Text Available A series of 3D oxalate-bridged ruthenium-based coordination polymers with the formula of {[ZII(bpy3][MIRu(C2O43]}n (ZII = Zn2+ (1, Cu2+ (3, 4, Ru2+ (5, 6, Os2+ (7, 8; MI = Li+, Na+; bpy = 2,2’-bipyridine and {[ZnII(bpy3](H2O[LiRu(C2O43]}n (2 has been synthesized at room temperature through a self-assembly reaction in aqueous media and characterized by single-crystal and powder X-ray diffraction, elemental analysis, infrared and diffuse reflectance UV–Vis spectroscopy and thermogravimetric analysis. The crystal structures of all compounds comprise chiral 3D honeycomb-like polymeric nets of the srs-type, which possess triangular anionic cages where [ZII(bpy3]2+ cationic templates are selectively embedded. Structural analysis reveals that the electronic configuration of the cationic guests is affected by electrostatic interaction with the anionic framework. Moreover, the MLCT bands gaps values for 1–8 can be tuned in a rational way by judicious choice of [ZII(bpy3]2+ guests. The 3D host-guest polymeric architectures can be used as self-supported heterogeneous photocatalysts for the reductive splitting of water, exhibiting photocatalytic activity for the evolution of H2 under UV light irradiation.

  7. Electrogenerated chemiluminescence quenching of Ru(bpy){sub 3} {sup 2+} (bpy=2,2 Prime -bipyridine) in the presence of acetaminophen, salicylic acid and their metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Haslag, Catherine S. [Department of Chemistry, Missouri State University, Springfield, Missouri 65897 (United States); Richter, Mark M., E-mail: MarkRichter@missouristate.edu [Department of Chemistry, Missouri State University, Springfield, Missouri 65897 (United States)

    2012-03-15

    Quenching of Ru(bpy) {sub 3}{sup 2+} (bpy=2,2 Prime -bipyridine) coreactant electrogenerated chemiluminescence (ECL) has been observed in the presence of acetaminophen, salicylic acid and related complexes. However, no quenching is observed with the acetylsalicylic acid. In most instances, quenching is observed with 100-fold excess of quencher (compared to ECL luminophore) with complete quenching observed between 10,000 and 100,000 fold excess. Fluorescence and UV-vis experiments coupled with bulk electrolysis support the formation of benzoquinone products upon electrochemical oxidation. The mechanism of quenching may involve the interaction of the electrochemically generated benzoquinone species with (i) the {sup Low-Asterisk }Ru(bpy){sub 3}{sup 2+} excited state or (ii) highly energetic coreactant radicals. - Highlights: Black-Right-Pointing-Triangle Efficient quenching of the electrogenerated chemiluminescence is observed. Black-Right-Pointing-Triangle Acetaminophen, salicylic acid and related compounds can be detected. Black-Right-Pointing-Triangle The mechanism of quenching involves benzoquinones formed upon electrolysis.

  8. Photochemistry and photophysics of a Pd(II) metalloporphyrin: Re(I) tricarbonyl bipyridine molecular dyad and its activity toward the photoreduction of CO2 to CO.

    Science.gov (United States)

    Schneider, Jacob; Vuong, Khuong Q; Calladine, James A; Sun, Xue-Zhong; Whitwood, Adrian C; George, Michael W; Perutz, Robin N

    2011-12-01

    The photochemistry and photophysics of the cationic molecular dyad, 5-{4-[rhenium(I)tricarbonylpicoline-4-methyl-2,2'-bipyridine-4'-carboxyamidyl]phenyl}-10,15,20-triphenylporphyrinatopalladium(II) ([Re(CO)(3)(Pic)Bpy-PdTPP][PF(6)]) have been investigated. The single crystal X-ray structure for the thiocyanate analogue, [Re(CO)(3)(NCS)Bpy-PdTPP], exhibits torsion angles of 69.1(9)°, 178.1(7)°, and 156.8(9)° between porphyrin plane, porphyrin-linked C(6)H(4) group, amide moiety, and Bpy, respectively. Steady-state photoexcitation (λ(ex) = 520 nm) of [Re(CO)(3)(Pic)Bpy-PdTPP][PF(6)] in dimethylformamide (DMF) results in substitution of Pic by bromide at the Re(I)Bpy core. When [Re(CO)(3)(Pic)Bpy-PdTPP][PF(6)] is employed as a photocatalyst for the reduction of CO(2) to CO in DMF/NEt(3) solution with λ(ex) > 420 nm, 2 turnovers (TNs) CO are formed after 4 h. If instead, a two-component mixture of PdTPP sensitizer and mononuclear [Re(CO)(3)(Pic)Bpy][PF(6)] catalyst is used, 3 TNs CO are formed. In each experiment however, CO only forms after a slight induction period and during the concurrent photoreduction of the sensitizer to a Pd(II) chlorin species. Palladium(II) meso-tetraphenylchlorin, the hydrogenated porphyrin analogue of PdTPP, has been synthesized independently and can be substituted for PdTPP in the two-component system with [Re(CO)(3)(Pic)Bpy][PF(6)], forming 9 TNs CO. An intramolecular electron transfer process for the dyad is supported by cyclic voltammetry and steady-state emission studies, from which the free energy change was calculated to be ΔG(ox)* = -0.08 eV. Electron transfer from Pd(II) porphyrin to Re(I) tricarbonyl bipyridine in [Re(CO)(3)(Pic)Bpy-PdTPP][PF(6)] was monitored using time-resolved infrared (TRIR) spectroscopy in the ν(CO) region on several time scales with excitation at 532 nm. Spectra were recorded in CH(2)Cl(2) with and without NEt(3). Picosecond TRIR spectroscopy shows rapid growth of bands assigned to the π-π* excited

  9. Synthesis, crystal structures, and magnetic properties of two three-dimensional octacyanotungstate(Ⅳ)-based bimetallic frameworks with 4,4'-bipyridine dioxide (4,4'-dpdo)

    Institute of Scientific and Technical Information of China (English)

    YUAN Mei; GAO Song; ZHAO Fei; ZHANG Wen; WANG Zhe-Ming

    2009-01-01

    The reaction of [HN(n-C4H9)3]3[WⅤ(CN)8]·4H2O, 4,4'-bipyridine dioxide(4,4'-dpdo), end MnCl2·4H2O or crystallizes in the orthorhombic system, space group P21212 with cell constants α=10.397(2) A, b=11.321(2) A, c=12.295(3) A and Z=2, whereas 2 crystallizes in the monoclinic system, space group P21/c with cell constants a=13.038(3) A, b=13.784(3) A, c=13.225(3) A, β=93.44(3)g and Z=4. In complex 1, each [WⅣ(CN)8]4- unit with a square antiprismatic geometry is connected to four Mn2 dimers through four bridging CN- ions forming wavelike alternating -W-Mn2-W-Mn2- layers, which are further linked through 4,4'-dpdo ligands coordinated to the Mn ions into a three-dimensional open framework. In complex 2, each [WⅣ(CN)8]4- ion still adopts a square antiprismallc geometry, whereas it bonds to seven copper ions through seven CN- ions leading to cage-like undulate layers further bridged by 4,4'-dpdo ligands into a three-dimensional network. Due to the bridging role of the long rigid 4,4"-dpdo ligand, there exist plenty of large cavities in the open frameworks of complexes 1 and 2 occupied by solvent clusters containing H2O or CH3OH molecules. To our knowledge, it is noted that 4,4'-dpdo displays a μ-4,4,4',4' mode, which was first experimentally observed, although predicted before. Magnetic studies show that complex 1 displays an antiferromagnetic coupling between MnⅡ ions, while complex 2 ex-hibits a weak ferromagnetic interaction between CuⅡ ions.

  10. Ligand field and intermolecular interactions tuning the magnetic properties of spin-crossover Fe(II) polymer with 4,4′-bipyridine

    International Nuclear Information System (INIS)

    A new spin crossover coordination polymer (SCO-CPs) of Fe(II)-4,4′-bipyridine (4,4′-bipy) family: (Fe(4,4′-bipy)2(H2O)2)·(4,4′-bipy)· 8(H2O)·2(ClO4) (3), which displays half spin transitions between 100 and 300 K, has been synthesized and structurally characterized. Compound 3 featured with two-dimensional (2-D) grids connected by hydrogen bonds and π…π packing between one-dimensional (1-D) chains, the 2-D grids expand to three-dimensional (3-D) architecture supported by a “S-shaped holder” involving lattice 4-4′-bipy, water molecules and perchlorate anion. We compared 3 with the other two analogous complexes: ((Fe(4,4′-bipy) (H2O)2 (NCS)2)·4,4′-bipy, 1 and (Fe(4,4′-bipy)2(NCS)2)·mSolv, 2) through Hirshfeld surfaces analysis, which revealed that the low ligand field strength (NCS−) and lone-pair…H contacts contribute to the stabilization of HS (high-spin) state of the Fe(II) ion, while the high ligand field strength (4,4′-bipy) and strong intermolecular contacts (hydrogen bonds and π…π packing interactions) make for the LS (low-spin) state. - Highlights: ●A new member of Fe(||)-4,4′-bipy family has been prepared. ●It displays half spin transitions tuned by ligand field and intermolecular interactions. ●We have made a detailed comparison of this new member with two other analogous complexes

  11. Oxovanadium(IV) Compounds of cis-[VOCl(N-N){sub 2}]{sup +} (N-N = 4,4'- and 5,5'-dimethyl-2,2'-bipyridine); Crystal Structure and Biological Activity

    Energy Technology Data Exchange (ETDEWEB)

    Nasser Ostad, S.; Tavajohi, Shohreh [Univ. of Medical Sciences, Tehran (Iran, Islamic Republic of); Masoomeh Emadi, S.; Amani, Vahid; Abedi, Anita [Islamic Azad Univ., Tehran (Iran, Islamic Republic of)

    2012-11-15

    Vanadium(IV) complexes in a general formula of cis-[VOX(N-N){sub 2}]{sup 0/+1}, (X=Cl., OH., SO{sub 4}{sup -2} and N-N = phen, bipy) have been reported. We considered the methyl-substituted bipyridine analogues, 4,4'-dimethyl-2,2'-bipyridine (4dmbpy) and 5,5'-dimethyl-2,2'-bipyridine (5dmbpy) as ligands since our last studies on cytotoxicity of oxovanadium(IV) exhibited that introduction of a methyl group into N-N ligands causes further enhanced cytotoxicity of the related complex. Totally, two new oxovanadium(IV), [VOCl(4dmbpy){sub 2}]·Cl·H{sub 2}O·C{sub 2}H{sub 5}OH (1) and [VOCl(5dmbpy){sub 2}]·Cl·H{sub 2}O·CH{sub 3}OH (2) were synthesized, proposing anticancer activity of the cationic part of the complexes, as ionic vanadium compounds show to increase membrane permeability with a potential for dose reduction.4 Both complexes were fully characterized by means of elemental analysis, IR and UV-Vis. spectroscopy as well as the X-ray diffraction method. Furthermore their cytotoxicity were assayed in three cell cultures, colorectal adenocarcinoma (Caco-2), colon carcinoma (HT-29) and breast ductal carcinoma (T47D) by means of MTT assay (MTT=3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide) and the results were compared with cisplatin, an anticancer drugs which shows limited activity on colon and breast cancers.

  12. Structure of a dinuclear cadmium complex with 2,2′-bipyridine, monodentate nitrate and 3-carboxy-6-methylpyridine-2-carboxylate ligands: intramolecular carbonyl(lone pair...π(ring and nitrate(π...π(ring interactions

    Directory of Open Access Journals (Sweden)

    Juan Granifo

    2015-08-01

    Full Text Available The centrosymmetric dinuclear complex bis(μ-3-carboxy-6-methylpyridine-2-carboxylato-κ3N,O2:O2;κ3O2:N,O2-bis[(2,2′-bipyridine-κ2N,N′(nitrato-κOcadmium] methanol monosolvate, [Cd2(C8H6NO42(NO32(C10H8N22]·CH3OH, was isolated as colourless crystals from the reaction of Cd(NO32·4H2O, 6-methylpyridine-2,3-dicarboxylic acid (mepydcH2 and 2,2′-bipyridine in methanol. The asymmetric unit consists of a CdII cation bound to a μ-κ3N,O2:O2-mepydcH− anion, an N,N′-bidentate 2,2′-bipyridine group and an O-monodentate nitrate anion, and is completed with a methanol solvent molecule at half-occupancy. The Cd complex unit is linked to its centrosymmetric image through a bridging mepydcH− carboxylate O atom to complete the dinuclear complex molecule. Despite a significant variation in the coordination angles, indicating a considerable departure from octahedral coordination geometry about the CdII atom, the Cd—O and Cd—N distances in this complex are surprisingly similar. The crystal structure consists of O—H...O hydrogen-bonded chains parallel to a, further bound by C—H...O contacts along b to form planar two-dimensional arrays parallel to (001. The juxtaposed planes form interstitial columnar voids that are filled by the methanol solvent molecules. These in turn interact with the complex molecules to further stabilize the structure. A search in the literature showed that complexes with the mepydcH− ligand are rare and complexes reported previously with this ligand do not adopt the μ-κ3 coordination mode found in the title compound.

  13. Recognition of self-assembled water-nitrate cluster in a Co(III)-2,2'-bipyridine host: Synthesis, X-ray structure, DNA cleavage, molecular docking and anticancer activity

    Indian Academy of Sciences (India)

    SUBRATA DAS; ANANDAN RANJANI; LOGANATHAN GAYATHRI; SUBHASISH SAHA; JORGE PASAN; DHARUMADURAI DHANASEKARAN; MOHAMMAD ABDULKADER AKBARSHA; MILAN MAJI; BHASKAR BISWAS

    2016-11-01

    A mononuclear cobalt(III) complex [Co(bpy)₂Cl₂]NO₃·2H₂O (1) (bpy = 2,2'-bipyridine) has been synthesized and crystallographically characterized. Self-assembly of the lattice water molecules from rectangular tetrameric water cluster interacts with nitrate anion along the c-axis forming a six membered hexagonal water-nitrate cluster. It presents a new mode of association of water molecules with nitrate molecules which is not predicted theoretically or found experimentally. The molecule effectively cleaves bacterial genomic DNA and shows important cytotoxicity against human hepatocarcinoma cell (HepG2).

  14. Di(isothiocyanato)bis(4-methyl-4’-vinyl-2,2’-bipyridine) Ruthenium(II) Films Deposited on Titanium Oxide-Coated, Fluorine-Doped Tin Oxide for an Efficient Solar Cell

    OpenAIRE

    Liu, Yi; Sugimoto, Ryuichi; Sumi, Katsuhiro

    2013-01-01

    Dye-sensitized titanium oxide electrodes were prepared by immobilizing a novel ruthenium complex, di(isothiocy- anato)bis(4-methyl-4’-vinyl-2,2’-bipyridine)ruthenium(II) [(NCS)_2(mvbpy)_2Ru(II)] or the ruthenium complex/sodium 4-vinylbenzenesulfonate onto the surface of a titanium oxide-coated, fluorine-doped tin oxide (TiO_2/FTO) electrode through a new electrochemically initiated film formation method, in which the electrolysis step and the film deposition step were individually performed. ...

  15. (2,2 '-Bipyridine-4,4 '-dicarboxylic acid-kappa N-2,N ')chlorido(2,2 ':6 ',2 ''-terpyridyl-kappa N-3,N ',N '')ruthenium(II) perchlorate ethanol monosolvate monohydrate

    DEFF Research Database (Denmark)

    Nielsen, A.; McKenzie, C. J.; Bond, A. D.

    2012-01-01

    center dot center dot O hydrogen bonds between the carboxyl groups and the crystal lattice water molecules into chains along [110]. Face-to-face stacking interactions are formed between terpyridine ligands, with interplanar separations of 3.66 (1) and 3.42 (1) angstrom, and between bipyridine-4......,4 '-dicarboxylic acid ligands, with interplanar separations of 3.65 (1) and 3.72 (1) angstrom. Three O atoms of the perchlorate ion are each disordered equally over two positions. The hydroxy group of the ethanol molecule is also disordered over two sites with refined occupancies of 0.794 (9) and 0.206 (9)....

  16. Coordination Chemistry of 2,2'-Bipyridyl- and 2,2':6',2″-Terpyridyl-Substituted BEDT-TTFs: Formation of a Supramolecular Capsule Motif by the Iron(II) Tris Complex of 2,2'-Bipyridine-4-thiomethyl-BEDT-TTF.

    Science.gov (United States)

    Wang, Qiang; Martin, Lee; Blake, Alexander J; Day, Peter; Akutsu, Hiroki; Wallis, John D

    2016-09-01

    Molecules of tris(2,2'-bipyridine-4-thiomethyl-BEDT-TTF)iron(II) (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) assemble in pairs to form a novel supramolecular capsular structure in the solid state. Three BEDT-TTF residues from one complex lie in the three grooves between coordinated bipyridines of the other complex, and vice versa, to form a capsule with 3-fold rotational symmetry and an internal volume of ca. 160 Å(3). Further aspects of the coordination chemistry of this ligand, its 6-substituted isomer, and the 2,2':6'2″-terpyridyl-4'-thiomethyl-BEDT-TTF analogue are described.

  17. Redox and catalytic properties of new polypyrrole modified electrodes functionalized by [Ru(bpea)(bpy)H2O]2+ complexes; bpea=N,N'-bis(2-pyridylmethyl)ethylamine, bpy=2,2'-bipyridine

    International Nuclear Information System (INIS)

    New ruthenium(II) complexes containing one or two pyrrole-functionalized polypyridylic ligands have been prepared in order to study their electrochemical behaviour in heterogeneous phase, after anodic polymerization from CH2Cl2 solution on an electrode surface. Complexes containing one pyrrole unit have general formula [Ru(bpea-pyr)(bpy)(L)]2+ (bpea-pyr=N-[3-bis(2-pyridylmethyl)aminopropyl]pyrrole, bpy=2,2'-bipyridine, L=Cl, complex 3, or L=H2O, complex 1), whereas compounds having two pyrrole units correspond to [Ru(bpea-pyr)(bpy-pyr)(L)]2+ (bpy-pyr=4-methyl-4'-pyrrolylbutyl-2,2'-bipyridine, L=Cl, complex 4, or L=H2O, complex 2). Upon oxidative polymerization, all complexes form highly stable polypyrrolic films on a graphite disk electrode surface. An electrode modified with complex 2 polypyrrole coating film, C/poly-2, has been tested as heterogeneous catalyst for the oxidation of benzyl alcohol, showing a remarkably high efficiency and notably improving the results obtained with analogous complexes in homogeneous phase

  18. Di-μ-acetato-κ4O:O′-μ-oxido-κ2O:O′-bis[cis-(2,2′-bipyridine-κ2N,N′-trans-(pyridine-κNruthenium(III] bis(hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    Akira Nagasawa

    2013-03-01

    Full Text Available The hemerythrin-type dinuclear title complex, [Ru2(CH3COO2O(C10H8N22(C5H5N2](PF62, consists of two RuIII ions with a six-coordinate octahedral geometry, bridged by an oxide and two acetate ligands, with a bidentate 2,2′-bipyridine ligand and a pyridine ligand bonding at terminal positions. The Ru—Ru distance and Ru—O—Ru angle are 3.2838 (3 Å and 121.79 (7°, respectively, and the average Ru—N(pyridine bond length is 2.164 (8 Å. Several C—H...F, C—H...O and C—H...N interactions generate a three-dimensional network in the crystal structure. π–π stacking interactions [centroid–centroid distance = 3.6389 (3 Å] between inversion-related 2,2′-bipyridine rings are also observed.

  19. Synthesis, structure and photoluminescence of (PLAGH){sub 2}[ZnCl{sub 4}] and comparative analysis of photoluminescence properties with tris(2,2′-bipyridine)ruthenium(II)

    Energy Technology Data Exchange (ETDEWEB)

    Radanović, Mirjana M. [University of Novi Sad, Faculty of Sciences, Novi Sad (Serbia); Jelić, Miodrag G., E-mail: jelicmgm@uns.ac.rs [University of Novi Sad, Faculty of Technical Sciences, Novi Sad (Serbia); Romčević, Nebojša Ž. [University of Belgrade, Institute of Physics, Belgrade (Serbia); Boukos, Nikos [National Centre for Scientific Research “Demokritos”, Institute of Materials Science, Athens (Greece); Vojinović-Ješić, Ljiljana S.; Leovac, Vukadin M. [University of Novi Sad, Faculty of Sciences, Novi Sad (Serbia); Hadžić, Branka B. [University of Belgrade, Institute of Physics, Belgrade (Serbia); Bajac, Branimir M. [University of Novi Sad, Faculty of Technology, Novi Sad (Serbia); Nađ, Laslo F. [University of Novi Sad, Faculty of Technical Sciences, Novi Sad (Serbia); Chandrinou, Chrysoula [National Centre for Scientific Research “Demokritos”, Institute of Materials Science, Athens (Greece); Baloš, Sebastian S. [University of Novi Sad, Faculty of Technical Sciences, Novi Sad (Serbia)

    2015-10-15

    Highlights: • New zinc(II) complex with pyridoxalaminoguanidine was synthesized. • The enhancement of the photoluminescence due to the compound formation was achieved. • Very high photoluminescence of Zn(II) compound was noticed. • Comparative analysis of photoluminescence with tris(2,2′-bipyridine) ruthenium(II) was provided. - Abstract: The first compound of zinc(II) containing pyridoxalaminoguanidine has been synthesized and characterized by elemental analysis, infrared spectra, conductometric measurements and X-ray crystallography. Single crystals of the compound were obtained in the reaction of methanolic solution of zinc(II) chloride and pyridoxalaminoguanidine hydrochloride. In this compound the coordination of chelate ligand is absent and tetrachlorido complex of zinc(II) with pyridoxalaminuguanidinium cation as contraion is obtained. Photoluminescence spectra were measured. Lorentzian multipeak technique was used to determine peak wavelengths and their intensities. Photoluminescence spectroscopy upon 325, 488 and 514 nm laser excitation light was used to obtain results. This novel compound of zinc(II) was compared to the well-known organic light emitting diode material—ruthenium(II) complex with bypiridine i.e., tris(2,2′-bipyridine)ruthenium(II), under the same circumstances and the identical experimental setup. A scheme of energy levels and transitions is proposed to explain the obtained experimental results.

  20. Bis[bis(2,2′-bipyridine-κ2N,N′(carbonato-κ2O,O′cobalt(III] 2-{4-[(carboxylatomethylcarbamoyl]benzamido}acetate hexahydrate

    Directory of Open Access Journals (Sweden)

    Niels-Patrick Pook

    2014-05-01

    Full Text Available The complex cation of the title compound, [Co(CO3(C10H8N22]2(C12H10N2O6·6H2O, contains a CoIII atom with a distorted octahedral coordination environment formed by four N atoms from two bidentate 2,2′-bipyridine ligands and one bidentate carbonate anion. The asymmetric unit is completed by one-half of the 2-({4-[(carboxylatomethylcarbamoyl]phenyl}formamidoacetate dianion, which is located on a centre of inversion, and by three water molecules. Two [Co(CO3(C10H8N22]+ cations are connected through C—H...O contacts by the uncoordinating anions. The aromatic rings of the 2,2′-bipyridine ligands and diacetate anions are involved in π–π stacking and C—H...π interactions. The centroid–centroid distances are in the range 3.4898 (4–3.6384 (5 Å. The crystal structure is stabilized by further O—H...O and N—H...O hydrogen bonds, which give rise to a three-dimensional supramolecular network.

  1. Synthesis, Crystal Structure, and Magnetic Properties of Tetraphenylarsonium Tetrachloro(oxalato)rhenate(IV) and Bis(2,2'-bipyridine)tetrachloro(&mgr;-oxalato)copper(II)rhenium(IV).

    Science.gov (United States)

    Chiozzone, Raúl; González, Ricardo; Kremer, Carlos; De Munno, Giovanni; Cano, Joan; Lloret, Francesc; Julve, Miguel; Faus, Juan

    1999-10-18

    Two new rhenium(IV) compounds of formula (AsPh(4))(2)[ReCl(4)(ox)] (1) and [ReCl(4)(&mgr;-ox)Cu(bipy)(2)] (2) (AsPh(4) = tetraphenylarsonium cation, ox = oxalate anion, and bipy = 2,2'-bipyridine) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. 1 and 2 crystallize in the monoclinic system, space groups P2(1)/c and P2(1)/n, respectively, with a = 22.250(5) Å, b = 11.245(3) Å, c = 19.089(4) Å, beta = 96.59(2) degrees, and Z = 4 for 1 and a = 9.421(2) Å, b = 16.909(4) Å, c = 16.179(4) Å, beta = 93.97(2) degrees, and Z = 4 for 2. The structure of 1 is made up of [ReCl(4)(ox)](2)(-) anions and AsPh(4)(+) cations held united by electrostatic forces. Rhenium(IV) is hexacoordinate, with two oxygens of a chelating ox and four chlorine atoms building a distorted octahedron around the metal atom. There is no contact between the [ReCl(4)(ox)](2)(-) anions, the shortest Re.Re and Cl.Cl distances being 10.345 and 7.209 Å, respectively. This anionic complex is coordinated to a [Cu(bipy)(2)](2+) cation in 2, through one oxalate-oxygen, giving a neutral heterometallic dinuclear unit. The Cu(II) ion shows a very distorted five-coordinated geometry, four bipy-nitrogens occuping the equatorial positions and the oxygen atom the apical one. The basal plane geometry is distorted toward the tetrahedron, the dihedral angle between the mean planes of the two bipy ligands is 37.6(2) degrees. These [ReCl(4)(&mgr;-ox)Cu(bipy)(2)] units are arranged in such a way that a chlorine atom of one of them points toward the copper atom of the neighboring one, forming helicoid chains. The intrachain Re.Cu distances through chloro and oxalato bridges are 4.658 and 4.798 Å, respectively. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8-300 K. 1 is a magnetically diluted Re(IV) complex, the great value of zero-field splitting of the ground level (D = 60 cm(-)(1)) accounting for the variation of chi(M)T with T in

  2. Assembly and property research on seven 0D–3D complexes derived from imidazole dicarboxylate and 1,2-bi(pyridin-4-yl)ethene

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Bao; Li, Qian; Lv, Lei; Yang, Dan-Dan; Wang, Qing; Huang, Ru-Dan, E-mail: huangrd@bit.edu.cn

    2015-03-15

    The hydrothermal reaction of transition metals, 1H-imidazole-4,5-dicarboxylic acid (H{sub 3}ImDC) and 1,2-bi(pyridin-4-yl)ethene (bpe) affords a series of new complexes, namely, [Mn(HImDC)(bpe)(H{sub 2}O)] (1), [M(H{sub 2}ImDC){sub 2}(H{sub 2}O){sub 2}]·(bpe) (M=Fe(2), Co(3), Zn(4), Cd(6)), [Zn{sub 3}(ImDC){sub 2}(bpe)(H{sub 2}O)]·3H{sub 2}O (5) and [Cd(H{sub 2}ImDC)(bpe)] (7), which are characterized by elemental analyses, IR, TG, XRPD and single crystal X-ray diffraction. Complex 1 exhibits a one dimensional (1D) zigzag chain with two types of irregular rings, and the 1D chains are linked to form a three dimensional (3D) supramolecular framework by the hydrogen bonding interactions (O–H∙∙∙O and O–H∙∙∙N). Complexes 2–4 and 6 are isomorphous, and they display the mononuclear structures. In these complexes, the O–H∙∙∙O and O–H∙∙∙N hydrogen bonds play an important role in sustaining the whole 3D supramolecular frameworks. Complex 5 shows a (3,3)-connected 3D framework with (10{sup 3}) topology, and the lattice water molecules as guest molecules exist in the 3D framework. Complex 7 is a wave-like two dimensional (2D) structure, in which the adjacent 1D chains point at the opposite directions. Moreover, the fluorescent properties of complexes 1–7 and the magnetic property of 1 have been investigated. The water vapor adsorption for complex 5 has been researched at 298 K. - Graphical abstract: Seven new complexes based on different structural characteristics have been hydrothermally synthesized by the mixed ligands. The fluorescent properties, the magnetic property and the water vapor adsorption have been investigated. - Highlights: • The semi-rigid ligand with C=C bonds and imidazole dicarboxylates with some advantages have been used. • A series of new complexes with different structural characteristics have been discussed in detail. • The fluorescent properties, the magnetic property and the water vapor adsorption have been

  3. Rhodium-Catalyzed/Copper-Mediated Tandem C(sp(2))-H Alkynylation and Annulation: Synthesis of 11-Acylated Imidazo[1,2-a:3,4-a']dipyridin-5-ium-4-olates from 2H-[1,2'-Bipyridin]-2-ones and Propargyl Alcohols.

    Science.gov (United States)

    Li, Ting; Wang, Zhiqiang; Xu, Kun; Liu, Wenmin; Zhang, Xu; Mao, Wutao; Guo, Yongming; Ge, Xiaolin; Pan, Fei

    2016-03-01

    A rhodium-catalyzed/copper-mediated tandem C(sp(2))-H alkynylation and intramolecular annulation of 2H-[1,2'-bipyridin]-2-ones with propargyl alcohols for the synthesis of 11-acylated imidazo[1,2-a:3,4-a']dipyridin-5-ium-4-olates is described.

  4. New ruthenium nitrosyl complexes with tris(1-pyrazolyl)methane (tpm) and 2,2'-bipyridine (bpy) coligands. Structure, spectroscopy, and electrophilic and nucleophilic reactivities of bound nitrosyl.

    Science.gov (United States)

    Videla, Mariela; Jacinto, Julian S; Baggio, Ricardo; Garland, María T; Singh, Priti; Kaim, Wolfgang; Slep, Leonardo D; Olabe, José A

    2006-10-16

    The new compound [Ru(bpy)(tpm)NO](ClO4)3 [tpm = tris(1-pyrazolyl)methane; bpy = 2,2'-bipyridine] has been prepared in a stepwise procedure that involves the conversion of [Ru(bpy)(tpm)Cl]+ into the aqua and nitro intermediates, followed by acidification. The diamagnetic complex crystallizes to exhibit distorted octahedral geometry around the metal, with the Ru-N(O) bond length 1.774(12) A and the RuNO angle 179.1(12) degrees , typical for a {RuNO}6 description. The [Ru(bpy)(tpm)NO]3+ ion (I) has been characterized by 1H NMR and IR spectroscopies (nu(NO) = 1959 cm(-1)) and through density functional theory calculations. Intense electronic transitions in the 300-350-nm region are assigned through time-dependent (TD)DFT as intraligand pi --> pi for bpy and tpm. The dpi --> pi(bpy) metal-to-ligand charge-transfer transitions appear at higher energies. Aqueous cyclic voltammetric studies show a reversible wave at 0.31 V (vs Ag/AgCl, 3 M Cl-), which shifts to 0.60 V in MeCN, along with the onset of a wave of an irreversible process at -0.2 V. The waves are assigned to the one- and two-electron reductions centered at the NO ligand, leading to species with {RuNO}(7) and {RuNO}(8) configurations, respectively. Controlled potential reduction of I in MeCN led to the [Ru(bpy)(tpm)NO]2+ ion (II), revealing a significant downward shift of nu(NO) to 1660 cm(-1) as well as changes in the electronic absorption bands. II was also characterized by electron paramagnetic resonance, showing an anisotropic signal at 110 K that arises from an S = 1/2 electronic ground state; the g-matrix components and hyperfine coupling tensor resemble the behavior of related {RuNO}7 complexes. Both I and II were characterized through their main reactivity modes, electrophilic and nucleophilic, respectively. The addition of OH- into I generated the nitro complex, with k(OH) = 3.05 x 10(6) M(-1) s(-1) (25 degrees C). This value is among the highest obtained for related nitrosyl complexes and correlates

  5. Tuning of Supramolecular Architectures of l-Valine-Containing Dicyanoplatinum(II) 2,2'-Bipyridine Complexes by Metal-Metal, π-π Stacking, and Hydrogen-Bonding Interactions.

    Science.gov (United States)

    Fu, Heidi Li-Ki; Po, Charlotte; He, Hexiang; Leung, Sammual Yu-Lut; Wong, Kam Sing; Yam, Vivian Wing-Wah

    2016-08-01

    A series of newly synthesized dicyanoplatinum(II) 2,2'-bipyridine complexes exhibits self-assembly properties in solution after the incorporation of the l-valine amino units appended with various hydrophobic motifs. These l-valine-derived substituents were found to have critical control over the aggregation behaviors of the complexes in the solution state. On one hand, one of the complexes was found to exhibit interesting circularly polarized luminescence (CPL) signals at low temperature due to the formation of chiral spherical aggregates in the temperature-dependent studies. On the other hand, systematic transformation from less uniform aggregates to well-defined fibrous and rod-like structures via Pt⋅⋅⋅Pt and π-π stacking interactions has also been observed in the mixed-solvent studies. These changes were monitored by UV/Vis absorption, emission, circular dichroism (CD), and CPL spectroscopies, and morphologies were studied by electron microscopy. PMID:27412571

  6. (2,2′-Bipyridine-κ2N,N′{[(3-methoxy-2-oxidobenzylidene-κO2hydrazono]methanolato-κ2N2,O}dimethyltin(IV

    Directory of Open Access Journals (Sweden)

    Islam Ullah Khan

    2008-04-01

    Full Text Available In the crystal structure of the title compound, [Sn(CH32(C9H8N2O3(C10H8N2], the Sn atom exhibits a pentagonal bipyramidal coordination geometry defined by two C, three N and two O atoms. The bond distances for Sn—C, Sn—N and Sn—O are in the ranges 2.097 (3–2.098 (3, 2.298 (2–2.623 (2 and 2.157 (2–2.266 (2 Å, respectively. The molecular structure of the monomeric compound is stabilized by three intramolecular C—H...O hydrogen bonds, all involving bipyridine C—H groups.

  7. Poly[[aqua(μ2-4,4′-bipyridine-κ2N:N′[μ3-3-bromo-2-(carboxylatomethylbenzoato-κ3O1:O1′:O2]cadmium] monohydrate

    Directory of Open Access Journals (Sweden)

    Yangmei Liu

    2012-08-01

    Full Text Available In the title compound, {[Cd(C9H5BrO4(C10H8N2(H2O]·H2O}n, the CdII atom has a distorted octahedral coordination geometry. Two N atoms from two 4,4′-bipyridine (bipy ligands occupy the axial positions, while the equatorial positions are furnished by three carboxylate O atoms from three 3-bromo-2-(carboxylatomethylbenzoate (bcb ligands and one O atom from a water molecule. The bipy and bcb ligands link the CdII atoms into a three-dimensional network. O—H...O hydrogen bonds and π–π interactions between the pyridine and benzene rings [centroid–centroid distance = 3.736 (4 Å] are present in the crystal.

  8. Poly[[(μ4-benzene-1,3,5-tricarboxylato-κ4O1:O1′:O2:O3bis(2,2-bipyridine-κ2N,N′(μ2-hydroxidodicopper(II] trihydrate

    Directory of Open Access Journals (Sweden)

    Mohamed N. El-kaheli

    2014-07-01

    Full Text Available In the title two-dimensional coordination polymer, {[Cu2(C9H3O6(OH(C10H8N22]·3H2O}n, each of the two independent CuII atoms is coordinated by a bridging OH group, two O atoms from two benzene-1,3,5-tricarboxylate (L ligands and two N atoms from a 2,2- bipyridine (bipy ligand in a distorted square-pyramidal geometry. Each L ligand coordinates four CuII atoms, thus forming a polymeric layer parallel to the bc plane with bipy molecules protruding up and down. The lattice water molecules involved in O—H...· O hydrogen bonding are situated in the inner part of each layer. The crystal packing is consolidated by π–π interactions between the aromatic rings of bipy ligands from neigbouring layers [intercentroid distance = 3.762 (3 Å].

  9. catena-Poly[[[pentaaquaeuropium(III]-μ-5-sulfonatoisophthalato-κ4O1,O1′:O3,O3′] 4,4'-bipyridine N,N′-dioxide hemisolvate trihydrate

    Directory of Open Access Journals (Sweden)

    Ai-Zhi Wu

    2010-11-01

    Full Text Available In the crystal structure of the title compound, {[Eu(C8H3O7S(H2O5]·0.5C10H8N2O2·3H2O}n, the EuIII coordination polymer displays a ribbon motif as the 5-sulfoisopthalate anion uses one of carboxyl –CO2 units to chelate to a Eu atom and the other to bind to other two Eu atoms; the sulfonyl –SO3 unit is not involved in coordination. Adjacent ribbons are linked by O—H...O hydrogen bonds, generating a three-dimensional network. The 4,4′-bipyridine-N,N′-dioxide molecule lies on an inversion centre and is hydrogen-bonded to the complex network. The coordination geometry of the Eu atom is a monocapped square antiprism.

  10. catena-Poly[[bis(μ2-4-aminobenzenesulfonato-κ2O:Odisilver]-bis(μ2-4,4′-bipyridine-κ2N:N′

    Directory of Open Access Journals (Sweden)

    Yong-Qiang Dai

    2008-12-01

    Full Text Available In the title compound, [Ag2(C6H6NO3S2(C10H8N22]n, the AgI atom is four-coordinated by two N atoms from two symmetry-related 4,4′-bipyridine (bipy and two O atoms from two independent 4-aminobenzenesulfonate (ABS ligands. The two inter-chain AgI atoms are bridged by two independent ABS ligands through weak Ag—O bonds and Ag...Ag attractions, forming a ladder-like chain coordination polymer [Ag2(ABS2(bipy2]n parallel to [001], which is further linked to generate a two-dimensional structure via N—H...O hydrogen-bonding interactions.

  11. Tuning of Supramolecular Architectures of l-Valine-Containing Dicyanoplatinum(II) 2,2'-Bipyridine Complexes by Metal-Metal, π-π Stacking, and Hydrogen-Bonding Interactions.

    Science.gov (United States)

    Fu, Heidi Li-Ki; Po, Charlotte; He, Hexiang; Leung, Sammual Yu-Lut; Wong, Kam Sing; Yam, Vivian Wing-Wah

    2016-08-01

    A series of newly synthesized dicyanoplatinum(II) 2,2'-bipyridine complexes exhibits self-assembly properties in solution after the incorporation of the l-valine amino units appended with various hydrophobic motifs. These l-valine-derived substituents were found to have critical control over the aggregation behaviors of the complexes in the solution state. On one hand, one of the complexes was found to exhibit interesting circularly polarized luminescence (CPL) signals at low temperature due to the formation of chiral spherical aggregates in the temperature-dependent studies. On the other hand, systematic transformation from less uniform aggregates to well-defined fibrous and rod-like structures via Pt⋅⋅⋅Pt and π-π stacking interactions has also been observed in the mixed-solvent studies. These changes were monitored by UV/Vis absorption, emission, circular dichroism (CD), and CPL spectroscopies, and morphologies were studied by electron microscopy.

  12. Synthesis, structural modelling and luminescence of a novel erbium(III) complex with 2,4-nonanedione and 2,2‧-bipyridine ligands for chitosan matrices doping

    Science.gov (United States)

    Martín-Ramos, P.; Chamorro-Posada, P.; Ramos Silva, M.; Pereira da Silva, P. S.; Martín, I. R.; Lahoz, F.; Lavín, V.; Martín-Gil, J.

    2015-03-01

    We report the synthesis, the Sparkle/PM7 semi-empirical quantum model for the ground state geometry and the absorption/luminescent properties of the Er3+ ternary complex [Er(nd)3(bipy)] (where Hnd is 2,4-nonanedione and bipy is 2,2‧-bipyridine). The solid-state electronic absorption spectra and the photoluminescent spectra show long-wavelength 4f-4f transitions which provide a potential use of the compound as a NIR-emitting material for the doping of polymer-based matrices for waveguides or for bio-analytical applications. The dispersion of the novel complex in a biocompatible chitosan film has been assessed.

  13. μ-Oxido-bis[chlorido(4,4′-di-tert-butyl-2,2′-bipyridine-κ2N,N′)dioxidomolybdenum(VI)] 0.2-hydrate

    OpenAIRE

    Gomes, Ana C.; José A. Fernandes; Gamelas, Carla A.; Isabel S. Gonçalves; Almeida Paz, Filipe A.

    2011-01-01

    The title hydrate, [Mo2Cl2O5(C18H24N2)2]·0.2H2O, has been isolated as the oxidation product of [Mo(η3-C3H5)Cl(CO)2(di-t-Bu-bipy)] (where di-t-Bu-bipy is 4,4′-di-tert-butyl-2,2′-bipyridine). A μ-oxide ligand bridges two similar MoCl(di-t-Bu-bipy)O2 units, having the terminal oxide ligands mutually cis, and the chloride and μ-oxide trans to each other. In the binuclear complex, the coordination geometries of the metal atoms can be describe...

  14. (2,2′-Bipyridine-κ2 N,N′)[2-tert-butyl­anilinato(2−)]dichloridooxido­molybdenum(VI) dichloro­methane hemisolvate

    OpenAIRE

    Alastair J. Nielson; Waters, Joyce M.

    2010-01-01

    The MoVI atom in the title structure, [Mo(C10H13N)Cl2O(C10H8N2)]·0.5CH2Cl2, has a distorted octa­hedral coord­ination sphere with cis-orientated oxide and imide ligands, trans-chloride ligands and the 2,2′-bipyridine (bipy) ligand N atoms lying trans to the oxide and imide ligands. An imide-ligand tert-butyl-methyl-group H atom makes a close approach with the oxide ligand (distance = 2.53 Å) and the imide-ligand N atom (distance = 2.41 Å). Another imide-ligand tert-butyl-methyl-group H atom m...

  15. Photoprocess of molecules encapsulated in porous solids X: Photosensitization of zeolite-Y encapsulated tris(2,2'-bipyridine-nickel-(II)ion by phenosafranine adsorbed onto the external surface of the nanoporous host

    Indian Academy of Sciences (India)

    Karuppannan Senthil Kumar; Sudha T; Paramasivam Natarajan

    2014-07-01

    Tris-(2,2'-bipyridine)-nickel-(II) complex ion encapsulated by zeolite-Y host has been synthesized by ship-in-a-bottle method. Photosensitization of nickel(II) complex (Ni(bpy)$^{2+}_{3}$) in the zeolite host by surface adsorbed phenosafranine dye was investigated by time-resolved fluorescence and absorption spectral measurements. Formation of nickel (II)-complex in the super cage of the host was ascertained by XRD, FTIR, solidstate NMR, diffuse reflectance UV-visible absorption spectroscopic techniques and ICP-OES measurements. Phenosafranine dye adsorbed on the external surface of zeolite-Y shows a decrease in fluorescence intensity with increased loading of the nickel(II) complex in zeolite-Y. Time-resolved emission studies show two excited state lifetimes for the photoexcited phenosafranine dye. Average fluorescence lifetimes of the dye in this case do not change with increase in the loading of the nickel(II) complex. However, relative contribution of short lifetime component increases when the amount of encapsulated nickel(II) complex is increased. The zeolite-Y host containing only bipyridyl ligand shows a marked decrease in fluorescence intensity. Fluorescence lifetimes of the dye however do not change with increased loading of bipyridyl while relative contribution of short lifetime component increases with an increase in the loading of bipyridyl in the host. This observation is interpreted to be due to electron transfer from the excited state of phenosafranine dye to the bipyridine. Picosecond pump-probe investigations confirm that the photoinduced electron transfer occurs from the surfaceadsorbed phenosafranine in the excited state to the nickel(II) complex within zeolite-Y cavity and also to the Ni(bpy)$^{2+}_{3}$ complex in contact with the phenosafranine dye co-adsorbed on the external surface of the host.

  16. Adsorption of gases and vapors on nanoporous Ni2(4,4'-Bipyridine)3(NO3)4 metal-organic framework materials templated with methanol and ethanol: structural effects in adsorption kinetics.

    Science.gov (United States)

    Fletcher, Ashleigh J; Cussen, Edmund J; Bradshaw, Darren; Rosseinsky, Matthew J; Thomas, K Mark

    2004-08-11

    Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of carbon dioxide, methanol, and ethanol sorption on adsorbents M and E over a range of temperatures with adsorbent structural characterization at different adsorbate (guest) loadings. The adsorption kinetics for methanol and ethanol adsorption on porous structure E obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. The corresponding adsorption kinetics for porous structure M follow a double exponential (DE) model, which is consistent with two different barriers for diffusion through the windows and along the pores in the structure. The former is a high-energy barrier due to the opening of the windows in the structure, required to allow adsorption to occur, while the latter is a lower-energy barrier for diffusion in the pore cavities. X-ray diffraction studies at various methanol and ethanol loadings showed that the host porous structures E and M underwent different scissoring motions, leading to an increase in unit cell volume with the space group remaining unchanged during adsorption. The results are discussed in terms of reversible adsorbate/adsorbent (host/guest) structural changes and the adsorption mechanism involving hydrogen-bonding interactions with specific surface sites for methanol and ethanol adsorption in relation to pore size and extent of filling. This paper contains the first evidence for individual kinetic barriers to diffusion through windows and pore cavities in flexible porous coordination polymer frameworks. PMID:15291578

  17. Reactivity of thiazolidine-2-thione towards CuI/CuII: Synthesis and structures of [3-(2-thiazolin-2-yl)thiazolidine-2-thione]copper(I) bromide and [bis(2,2′-bipyridine)nitratocopper(II)] nitrate

    Indian Academy of Sciences (India)

    Tarlok S Lobana; Anu Rani; Amanpreet K Jassal; Jerry P Jasinski

    2015-01-01

    Thiazolidine-2-thione (L1,NC3H5S2) reacted with copper(I) bromide in CH3CN under aerobic conditions and transformed through C-S bond cleavage into 3-(2-thiazolin-2-yl)thiazolidine-2-thione (L2, C3H4S2N-C3H4SN). This thio-ligand L2 with CuI ion yielded a three coordinate complex, [3-(2-Thiazolin-2-yl)thiazolidine-2-thione]copper(I)bromide 1a which crystallized in the triclinic system with the space group P1 as reported earlier. Treatment of 1a with bis(diphenylphosphino)methane (dppm) in dichloromethane also formed [3-(2-thiazolin-2-yl)thiazolidine-2-thione]copper(I) bromide 1b but it crystallized into the triclinic system with a new space group, P-1: 296(2) K, a, 7.3890(19); b, 8.473(2); c, 9.491(2) Å; , 70.273(5); , 67.170(5); , 84.949(5)°; R, 6.79%. Reactions of copper(II) nitrate with thiazolidine-2-thione followed by the addition of 2,2′-bipyridine or with 2,2′-bipyridine first followed by the addition of thiazolidine-2-thione, gave blue crystals in both the cases. The x-ray crystallography revealed stoichiometry of the complex formed as: [Cu(2-N,N′-bipy)2(1-ONO2)](NO3) 2, which crystallized in monoclinic crystal system with space group, P21/n(14). Crystal data: 173(2) K, a, 11.318(1), b, 12.160(1), c, 14.967(1) Å; = 98.01(1)°, R, 3.99%; 296(2) K, a, 11.340(5), b, 12.249(5), c, 15.065(6) Å; = 98.04(2)◦, R, 4.09%.

  18. Adsorption dynamics of gases and vapors on the nanoporous metal organic framework material Ni2(4,4'-bipyridine)3(NO3)4: guest modification of host sorption behavior.

    Science.gov (United States)

    Fletcher, A J; Cussen, E J; Prior, T J; Rosseinsky, M J; Kepert, C J; Thomas, K M

    2001-10-17

    This study combines measurements of the thermodynamics and kinetics of guest sorption with powder X-ray diffraction measurements of the nanoporous metal organic framework adsorbent (host) at different adsorptive (guest) loadings. The adsorption characteristics of nitrogen, argon, carbon dioxide, nitrous oxide and ethanol and methanol vapors on Ni2(4,4'-bipyridine)3(NO3)4 were studied over a range of temperatures as a function of pressure. Isotherm steps were observed for both carbon dioxide and nitrous oxide adsorption at approximately 10-20% of the total pore volume and at approximately 70% of total pore volume for methanol adsorption. The adsorption kinetics obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. At high surface coverage, both methanol and ethanol adsorption follow a combined barrier resistance/diffusion model. The rates of adsorption in the region of both the carbon dioxide and methanol isotherm steps were significantly slower than those observed either before or after the step. X-ray diffraction studies at various methanol loadings showed that the host structure disordered initially but underwent a structural change in the region of the isotherm step. These isotherm steps are ascribed to discrete structural changes in the host adsorbent that are induced by adsorption on different sites. Isotherm steps were not observed for ethanol adsorption, which followed a Langmuir isotherm. Previous X-ray crystallography studies have shown that all the sites are equivalent for ethanol adsorption on Ni2(4,4'-bipyridine)3(NO3)4, with the host structure undergoing a scissoring motion and the space group remaining unchanged during adsorption. The activation energies and preexponential factors for methanol and ethanol adsorption were calculated for each pressure increment at which the linear driving force model was obeyed. There was a good correlation between activation energy and ln(preexponential factor), indicating a

  19. Influence of the Torsion Angle in 3,3'-Dimethyl-2,2'-bipyridine on the Intermediate Valence of Yb in (C5Me5)2 Yb(3,3'-Me2-bipy)

    Energy Technology Data Exchange (ETDEWEB)

    Nocton, Gr& #233; gory; Booth, Corwin H.; Maron, Laurent; Andersen, Richard A.

    2014-06-26

    The synthesis and X-ray crystal structures of Cp-2*Yb(3,3'-Me(2)bipy) and [Cp-2 Yb(3,3'-Me(2)bipy)][Cp-2 YbCl1.6I0.4]center dot CH2Cl2 are described. In both complexes, the NCCN torsion angles are approximately 40 degrees. The temperature-independent value of n(f) of 0.17 shows that the valence of ytterbium in the neutral adduct is multiconfigurational, in reasonable agreement with a CASSCF calculation that yields a n(f) value of 0.27; that is, the two configurations in the wave function are f(13)(pi(1))(1) and f(14)(pi(1))(0) in a ratio of 0.27:0.73, respectively, and the open-shell singlet lies 0.28 eV below the triplet state (n(f) accounts for f-hole occupancy; that is, n(f) = 1 when the configuration is f(13) and n(f) = 0 when the configuration is f(14)). A correlation is outlined between the value of nf and the individual ytterbocene and bipyridine fragments such that, as the reduction potentials of the ytterbocene cation and the free x,x'-R-2-bipy ligands approach each other, the value of nf and therefore the f(13):f(14) ratio reaches a maximum; conversely, the ratio is minimized as the disparity increases.

  20. Synthesis, spectral and single crystal X-ray structural studies on bis(2,2’-bipyridinesulphidoM(II (M = Cu or Zn and diaqua 2,2’-bipyridine zinc(IIsulphate dihydrate

    Directory of Open Access Journals (Sweden)

    ARUMUGAM MANOHAR

    2010-08-01

    Full Text Available Reaction of bis(diethanoldithiocarbamatocopper(II, [Cu(deadtc2] and bis(di-n-propyldithiocarbamatozinc(II, [Zn(dnpdtc2] complexes with 2,2’-bipyridine (2,2’-bipy (1:1 ratio in ethanol was investigated. Simple mixing of the reactants in 1:1 ratio resulted in five-coordinated [Cu(2,2’--bipy2S]•CH3CH2OSO3H (1 and [Zn(2,2’-bipy2S]•CH3CH2OSO3H·2H2O (2. Refluxing the reactants and cooling the contents result in the formation of [Zn(2,2’-bipy(H2O2]SO4 (3 and [Cu(2,2’-bipy(H2O2]SO4 (4. Complexes 1 and 2 are monomeric with trigonal bipyramidal geometry. A distorted octahedral environment was observed in complexes 3 and 4. The crystal structure of 4 has already been reported in the literature. Crystal structures of 1, 2 and 3 are reported in this paper. The M–S distances in 1 and 2 are 2.318(1 Å and 2.323 Å, respectively. The N–M–S angles are larger than the N–M–N angles due to the steric requirements.

  1. Poly[diaquabis(μ-4,4′-bipyridine-κ2N:N′bis(ethane-1,2-diol-κObis(μ-sulfato-κ2O:O′dicobalt(II

    Directory of Open Access Journals (Sweden)

    Kai-Long Zhong

    2013-04-01

    Full Text Available In the title compound, [Co2(SO42(C10H8N22(C2H6O22(H2O2]n, there are two crystallographically independent CoII ions, each of which lies on a twofold rotation axis and has a slightly distorted octahedral environment. One CoII ion is coordinated by two N atoms from two bridging 4,4′-bipyridine (4,4′-bipy ligands, two O atoms from two sulfate ions and two O atoms from aqua ligands. The second CoII ion is similar but with ethane-1,2-diol ligands in place of water molecules. The sulfate anions act as bridging ligands to link two adjacent CoII ions together, leading to the formation of linear ...Co1Co2Co1Co2...chains along the a axis. Adjacent chains are further bridged by 4,4′-bipy ligands, which are also located on the twofold rotation axis, resulting in a two-dimensional layered polymer extending parallel to (001. In the crystal, the layers are linked by extensive O—H...O hydrogen-bonding interactions involving the O atoms of the water molecules and ethane-1,2-diol molecules, resulting in a three-dimensional supramolecular network.

  2. Bis (4,4′-dimethyl-2,2′-bipyridine) ruthenium (Ⅱ) Complexes Containing 2-Arylimidazo- [4,5-f ] [ 1,10 ] phenanthroline: Syntheses, Characterization and Third-order Nonlinear Optical Properties

    Institute of Scientific and Technical Information of China (English)

    CHAO,Hui(巢晖); LI,Rrn-Hua(李润华); HUANG,Qi-Wen(黄绮雯); JI,Liang-Nian(计亮年)

    2002-01-01

    Four novel mononuclear ruthenium(Ⅱ) complexes [ Ru(dmb)2L]2+ [dmp = 4,4′-dimethyl-2,2′-bipyridine, L = imidazo-[4,5-f][1,10]phenanthroline(IP), 2-phenylimidazo-[4,5-f][1,10]phenanthroline(PIP),2-(4′-hydroxyphenyl)imidazo-[4,5-f][1, 10]phenanthroline(HOP), 2-(4′-dimethylaminophenyl) imidazo-[4, 5-f] [1, 10] phenanthroline(DMNP)]were synthesized and characterized by ES-MS,1H NMR,UVvis and electrochemistry.The nonlinear optical properties of the ruthenium(Ⅱ) complexes were investigated by Z-scan techniques with 12 ns laser pulse at 540nm,and all of them exhibitboth nonlinear optical (NLO)absorption and self-defocusing effect. The corresponding effective NLO susceptibility |x3|of the complexes is in the range of 2.68×10-12 -4.57×10-12esu.

  3. μ-Oxido-bis[chlorido(4,4′-di-tert-butyl-2,2′-bipyridine-κ2N,N′dioxidomolybdenum(VI] 0.2-hydrate

    Directory of Open Access Journals (Sweden)

    Ana C. Gomes

    2011-12-01

    Full Text Available The title hydrate, [Mo2Cl2O5(C18H24N22]·0.2H2O, has been isolated as the oxidation product of [Mo(η3-C3H5Cl(CO2(di-t-Bu-bipy] (where di-t-Bu-bipy is 4,4′-di-tert-butyl-2,2′-bipyridine. A μ-oxide ligand bridges two similar MoCl(di-t-Bu-bipyO2 units, having the terminal oxide ligands mutually cis, and the chloride and μ-oxide trans to each other. In the binuclear complex, the coordination geometries of the metal atoms can be described as highly distorted octahedra. Individual complexes co-crystallize with a partially occupied water molecule of crystallization (occupancy factor = 0.20; H atoms not located, with the crystal packing being mediated by the need to effectively fill the available space. A number of weak C—H...O and C—H...Cl interactions are present.

  4. Synthesis, Structure and Properties of a Novel Infinite Triple Helices Coordination Polymer { [Co(4, 4′-bipyridine) (4, 4′-azobispyridine)2(NCS)2]·H2O }n%新颖无限三股螺旋钴配位聚合物{[Co(4,4′-bipyridine)(4,4′-azobispyridine)2(NCS)2]·H2O}n的合成、结构和性质的研究

    Institute of Scientific and Technical Information of China (English)

    李宝龙; 李宝宗; 徐正; 陈久桐

    2003-01-01

    The novel complex { [ Co (bipy) (azpy) 2 (NCS) 2 ] @ H2O } n (where bipy = 4, 4′-bipyridine, azpy = 4, 4′-azobisp-yridine) has been synthesized and characterized by elemental analyses, IR, UV, thermal analyses, and vari-able-temperature magnetic susceptibility. The crystal (C32H26CoN12OS2, Mr = 717.70) belongs to the orthorhombic,space group Pnna, a =2. 21312(16)nm, b = 1.40403(10)nm, c = 1. 14237(8)nm, V=3. 5497(4)nm3, Z =4,Dc = 1. 343g @ cm-3, μ=0. 645mm-1, F(000) = 1476, and final R1 =0. 0691, wR2 =0. 1129 for 231 parametersand 1674 observed reflections [ I > 2.00 σ(I) ]. The Co (Ⅱ) atom is, in a distorted octahedral geometry, coordi-nated by six nitrogen atoms from two bridging bipy, two monodentate azpy, and two thiocyanate groups. Thebridging ligand bipy links Co (Ⅱ) atoms to form the infinite "rod" with terminal coordination azpy ligand acting assidearms. Unprecedented three parallel interpenetrating two-dimensional (4, 4) networks and novel infinite triplehelices are formed via hydrogen-bonding interactions. CCDC: 155588.

  5. Self-assembly of multinuclear coordination species with chiral bipyridine ligands: silver complexes of 5,6-CHIRAGEN(o,m,p-xylidene) ligands and equilibrium behaviour in solution.

    Science.gov (United States)

    Mamula, O; Monlien, F J; Porquet, A; Hopfgartner, G; Merbach, A E; von Zelewsky, A

    2001-01-19

    The complexation reactions between Ag- and a series of enantiopure ligands belonging to the CHIRAGEN (from CHIRAlity GENerator) family (L1, L2, L3, based on (-)-5,6-pinene bipyridine) have been studied in solution. It has been shown that the length of the bridge plays a fundamental role in the self-assembly processes leading to different compounds: mononuclear complexes (with L3), mixtures of polynuclear complexes (with L2) and circular helicates (with L 1). Although the absolute configuration of the chiral centres in all three ligands is the same, the metal-centred chirality of L3 (delta) is inverted with respect to that in the other two complexes with L1 and L2 (delta). The metal configuration is thus opposite in the mononuclear complex with respect to the polynuclear species. Detailed thermodynamic studies were carried out for the Ag+ and L1 ligand system by 1H and 109Ag NMR spectroscopy (as a function of concentration, temperature and pressure). At low temperature and high pressure, the [Ag6L1(6)]6+ hexanuclear circular helicate forms a tetranuclear circular helicate [Ag4L1(4)]4+: 2[Ag6L1(6)]6+ 3 [Ag4L1(4)]4+. The thermodynamics parameters, obtained by temperature and pressure variation, have the following values: K298 = (8.7 +/- 0.7) x 10(-5) mol x kg(-1), deltaHo = -15.65 +/- 0.8 kJ x mol(-1), deltaSo = -130.2 +/- 3 J x mol(-1) x K(-1) and deltaVo(256 K)= -160 +/- 12 cm3 x mol(-1). The reaction volume calculated according to Connolly's method indicates that the calculated structure of [Ag4L1(4)]4+ is plausible. Both the signs and large magnitudes of deltaSo and deltaVo are counterintuitive, yet can be understood by modelling methods. PMID:11271539

  6. Theoretical and experimental spectroscopic studies of the first highly luminescent binuclear hydrocinnamate of Eu(III), Tb(III) and Gd(III) with bidentate 2,2'-bipyridine ligand

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Lippy F.; Correa, Charlane C.; Garcia, Humberto C. [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG 36036-330 (Brazil); Martins Francisco, Thiago [Departamento de Física-ICEx, Universidade Federal de Minas Gerais, Pampulha, Belo Horizonte-MG 30123-970 (Brazil); Ribeiro, Sidney J.L. [Instituto de Química, Universidade Estadual Paulista Júlio de Mesquita Filho-UNESP, CP 355, Araraquara-SP 14801-970 (Brazil); Dutra, José Diogo L.; Freire, Ricardo O. [Pople Computational Chemistry Laboratory, Departamento de Química, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000 (Brazil); Machado, Flávia C., E-mail: flavia.machado@ufjf.edu.br [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG 36036-330 (Brazil)

    2014-04-15

    In this paper, the synthesis of three new binuclear lanthanide (III) complexes [Ln{sub 2}(cin){sub 6}(bpy){sub 2}] (Ln=Eu (1), Tb (2), Gd (3), cin=hydrocinnamate anion; bpy=2,2'-bipyridine), and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermal analysis (TGA/DTA) are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. Crystal structures of 1–3 reveal that all compounds are isostructural and that each lanthanide ion is nine-coordinated by oxygen and nitrogen atoms in an overall distorted tricapped trigonal-prismatic geometry. Eu(III) complex structure was also calculated using the Sparkle model for lanthanide complexes and the intensity parameters (Ω{sub 2}, Ω{sub 4}, and Ω{sub 6}), calculated from the experimental data and from Sparkle/PM3 model. The theoretical emission quantum efficiencies obtained for Sparkle/PM3 structures are in excellent agreement with the experimental values, clearly attesting to the efficacy of the theoretical models. The theoretical procedure applied here shows that the europium binuclear compound displays a quantum yield about 65% suggesting that the system can be excellent for the development of efficient luminescent devices. Highlights: • First binuclear Ln{sup 3+}-hydrocinnamate have been synthesized and characterized. • Eu{sup 3+}, Tb{sup 3+} and Gd{sup 3+} complexes photoluminescence properties were investigated. • Theoretical approaches for Eu{sup 3+} complex luminescence has been performed. • An energy level diagram is used to establish the ligand-to-metal energy transfer. • 65% Quantum yield suggests an excellent system for luminescent devices.

  7. Synthesis, Structure and Fluorescence of a Copper(II) Complex [Cu2(bipy)2(Hpht)2Cl](Hpht) (bipy = 2,2'-Bipyridine, H2pht = o-Phthalic Acid)

    Institute of Scientific and Technical Information of China (English)

    LI Qiang; ZHENG Fa-Kun; CAI Li-Zhen; CHEN Wen-Tong; GUO Guo-Cong; HUANG Jin-Shun

    2005-01-01

    The title complex [Cu2(bipy)2(Hpht)2Cl](Hpht) (bipy = 2,2’-bipyridine, H2pht = o-phthalic acid) has been synthesized in the NaOH aqueous solution of CuCl2, Gd(NO3)3, bipy and H2pht, and its crystal structure was determined by single-crystal X-ray diffraction method. It crystallizes in triclinic, space group P, C44H31ClCu2N4O12, Mr = 970.26, a = 8.175(2), b = 16.254(4), c = 16.946(4) (A), α = 62.966(6), β = 84.833(8), γ = 84.348(8)°, V = 1993.4(8) (A)3, Z = 2, Dc = 1.616 g/cm3, F(000) = 988 and μ = 1.207 mm-1. The final R = 0.0429 and wR = 0.0843 for 5682 observed reflections with I > 2σ(I). Each copper(II) atom displays a distorted square-pyramidal geometry with two nitrogen atoms of one chelate 2,2’-bipy molecule, two oxygen atoms from two different bridging carboxylate groups of Hphtˉand one bridging chloride atom occupying the apical position. The two copper(II) atoms are connected by a μ2-Cl atom and two bridging Hpht- ligands in a syn-syn coordination mode to form an isolated dinuclear unit. The molecular structure is extended to a one-dimensional wavy chain through hydrogen bonds. The title complex exhibits blue fluorescent emission at 443 nm (λex = 372 nm) in the solid state at room temperature.

  8. A New 3D Layered-pillared Cobalt(II)-organic Framework Constructed by Imidazole-4,5-dicarboxylic Acid (H_3IDC) and 4,4'-Bipyridine (bipy)

    Institute of Scientific and Technical Information of China (English)

    YUAN Li; LU Wen-Guan

    2011-01-01

    A new 3D metal-organic framework of {[Co3(IDC)2(bipy)2(py)2]·7H2O}n (1) was obtained by the hydrothermal reaction of Co(NO3)2·6H2O, imidazole-4,5-dicarboxylic acid (H3IDC), 4,4'-bipyridine (bipy), and pyridine (py), and structurally characterized by elemental analysis, infrared spectroscopy, thermal gravimetric analysis, and single-crystal X-ray diffraction. X-ray diffraction crystal structural analysis reveals that it crystallizes in orthorhombic system, space group Pccn with a = 11.1040(3), b = 19.8834(5), c = 21.3025(5), V = 4703.3(2)3, Mr = 1079.63, Z = 4, Dc = 1.525 Mg·m-3, F(000) = 2212, μ(CuKα) = 8.855 mm-1, the final R = 0.0331 and wR = 0.0713 for 2525 observed reflections with I ≥ 2σ(I). In compound 1, each cobalt(II) ion is six-coordinated with a slightly distorted octahedral coordination geometry, and each μ3-IDC3- acts as a bridge to bond three neighboring Co(II) ions, leading to an infinite 2D network layer structure of [Co3(IDC)2]n with Kagomé lattice. The adjacent layers are further linked by μ2-bipy to form an infinite 3D layered-pillared framework architecture of [Co3(IDC)2(bipy)2(py)2]n.

  9. (Anilino{(Z-2-[(E-5-bromo-3-methoxy-2-oxidobenzylidene]hydrazin-1-ylidene-κ2O2,N2}methanethiolato-κS(4,4′-dimethyl-2,2′-bipyridine-κ2N,N′zinc N,N-dimethylformamide monosolvate

    Directory of Open Access Journals (Sweden)

    Jinsa Mary Jacob

    2012-08-01

    Full Text Available The asymmetric unit of the title compound, [Zn(C15H12BrN3O2S(C12H12N2]·C3H7NO, contains two independent molecules with a similar structure. The doubly deprotonated Schiff base ligand O,N,S-chelates to the metal atom, and the three coordinating atoms along with one N atom of the substituted 2,2′-bipyridine ligand constitute the square plane of the distorted square pyramid surrounding the metal atom. The apical site is occupied by the second N atom of the substituted 2,2′-bipyridine. The secondary amine group of the Schiff base dianion forms a hydrogen bond to the O atom of the dimethylformamide solvent. In the crystal, the phenyl ring of one of the two Schiff base anions is disordered over two positions in a 1:1 ratio. The crystal studied is a racemic twin.

  10. (Anilino{(Z)-2-[(E)-5-bromo-3-meth-oxy-2-oxidobenzyl-idene]hydrazin-1-yl-idene-κ(2)O(2),N(2)}methane-thiol-ato-κS)(4,4'-di-methyl-2,2'-bipyridine-κ(2)N,N')zinc N,N-dimethyl-formamide monosolvate.

    Science.gov (United States)

    Jacob, Jinsa Mary; Prathapachandra Kurup, M R; Ng, Seik Weng

    2012-08-01

    The asymmetric unit of the title compound, [Zn(C(15)H(12)BrN(3)O(2)S)(C(12)H(12)N(2))]·C(3)H(7)NO, contains two independent mol-ecules with a similar structure. The doubly deprotonated Schiff base ligand O,N,S-chelates to the metal atom, and the three coordinating atoms along with one N atom of the substituted 2,2'-bipyridine ligand constitute the square plane of the distorted square pyramid surrounding the metal atom. The apical site is occupied by the second N atom of the substituted 2,2'-bipyridine. The secondary amine group of the Schiff base dianion forms a hydrogen bond to the O atom of the dimethyl-formamide solvent. In the crystal, the phenyl ring of one of the two Schiff base anions is disordered over two positions in a 1:1 ratio. The crystal studied is a racemic twin. PMID:22904750

  11. Crystal structures of tetramethylammonium (2,2′-bipyridinetetracyanidoferrate(III trihydrate and poly[[(2,2′-bipyridine-κ2N,N′di-μ2-cyanido-dicyanido(μ-ethylenediamine(ethylenediamine-κ2N,N′cadmium(IIiron(II] monohydrate

    Directory of Open Access Journals (Sweden)

    Songwuit Chanthee

    2016-05-01

    Full Text Available The crystal structures of the building block tetramethylammonium (2,2′-bipyridine-κ2N,N′tetracyanidoferrate(III trihydrate, [N(CH34][Fe(CN4(C10H8N2]·3H2O, (I, and a new two-dimensional cyanide-bridged bimetallic coordination polymer, poly[[(2,2′-bipyridine-κ2N,N′di-μ2-cyanido-dicyanido(μ-ethylenediamine-κ2N:N′(ethylenediamine-κ2N,N′cadmium(IIiron(II] monohydrate], [CdFe(CN4(C10H8N2(C2H8N22]·H2O, (II, are reported. In the crystal of (I, pairs of [Fe(2,2′-bipy(CN4]− units (2,2′-bipy is 2,2′-bipyridine are linked together through π–π stacking between the pyridyl rings of the 2,2′-bipy ligands to form a graphite-like structure parallel to the ab plane. The three independent water molecules are hydrogen-bonded alternately with each other, forming a ladder chain structure with R44(8 and R66(12 graph-set ring motifs, while the disordered [N(CH34]+ cations lie above and below the water chains, and the packing is stabilized by weak C—H...O hydrogen bonds. The water chains are further linked with adjacent sheets into a three-dimensional network via O—H...O hydrogen bonds involving the lattice water molecules and the N atoms of terminal cyanide groups of the [Fe(2,2′-bipy(CN4]− building blocks, forming an R44(12 ring motif. Compound (II features a two-dimensional {[Fe(2,2′-bipy(CN4Cd(en2]}n layer structure (en is ethylenediamine extending parallel to (010 and constructed from {[Fe(2,2′-bipy(CN4Cd(en]}n chains interlinked by bridging en ligands at the Cd atoms. Classical O—H...N and N—H...O hydrogen bonds involving the lattice water molecule and N atoms of terminal cyanide groups and the N—H groups of the en ligands are observed within the layers. The layers are further connected via π–π stacking interactions between adjacent pyridine rings of the 2,2′-bipy ligands, completing a three-dimensional supramolecular structure.

  12. Triaqua-1κO,2κ2O-bis(2,2′-bipyridine-1κ2N,N′;2κ2N,N′-chlorido-1κCl-μ-terephthalato-1:2κ2O1:O4-dicopper(II nitrate monohydrate

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2012-06-01

    Full Text Available In the binuclear title compound, [Cu2(C8H4O4Cl(C10H8N22(H2O3]NO3·H2O, the two crystallographically independent CuII ions have similar coordination environments. One of the CuII ions has a square-pyramidal arrangement, which is defined by a water molecule occupying the apical position, with the equatorial ligators consisting of two N atoms from a 2,2′-bipyridine molecule, one carboxylate O atom from a terephthalate ligand and one O atom from a water molecule. The other CuII ion has a similar coordination environment, except that the apical position is occupied by a chloride ligand instead of a water molecule. An O—H...O and O—H...Cl hydrogen-bonded three-dimensional network is formed between the components.

  13. The role of acid in the formation of hydrogen-bonded networks featuring 4,4'-dicarboxy-2,2'-bipyridine (H2dcbp): Synthesis, structural and magnetic characterisation of {[Cu(H2dcbp)Cl2].H2O}2 and [Cu(H2dcbp)(NO3)2(H2O)

    OpenAIRE

    Tynan, Eithne; Jensen, Paul; Lees, Anthea C.; Moubaraki, Boujemaa; Murray, Keith S.; Kruger, Paul E.

    2005-01-01

    Reported herein are the synthesis, structural and magnetic characterisation of two hydrogen-bonded networks featuring the 4,4?-dicarboxy-2,2?-bipyridine (H2dcbp) ligand: {[Cu(H2dcbp)(Cl)2]·H2O}2 1 and [Cu(H2dcbp)(NO3)2(H2O)] 2. Compounds 1 and 2 result from the reaction of CuCl2 and Cu(NO3)2, respectively, with H2dcbp under hydrothermal conditions in the presence of either HCl or HNO3. The acid ensures that H2dcbp remains protonated and provides the anions required for charge balance irrespec...

  14. Structure of a dinuclear cadmium complex with 2,2'-bi-pyridine, monodentate nitrate and 3-carb-oxy-6-methyl-pyridine-2-carboxyl-ate ligands: intra-molecular carbon-yl(lone pair)⋯π(ring) and nitrate(π)⋯π(ring) inter-actions.

    Science.gov (United States)

    Granifo, Juan; Suarez, Sebastián; Baggio, Ricardo

    2015-08-01

    The centrosymmetric dinuclear complex bis-(μ-3-carb-oxy-6-methyl-pyridine-2-carboxyl-ato)-κ(3) N,O (2):O (2);κ(3) O (2):N,O (2)-bis-[(2,2'-bi-pyridine-κ(2) N,N')(nitrato-κO)cadmium] methanol monosolvate, [Cd2(C8H6NO4)2(NO3)2(C10H8N2)2]·CH3OH, was isolated as colourless crystals from the reaction of Cd(NO3)2·4H2O, 6-methyl-pyridine-2,3-di-carb-oxy-lic acid (mepydcH2) and 2,2'-bi-pyridine in methanol. The asymmetric unit consists of a Cd(II) cation bound to a μ-κ(3) N,O (2):O (2)-mepydcH(-) anion, an N,N'-bidentate 2,2'-bi-pyridine group and an O-mono-dentate nitrate anion, and is completed with a methanol solvent mol-ecule at half-occupancy. The Cd complex unit is linked to its centrosymmetric image through a bridging mepydcH(-) carboxyl-ate O atom to complete the dinuclear complex mol-ecule. Despite a significant variation in the coordination angles, indicating a considerable departure from octa-hedral coordination geometry about the Cd(II) atom, the Cd-O and Cd-N distances in this complex are surprisingly similar. The crystal structure consists of O-H⋯O hydrogen-bonded chains parallel to a, further bound by C-H⋯O contacts along b to form planar two-dimensional arrays parallel to (001). The juxtaposed planes form inter-stitial columnar voids that are filled by the methanol solvent mol-ecules. These in turn inter-act with the complex mol-ecules to further stabilize the structure. A search in the literature showed that complexes with the mepydcH(-) ligand are rare and complexes reported previously with this ligand do not adopt the μ-κ(3) coordination mode found in the title compound. PMID:26396748

  15. Analysis of Binding Properties Between β-Cyclodextrin Bipyridine-ruthenium Derivative and Vitamins by Their Fluorescence Spectra%β-环糊精联吡啶钌衍生物与维生素包络作用的荧光光谱分析

    Institute of Scientific and Technical Information of China (English)

    郑珊珊; 陈红; 祁彦涛; 王秀华; 樊华军; 赵莹莹; 张帆; 杨帆; 汤杰

    2013-01-01

    This paper presents a research of the binding interaction of a new synthetized β-cyclodextrin bipyridine-ruthenium derivative[β-CD-Ru(bpy) 3] with a series of vitamins using fluorescent spectrometry.The performance of fluorescence emission ofβ-CD-Ru(bpy) 3 was excellent due to the existence of the center of bipyridine-ruthenium.Based on the effect of molecular recognition betweenβ-cyclodextrin and guest molecule,the fluorescence quenching occured because of the energy transfer between theβ-CD-Ru (bpy) 3 and the vitamin when a kind of vitamin was added.According to the quantitative value of fluorescence quenching,the binding constants of the new derivative with respect to various vitamins were determined by Benesi-Hildebrand Equation.The results show that the binding capacities of the vitamins withβ-CD-Ru (bpy) 3 were in a descending sequence of VB12>VK3 >VC>VA.%合成了一种新型的β-环糊精联吡啶钌衍生物[β-CD-Ru(bpy)3],采用分子荧光光谱法研究了该衍生物对一系列维生素的包络作用.β-CD-Ru(bpy)3的结构中含有发光活性基团联吡啶钌中心,因此具有良好的荧光特性.当加入与β-环糊精有主客体识别作用的维生素时,β-CD-Ru(bpy)3与维生素之间发生能量转移从而导致主体分子发生荧光猝灭.采用Benesi-Hildebrand方程,根据其猝灭值计算了该衍生物与各种维生素的包络常数.实验结果表明,维生素与β-CD-Ru(bpy)3包络作用大小顺序为维生素B12>维生素K3>维生素C>维生素A.

  16. (2,2′-Bipyridine-4,4′-dicarboxylic acid-κ2N,N′chlorido(2,2′:6′,2′′-terpyridyl-κ3N,N′,N′′ruthenium(II perchlorate ethanol monosolvate monohydrate

    Directory of Open Access Journals (Sweden)

    Anne Nielsen

    2012-01-01

    Full Text Available In the title compound, [RuCl(C15H11N3(C12H8N2O4]ClO4·C2H5OH·H2O, the geometry of the ClN5 coordination set around the RuII atom is close to octahedral, but distorted on account of the limited bite angles of the polypyridyl ligands. The complexes are linked by O—H...O hydrogen bonds between the carboxyl groups and the crystal lattice water molecules into chains along [110]. Face-to-face stacking interactions are formed between terpyridine ligands, with interplanar separations of 3.66 (1 and 3.42 (1 Å, and between bipyridine-4,4′-dicarboxylic acid ligands, with interplanar separations of 3.65 (1 and 3.72 (1 Å. Three O atoms of the perchlorate ion are each disordered equally over two positions. The hydroxy group of the ethanol molecule is also disordered over two sites with refined occupancies of 0.794 (9 and 0.206 (9.

  17. Synthesis and crystal structures of new complexes of Np(V) glycolate with 2,2'-bipyridine, [NpO2(C10H8N2)(OOC2H2OH)].1.5H2O and [NpO2(C10H8N2)(OOC2H2OH)].2.5H2O

    International Nuclear Information System (INIS)

    Single crystals were prepared, and the structures of two complexes of Np(V) glycolate with 2,2'-bipyridine of the compositions [NpO2(C10H8N2)(OOC2H2OH)].1.5H2O (I) and [NpO2(C10H8N2)(OOC2H2OH)]2.5H2O (II) were studied. The structures of the compounds are based on neptunyl-glycolate chains in which the glycolate anion manifests its complexation ability in different manner. In structure I, the bidentate-bridging anion links the adjacent NpO2- cations through the oxygen atoms of the carboxylate group. The neptunyl-glycolate chains of I exhibits the mutual coordination of the NpO2- cations acting toward each other simultaneously as ligands and coordinating centers. In compound II, the glycolate anion is bidentately coordinated to one neptunium atom to form a planar five-membered metallocycle [NpOCCO]. The O atom external with respect to the metallocycle is in the coordination environment of the adjacent neptunyl. The nitrogen-containing molecular ligand Bipy is included into the coordination environment of Np. The coordination polyhedron of the Np atoms in both structures is a pentagonal bipyramid in which the average Np-N bond length is 2.666 Aa (I) and 2.596 Aa (II). (orig.)

  18. Linearly Tetrameric Water Cluster Stabilized by Cyano Groups of Multicomplex [Zn(2,2’-bipyridine)3][Zn(CN)4]·2H2O%[Zn(2,2’-bipyridine)3][Zn(CN)4]·2H2O复配物中线型四聚水簇

    Institute of Scientific and Technical Information of China (English)

    曹鹏; 何军

    2016-01-01

    A hydrothermal reaction of Zn(CN)2, 2,2’-bipyridine(bipy)afforded a novel multicomplex, [Zn(bipy)3][Zn(CN)4]·2H2O(1), which features a 2D supramolecular network assembled from unprecedented linear water tetramers and anionic [Zn(CN)4]2- moieties through intricate hydrogen bonding interactions. Single-crystal X-ray diffraction, FT-IR, thermogravimetric analysis and photoluminescence spectrum of 1 also have been discussed. 1 exhibits strong photoluminescence maximized at 437 nm upon 310 nm excitation at ambient temperature, of which is close to that of the greenish light.%通过水热合成法,利用Zn(CN)2,2,2’-联吡啶合成出一种新颖的复配物[Zn(bipy)3][Zn(CN)4]·2H2O(1),它的特点是通过复杂的氢键作用,将一种结构新颖的线性四聚体水簇和[Zn (CN)4]2-负电基团连接组装成一种二维超分子网络。并对1进行了包括单晶X-射线衍射、红外、热重以及荧光发射在内的表征与分析。研究发现在室温下310 nm的紫外光激发下,1表现出强烈的荧光发射性质,且发射光波长为437 nm,与绿光非常接近。

  19. Novel thioarsenates {[Mn(2,2'-bipy)2(SCN)][Mn(2,2'-bipy)](As(V)S4)}2 and {[Mn(2,2'-bipy)2(SCN)]2[As(III)2(S2)2S2]}: introducing an anionic second ligand to modify MnII complex cations of 2,2'-bipyridine.

    Science.gov (United States)

    Liu, Guang-Ning; Guo, Guo-Cong; Wang, Ming-Sheng; Huang, Jin-Shun

    2014-03-14

    Two novel manganese thioarsenates, {[Mn(2,2'-bipy)2(SCN)][Mn(2,2'-bipy)](As(V)S4)}2 (1, 2,2'-bipy = 2,2'-bipyridine) and {[Mn(2,2'-bipy)2(SCN)]2[As(III)2(S2)2S2]} (2), containing thiocyanate-modified Mn-2,2'-bipy complex cations were synthesized. They feature two terminal [Mn(2,2'-bipy)2(SCN)](+) complex cations bridged by a polyanion {[Mn(2,2'-bipy)]2(As(V)S4)2}(2-) for 1 and a cyclic thioarsenate anion (As(III)2S6)(2-) for 2. In 2, the [As(III)2(S2)2S2](2-) anion can be described as two (As(III)S3)(3-) trigonal-pyramids interlinked through S-S bonds. The method to obtain new metal complex cations shown here, introducing an anionic second ligand to modify the number of coordination sites and the charges of the metal complex cations simultaneously, is different from the traditional methods, varying either the TM center or the organic ligand or employing mixed neutral organic ligands, and may open up a new route for preparing novel chalcogenidometalates. Compounds 1 and 2 exhibit wide optical gaps of 2.20 and 2.67 eV, respectively, and photoluminescence with the emission maxima occurring around 440 nm. Magnetic measurements show the presence of antiferromagnetic interactions between Mn(II) centers in the two compounds.

  20. DNA hybridization biosensor using chitosan-carbon nanotubes composite film as an immobilization platform and [Cu(bpy)(MBZ){sub 2}(H{sub 2}O)] (bpy = 2,2'-bipyridine, MBZ = p-methylbenzoate) as a novel redox indicator

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qingxiang, E-mail: axiang236@126.co [Department of Chemistry and Environment Science, Zhangzhou Normal University, Zhangzhou 363000 (China) and Fujian Province University Key Laboratory of Analytical Science, Zhangzhou Normal University, Zhangzhou 363000 (China); Shi Juanlan; Ni Jiancong; Gao Fei; Gao Feng [Department of Chemistry and Environment Science, Zhangzhou Normal University, Zhangzhou 363000 (China); Weng Wen [Department of Chemistry and Environment Science, Zhangzhou Normal University, Zhangzhou 363000 (China); Fujian Province University Key Laboratory of Analytical Science, Zhangzhou Normal University, Zhangzhou 363000 (China); Jiao Kui, E-mail: kjiao@qust.edu.c [College of Chemistry and Molecular Engineering, Qingdao University and Science and Technology, Qingdao 266042 (China)

    2011-04-15

    Research highlights: Chitosan-carbon nanotubes composite was used as a platform for DNA immobilization. Discrimination of a synthetic copper complex to ds- and ss-DNA was obtained. Hybridization detection was performed using the copper complex as an indicator. Good specificity and high sensitivity were achieved on the constructed DNA biosensor. - Abstract: In this paper, a new DNA hybridization detection strategy was developed based on the immobilization of capture probe DNA on a chitosan (CS)-carbon nanotubes (CNTs) composite modified glassy carbon electrode (CS-CNTs/GCE) and the use of a copper complex, [Cu(bpy)(MBZ){sub 2}(H{sub 2}O)] (bpy = 2,2'-bipyridine, MBZ = p-methylbenzoate), as a new redox hybridization indicator. The electrochemical characterization experiments showed that the nanocomposite film of CS-CNTs could effectively immobilize the capture probe DNA and greatly improve the electron-transfer reactions of the electroactive molecules. Electrochemical and fluorescent spectroscopic analysis revealed that the polypyridyl copper complex of [Cu(bpy)(MBZ){sub 2}(H{sub 2}O)] bound to DNA via a typical intercalation mode. Surface studies further showed that the copper complex can discriminate between double-stranded and single-stranded DNA that immobilized on the surface of CS-CNTs/GCE. When being utilized as a redox indicator for the detection of hybridization for short DNA species related to phosphinothricin acetyltransferase (PAT), the indicator showed good specificity for recognizing the complementary, three-base mismatched and non-complementary DNA. Under the optimized conditions, the oxidation peak currents of the copper complex enhanced linearly with increases in the concentration of the complementary sequence in the range from 5.0 x 10{sup -10} to 1.0 x 10{sup -8} M. A detection limit of 5.0 x 10{sup -10} M was also obtained based on the constructed DNA biosensor.

  1. Synthesis and Characterization of Chiral Mercury(II) and Cadmium(II) Complexes with 3,3'-Bipyridine-5,5',6,6'-tetramethyl-2,2'-dimethoxy-1,1'-biphenyl

    Institute of Scientific and Technical Information of China (English)

    FANG Yu; XUAN Wei-Min; ZHU Cheng-Feng; YUAN Guo-Zan; CUI Yong

    2011-01-01

    Two homochiral mercury (1) and cadmium (2) complexes derived from chiral twisted biphenyl pyridine ligand (3,3'-bipyridine-5,5',6,6'-tetramethyl-2,2'-dimethoxy-1,1'-biphenyl) have been synthesized and characterized by IR, microanalysis, TGA, UV-Vis, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 2. For 1, a = 14.2038(16), b = 14.3630(17), c = 7.0257(8), V = 1433.3(3)3, Mr = 878.91, Dc = 2.037 g/cm3, μ = 7.549 mm-1, F(000) = 824, the final GOF = 1.017, R = 0.0296 and wR = 0.0645 for 2925 observed reflections with I 2σ(I). For 2, a = 14.212(3), b = 14.392(3), c = 7.0498(14), V = 1442.0(5)3, Mr = 790.72, Dc = 1.821 g/cm3, μ = 2.924 mm–1, F(000) = 760, the final GOF = 1.075, R = 0.0340 and wR = 0.0834 for 3144 observed reflections with I 2σ(I). The crystal structures of 1 and 2 are isostructural and each adopts a two-dimensional supramolecular network which contains the C–H···π interactions.

  2. An octanuclear molybdenum(VI) complex containing coordinatively bound 4,4'-di-tert-butyl-2,2'-bipyridine, [Mo8O22(OH)4(di-tBu-bipy)4]: synthesis, structure, and catalytic epoxidation of bio-derived olefins.

    Science.gov (United States)

    Amarante, Tatiana R; Neves, Patrícia; Tomé, Cátia; Abrantes, Marta; Valente, Anabela A; Paz, Filipe A Almeida; Pillinger, Martyn; Gonçalves, Isabel S

    2012-03-19

    The reaction of [MoO(2)Cl(2)(di-tBu-bipy)] (1) (di-tBu-bipy = 4,4'-di-tert-butyl-2,2'-bipyridine) with water at 100-120 °C in a Teflon-lined stainless steel autoclave, in an open reflux system, or in a microwave synthesis system gave the octanuclear complex [Mo(8)O(22)(OH)(4)(di-tBu-bipy)(4)] (2) as a microcrystalline powder in good yields. Single crystals of 2 suitable for X-ray diffraction were obtained by the reaction of MoO(3) and di-tBu-bipy in water at 160 °C for 3 days. The molecular structure of 2 comprises a purely inorganic core, Mo(4)O(8)(μ(3)-OH)(2)(μ(2)-O)(2), attached to two peripheral oxo-bridged binuclear units, Mo(2)O(4)(μ(2)-O)(2)(OH)(di-tBu-bipy)(2). The inorganic core is composed of a unique assembly of four {MoO(5)} distorted square pyramids connected to each other via edge-sharing. Overall, the octanuclear complex adopts a highly distorted form strongly resembling an "S"-shaped molecular unit. Complex 2 was applied in the catalytic epoxidation of the biorenewable olefins DL-limonene (Lim) and methyl oleate (Ole), using tert-butylhydroperoxide (TBHP) as an oxygen donor, under mild reaction conditions (55 °C, air). The reactions of Lim and Ole gave the respective epoxide monomers in fairly high selectivities at high conversions (89% 1,2-epoxy-p-menth-8-ene selectivity at 96% Lim conversion; 99% methyl 9,10-epoxystearate selectivity at 94% Ole conversion, reached within 24 h reaction). Iodometric titrations revealed no measurable "non-productive" decomposition of TBHP. PMID:22372402

  3. Involvement of a binuclear species with the Re-C(O)O-Re moiety in CO2 reduction catalyzed by tricarbonyl rhenium(I) complexes with diimine ligands: strikingly slow formation of the Re-Re and Re-C(O)O-Re species from Re(dmb)(CO)3S (dmb = 4,4'-dimethyl-2,2'-bipyridine, S = solvent).

    Science.gov (United States)

    Hayashi, Yukiko; Kita, Shouichi; Brunschwig, Bruce S; Fujita, Etsuko

    2003-10-01

    Excited-state properties of fac-[Re(dmb)(CO)(3)(CH(3)CN)]PF(6), [Re(dmb)(CO)(3)](2) (where dmb = 4,4'-dimethyl-2,2'-bipyridine), and other tricarbonyl rhenium(I) complexes were investigated by transient FTIR and UV-vis spectroscopy in CH(3)CN or THF. The one-electron reduced monomer, Re(dmb)(CO)(3)S (S = CH(3)CN or THF), can be prepared either by reductive quenching of the excited states of fac-[Re(dmb)(CO)(3)(CH(3)CN)]PF(6) or by homolysis of [Re(dmb)(CO)(3)](2). In the reduced monomer's ground state, the odd electron resides on the dmb ligand rather than on the metal center. Re(dmb)(CO)(3)S dimerizes slowly in THF, k(d) = 40 +/- 5 M(-1) s(-1). This rate constant is much smaller than those of other organometallic radicals which are typically 10(9) M(-1) s(-1). The slower rate suggests that the equilibrium between the ligand-centered and metal-centered radicals is very unfavorable (K approximately 10(-4)). The reaction of Re(dmb)(CO)(3)S with CO(2) is slow and competes with the dimerization. Photolysis of [Re(dmb)(CO)(3)](2) in the presence of CO(2) produces CO with a 25-50% yield based on [Re]. A CO(2) bridged dimer, (CO)(3)(dmb)Re-CO(O)-Re(dmb)(CO)(3) is identified as an intermediate. Both [Re(dmb)(CO)(3)](2)(OCO(2)) and Re(dmb)(CO)(3)(OC(O)OH) are detected as oxidation products; however, the previously reported formato-rhenium species is not detected. PMID:14505419

  4. 6,6 '-bis (5,5,8,8-tetramethyl-5,6,7,8-tetra-hydro-benzo 1,2,4 triazine-3-yl) 2,2 ' bipyridine, an effective extracting agent for the separation of americium(III) and curium(III) from the lanthanides

    International Nuclear Information System (INIS)

    The extraction of americium(III), curium(III), and the lanthanides(III) from nitric acid by 6,6'- bis (5,5,8,8-tetramethyl-5,6,7,8-tetra-hydro-benzo[1,2,4]triazine-3-yl)-[2,2'] bipyridine (CyMe4-BTBP) has been studied. Since the extraction kinetics were slow, N,N'-dimethyl-N,N'-di-octyl-2-(2-hexyl-oxy-ethyl)malonamide (DMDOHEMA) was added as a phase transfer reagent. With a mixture of 0.01 M CyMe4-BTBP + 0.25 M DMDOHEMA in n -octanol, extraction equilibrium was reached within 5 min of mixing. At a nitric acid concentration of 1 M, an americium(III) distribution ratio of approx. 10 was achieved. Americium(III)/lanthanide(III) separation factors between 50 (dysprosium) and 1500 (lanthanum) were obtained. Whereas americium(III) and curium(III) were extracted as di-solvates, the stoichiometries of the lanthanide(III) complexes were not identified unambiguously, owing to the presence of DMDOHEMA. In the absence of DMDOHEMA, both americium(III) and europium(III) were extracted as di-solvates. Back-extraction with 0.1 M nitric acid was thermodynamically possible but rather slow. Using a buffered glycolate solution of pH=4, an americium(III) distribution ratio of 0.01 was obtained within 5 min of mixing. There was no evidence of degradation of the extractant, for example, the extraction performance of CyMe4-BTBP during hydrolysis with 1 M nitric acid did not change over a two month contact. (authors)

  5. Syntheses and luminescence properties of ternary europium complexes with succinic acid derivative and 2,2'-bipyridine%铕-丁二酸衍生物-2,2'-联吡啶三元配合物的合成和荧光性质研究

    Institute of Scientific and Technical Information of China (English)

    刘胜利; 欧阳涛; 禹良才; 朱金良

    2011-01-01

    Six temary Eu ( Ⅲ ) complexes were synthesized by using succinic acid ( L1 ) , methyl - succinic acid ( L2 ) , methylene - succinic acid ( L3 ) , mercapto - succinic acid ( L4 ) , bromo - succinic acid ( L5) , hydroxy - succinic acid ( L6) as the first ligand and 2,2' - bipyridine ( bipy) as the second ligand. The compositions of complexes were Eu2 ( L) 3bipy · 2H2O (L = succinic acid and its derivatives) which were characterized by TG -DTG and rare earth compleximetry. Their properties were characterized by means of IR spectra and fluorescence spectra at room temperature. Fluorescence spectroscopy showed that the changes of substituents had small influence on the positions of complexes ' excitation peaks and emission peaks. but large on the fluorescence intensity, and the fluorescence intensity of complexes decreased in the order of substituents: - SH, - Br, - H, - OH, - CH3 , -CH2.%分别以丁二酸(L1)、2-甲基丁二酸(L2)、2-亚甲基丁二酸(L3)、2-巯基丁二酸(L4)、2-澳基丁二酸(L5)、2-羟基丁二酸(L6)为第一配体,2,2-联吡啶(bipy)为第二配体,合成了6种稀土铕的三元配合物,通过差热分析及稀土络合滴定确定了配合物的组成为Eu2(L)3bipy·2H2O(L=丁二酸及其衍生物).通过红外光谱、荧光光谱表征了配合物的性质.对6种配合物进行荧光光谱研究,结果表明:配体取代基的变化对配合物荧光激发蜂和发射蜂的位置变化影响很小,但对配合物的荧光强度有较大影响,其配合物的荧光强度大小为:-SH>-Br>-H>-OH>-CH3>-CH2.

  6. Energy-transfer rate in crystals of double-complex salts composed of [Ru(N-N)3](2+) (N-N = 2,2'-bipyridine or 1,10-phenanthroline) and [Cr(CN)6](3-): effect of relative orientation between donor and acceptor.

    Science.gov (United States)

    Otsuka, T; Sekine, A; Fujigasaki, N; Ohashi, Y; Kaizu, Y

    2001-07-01

    A block single-crystal was obtained using a diffusion method with a concentrated acetone-water (vol. 1/1) solution of [Ru(phen)(3)]Cl(2).6H(2)O (phen = 1,10-phenanthroline) and a concentrated aqueous solution of K(3)[Cr(CN)(6)], without evaporating solvents. The crystal was identified as a double-complex salt including two acetone and fourteen solvent water molecules, [Ru(phen)(3)](2)[Cr(CN)(6)]Cl.2(CH(3))(2)CO.14H(2)O (1). Measurement of the X-ray diffraction pattern of the double-complex salt was performed using an X-ray diffractometer with an Imaging-Plate (IP) Weissenberg camera. 1 crystallizes in the triclinic space group P1, with a = 13.930(5) A, b = 14.783(5) A, c = 11.137(6) A, alpha = 89.87(4) degrees, beta = 107.47(3) degrees, gamma = 96.68(3) degrees, and Z = 2. The crystal structure is very different from that of [Ru(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O (2) (bpy = 2,2'-bipyridine), which could be obtained using the same procedure and crystallizes in the monoclinic space group C2, with a = 22.414(2) A, b = 13.7686(15) A, c = 22.207(2) A, beta = 90.713(8) degrees, and Z = 4. The distance between the central-metal ions of ruthenium(II) and chromium(III) complexes in [Ru(phen)(3)](2)[Cr(CN)(6)]Cl.2(CH(3))(2)CO.14H(2)O (7.170 A) is shorter than that in [Ru(bpy)(3)](2)[Cr(CN)(6)]Cl.8H(2)O (9.173 A) by about 2 A, while the rate of energy transfer from the (3)MLCT state of [Ru(N-N)(3)](2+) to the (2)E(g) state of [Cr(CN)(6)](3-) in the former salt (9.5 x 10(5) s(-1)) is far slower than that in the latter one (6.0 x 10(6) s(-1)) at 77 K. These results indicate that the energy-transfer rate strongly depends, not upon the distance between central metal ions, rather, upon the mutual relative orientation between the donor and the acceptor complexes in double-complex salts.

  7. Selective Zn2+ sensing using a modified bipyridine complex

    Energy Technology Data Exchange (ETDEWEB)

    Akula, Mahesh; El-Khoury, Patrick Z.; Nag, Amit; Bhattacharya, Anupam

    2014-06-01

    A novel fluorescent Zn2+ sensor, 4-(pyridin-2-yl)-3H-pyrrolo[2, 3-c]quinoline (PPQ), has been designed, synthesized and characterized by various spectroscopic and analytical techniques. PPQ exhibits superior detection of Zn2+ in the presence of various cations tested, including Cd2+ and Hg2+, via wavelength shifted fluorescence intensity enhancement. The emission wavelength at 500 nm, ensures probable noninterference from cellular components while performing biological applications.

  8. [Cu(bpy)(H2O)(mal)]·H2O配合物的拓扑结构及磁性研究%Syntheses, characterization and magnetic property of copper with malonic acid and 2,2'-bipyridine complex

    Institute of Scientific and Technical Information of China (English)

    金陵; 朱红林

    2013-01-01

    The title compound [ Cu ( bpy ) { H2O ) ( mal) ] · H2O(bpy =2,2'-Bipyridine,mal = malonic acid) was synthesized in water-methanol solution. The crystal structure was determined by single-crystal x-ray diffraction analysis. The crystal belongs to triclinic with space group P-1 ,a = 7. 132( 1)A, 6 = 10. 404 (2) A,c = 10. 694 (2) A, a = 105. 85 (3)°,β = 104.53(3)°, r = 105. 28 (3 ) °, V = 690.4 (2) (A3),DC = 1.721 g ·cm-3 ,Z = 2. In the title complex,the Cu( II ) ion is five-coordinated, forming a square pyramidal CuN2O, coordination environment. The complex was characterized by IR spectrum, Elemental analysis, X-ray powder diffraction, thermal analysis, magnetic property. The 3D topology analysis of the title compound showed an uncommon 4,6-connected bi-nodal fsc topology. The complex is ferromagnetic and obeys Curie-Weiss law with Xm ( T - 0. 27) = 0. 85 cm3 · K · mol-1 between 2 ~ 300 K (Xm being magnetic susceptibility per one Cu2+ ion).%应用溶液法合成标题配合物[Cu(bpy)(H2O) (mal)]·H2O(bpy=2,2'-联吡啶,mal=丙二酸).通过X射线衍射法测定配合物的晶体结构,其晶体学数据如下:三斜,P-1,a=7.132(1)(A),b=10.404(2)(A),c=10.694(2)(A);α=105.85(3)°,β=104.53(3)°,γ=105.28(3)°,V=690.4(2)((A)3),Dc=1.721 g·cm-3,Z=2.在标题化合物中,中心Cu(Ⅱ)离子配位数为5,构成CuN2O3四方锥配位模式.并对其进行红外光谱、元素分析、粉末X射线衍射、差热、磁性等表征.配合物的3D拓扑分析可简化含有(4,6)-双节点fsc拓扑网络,配合物在2~300 K区间遵循韦斯定理xm(T-0.27)=0.85 cm3·K·mol-1,磁性测试结果表明Cu2+离子之间存在铁磁作用.

  9. Synthesis, Superoxide Dismutase Mimetic and Anticancer Activities of Metal Complexes of 2,2-Dimethylpentanedioic Acid(2dmepdaH2 and 3,3-Dimethylpentanedioic acid(3dmepdaH2: X-Ray Crystal Structures of [Cu(3dmepda(bipy]2⋅6H2O and [Cu(2dmepda(bipy(EtOH]2⋅4EtOH(bipy=2,2′Bipyridine

    Directory of Open Access Journals (Sweden)

    Carol Deegan

    2005-03-01

    Full Text Available 2,2-dimethylpentanedioic acid (2dmepdaH2 and 3,3-dimethylpentanedioic acid (3dmepdaH2 reacted with copper(II acetate to give [Cu(2dmepda(H2O3]2 (1 and [Cu(3dmepda(H2O3]2 (2. Reaction of (1 and (2 with 1,10-phenanthroline and 2,2′-bipyridine yielded [Cu(2dmepda(phen(H2O]20.5phen (3, [Cu(2dmepda(bipy(H2O]2 (4, [Cu(2dmepda(bipy(EtOH]2⋅2EtOH (4A, [Cu(3dmepda(phen(H2O]2 (5, and [Cu(3dmepda(bipy(H2O]2⋅ (6. The structures of (4A and (6 each consists of a [Cu(bipy(dicarboxylate(solvent]2 dimer. The superoxide dismutase (SOD mimetic activity of the novel copper complexes and their manganese analogues was investigated. The dimethyl sulphoxide(DMSO soluble complexes (1–(4 and (6 were assessed for their cancer chemotherapeutic potential towards hepatocellular carcinoma and kidney adenocarcinoma cell lines. The 1,10-phenanthroline containing complex [Cu(2dmepda(phen(H2O]20.5phen (3 was the most potent with activity that compares well to that of cisplatin.

  10. A bi-TTF with a bipyridine spacer: 4,4′-bis[(3,6,7-trimethylsulfanyltetrathiafulvalen-2-ylsulfanylmethyl]-2,2′-bipyridine

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Legros

    2008-12-01

    Full Text Available The title compound, C30H28N2S16, is a precursor to hybrid magnetic materials. The complete molecule is generated by a crystallographic inversion centre. In the crystal structure, the TTF core is not planar and adopts a chair conformation; the two C3S2 rings are folded around the S...S hinges, the dihedral angles being 17.14 (8 and 13.46 (7°. There is a short S...S contact [3.4863  (14 Å] in the crystal structure.

  11. Effects of Br substituent on catalytic performance of Ru-bda (H2bda = 2,2′-bipyridine-6,6′-dicarboxylic acid) catalysts for water oxidation%溴的吸电子效应对Ru-bda(H2bda =2,2′-联吡啶-6,6′-二羧基)型催化剂催化水氧化的性能影响

    Institute of Scientific and Technical Information of China (English)

    刘昭; 高岩; 于泽; 张敏; 刘建辉

    2015-01-01

    表明催化剂2和3与催化剂1的反应机理有所不同.由于催化剂1发生二级反应即在催化水氧化过程中发生双分子间的自由基耦合反应,而催化剂2和3的反应级数均小于2,说明核心配体上的Br取代基的吸电子效应导致催化剂2和3的反应机理发生改变,在水氧化反应过程中部分催化剂2和3分子发生了单分子反应,即水分子亲核进攻机理.当轴向配体由4-甲基吡啶替换为异喹啉时,对比催化剂4和5的催化水氧化活性和动力学研究,也可以得到类似的结果.但与催化剂2和3相比,催化剂5的反应级数降低不明显,说明催化体系中只有一部分分子发生一级反应,大部分分子发生二级反应.这说明在以化合物5为催化剂的水氧化体系中,除了核心配体上Br的吸电子效应对催化剂机理产生影响之外,轴向配体的异喹啉的π-π堆积效应也有重要影响(异喹啉的π-π堆积效应能够促进单核催化剂发生二级反应),并且后者产生的影响占  主导位置,从而导致催化剂5的反应级数降低的不明显.%A series of new Ru-bda catalysts with Br modification on the equatorial ligand, [Ru(Ln)(picoline)2] (H2L1 = 4-Br-2,2′-bipyridine-6,6′-dicarboxylic acid (4-Br-bda),2;H2L2 = 4,4′-diBr-bda,3) and [Ru(L1)(isoquinoline)2]5, were synthesized for catalytic water oxidation. Compared with the un-substituted catalysts, the catalysts modified with Br displayed a marked change in the catalytic activities and reaction orders. The results confirm that the electronic effect of Br has a large effect on the kinetics and leads to the change in reaction orders.

  12. New Ruthenium Complexes Based on Tetradentate Bipyridine Ligands for Catalytic Hydrogenation of Esters.

    Science.gov (United States)

    Wang, Fangyuan; Tan, Xuefeng; Lv, Hui; Zhang, Xumu

    2016-08-01

    New bipyridinemethanamine-containing tetradentate ligands and their corresponding ruthenium complexes have been synthesized. The synthesized complexes performed well in the hydrogenation of a variety of esters with high efficiency (TON up to 9700) giving alcohols in good yields. PMID:27385062

  13. Vitamin C derivatives as new coreactants for tris(2,2'-bipyridine)ruthenium(II) electrochemiluminescence

    International Nuclear Information System (INIS)

    Highlights: → Ru(bpy)32+ electrochemiluminescence of vitamin C derivatives have been investigated. → Ascorbyl phosphate and ascorbyl palmitate show intense electrochemiluminescence. → Ascorbyl 2-phosphate was detected with high sensitivity. → This study provides a new way to detect vitamin C derivatives. - Abstract: Vitamin C derivatives (VCDs) have been widely used as the alternative and stable sources of vitamin C, and accordingly exhibit many new applications, such as anti-tumor and central nervous system drug delivery. In this study, their Ru(bpy)32+ electrochemiluminescence (ECL) properties have been investigated for the first time using well-known ascorbyl phosphate and ascorbyl palmitate as representative VCDs. Ascorbyl phosphate and ascorbyl palmitate are VCDs with different substituted positions. Both of them increase Ru(bpy)32+ ECL, indicating that other VCDs may also enhance Ru(bpy)32+ ECL signal. The calibration plot for ascorbyl phosphate is linear from 3 x 10-6 to 1.0 x 10-3 M with a detection limit of 1.4 x 10-6 M at a signal-to-noise ratio of 3. The relative standard deviation is 3.6% for six replicate measurements of 0.01 mM ascorbyl 2-phosphate solution. The proposed method is about one order of magnitude more sensitive than electrochemical and UV-vis methods for the determination of ascorbyl phosphate, and is used successfully for the determination of ascorbyl phosphate in whitening and moisturising body wash.

  14. 5,5′-Bis[(trimethylsilylmethyl]-2,2′-bipyridine

    Directory of Open Access Journals (Sweden)

    George V. Meehan

    2008-02-01

    Full Text Available The molecule of the title compound, C18H28N2Si2, occupies a special position on an inversion centre. The Si—CH2—C(ipso plane is approximately orthogonal to the plane of the pyridine rings, the corresponding dihedral angle being 82.0 (2°.

  15. Sensitive fluorescence detection of lysozyme using a tris(bipyridine)ruthenium(II) complex containing multiple cyclodextrins.

    Science.gov (United States)

    Zhang, Fan; Zhao, Ying-Ying; Chen, Hong; Wang, Xiu-Hua; Chen, Qiong; He, Pin-Gang

    2015-04-18

    A new series of photoactive metallocyclodextrins with increased fluorescence intensity upon binding with ssDNAs/aptamers has been demonstrated to sensitively and selectively detect lysozyme. The detection mechanism relies on the formation of an aptamer-lysozyme complex, which leads to reduction of fluorescence intensity.

  16. Bipyridine (2,2′-dipyridyl) potentiates Escherichia coli lethality induced by nitrogen mustard mechlorethamine

    Energy Technology Data Exchange (ETDEWEB)

    De Alencar, T.A.M.; Wilmart-Gonçalves, T.C.; Vidal, L.S.; Fortunato, R.S.; Leitão, A.C. [Laboratório de Radiobiologia Molecular (Brazil); Lage, C., E-mail: claudia_lage_dna@yahoo.com.br [Laboratório de Radiações em Biologia (Brazil)

    2014-07-15

    Highlights: • Reduction of Fe{sup 2+} ensues a respiratory burst to reduce the oxidized iron pool. • Through Harber–Weiss recycling, superoxide electrons can reduce oxidized iron. • Redox imbalance sensitized repair proficient Escherichia coli to mustard lethal crosslinks. • A stronger synergism impacted survival of a superoxide dismutase-deficient strain. • Anti-cancer cocktails added of an iron chelator may impact hypoxia and genotoxicity. - Abstract: Alkylating agents are used in anti-tumor chemotherapy because they bind covalently to DNA and generate adducts that may lead to cell death. Bifunctional (HN2) and monofunctional (HN1) nitrogen are two such agents, and HN2 was the first drug successfully employed in anti-leukemia chemotherapy. Currently, HN2 is used either alone or combined with other drugs to treat Hodgkin's disease. It is well known that several crosslinking agents require metabolic activation via reactive oxygen species (ROS) to exert their lethal effects. The objective of this work was therefore to determine whether the abovementioned mustards would also require metabolic activation to exert lethal action against Escherichia coli. For this purpose, we measured survival following exposure to HN2 in E. coli strains that were deficient in nucleotide excision repair (uvrA NER mutant), base excision repair (xthA nfo nth fpg BER mutant) or superoxide dismutase (sodAB mutant) activity. We also performed the same experiments in cells pretreated with an iron chelator (2,2′-dipyridyl, DIP). The NER and BER mutants were only sensitive to HN2 treatment (survival rates similar to those of the wild-type were achieved with 5-fold lower HN2 doses). However, wild-type and sodAB strains were not sensitive to treatment with HN2. In all tested strains, survival dropped by 2.5-fold following pretreatment with DIP compared to treatment with HN2 alone. Furthermore, DIP treatment increased ROS generation in both wild type and sodAB-deficient strains. Based on these data and on the survival of the SOD-deficient strain, we suggest that the increased production of ROS caused by Fe{sup 2+} chelation may potentiate the lethal effects of HN2 but not HN1. This potentiation may arise as a consequence of enhancement in the number of or modification of the type of lesions formed. No sensitization was observed for the non-crosslinkable HN2 analog, HN1.

  17. Ensemble and single-molecule studies on fluorescence quenching in transition metal bipyridine-complexes.

    Directory of Open Access Journals (Sweden)

    Dominik Brox

    Full Text Available Beyond their use in analytical chemistry fluorescent probes continuously gain importance because of recent applications of single-molecule fluorescence spectroscopy to monitor elementary reaction steps. In this context, we characterized quenching of a fluorescent probe by different metal ions with fluorescence spectroscopy in the bulk and at the single-molecule level. We apply a quantitative model to explain deviations from existing standard models for fluorescence quenching. The model is based on a reversible transition from a bright to a dim state upon binding of the metal ion. We use the model to estimate the stability constants of complexes with different metal ions and the change of the relative quantum yield of different reporter dye labels. We found ensemble data to agree widely with results from single-molecule experiments. Our data indicates a mechanism involving close molecular contact of dye and quenching moiety which we also found in molecular dynamics simulations. We close the manuscript with a discussion of possible mechanisms based on Förster distances and electrochemical potentials which renders photo-induced electron transfer to be more likely than Förster resonance energy transfer.

  18. Synthesis and Coordination Behavior of a Bipyridine Platinum(II) Complex with Thioglucose

    OpenAIRE

    Tsuji, Takaaki; Kuwamura, Naoto; Yoshinari, Nobuto; Konno, Takumi

    2013-01-01

    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/ic400287g

  19. Bridging function mediated intermetallic coupling in diruthenium-bis(bipyridine) complexes

    Indian Academy of Sciences (India)

    Soma Chakraborty; Biplab Mondal; Biprajit Sarkar; Goutam Kumar Lahiri

    2002-08-01

    The interactions of potentially dinucleating bridging functionalities (I-VI) with the ruthenium-bis(bypyridine) precursor [RuII(bpy)2(EtOH)2]2+ have been explored. The bridging functions I, II and VI directly result in the expected dinuclear complexes of the type [(bpy)2RuII{L}RuII(bpy)2]+ (1, 2, 7 and 8) ( = 0, = 4 and = -2, = 2). The bridging ligand III undergoes N-N or N-C bond cleavage reaction on coordination to the RuII(bpy)2 core which eventually yields a mononuclear complex of the type [(bpy)2RuII(L)]+, 3, where L = -OC6H3(R)C(R′)=N-H. However, the electrogenerated mononuclear ruthenium(III) congener, 3+ in acetonitrile dimerises to [(bpy)2RuIII {-OC6H3(R)C(R′)=N-N=(R′)C(R)C6H3O-}RuIII(bpy)2]4+ (4). In the presence of a slight amount of water content in the acetonitrile solvent the dimeric species (4) reduces back to the starting ruthenium(II) monomer (3). The preformed bridging ligand IV undergoes multiple transformations on coordination to the Ru(bpy)2 core, such as hydrolysis of the imine groups of IV followed by intermolecular head-to-tail oxidative coupling of the resultant amino phenol moieties, which in turn results in a new class of dimeric complex of the type [(bpy)2RuII {-OC6H4-N=C6H3(=NH)O-}RuII(bpy)2]2+ (5). In 5, the bridging ligand comprises of two , chelating binding sites each formally in the semiquinone level and there is a -benzoquinonediimine bridge between the metal centres. In complex 6, the preformed bridging ligand, 3,6-bis(3,5-dimethylpyrazol-1-yl)-1,2-dihydro-1,2,4,5- tetrazine, H2L (V) undergoes oxidative dehydrogenation to aromatic tetrazine based bridging unit, 3,6-bis(3,5-dimethylpyrazol-1-yl)-1,2,4,5-tetrazine, L. The detailed spectroelectrochemical aspects of the complexes have been studied in order to understand the role of the bridging units towards the intermetallic electronic coupling in the dinuclear complexes.

  20. 4,4′-Di-tert-butyl-2,2′-bipyridine

    Directory of Open Access Journals (Sweden)

    Tatiana R. Amarante

    2009-08-01

    Full Text Available In the title compound, C18H24N2, the molecular unit adopts a trans conformation around the central C—C bond [N—C—C—N torsion angle of 179.2 (3°], with the two aromatic rings almost coplanar [dihedral angle of only 0.70 (4°]. The crystal packing is driven by co-operative contacts involving weak C—H...N and C—H...π interactions, and also the need to fill effectively the available space.

  1. Novel Coordination Polymers Constructed from 4,4'-Bipyridine and Phosphate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ The synthesis of open-fiamework metal phosphates has been a subject of intense research owing to their interesting structural chemistry and potential applications as ionexchangers, catalysts and adsorbents. A large number of these materials are synthesized in the presence of organic amines as structure-directing agents. Recently, many research activities have focused on the synthesis of inorganic-organic hybrid frameworks. As compared with inorganic ligands, the advantage of using organic multidentate ligands is the efficacy of rational design of crystalline solids through their coordinating propensities and geometries.

  2. Novel Coordination Polymers Constructed from 4,4'-Bipyridine and Phosphate

    Institute of Scientific and Technical Information of China (English)

    Kwang-Hwa; Lii

    2001-01-01

    The synthesis of open-fiamework metal phosphates has been a subject of intense research owing to their interesting structural chemistry and potential applications as ionexchangers, catalysts and adsorbents. A large number of these materials are synthesized in the presence of organic amines as structure-directing agents. Recently, many research activities have focused on the synthesis of inorganic-organic hybrid frameworks. As compared with inorganic ligands, the advantage of using organic multidentate ligands is the efficacy of rational design of crystalline solids through their coordinating propensities and geometries.  ……

  3. Characterization of electrochemiluminescence of tris(2,2'-bipyridine)ruthenium(II) with glyphosate as coreactant in aqueous solution

    International Nuclear Information System (INIS)

    Glyphosate, a phosphorus-containing amino acid type herbicide was used as a coreactant for studying of electrochemiluminescence (ECL) reaction of tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)32+] in an aqueous solution. In a phosphate buffer solution of pH 8, glyphosate itself was known to be electrochemically inactive at glassy carbon electrode, however, it participated in a homogeneous chemical reaction with the electrogenerated Ru(bpy)33+, and resulted in producing Ru(bpy)32+ species at the electrode surface. Kinetic and mechanistic information for the catalysis of glyphosate oxidation were evaluated by the steady-state voltammetric measurement with an ultramicroelectrode. The simulated cyclic voltammogram based on this mechanism was in good agreement with that obtained experimentally. ECL reaction of Ru(bpy)32+/glyphosate system was found to be strongly dependent on the media pH. In a pH region of 5-9, an ECL wave appeared at ca. +1.1 V vs. Ag/AgCl, which was caused by the generation of *Ru(bpy)32+ via a Ru(bpy)33+-mediated oxidation of glyphosate. When pH >10, a second ECL wave was observed at ca. +1.35 V vs. Ag/AgCl, which was believed to be associated with a reaction between Ru(bpy)33+ and the species from direct oxidation of GLYP at a GC electrode surface.

  4. cis-Aquabis(2,2′-bipyridine-κ2N,N′fluoridochromium(III bis(perchlorate dihydrate

    Directory of Open Access Journals (Sweden)

    Torben Birk

    2010-02-01

    Full Text Available The title mixed aqua–fluoride complex, [CrF(C10H8N22(H2O](ClO42·2H2O, has been synthesized by aquation of the corresponding difluoride complex using lanthanide(III ions as F− acceptors. The complex crystallizes with a CrIII ion at the center of a distorted octahedral coordination polyhedron with a cis arrangement of ligands. The crystal packing shows a hydrogen-bonding pattern involving water molecules, the coordinated F atom and the perchlorate anions

  5. Characterization of electrochemiluminescence of tris(2,2'-bipyridine)ruthenium(II) with glyphosate as coreactant in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jiye, E-mail: jin@shinshu-u.ac.j [Department of Chemistry, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Takahashi, Fumiki; Kaneko, Tsutomu; Nakamura, Toshio [Department of Chemistry, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan)

    2010-08-01

    Glyphosate, a phosphorus-containing amino acid type herbicide was used as a coreactant for studying of electrochemiluminescence (ECL) reaction of tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy){sub 3}{sup 2+}] in an aqueous solution. In a phosphate buffer solution of pH 8, glyphosate itself was known to be electrochemically inactive at glassy carbon electrode, however, it participated in a homogeneous chemical reaction with the electrogenerated Ru(bpy){sub 3}{sup 3+}, and resulted in producing Ru(bpy){sub 3}{sup 2+} species at the electrode surface. Kinetic and mechanistic information for the catalysis of glyphosate oxidation were evaluated by the steady-state voltammetric measurement with an ultramicroelectrode. The simulated cyclic voltammogram based on this mechanism was in good agreement with that obtained experimentally. ECL reaction of Ru(bpy){sub 3}{sup 2+}/glyphosate system was found to be strongly dependent on the media pH. In a pH region of 5-9, an ECL wave appeared at ca. +1.1 V vs. Ag/AgCl, which was caused by the generation of *Ru(bpy){sub 3}{sup 2+} via a Ru(bpy){sub 3}{sup 3+}-mediated oxidation of glyphosate. When pH >10, a second ECL wave was observed at ca. +1.35 V vs. Ag/AgCl, which was believed to be associated with a reaction between Ru(bpy){sub 3}{sup 3+} and the species from direct oxidation of GLYP at a GC electrode surface.

  6. Hydrothermal Synthesis and Crystal Structure of Manganese(Ⅱ) Coordination Polymer Assembled by 4-Sulfophthalate and 4,4'-Bipyridine

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Introduction The rational design and synthesis of metal-directed supramolecular framework compounds have received much attention in coordination chemistry because of their potential applications in catalysis, molecular selection, nonlinear optics, ion exchange, and microelectronics[1-4].

  7. Host–guest complexes of mixed glycol-bipyridine cryptands: prediction of ion selectivity by quantum chemical calculations, part V

    OpenAIRE

    Svetlana Begel; Ralph Puchta; Rudi van Eldik

    2013-01-01

    The selectivity of the cryptands [2.2.bpy] and [2.bpy.bpy] for the endohedral complexation of alkali, alkaline-earth and earth metal ions was predicted on the basis of the DFT (B3LYP/LANL2DZp) calculated structures and complex-formation energies. The cavity size in both cryptands lay between that for [2.2.2] and [bpy.bpy.bpy], such that the complexation of K+, Sr2+ and Tl3+ is most favorable. While the [2.2.bpy] is moderately larger, preferring Rb+ complexation and demonstrating equal priorit...

  8. Design, Synthesis and Properties of Bipyridine-capped Oligothiophenes for Directed Energy and Electron Transfer in Molecular Electronic Applications

    OpenAIRE

    Nurkkala, Lasse

    2007-01-01

    The earliest landmark in computer technology was construction of the Electronic Numerial Integrator and Computer, ENIAC. Computational switching was performed with vacuum tubes and relays, rather large in size, making this computer rather unwieldy. The next milestone came with the integration of transistors into computers as the switching component. Since then, transistors have been miniaturised dramatically, resulting in the amount of components integrated on a computer chip increasing logar...

  9. Vitamin C derivatives as new coreactants for tris(2,2'-bipyridine)ruthenium(II) electrochemiluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yali; Li Haijuan; Han Shuang; Hu Lianzhe [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100864 (China); Parveen, Saima [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100864 (China); Department of Chemistry, Baghdad-ul-Jadeed Campus, The Islamia University of Bahawalpur, Bahawalpur (Pakistan); Xu Guobao, E-mail: guobaoxu@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China)

    2011-09-09

    Highlights: {yields} Ru(bpy){sub 3}{sup 2+} electrochemiluminescence of vitamin C derivatives have been investigated. {yields} Ascorbyl phosphate and ascorbyl palmitate show intense electrochemiluminescence. {yields} Ascorbyl 2-phosphate was detected with high sensitivity. {yields} This study provides a new way to detect vitamin C derivatives. - Abstract: Vitamin C derivatives (VCDs) have been widely used as the alternative and stable sources of vitamin C, and accordingly exhibit many new applications, such as anti-tumor and central nervous system drug delivery. In this study, their Ru(bpy){sub 3}{sup 2+} electrochemiluminescence (ECL) properties have been investigated for the first time using well-known ascorbyl phosphate and ascorbyl palmitate as representative VCDs. Ascorbyl phosphate and ascorbyl palmitate are VCDs with different substituted positions. Both of them increase Ru(bpy){sub 3}{sup 2+} ECL, indicating that other VCDs may also enhance Ru(bpy){sub 3}{sup 2+} ECL signal. The calibration plot for ascorbyl phosphate is linear from 3 x 10{sup -6} to 1.0 x 10{sup -3} M with a detection limit of 1.4 x 10{sup -6} M at a signal-to-noise ratio of 3. The relative standard deviation is 3.6% for six replicate measurements of 0.01 mM ascorbyl 2-phosphate solution. The proposed method is about one order of magnitude more sensitive than electrochemical and UV-vis methods for the determination of ascorbyl phosphate, and is used successfully for the determination of ascorbyl phosphate in whitening and moisturising body wash.

  10. Aquabis(3′-hydroxy-2,2′-bipyridine-3-olato-κ2N,N′)zinc(II)

    OpenAIRE

    Chao Hou; Shi Guo Zhang

    2008-01-01

    In the title complex, [Zn(C10H7N2O2)2(H2O)], the ZnII ion and water O atom are located on a crystallographic twofold rotation axis and the metal atom assumes a distorted trigonal-bipyramidal ZnN4O coordination geometry. An intramolecular O—H...O hydrogen bond occurs within the ligand and intermolecular O—H...O hydrogen bonds involving the water molecule result in a sheet structure in the crystal structure. In addition, a short C—O...π contact between the O atom of the d...

  11. Aqua­bis(3′-hydr­oxy-2,2′-bipyridine-3-olato-κ2 N,N′)zinc(II)

    OpenAIRE

    Zhang, Shi Guo; Hou, Chao

    2008-01-01

    In the title complex, [Zn(C10H7N2O2)2(H2O)], the ZnII ion and water O atom are located on a crystallographic twofold rotation axis and the metal atom assumes a distorted trigonal-bipyramidal ZnN4O coordination geometry. An intra­molecular O—H⋯O hydrogen bond occurs within the ligand and inter­molecular O—H⋯O hydrogen bonds involving the water mol­ecule result in a sheet structure in the crystal structure. In addition, a short C—O⋯π contact between the O atom of the deprotonated hydroxyl group...

  12. 1,1′-Bicyclohexyl-1,1′-diyl 2,2′-bipyridine-3,3′-dicarboxylate

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2012-06-01

    Full Text Available The title compound, C24H26N2O4, lies about a crystallographic twofold rotation axis. The cyclohexane rings adopts a chair conformation. The two pyridine rings form a dihedral angle of 41.02 (4°. In the crystal, molecules are linked via C—H...O and C—H...N hydrogen bonds into a layer parallel to the bc plane.

  13. Synthesis, structures, spectroscopy and antimicrobial properties of complexes of copper(II) with salicylaldehyde N-substituted thiosemicarbazones and 2,2'-bipyridine or 1,10-phenanthroline.

    Science.gov (United States)

    Lobana, Tarlok S; Indoria, Shikha; Jassal, Amanpreet Kaur; Kaur, Harpreet; Arora, Daljit S; Jasinski, Jerry P

    2014-04-01

    Among the biometals (Cu, Co, Ni-cofactors in many enzymes), copper derivatives of O, N, S-donor salicylaldehyde thiosemicarbazones have received considerable attention owing to their potential biological applications. Eight new complexes of salicylaldehyde-N-substituted thiosemicarbazones [5-MeO-2-HO-C₆H₄-C(2)(H)N(3)-N(2)H-C(1)(S)-N(1)HR; R = Me, H2L(1); Et, H₂L(1), Ph, H₂L(3), H, H₂L(4)] with copper(II), namely, [Cu(κ(3)-O,N,S-L)( κ(2)-N,N-L')] {(L)(2-) = (L(1))(2-), L' = bipy, 1, phen, 2; (L)(2-) = (L(2))(2-), L' = bipy, 3, phen, 4; (L)(2-) = (L(3))(2-), L' = bipy, 5, phen, 6; (L)(2-) = (L(4))(2-), L' = bipy, 7, phen, 8} have been isolated. Complexes have slightly distorted square pyramidal geometry around the metal center (τ parameter = 0.243-0.357) and display weak to intense fluorescence in the region, 375-475 nm. These copper complexes have shown significant growth inhibitory activity (antimicrobial activity) against Staphylococcus aureus (MTCC740), methicillin resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae 1 (MTCC109), Shigella flexneri (MTCC1457), Pseudomonas aeruginosa (MTCC741) and Candida albicans (MTCC227). The activity against MRSA is an interesting observation as the commercially available gentamycin is found to be inactive against this bacterial strain. Specifically complex 5 formed by 5-methoxysalicylaldehyde-N-phenylthiosemicatbazone has shown novel antimicrobial activity against various bacteria and yeast investigated. PMID:24583354

  14. 2,2′-Dimethyl-4,4′-bipyridine

    Directory of Open Access Journals (Sweden)

    Wilhelm Seichter

    2008-07-01

    Full Text Available In the crystal structure of the title compound, C12H12N2, the molecule is twisted around the central C—C bond, with a dihedral angle of 8.32 (5° between the mean planes of the pyridyl rings. The crystal structure is stabilized by arene stacking interactions, with a distance of 3.81 (1 Å between the ring centroids.

  15. Aquabis(3′-hydroxy-2,2′-bipyridine-3-olato-κ2N,N′zinc(II

    Directory of Open Access Journals (Sweden)

    Chao Hou

    2008-09-01

    Full Text Available In the title complex, [Zn(C10H7N2O22(H2O], the ZnII ion and water O atom are located on a crystallographic twofold rotation axis and the metal atom assumes a distorted trigonal-bipyramidal ZnN4O coordination geometry. An intramolecular O—H...O hydrogen bond occurs within the ligand and intermolecular O—H...O hydrogen bonds involving the water molecule result in a sheet structure in the crystal structure. In addition, a short C—O...π contact between the O atom of the deprotonated hydroxyl group and a nearby pyridine ring [O...Cg = 3.977 (2 Å, where Cg is the centroid of the pyridine ring] is observed.

  16. cis-Aquabis(2,2'-bipyridine2N,N')-fluoridochromium(III) bis(perchlorate) dihydrate

    DEFF Research Database (Denmark)

    Birk, Torben; Bendix, Jesper

    2010-01-01

    The title mixed aqua-fluoride complex, [CrF(C(10)H(8)N(2))(2)(H(2)O)](ClO(4))(2)·2H(2)O, has been synthesized by aqua-tion of the corresponding difluoride complex using lanthan-ide(III) ions as F(-) acceptors. The complex crystallizes with a Cr(III) ion at the center of a distorted octa......-hedral coordination polyhedron with a cis arrangement of ligands. The crystal packing shows a hydrogen-bonding pattern involving water mol-ecules, the coordinated F atom and the perchlorate anions....

  17. Self-assembly of metalloporphyrins: first TPP-bipy coordination polymer with CoII (TPP=meso-tetraphenylporphyrin and bipy=4,4´-bipyridine)

    OpenAIRE

    Fidalgo Marijuan, Arkaitz; Barandika Argoitia, Miren Gotzone; Bazán Blau, Begoña del Pilar; Urtiaga Greaves, Miren Karmele; Arriortua Marcaida, María Isabel

    2015-01-01

    Póster presentado en: 11th International Symposium on Applied Bioinorganic Chemistry. 2-5 Diciembre 2011. Barcelona, España (ISABC 2011) Supramolecular entities based on self-assembly of metalloporphyrins are paradigmatic examples of the great efficiency of the nanodevices used by natural systems in photosynthesis, oxygen transport, electron transfer and catalysis. Obtaining supramolecular entities may be approached by different strategies of synthetic design. One of them consists on t...

  18. Selective oxidation of benzyl alcohol with tert-butylhydroperoxide catalysed via Mn (II) 2, 2-bipyridine complexes immobilized over the mesoporous hexagonal molecular sieves (HMS)

    Indian Academy of Sciences (India)

    Vahid Mahdavi; Mahdieh Mardani

    2012-09-01

    A series ofMn(II)bipy complexes with different loading of Mn2+ supported on HMS was prepared. These samples were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), Thermogravimetric and Differential Scanning Calorimetry (TG-DSC), Ultraviolet and Visible spectra (UV-Vis) and Fourier transforms Infrared (FT-IR). The catalytic activity of the supportedMn(II)bipy complexes, [Mn(bipy)2]2+/HMS was evaluated in the oxidation of benzyl alcohol in the liquid phase using tert-butylhydroperoxide (TBHP) as an oxidant. The effects of Mn2+ loading and various solvents on the conversion and selectivity were studied. A second order function for the variation in catalytic activity with respect to the loading of Mn2+ ions in different catalyst samples was observed. The activity of the [Mn(bipy)2]2+/HMS catalyst differs with the type of the solvent and in this case, acetonitrile gives the best conversion results. The kinetic of benzyl alcohol oxidation was investigated at temperatures of 27, 46, 60, 75 and 90°C using [Mn(bipy)2]2+/HMS and excess TBHP. The order of reaction with respect to benzyl alcohol was determined to be pseudo-first order. The value of the apparent activation energy was also determined.

  19. Electrogenerated chemiluminescence reaction of tris(2,2'-bipyridine)ruthenium(II) with 2,5-dimethylthiophene as co-reactant in aqueous solution

    International Nuclear Information System (INIS)

    A novel effective co-reactant for electrogenerated chemiluminescence (ECL) of Ru(bpy)32+ has been found. α-Position-dialkylated thiophene derivatives such as 2,5-dimethylthiophene (DMT) could be used as a co-reactant for Ru(bpy)32+ ECL. The reaction mechanism of the Ru(bpy)32+/DMT system was proposed on the basis of the identification of the reaction product, the relationship between the molecular structure and the chemiluminescent intensity, and the electrochemical study. The obtained reaction mechanism was similar to that of the Ru(bpy)32+/aliphatic tertiary amine system. Based on these results, the preliminary studies of the Ru(bpy)32+ ECL detection system using DMT as a co-reactant were performed. Under the optimal ECL conditions, the plot of ECL intensity versus the concentration of Ru(bpy)32+ was linear over the concentration range 1.0 x 10-8 to 1.5 x 10-7 M (determination coefficient = 0.9996)

  20. Synthesis and spectroscopic studies on chromium(III) complex containing mixed-valence chrysenesemiquinone-chrysenecatecholate ligands and 2,2'-bipyridine coligand

    Science.gov (United States)

    Attia, Attia S.

    2007-08-01

    The synthesis and spectroscopic properties of Cr(bpy)(chrySQ)(chryCat), a complex containing chromium(III) metal ion and chrysenequinone ligand in its partially reduced (chrySQ) and fully reduced (chryCat) forms, are described. The complex has been prepared by two different routes from Cr(CO) 6 and Cr(chrySQ) 3. Variable temperature magnetic susceptibility measurements indicated a strong antiferromagnetic coupling between Cr(III) ( S = 3/2) and chrysenesemiquinone radical ( S = 1/2), giving a magnetic coupling constant J = -342 cm -1. Ligand-based redox couples were observed in the electrochemical studies that consist of quasi-reversible chrySQ/chryCat and bpy/bpy rad - reductions and chryCat/chrySQ oxidation at negative potentials and irreversible chrySQ/chryBQ oxidation at positive potential. However, the metal was inert in the studied potential range. The electronic spectra of the complex revealed interesting properties. In addition to interaligand π-π * and n-π * transitions, other bands corresponding to Cr(t 2g) → chrySQ(π *) and Cr(t 2g) → bpy(π *) metal-to-ligand charge-transfer MLCT transitions were observed. The infrared spectral analysis was informative in assigning the vibrations due to SQ and Cat ligands. Also, it was a useful tool in confirming the coordination of bpy ligand to chromium metal ion.

  1. Synthesis, 2D NMR, electrochemistry and luminescence of ruthenium (II) complexes with 2,2-bipyridine and 5-(ω-bromoalkylamido)-1, 10-phenanthroline

    International Nuclear Information System (INIS)

    The efficient synthesis of 5-(5-bromovaleramido)-1, 10-phenanthroline, 5-(6-bromohexanamido)-1,10-phenanthroline, and 5-(11-bromoundecanamido)-1, 10-phenanthroline are described, which reacted with cis-Ru(bpy)2Cl2.2H2O and sodium hexafluorophosphate to form Ru(bpy)2[phen-NHCO(CH2)nBr](PF6)2 (n=4, 5 or 10; phen=1,10-phenanthroline). The intricate 1H NMR spectra at low field of these complexes were completely assigned in virtue of 1H-1H COSY technique. Cyclic voltammetry was used to study electrochemical behaviours of these complexes, and their luminescent properties were investigated with fluorescent spectra. (author)

  2. Ruthenium(II) bipyridine complexes bearing quinoline-azoimine (NN‧N″) tridentate ligands: Synthesis, spectral characterization, electrochemical properties and single-crystal X-ray structure analysis

    Science.gov (United States)

    Al-Noaimi, Mousa; Abdel-Rahman, Obadah S.; Fasfous, Ismail I.; El-khateeb, Mohammad; Awwadi, Firas F.; Warad, Ismail

    Four octahedral ruthenium(II) azoimine-quinoline complexes having the general molecular formula [RuII(Lsbnd Y)(bpy)Cl](PF6) {Lsbnd Y = YC6H4Ndbnd NC(COCH3)dbnd NC9H6N, Y = H (1), CH3 (2), Br (3), NO2 (4) and bpy = 2,2‧-bipyrdine} were synthesized. The azoimine-quinoline based ligands behave as NN‧N″ tridentate donors and coordinated to ruthenium via azo-N‧, imine-N‧ and quinolone-N″ nitrogen atoms. The composition of the complexes has been established by elemental analysis, spectral methods (FT-IR, electronic, 1H NMR, UV/Vis and electrochemical (cyclic voltammetry) techniques. The crystal structure of complex 1 is reported. The Ru(II) oxidation state is greatly stabilized by the novel tridentate ligands, showing Ru(III/II) couples ranging from 0.93-1.27 V vs. Cp2Fe/Cp2Fe+. The absorption spectrum of 1 in dichloromethane was modeled by time-dependent density functional theory (TD-DFT).

  3. 1,1'-Diethyl-4,4'-bipyridine-1,1'-diium bis(1,1,3,3-tetracyano-2- ethoxypropenide) : multiple C-H⋯N hydrogen bonds form a complex sheet structure

    OpenAIRE

    Setifi, Z.; Lehchili, F.; Setifi, F.; Beghidja, A.; Ng, S W; Glidewell, C.

    2014-01-01

    The authors acknowledge the Algerian ATRST (Agence The´matique de Recherche en Sciences et Technologie; PNR project) and the Ministry of Higher Education of Malaysia (grant No. UM.C/HIR-MOHE/SC/03) for financial support.

  4. Negative Ames-test of cis-di(thiocyanato)-N,N'-bis(4,4'-dicarboxy-2,2'-bipyridine)Ru(II), the sensitizer dye of the nanocrystalline TiO2 solar cell

    NARCIS (Netherlands)

    Vries, J.G. de; Scholtens, B.J.R.; Maes, I.; Grätzel, M.; Winkel, S.; Burnside, S.; Wolf, M.; Hinsch, A.; Kroon, J.M.; Ahlse, M.; Tjerneld, F.; Ferrero, G.; Bruno, E.; Hagfeldt, A.; Bradbury, C.; Carlsson, P.; Pettersson, H.; Verspeek-Rip, C.M.; Enninga, I.C.

    2000-01-01

    Dye-sensitized nanocrystalline TiO2 solar cells are currently under development. Since these cells contain an electrolyte solution we reviewed the health and safety aspects in view of indoor applications, where personal contact cannot be excluded. Only small amounts of chemicals are present in each

  5. Influence of diluent alkyl substitution on the extraction of Am(III) and Eu(III) by a 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine ligand dissolved in alkylated cyclohexanone diluents

    International Nuclear Information System (INIS)

    Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe4-BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO3, 3-methylcyclohexanone and 4-methylcyclohexanone gave comparable results to cyclohexanone whereas in the extractions from 4 M HNO3, 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone all gave superior results. For the monomethylated diluents, DAm and SFAm/Eu decreased in the order of alkyl substitution 2 > 4 ∝ 3. However, alkyl substitution of cyclohexanone significantly slows down the extraction kinetics compared to cyclohexanone, and the position of alkyl substitution was found to play an important role in the solvents properties. 3-Methylcyclohexanone was identified as the most promising of the diluents. (orig.)

  6. Soluble redox-active polymetallic chains [{Ru-0(CO)(L)(bpy)}(m)](n) (bpy=2,2 '-bipyridine, L = PrCN, Cl-; m=0,-1): Electrosynthesis and characterization

    NARCIS (Netherlands)

    F. Hartl; A.K. Renfrew; F. Lafolet; T. Mahabiersing; M.J. Calhorda; S. Chardon-Noblat; M. Haukka; A. Deronzier

    2009-01-01

    Electrochemical and spectroelectrochemical techniques were employed to study in detail the formation and so far unreported spectroscopic properties of soluble electroactive molecular chains with nonbridged metal-metal backbones, namely, [{Ru-0(CO)(PrCN)(bpy)}(m)](n) (m = 0, -1) and [{Ru-0(CO)(bpy)Cl

  7. Bis(μ2-benzoato-κ2O:O′bis[(benzoato-κ2O,O′bis(4,4′-bipyridine-κNcobalt(II]–benzoic acid (1/6

    Directory of Open Access Journals (Sweden)

    Rodolfo Peña-Rodríguez

    2014-01-01

    Full Text Available In the title compound, [Co2(C7H5O24(C10H8N24]·6C6H5COOH, the centrosymmetric cobalt dimer co-crystallizes with six molecules of benzoic acid. Each CoII atom is coordinated by four O atoms in a distorted square-planar arrangement while the N atoms are located in apical positions. The dihedral angles between the rings comprising each of the 4,4′-bipyridyl ligands are 25.2 (2 and 22.8 (2°. In the crystal, the three-dimensional network is assembled by O—H...O and C—H...O hydrogen bonds.

  8. Theoretical studies on the geometrical and electronic structures of supramolecule bis(2,2‧-bipyridine)-5-amino-1,10-phenanthroline ruthenium(II)/functionalized SWCNT dyads

    Science.gov (United States)

    Ahmadnezhad, M.; Darvish Ganji, M.; Rezvani, M.

    2015-11-01

    Functionalization of carbon nanotube (CNT) with multiple redox and photo active entities is one of the extensive processes due to its importance in building molecular or supramolecular electronic devices, solar energy storage and conversion systems. Thus, to have better understanding about structural aspects and correct electronic structure of these large systems, the quantum studies have gained increased popularity. In present study, we have investigated the structural and electronic properties of functionalized CNTs (fCNTs) with [Ru(bpy)2(5-NH2-1,10-phen)]+2, (Ru-bpy-phen)+2, supramolecule based on DFT calculations. Main attention has been applied to obtain stable configuration, binding energies and effect of functionalization on electronic behavior of the selected supramolcule. We also evaluate the effect of nanotube's diameter and chirality on electronic properties of considered supramolecule. Calculated binding energies show that interaction between the (Ru-bpy-phen)+2 and the host CNTs depends on the tube diameter while the chirality doesn't affect significantly on the binding nature of respected complex. We have also investigated the influence of non-local dispersion interactions (vdW) and temperature on the stability and electronic structure of the considered system. Results obtained from the ab initio MD simulations showed that increasing the temperature can affect the distance between C and N atoms in the linkage position. The charge analysis indicates the existence of remarkable charge transfer between (Ru-bpy-phen)+2 as donor and fCNTs as acceptor moieties in the isolated molecule. In the presence of vdW forces and at higher temperature, the charge transfer was decreased but the direction of transferred charge remains unchanged.

  9. MOF Formation vs. Reversible High Ligand Uptake in Anhydrous Halides: Two Opposing Aspects of 3[La2Cl6(4,4'-bipy)5]•4(4,4'-bipy)

    OpenAIRE

    Höller, Christoph J.; Matthes, Philipp; Beckmann, Jens; Mueller-Buschbaum, Klaus

    2009-01-01

    Abstract Construction of the framework structure 3?[La2Cl6(4,4?-bipy)5]?4(4,4?-bipy) (1), bipy = 4,4'-bipyridine, C10H8N2, is achieved by reaction of the anhydrous halide LaCl3 with molten 4,4'-bipyridine. Five equivalents of bipyridine are used for the framework construction linking LaCl3 units to give an extended, three-dimensional MOF. Furthermore four additional equivalents of bipyridine per LaCl3 unit are incorporated within the crystalline MOF, which is thereby completely fi...

  10. Rhenium(IV) compounds inducing apoptosis in cancer cells.

    Science.gov (United States)

    Martínez-Lillo, José; Mastropietro, Teresa F; Lappano, Rosamaria; Madeo, Antonio; Alberto, Marta E; Russo, Nino; Maggiolini, Marcello; De Munno, Giovanni

    2011-05-14

    The anticancer properties of a series of mononuclear Re(IV) compounds of formula ReCl(4)L (where L is bpy = 2,2'-bipyridine; bpym = 2,2'-bipyrimidine; dmbpy = 4,4'-dimethyl-2,2'-bipyridine; phen = 1,10-phenanthroline) were investigated for the first time. All compounds displayed potent in vitro antiproliferative activity against selected cancer cells.

  11. Métodos sintéticos para preparação de 2,2'-bipiridinas substituídas

    Directory of Open Access Journals (Sweden)

    Donnici Claudio Luis

    2002-01-01

    Full Text Available The 2,2'-bipyridine has been entitled as the most widely used ligand. Nowadays there is a large variety of known molecules comprising at least two 2,2'-bipyridine units and the number of applications in many areas such as catalysis, new materials, optoeletronics and electrochemistry have increased very much in the past decades. Nevertheless, there is no article that gives an overview of the main synthetic methods for obtaining the substituted 2,2'-bipyridines, generally non available. This article presents a synthetic discussion about the three different methods (coupling reaction, ciclo-functionalization and functionalization of the heteroaromatic rings of 2,2'-bipyridine for preparing these heterocyclic compounds and also provides a practical and fundamental guide, for obtaining more than eighty different symmetric and unsymmetrical substituted 2,2'-bipyridines, shown in a table with the corresponding references.

  12. Coupling of the 4f Electrons in Lanthanide Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Kazhdan, Daniel [Univ. of California, Berkeley, CA (United States)

    2008-09-01

    (C5Me5)2LnOTf where Ln = La, Ce, Sm, Gd, and Yb have been synthesized and these derivatives are good starting materials for the synthesis of (C5Me5)2LnX derivatives. (C5Me5)2Ln(2,2'-bipyridine), where Ln = La, Ce, Sm, and Gd, along with several methylated bipyridine analogues have been synthesized and their magnetic moments have been measured as a function of temperature. In lanthanum, cerium, and gadolinium complexes the bipyridine ligand ligand is unequivocally the radical anion, and the observed magnetic moment is the result of intramolecular coupling of the unpaired electron on the lanthanide fragment with the unpaired electron on the bipyridine along with the intermolecular coupling between radicals. Comparison with the magnetic moments of the known compounds (C5Me5)2Sm(2,2'-bipyridine) and (C5Me5)2Yb(2,2'-bipyridine) leads to an understanding of the role of the SmII/SmIII and YbII/YbIII couple in the magnetic properties of (C5Me5)2Sm(2,2'-bipyridine) and (C5Me5)2Yb(2,2'-bipyridine). In addition, crystal structures of (C5Me5)2Ln(2,2'-bipyridine) and [(C5Me5)2Ln(2,2'-bipyridine)][BPh4](Ln= Ce and Gd), where the lanthanide is unequivocally in the +3 oxidation state, give the crystallographic characteristics of bipyridine as an anion and as a neutral ligand in the same coordination environment, respectively. Substituted bipyridine ligands coordinated to (C5Me5)2Yb are studied to further understand how the magnetic coupling in (C5Me5)2Yb(2,2'-bipyridine) changes with substitutions. In the cases of (C5Me5)2Yb(5,5&apos

  13. Influence of diluent alkyl substitution on the extraction of Am(III) and Eu(III) by a 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine ligand dissolved in alkylated cyclohexanone diluents

    Energy Technology Data Exchange (ETDEWEB)

    Distler, P.; Spendlikova, I. [Czech Technical Univ., Prague (Czech Republic). Dept. of Nuclear Chemistry; John, J. [Czech Technical Univ., Prague (Czech Republic). Dept. of Nuclear Chemistry; Czech Technical Univ., Prague (Czech Republic). Centre for Radiochemistry and Radiation Chemistry; Harwood, L.M.; Hudson, M.J.; Lewis, F.W. [Reading Univ., Berkshire (United Kingdom). Dept. of Chemistry

    2012-07-01

    Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe{sub 4}-BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO{sub 3}, 3-methylcyclohexanone and 4-methylcyclohexanone gave comparable results to cyclohexanone whereas in the extractions from 4 M HNO{sub 3}, 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone all gave superior results. For the monomethylated diluents, D{sub Am} and SF{sub Am/Eu} decreased in the order of alkyl substitution 2 > 4 {proportional_to} 3. However, alkyl substitution of cyclohexanone significantly slows down the extraction kinetics compared to cyclohexanone, and the position of alkyl substitution was found to play an important role in the solvents properties. 3-Methylcyclohexanone was identified as the most promising of the diluents. (orig.)

  14. Preparation and reactivity of mixed-ligand ruthenium(II) hydride complexes with phosphites and polypyridyls.

    Science.gov (United States)

    Albertin, Gabriele; Antoniutti, Stefano; Bacchi, Alessia; D'Este, Claudia; Pelizzi, Giancarlo

    2004-02-23

    Chloro complexes [RuCl(N-N)P3]BPh4 (1-3) [N-N = 2,2'-bipyridine, bpy; 1,10-phenanthroline, phen; 5,5'-dimethyl-2,2'-bipyridine, 5,5'-Me2bpy; P = P(OEt)3, PPh(OEt)2 and PPh2OEt] were prepared by allowing the [RuCl4(N-N)].H2O compounds to react with an excess of phosphite in ethanol. The bis(bipyridine) [RuCl(bpy)2[P(OEt)3

  15. Formtreue Macrocyclen mit 2,2´-Bipyridinen: Synthese, Selbstorganisation und Komplexierung

    OpenAIRE

    Henze, Oliver

    2010-01-01

    Summary The report describes the syntheses of pyridines, 2,2ý-bipyridines and benzene derivatives and the connection of these units using the chemo- and regioselectivity in Pd° catalysed couplings. So the construction of rigid bipyridine building blocks for the generation of macrocycles with donor positions was achieved. The Sonogashira cross-coupling of these building blocks gave a macrocycle with a size of approx. 2.0 x 1.2 nm. The Macrocycle has two rotating bipyridine donor un...

  16. Exceptionally long-lived light-emitting electrochemical cells: multiple intra-cation π-stacking interactions in [Ir(C^N)2(N^N)][PF6] emitters

    OpenAIRE

    Buenzli, Andreas M.; Constable, Edwin C.; Housecroft, Catherine E.; Prescimone, Alessandro; Zampese, Jennifer A.; Longo, Giulia; Gil-Escrig, Lidon; Pertegas, Antonio; Orti, Enrique; Bolink, Henk J.

    2015-01-01

    A series of cyclometalated iridium(III) complexes [Ir(C^N)2(N^N)][PF6] (N^N = 2,2′-bipyridine (1), 6-phenyl-2,2′-bipyridine (2), 4,4′-di-tert-butyl-2,2′-bipyridine (3), 4,4′-di-tert-butyl-6-phenyl-2,2′-bipyridine (4); HC^N = 2-(3-phenyl)phenylpyridine (HPhppy) or 2-(3,5-diphenyl)phenylpyridine (HPh2ppy)) are reported. They have been synthesized using solvento precursors so as to avoid the use of chlorido-dimer intermediates, chloride ion contaminant being detrimental to the performance of [Ir...

  17. A density functional theory study of the electronic properties of Os(II) and Os(III) complexes immobilized on Au(111)

    DEFF Research Database (Denmark)

    O'Boyle, N.M.; Albrecht, Tim; Murgida, D.H.;

    2007-01-01

    We present a density functional theory (DFT) study of an osmium polypyridyl complex adsorbed on Au(111). The osmium polypyridyl complex [Os(bpy)(2)(P0P)Cl](n+) [bpy is 2,2'-bipyridine, P0P is 4,4'-bipyridine, n = 1 for osmium(II), and n = 2 for osmium(III)] is bound to the surface through the fre...

  18. Binding of copper(II) polypyridyl complexes to DNA and consequences for DNA-based asymmetric catalysis

    NARCIS (Netherlands)

    Draksharapu, Apparao; Boersma, Arnold J; Leising, Miriam; Meetsma, Auke; Browne, Wesley R; Roelfes, Gerard

    2015-01-01

    The interaction between salmon testes DNA (st-DNA) and a series of Cu-II polypyridyl complexes, i.e. [Cu(dmbpy)(NO3)(2)] (1) (dmbpy = 4,4'-dimethyl-2,2'-bipyridine), [Cu(bpy)(NO3)(2)] (2) (bpy = 2,2'-bipyridine), [Cu(phen)(NO3)(2)] (3) (phen = phenanthroline), [Cu(terpy)(NO3)(2)]center dot H2O (4) (

  19. Oligomeric complexes of some heteroaromatic ligands and aromatic diamines with rhodium and molybdenum tetracarboxylates: 13C and 15N CPMAS NMR and density functional theory studies.

    Science.gov (United States)

    Leniak, Arkadiusz; Kamieński, Bohdan; Jaźwiński, Jarosław

    2015-05-01

    Seven new oligomeric complexes of 4,4'-bipyridine; 3,3'-bipyridine; benzene-1,4-diamine; benzene-1,3-diamine; benzene-1,2-diamine; and benzidine with rhodium tetraacetate, as well as 4,4'-bipyridine with molybdenum tetraacetate, have been obtained and investigated by elemental analysis and solid-state nuclear magnetic resonance spectroscopy, (13)C and (15)N CPMAS NMR. The known complexes of pyrazine with rhodium tetrabenzoate, benzoquinone with rhodium tetrapivalate, 4,4'-bipyridine with molybdenum tetrakistrifluoroacetate and the 1 : 1 complex of 2,2'-bipyridine with rhodium tetraacetate exhibiting axial-equatorial ligation mode have been obtained as well for comparison purposes. Elemental analysis revealed 1 : 1 complex stoichiometry of all complexes. The (15)N CPMAS NMR spectra of all new complexes consist of one narrow signal, indicating regular uniform structures. Benzidine forms a heterogeneous material, probably containing linear oligomers and products of further reactions. The complexes were characterized by the parameter complexation shift Δδ (Δδ = δcomplex  - δligand). This parameter ranged from around -40 to -90 ppm in the case of heteroaromatic ligands, from around -12 to -22 ppm for diamines and from -16 to -31 ppm for the complexes of molybdenum tetracarboxylates with 4,4'-bipyridine. The experimental results have been supported by a density functional theory computation of (15)N NMR chemical shifts and complexation shifts at the non-relativistic Becke, three-parameter, Perdew-Wang 91/[6-311++G(2d,p), Stuttgart] and GGA-PBE/QZ4P levels of theory and at the relativistic scalar and spin-orbit zeroth order regular approximation/GGA-PBE/QZ4P level of theory. Nucleus-independent chemical shifts have been calculated for the selected compounds. PMID:25614975

  20. Organic-Disulfonate Ligand Manganese(Ⅱ) Coordination Compound%有机二磺酸锰配合物

    Institute of Scientific and Technical Information of China (English)

    宋玉梅; 庞洁

    2005-01-01

    The crystal structure of [Mn (BDA) (bpy)2(H2O)] (H2O)2 (1)(BDA =6,6' -dibromo-2,2' -dimethoxy- 1,1' -bi-naphthylene-4,4'-disulfonate, bpy=2,2'-bipyridine) composes of a manganese center which is surrounded by twonitrogen atoms from 2,2'-bipyridine and four oxygen atoms from three water and sulfonate group of BDA that alsoparticipate in H-bonding interactions to form 3D network as well as some uncoordinated water. CCDC: 277922.

  1. Living atom transfer radical polymerization of 4-acetoxystyrene

    DEFF Research Database (Denmark)

    Gao, Bo; Chen, Xianyi; Ivan, Bela;

    1997-01-01

    Living atom transfer radical polymerization (ATRP) of 4-acetoxystyrene (1), a protected 4-vinylphenol, leading to poly(4-acetoxystyrene) with well-defined molecular weight and narrow molecular weight distribution was carried out in bulk with a,a'-dibromoxylene(2)/CuBr/2,2-bipyridine(bpy) as initi......Living atom transfer radical polymerization (ATRP) of 4-acetoxystyrene (1), a protected 4-vinylphenol, leading to poly(4-acetoxystyrene) with well-defined molecular weight and narrow molecular weight distribution was carried out in bulk with a,a'-dibromoxylene(2)/CuBr/2,2-bipyridine...

  2. A Rapid Synthetic Method for the Preparation of Two Tris-Cobalt(III) Compounds.

    Science.gov (United States)

    Jackman, Donald C.; Rillema, D. Paul

    1989-01-01

    Reports a method of preparation for tris(ethylenediamine)cobalt(III) and tris(2,2'-bipyridine)cobalt(III) that will shorten the preparation time by approximately 3 hours. Notes the time for synthesis and isolation of compound one was 1 hour (yield 38 percent) while compound two took 50 minutes (yield 71%). (MVL)

  3. Solvent effect on thermodynamics of Ag(I) coordination to tripodal polypyridine ligands

    DEFF Research Database (Denmark)

    Del Piero, Silvia; Melchior, Andrea; Menotti, Davide;

    2009-01-01

      An investigation on the thermodynamics of complex formation between Ag(I) ion and different tripodal ligands (tris[(2-pyridyl)methyl]amine) (TPA) and 6,6'-bis[bis(2-pyridylmethyl)aminomethyl]-2,2'-bipyridine (BTPA) has been carried out in the aprotic solvents dimethylsulfoxide (DMSO) and dimeth...

  4. Construction of Insulin 18-mer Nanoassemblies Driven by Coordination to Iron(II) and Zinc(II) Ions at Distinct Sites

    DEFF Research Database (Denmark)

    Munch, Henrik K.; Nygaard, Jesper; Christensen, Niels Johan;

    2016-01-01

    coordination with two different metal ions. Selective attachment of an abiotic 2,2′-bipyridine (bipy) ligand to HI, yielding HI–bipy, enabled ZnII-binding hexamers to SA into trimers of hexamers, [[HI–bipy]6]3, driven by octahedral coordination to a FeII ion. The structures were studied in solution by small...

  5. Chromogenic detection of Sarin by discolouring decomplexation of a metal coordination complex.

    Science.gov (United States)

    Ordronneau, Lucie; Carella, Alexandre; Pohanka, Miroslav; Simonato, Jean-Pierre

    2013-10-11

    An innovative chromogenic sensing concept based on decomplexation of a tris-(bipyridine)iron(II) coordination complex has been developed for the detection of organophosphorus nerve agents. It was evaluated both on a simulant and real Sarin in vapour and liquid phases.

  6. Chemical topology: Tying up some loose ends

    Science.gov (United States)

    Fenlon, Edward E.

    2010-03-01

    A linear molecule containing three bipyridine ligands can be wrapped around a single metal-ion template to form an open-knot complex. The loose ends of the knot can be 'tied' together through esterification or olefin-metathesis reactions to form closed knots that do not unravel when the metal template is removed.

  7. Triggering Gel Formation and Luminescence through Donor-Acceptor Interactions in a C3 -Symmetric Tris(pyrene) System.

    Science.gov (United States)

    Lai, Thanh-Loan; Pop, Flavia; Melan, Caroline; Canevet, David; Sallé, Marc; Avarvari, Narcis

    2016-04-18

    Straightforward modulation of the gelation, absorption and luminescent properties of a tris(pyrene) organogelator containing a C3 -symmetric benzene-1,3,5-tricarboxamide central unit functionalized by three 3,3'-diamino-2,2'-bipyridine fragments is achieved through donor-acceptor interactions in the presence of tetracyanoquinodimethane. PMID:26864120

  8. Highly selective CO2 adsorption accompanied with low-energy regeneration in a two-dimensional Cu(II) porous coordination polymer with inorganic fluorinated PF6(-) anions.

    Science.gov (United States)

    Noro, Shin-ichiro; Hijikata, Yuh; Inukai, Munehiro; Fukushima, Tomohiro; Horike, Satoshi; Higuchi, Masakazu; Kitagawa, Susumu; Akutagawa, Tomoyuki; Nakamura, Takayoshi

    2013-01-01

    High selectivity and low-energy regeneration for adsorption of CO(2) gas were achieved concurrently in a two-dimensional Cu(II) porous coordination polymer, [Cu(PF(6))(2)(4,4'-bpy)(2)](n) (4,4'-bpy = 4,4'-bipyridine), containing inorganic fluorinated PF(6)(-) anions that can act as moderate interaction sites for CO(2) molecules.

  9. Cluster-controlled dimerisation in supramolecular ruthenium photosensitizer-polyoxometalate systems.

    Science.gov (United States)

    Heussner, Kirsten; Peuntinger, Katrin; Rockstroh, Nils; Rau, Sven; Streb, Carsten

    2015-01-01

    A supramolecular reaction system is reported where a labile molecular metal oxide cluster enables the unprecedented dimerisation of ruthenium photosensitizers [Ru(L)2(tmbiH2)](2+) (L = 4,4'-di-tert-butyl-2,2'-bipyridine (1a) or 2,2'-bipyridine (1b); tmbiH2 = 5,5',6,6'-tetramethyl-2,2'-bibenzimidazole). In the presence of [Mo8O26](4-) clusters (2) the dimerisation is triggered by the in situ conversion of [Mo8O26](4-) to [Mo6O19](2-) which results in the release of hydroxide ions. Simultaneous deprotonation of the pH-sensitive tmbiH2-ligands starts the dimerisation, resulting in the formation of the dinuclear complex [(Ru(L)2)2(tmbi)](2+) (L = 4,4'-di-tert-butyl-2,2'-bipyridine (3) or 2,2'-bipyridine (4)). The dimerisation reaction can be suppressed when 2 is replaced by a stable polyoxomolybdate cluster, [Mo5O15(PhPO3)2](4-) (5) and the reaction between 1a and 5 leads to the formation of hydrogen-bonded supramolecular aggregates 6. The solution and solid-state interactions in these systems were investigated using a range of spectroscopic and crystallographic techniques and compounds 3, 4 and 6 were characterized using single-crystal XRD. PMID:25381808

  10. Multistep electrochemical reduction path of clusters [Os3(CO)10(α-diimine)]: Comparison of electrochemical and photochemical Os-Os(α-diimine) bond cleavage

    NARCIS (Netherlands)

    F. Hartl; J.W.M. van Outersterp

    2006-01-01

    Electrochemical reduction of the triangular clusters [Os-3(CO)(10)(alpha-dimine)] (alpha-dimine = 2,2'-bipyridine (bpy), 2,2'-bipyrimidine (bpym)) and [Os-3(CO)(10)(mu-bpym) ReBr(CO)(3)] produces primarily the corresponding radical anions. Their stability is strongly determined by the pi acceptor ab

  11. Gallium and Functionalized-Porphyrins Combine to Form Potential Lysosome-Specific Multimodal Bioprobes.

    Science.gov (United States)

    Pan, Jie; Harriss, Bethany I; Chan, Chi-Fai; Jiang, Lijun; Tsoi, Tik-Hung; Long, Nicholas J; Wong, Wing-Tak; Wong, Wai-Kwok; Wong, Ka-Leung

    2016-07-18

    A water-soluble bimetallic normal ("cold") and radiochemical ("hot") gallium-porphyrin-ruthenium-bipyridine complex (GaporRu-1) has been synthesized by microwave methodology in short reaction times with good (>85%) yields. (68)GaporRu-1 is demonstrated to be a potential multimodal and functional bioprobe for positron emission tomography (PET), lysosome specific optical imaging, and photodynamic therapy. PMID:27355871

  12. In Vitro Polarized Resonance Raman Study of N719 and N719-TBP in Dye Sensitized Solar Cells

    DEFF Research Database (Denmark)

    Hassing, Søren; Jernshøj, Kit Drescher; Lund, Torben;

    2016-01-01

    Abstract: The working efficiency of dye-sensitized solar cells (DSCs) depends on the long-term stability of the dye itself and on the microscopic structure of the dye-semiconductor interface. Previous experimental studies of DSCs based on ruthenium dye with bipyridine ligands (N719) adsorbed...

  13. Electron transfer patterns of the di-heme protein cytochrome c(4) from Pseudomonas stutzeri

    DEFF Research Database (Denmark)

    Raffalt, Anders Christer; Schmidt, L.; Christensen, Hans Erik Mølager;

    2009-01-01

    We report kinetic data for the two-step electron transfer (ET) oxidation and reduction of the two-domain di-heme redox protein Pseudomonas stutzeri cytochrome (cyt) c(4) by [Co(bipy)(3)](2- 3-) (bipy = 2,2'-bipyridine). Following earlier reports, the data accord with both bi- and tri-exponential ...

  14. Cu(Ⅰ) and Cu(Ⅱ) helical complexes formed with oligobipyridine ligand

    Institute of Scientific and Technical Information of China (English)

    舒谋海; 付有君; 孙为银; 唐雯霞; 张文剑; 段春迎

    1999-01-01

    A new asymmetric oligobipyridine ligand, 1-(5’-methyl-2, 2’-bipyridin-5-yl)-2-(6’-methyl-2, 2’-bipyridin-6-yl)ethane (L), in which the bipyridine units are bridged by CH2CH2 at 5, 6’-position has been synthesized. The ligand L reacts with Cu(Ⅰ) and Cu(Ⅱ) ions giving double-stranded helical complexes [Cu2ⅠL2] (ClO4)2·Et2O (1) and [Cu2ⅡL2 (OH) (H2O)][ClO4]3(2), respectively. Complexes 1 and 2 were characterized by X-ray diffraction analyses, ES-MS, ESR and cyclic voltammetry, etc. Differing from the oligobipyridine ligands bridged by CH2CH2 at 6,6’-or 5,5’-position, the ligand L not only forms a double-stranded helicate with Cu(Ⅰ) ion, but also gives a double-stranded helicate with Cu(Ⅱ) ion. The results show that the linkage mode of the spacer group to the bipyridine units exerts a great impact on the formation of helix.

  15. Chiral metal complexes. 4. Stereoselective deuterium exchange at the coordinated NH/sub 2/ group of L-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Vagg, R.S. (Macquarie Univ., North Ryde, Australia); Williams, P.A.

    1983-01-19

    This communication details results of initial /sup 1/H NMR investigations on one of the simplest of these ternary compounds, namely ..delta..,..lambda..-((L-alaninato)bis(2,2-bipyridine)ruthenium(II)) perchlorate. Possible mechanisms of deuterium exchange for chiral ruthenium complexes are presented in this study.

  16. Synthesis of Dendritic-Linear Block Copolymers by Atom Transfer Radical Polymerization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The dendritic polyarylether 2-bromoisobutyrate as the macromolecular initiator for the controlled free radical polymerization of styrene was investigated. The polymerization was carried out with CuBr/2,2′-bipyridine catalyst at 110℃. It is found that the hybrid dendritic-linear block copolymers possess well-defined molecular weights and low polydispersities.

  17. Study of the emission oxidative reactions of ruthenium (II) complex by cationic compounds in anionic micelles

    International Nuclear Information System (INIS)

    The oxidative quenching of the emission of the tetraanionic complex tris (4,4' dicarboxylate - 2,2' - bipyridine ruthenium (II) in aqueous solution, by both organic and inorganic compounds in presence of anionic detergents, above and below the critical micelle concentration is studied. The organic cations, the inorganic ion and detergents used are shown. (M.J.C.)

  18. Fermi level alignment in molecular nanojunctions and its relation to charge transfer

    DEFF Research Database (Denmark)

    Stadler, Robert; Jacobsen, Karsten Wedel

    2006-01-01

    by orders of magnitude. We present a quantitative analysis of the relation between this level alignment (which can be estimated from charging free molecules) and charge transfer for bipyridine and biphenyl dithiolate (BPDT) molecules attached to gold leads based on density functional theory calculations...

  19. A family of Ru(II) complexes built on a novel sexipyridine building block: synthesis, photophysical properties and the rare structural characterization of a triruthenium species.

    Science.gov (United States)

    Laramée-Milette, Baptiste; Lussier, Félix; Ciofini, Ilaria; Hanan, Garry S

    2015-07-01

    A new tris-2'',4'',6''-(2,2'-bipyridin-4-yl)-1'',3'',5''-triazine ligand and its family of ruthenium coordination complexes are described along with their characterization by electrochemical and photophysical methods as well as a rare single crystal X-ray analysis of a triruthenium polypyridine complex. PMID:26037408

  20. A chemical system that mimics decoding operations.

    Science.gov (United States)

    Giansante, Carlo; Ceroni, Paola; Venturi, Margherita; Sakamoto, Junji; Schlüter, A Dieter

    2009-02-23

    The chemical information stored in equilibrium mixtures of molecular species is larger than the sum of information carried by the individual molecules. Protonation equilibria in dilute dichloromethane solution of a shape-persistent macrocycle bearing two 2,2'-bipyridine units and two Coumarin 2 moieties (see figure) can be exploited to mimic decoding operations.

  1. Ruthenium(II)- bipyridyl with extended -system: Improved thermo-stable sensitizer for efficient and long-term durable dye sensitized solar cells

    Indian Academy of Sciences (India)

    M Chandrasekharam; G Rajkumar; Ch Srinivasa Rao; T Suresh; P Y Reddy; Y Soujanya

    2011-09-01

    A new extended thermo-stable high molar extinction coefficient bipyridyl ruthenium(II) complex "cis-Ru(4,4'-bis(3,5-di-tert-butylphenyl)-2,2'-bipyridine)(Ln)(NCS)2 H101", where Ln = 4,4'-dicarboxylic acid-2,2'-bipyridine; was synthesized and characterized by 1H-NMR, FT-IR and ESI-MASS spectroscopes. The H101 sensitized solar cell constructed with an active area of 0.54 cm2 in combination with an ionic liquid electrolyte exhibited broader photocurrent action spectrum with solar-to-electric energy conversion efficiency () of 5.89 (JSC = 12.14 mA/cm2, VOC = 690 V, fill factor = 0.699) under Air Mass (AM) 1.5 sunlight, while the reference `cis-Ru(4,4'-dinonyl-2,2'-bipyridine)(Ln)(NCS)2', Z907 sensitized solar cell exhibited -value of 5.17% (JSC = 11.93 mA/cm2, VOC = 650 V, fill factor = 0.666). TGA analysis of H101 showed extended thermal-stability and under continuous light exposure and aging at 55°C, the DSSC retained 85% of its initial -value, while under comparable conditions Z907 sensitized solar cell retained 88%. As compared to 4,4'-dinonyl-2,2'-bipyridine in Z907, the new ancillary bipyridyl ligand `4,4'-bis(3,5-di-tert-butylphenyl)-2,2'-bipyridine’ in H101 shifts the absorption bands remarkably towards blue. The Density Functional Theory (DFT) and Time-Dependent DFT excited state calculations of the new sensitizer show that the first three HOMOs have t2g character with sizeable mixing from the NCS ligands with -bonding orbitals of 4,4'-bis(3,5-di-tert-butylphenyl)-2,2'-bipyridine. The LUMO is a *-orbital localized on the 4,4-dicarboxylic acid-2,2'-bipyridine and higher un-occupied frontier orbitals have *-combinations with 4,4'-bis(3,5-di-tert-butylphenyl)-2,2'-bipyridine.

  2. Photonics of a conjugated organometallic Pt-Ir polymer and its model compounds exhibiting hybrid CT excited states.

    Science.gov (United States)

    Soliman, Ahmed M; Fortin, Daniel; Zysman-Colman, Eli; Harvey, Pierre D

    2012-04-13

    Trans- dichlorobis(tri-n-butylphosphine)platinum(II) reacts with bis(2- phenylpyridinato)-(5,5'-diethynyl-2,2'-bipyridine)iridium(III) hexafluorophosphate to form the luminescent conjugated polymer poly[trans-[(5,5'-ethynyl-2,2'-bipyridine)bis(2- phenylpyridinato)-iridium(III)]bis(tri-n-butylphosphine)platinum(II)] hexafluorophosphate ([Pt]-[Ir])n. Gel permeation chromatography indicates a degree of polymerization of 9 inferring the presence of an oligomer. Comparison of the absorption and emission band positions and their temperature dependence, emission quantum yields, and lifetimes with those for models containing only the [Pt] or the [Ir] units indicates hybrid excited states including features from both chromophores.

  3. Synthesis and characterization of nanowire coils of organometallic coordination polymers for controlled cargo release.

    Science.gov (United States)

    Liang, Guodong; Ni, Huan; Bao, Suping; Zhu, Fangming; Gao, Haiyang; Wu, Qing

    2014-06-12

    Nanowire coils of organometallic coordination polymers have been synthesized for the first time by using the emulsion periphery polymerization technique. An amphiphilic triblock copolymer terminated with inclusion complex of β-cyclodextrin and 4,4'-bipyridine self-assembles into oil-in-water emulsion in a toluene/water mixture. Subsequent coordination of bipyridine with Ni(II) in periphery of emulsions results in the formation of coordination polymer nanowire coils. The nanowire coils are composed of nanowires with diameter of 2 nm. Nanowire coils exhibit enhanced thermal stability in contrast to their parent triblock copolymer. Interestingly, nanowire coils are capable of encapsulating organic cargoes. Encapsulated cargoes can be selectively extracted from nanowire coils without damaging nanowire coils. Nanowire coils are potential candidates for encapsulating and controlled release of organic cargoes. PMID:24842771

  4. 配位聚合物[Mn(4,4'-bpy)1.5(H2O)3](CIO4)·(4,4'-bpy)(L)·H2O的水热合成和晶体结构%Hydrothermal Synthesis and Crystal Structure of Coordination Polymer [Mn(4,4'-bpy)1.5(H2O)3] (ClO4)· (4,4'-bpy)(L)· H2O

    Institute of Scientific and Technical Information of China (English)

    黄妙龄

    2007-01-01

    The title compound, [Mn(4,4'-bpy)1.5(H2O)3](C1O4)·(4,4'-bpy)(L)· H2O(1), where L=2,4,6-trimethylbenzoic acid, was synthesized and its crystal structure was determined by X-ray diffraction analysis. The crystal is of triclinic, space group P(-1) with a=2.929 9(6) nm, b=1.0364(2) nm, c=8.222 0(1) nm, α=105.300(2)°, β=97.495(2)°,0.135 2. The Mn atoms are octahedrally coordinated by three N atoms of three 4,4'-bipyridine ligands and three O atoms of water. The complex shows a one-dimensional chain structure bridged by water and 4,4'-bipyridine molecules. CCDC: 615707.

  5. Organic-Ruthenium(II Polypyridyl Complex Based Sensitizer for Dye-Sensitized Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Lingamallu Giribabu

    2011-01-01

    Full Text Available A new high molar extinction coefficient organic-ruthenium(II polypyridyl complex sensitizer (RD-Cou that contains 2,2,6,6-tetramethyl-9-thiophene-2-yl-2,3,5,6,6a,11c-hexahydro1H,4H-11oxa-3a-aza-benzoanthracene-10-one as extended -conjugation of ancillary bipyridine ligand, 4,4-dicaboxy-2,26,2-bipyridine, and a thiocyanate ligand in its molecular structure has been synthesized and completely characterized by CHN, Mass, 1H-NMR, UV-Vis, and fluorescence spectroscopies as well as cyclic voltammetry. The new sensitizer was tested in dye-sensitized solar cells using a durable redox electrolyte and compared its performance to that of standard sensitizer Z-907.

  6. Development of high efficiency 100% aqueous cobalt electrolyte dye-sensitised solar cells.

    Science.gov (United States)

    Ellis, Hanna; Jiang, Roger; Ye, Sofie; Hagfeldt, Anders; Boschloo, Gerrit

    2016-03-28

    In this study we report the application of three cobalt redox shuttles in 100% aqueous electrolyte dye-sensitised solar cells (DSCs). By using chloride as a counter-ion for cobalt bipyridine, cobalt phenanthroline and cobalt bipyridine pyrazole, the redox shuttles were made water soluble; no surfactant or further treatment was necessary. A simple system of merely the redox shuttles and 1-methylbenzimidazole (MBI) in water as an electrolyte in combination with an organic dye and a mesoporous PEDOT counter electrode was optimised. The optimisation resulted in an average efficiency of 5.5% (record efficiency of 5.7%) at 1 sun. The results of this study present promising routes for further improvements of aqueous cobalt electrolyte DSCs. PMID:26931779

  7. High efficiency solid-state sensitized heterojunction photovoltaic device

    KAUST Repository

    Wang, Mingkui

    2010-06-01

    The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.

  8. C-Methylcalix[4]resorcinarene–1,4-bis(pyridin-3-yl-2,3-diaza-1,3-butadiene (1/2

    Directory of Open Access Journals (Sweden)

    Konstantin A. Udachin

    2012-02-01

    Full Text Available In the title compound, 2C12H10N4·C32H32O8, the calixarene adopts a rctt conformation with dihedral angles of 138.40 (1 and 9.10 (1° between the opposite rings. The dihedral angles between the rings of the pyridine derivative are 8.80 (1 and 9.20 (1°. In the crystal, adjacent C-methylcalix[4]resorcinarene molecules are connected into columns parallel to [010] by O—H...O hydrogen bonds. O—H...N hydrogen bonds between the axial phenoxyl groups and bipyridine molecules link the columns into sheets parallel to (011, which are connected by O—H...N hydrogen bonds. Further O—H...N hydrogen bonds link the bipyridine and C-methylcalix[4]resorcinarene molecules, giving rise to a three-dimensional network.

  9. Trapping of Zn-Complex with Bis(tetrazole) Ligand during the Demko-Sharpless' Tetrazole Synthesis%Sharpless四唑合成中捕获双四唑锌配合物

    Institute of Scientific and Technical Information of China (English)

    王立中; 王锡森; 李咏华; 白志平; 熊仁根; 熊明; 李国武

    2002-01-01

    The reaction of malononitrile with ZnCl2 and NaN3 in the presence of 2, 2'-bipyridine and water affords the firstbis(tetrazole) Zn-complex intermediate, mono(2, 2'-bipyridine) bis(tetrazolyl) methane aqua zinc (Ⅱ), [Zn(2, 2'-bpy) (BTZ) (H2O) ] @ (H2O)2 (1) which gives a clue for Demko-Sharpless' tetrazole synthesis. Crystal data for 1:C13H18N10O4Zn, Mr =443.74, monoclinic, space group P21/c, a= 12. 5705(18), b = 16. 078(2), c =9. 1921(13)A, β=95.010(3)°, V=1850.7(5)A3, Z=4. CCDC: 197788.

  10. Synthesis and crystal structure of Pb(Bipy)2B12H12

    International Nuclear Information System (INIS)

    Lead complex with B12H122- anion and 2,2' bipyridine-lead(2) dodecahydro-closo-dodecaborate di(2,2' bipyridine) is synthesized and characterized by IF, UV and NMR spectrography methods. According to roentgen-structural analysis the crystals belong to monoclinic syngony, sp.gr. C2/m,a=17.872(4), b=18.672(5), c=9.228(7)A, β=109.11(4), V=2910(2)A3, Z=4. The structure consists of Pb2(Bipy)4(B12H12)2 dimeric units. The Pb-B distances are within the limits of 3.313-3.514A. 11 refs.; 2 figs.; 2 tabs

  11. Supramolecular effects in dendritic systems containing photoactive groups

    Directory of Open Access Journals (Sweden)

    GIANLUCA CAMILLO AZZELLINI

    2000-03-01

    Full Text Available In this article are described dendritic structures containing photoactive groups at the surface or in the core. The observed supramolecular effects can be attributed to the nature of the photoactive group and their location in the dendritic architecture. The peripheric azobenzene groups in these dendrimeric compounds can be regarded as single residues that retain the spectroscopic and photochemical properties of free azobenzene moiety. The E and Z forms of higher generation dendrimer, functionalized with azobenzene groups, show different host ability towards eosin dye, suggesting the possibility of using such dendrimer in photocontrolled host-guest systems. The photophysical properties of many dendritic-bipyridine ruthenium complexes have been investigated. Particularly in aerated medium more intense emission and a longer excited-state lifetime are observed as compared to the parent unsubstituted bipyridine ruthenium complexes. These differences can be attributed to a shielding effect towards dioxygen quenching originated by the dendritic branches.

  12. Peptide Nucleic Acid with a Lysine Side Chain at the β-Position: Synthesis and Application for DNA Cleavage.

    Science.gov (United States)

    Sugiyama, Toru; Kuwata, Keiko; Imamura, Yasutada; Demizu, Yosuke; Kurihara, Masaaki; Takano, Masashi; Kittaka, Atsushi

    2016-01-01

    This paper reports the synthesis of new β-Lys peptide nucleic acid (PNA) monomers and their incorporation into a 10-residue PNA sequence. PNA containing β-Lys PNA units formed a stable hybrid duplex with DNA. However, incorporation of β-Lys PNA units caused destabilization of PNA-DNA duplexes to some extent. Electrostatic attractions between β-PNA and DNA could reduce this destabilization effect. Subsequently, bipyridine-conjugated β-Lys PNA was prepared and exhibited sequence selective cleavage of DNA. Based on the structures of the cleavage products and molecular modeling, we reasoned that bipyridine moiety locates within the minor groove of the PNA-DNA duplexes. The lysine side chain of β-PNA is a versatile handle for attaching various functional molecules. PMID:27373637

  13. Chiral Cu(II-catalyzed enantioselective β-borylation of α,β-unsaturated nitriles in water

    Directory of Open Access Journals (Sweden)

    Lei Zhu

    2015-10-01

    Full Text Available The promising performance of copper(II complexes was demonstrated for asymmetric boron conjugate addition to α,β-unsaturated nitriles in water. The catalyst system, which consisted of Cu(OAc2 and a chiral 2,2′-bipyridine ligand, enabled β-borylation and chiral induction in water. Subsequent protonation, which was accelerated in aqueous medium, led to high activity of this asymmetric catalysis. Both solid and liquid substrates were suitable despite being insoluble in water.

  14. Theoretical studies of -NH₂ and -NO₂ substituted dipyridines.

    Science.gov (United States)

    Liu, Hui; Wang, Fang; Wang, Gui-Xiang; Gong, Xue-Dong

    2012-10-01

    In this work, the experimental synthesized bipyridines 3,3'-Dinitro-2,2'-bipyridine (DNBPy), 3,3'-Dinitro-2,2'-bipyridine-1,1'-dioxide (DNBPyO), and (3-Nitro-2-pyridyl)(5-nitro-2-pyridyl) amine (NPyA), and a set of designed dipyridines that have similar frameworks but different linkages and substituents with NPyA were studied theoretically at the B3LYP/6-31G* level of density functional theory. The gas-phase heats of formation were predicted based on the isodesmic reactions and the condensed-phase heats of formation and heats of sublimation were estimated in the framework of the Politzer approach. The crystal densities have been computed from molecular packing. Results show that this method gives a good estimation of density in comparison with the available experimental data for DNBPy, DNBPyO, and NPyA. The predicted detonation velocities and pressures indicate that the performance of dipyridines linked with -O-, -NH-, or -CH₂- bridges have not been improved compared with that of the directly linked dipyridines, but all derivatives have better detonation properties than DNBPy, DNBPyO, and NPyA because of the presence of more nitro groups. An analysis of the bond dissociation energies (BDEs) or the impact sensitivity (h₅₀) suggests that introduction of different bridges but not substituents has little influence on thermal stability. The calculated h₅₀ may be more reliable than BDE for predicting stability. Four bridged bipyridines have quite good detonation performance and low sensitivity. PMID:22648786

  15. Oxidation of Alcohols Catalyzed by Ruthenium Complexes with Iodosylbenzene as Oxidant

    Institute of Scientific and Technical Information of China (English)

    Zi Qiang LEI; Qiao Xiang KANG; Xiang Zhen BAI; Zhi Wang YANG; Qing Hua ZHANG

    2005-01-01

    Five ruthenium complexes such as Phen-Ru-Phen, Phen-Ru-Bipy, Phen-Ru-Quin,Quin-Ru-Quin and Bipy-Ru-Quin (where Phen=1, 10-phenanthroline, Quin=8-hydroxyquinoline,Bipy=2, 2′-bipyridine) were synthesized and used as catalysts for the oxidation of benzylic and primary aliphatic alcohols with iodosylbenzene as oxidant. The oxidations were carried out at room temperature, affording the corresponding aldehydes and ketones with high selectivity.

  16. Deactivation of signal amplification by reversible exchange catalysis, progress towards in vivo application.

    Science.gov (United States)

    Mewis, Ryan E; Fekete, Marianna; Green, Gary G R; Whitwood, Adrian C; Duckett, Simon B

    2015-06-18

    The catalyst which is used in the signal amplification by reversible exchange (SABRE) process facilitates substrate hyperpolarisation while acting to speed up the rate of relaxation. Consequently, the lifetime over which the hyperpolarised contrast agent is visible is drastically reduced. We show that the addition of a chelating ligand, such as bipyridine, rapidly deactivates the SABRE catalyst thereby lengthening the agent's relaxation times and improving the potential of SABRE for diagnostic MRI. PMID:25989727

  17. Multi-responsive metal-organic lantern cages in solution.

    Science.gov (United States)

    Brega, Valentina; Zeller, Matthias; He, Yufan; Lu, H Peter; Klosterman, Jeremy K

    2015-03-25

    Soluble copper-based M4L4 lantern-type metal-organic cages bearing internal amines were synthesized. The solution state integrity of the paramagnetic metal-organic cages was demonstrated using NMR, DLS, MS, and AFM spectroscopy. 1D supramolecular pillars of pre-formed cages or covalent host-guest complexes selectively formed upon treatment with 4,4'-bipyridine and acetic anhydride, respectively.

  18. Lanthanide modification of CdSe/ZnS core/shell quantum dots

    DEFF Research Database (Denmark)

    Dethlefsen, Johannes Rytter; Mikhailovsky, Alexander A.; Burks, Peter T.;

    2012-01-01

    Lanthanide-modified CdSe quantum dots (CdSe(Ln) QDs) have been prepared by heating a solution of Cd(oleate)(2), SeO2, and Ln(bipy)(S2CNEt2)(3) (bipy = 2,2'-bipyridine) to 180-190 degrees C for 10-15 min. The elemental compositions of the resulting CdSe(Ln) cores and CdSe(Ln)/ZnS core/shell QDs show...

  19. Synthesis of asymmetric supramolecular compounds using a Ni(0) catalysed homo-coupling approach

    NARCIS (Netherlands)

    Cassidy, Lynda; Horn, Sabine; Cleary, Laura; Halpin, Yvonne; Browne, Wesley R.; Vos, Johannes G.

    2009-01-01

    The synthesis and characterisation of a series of dinuclear ruthenium and osmium polypyridyl metal complexes based on the bridging ligands [5-(5'-bipyridin-2',2 ''-yl)-3-(pyridin-2-yl)]-1,2,4-triazole (Hpytr-bipy), 2,2 ''-bis(pyridin-2 '' yl)-5,5 ''-bis(pyridin-3 ''-yl) (bipy-bipy) and 5,5'-bis(pyri

  20. (Cyclopentadienylamine)scandium(2,3-dimethyl-1,3-butadiene) : A 1,3-diene complex of scandium with Sc(I)- and Sc(III)-like reactivity

    NARCIS (Netherlands)

    Beetstra, D.J.; Meetsma, A.; Hessen, B.; Teuben, J.H

    2003-01-01

    The scandium 2,3-dimethyl-1,3-butadiene complex [eta(5),eta(1)-C5H4(CH2)(2)NMe2]Sc(C6H10) (2) reacts with PhCN via initial nitrile insertion into the Sc-diene bond to give a dimeric mu(2)-imido species, but with a 2,2'-bipyridine via the elimination of the free diene. The latter shows that 2 can be

  1. Examining Rhodium Catalyst complexes for Use with Conducting Polymers Designed for Fuel Cells in Preparing Biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Carpio, M.M.; Kerr, J.B.

    2005-01-01

    Biosensing devices are important because they can detect, record, and transmit information regarding the presence of, or physiological changes in, different chemical or biological materials in the environment. The goal of this research is to prepare a biosensing device that is effective, quick, and low cost. This is done by examining which chemicals will work best when placed in a biosensor. The first study involved experimenting on a rhodium catalyst complexed with ligands such as bipyridine and imidazole. The rhodium catalyst is important because it is reduced from RhIII to RhI, forms a hydride by reaction with water and releases the hydride to react with nicotinamide adenine dinucleotide (NAD+) to selectively produce 1,4-NADH, the reduced form of NAD+. The second study looked at different types of ketones and enzymes for the enzyme-substrate reaction converting a ketone into an alcohol. Preliminary results showed that the rhodium complexed with bipyridine was able to carry out all the reactions, while the rhodium complexed with imidazole was not able to produce and release hydrides. In addition, the most effective ketone to use is benzylacetone with the enzyme alcohol dehydrogenase from baker’s yeast. Future work includes experimenting with bis-imidazole, which mimics the structure of bipyridine to see if it has the capability to reduce and if the reduction rate is comparable to the bipyridine complex. Once all testing is completed, the fastest catalysts will be combined with polymer membranes designed for fuel cells to prepare biosensing devices that can be used in a variety of applications including ones in the medical and environmental fields.

  2. Lewis Acid Catalyzed Friedel-Crafts Alkylation of Alkenes with Trifluoropyruvates.

    Science.gov (United States)

    Xiang, Bin; Xu, Teng-Fei; Wu, Liang; Liu, Ren-Rong; Gao, Jian-Rong; Jia, Yi-Xia

    2016-05-01

    A Friedel-Crafts alkylation reaction of styrenes with trifluoropyruvates has been developed, which delivered allylic alcohols in excellent yields (up to 98%) using the Ni(ClO4)2·6H2O/bipyridine complex as a catalyst. The asymmetric reaction was catalyzed by the chiral Cu(OTf)2/bisoxazoline complex to afford the corresponding chiral allylic alcohols bearing trifluoromethylated quaternary stereogenic centers in moderate enantioselectivities (up to 75% ee). PMID:27028539

  3. PFO-BPy Solubilizers for SWNTs: Modelling of Polymers from Oligomers

    OpenAIRE

    Glanzmann, Livia N.; Mowbray, Duncan J.; Rubio, Angel

    2014-01-01

    Due to their exeptional physical properties, single walled carbon nanotubes (SWNTs) embedded in organic polymers (polymer-SWNT hybrid systems) are promising materials for organic photovoltaic (OPV) devices. Already at the SWNT sorting and debundling step, polymers such as the copolymer of 9,9-dioctylfluorenyl-2,7-diyl and bipyridine (PFO-BPy) are used as solubilizers. However, to model polymer-SWNT hybrid systems, we must first determine the smallest oligomer needed to sufficiently describe t...

  4. Reversible supramolecular assembly at specific DNA sites: nickel-promoted bivalent DNA binding with designed peptide and bipyridyl-bis(benzamidine) components.

    Science.gov (United States)

    Sánchez, Mateo I; Mosquera, Jesús; Vázquez, M Eugenio; Mascareñas, José L

    2014-09-01

    At specific DNA sites, nickel(II) salts promote the assembly of designed components, namely a bis(histidine)-modified peptide that is derived from a bZIP transcription factor and a bis(benzamidine) unit that is equipped with a bipyridine. This programmed supramolecular system with emergent properties reproduces some key characteristics of naturally occurring DNA-binding proteins, such as bivalence, selectivity, responsiveness to external agents, and reversibility.

  5. Novel Zn(II) ladder-like coordination polymer constructed from designed ferrocenyl ligand

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Reaction of Zn(NO3)2.6H2O with 3-(4-carboxylphenylamino)-1-ferrocenyl-2-butylen-1-one (HL) and 4,4'-bipyridine (4,4'-bipy) in methanol solution resulted in a novel ladder-like coordination polymer {[Zn2L2(μ2-L)2(4,4'-bipy)2].MeOH}n (1). Its crystal structure, thermal and electrochemical properties axe presented.

  6. Aufbau und Untersuchung multivalenter metallosupramolekularer Wirtsysteme

    OpenAIRE

    Linder, Igor

    2015-01-01

    The present thesis describes the construction of differently shaped di- to hexavalent crown ethers by coordination-driven self-assembly and their investigations according (pseudo¬-) rotaxane formation and kinetics of the dynamic ligand exchange. First, bipyridine and terpyridine ligand moieties as well as crown ether host moieties were synthesized. Then a toolbox of crown ether-substituted bi- and terpyridines was created by connecting the host and ligand moieties by Sonogashira reactio...

  7. PREPARATION OF PHOTOFUNCTIONAL POLYMER THIN FILMS BY LANGMUIR-BLODGETT TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Tokuji Miyashita; Tatsuo Taniguchi; Yoshihito Fukasawa

    1999-01-01

    Polymer LB films containing photofuntional groups were prepared by the copolymerization of N-dodecylacrylamide (DDA), which has an excellent property to form a stable monolayer and LB multilayers with photofunctional monomers. Tris(2, 2'-bipyridine) ruthenium complex, Ru(bpy)32+, one of the most wellknown redox-active sensitizer, was incorporated into the DDA copolymer. The photogalvanic effect based on the photoinduced electron transfer using the ruthenium complex in the polymer LB monolayer was discussed.

  8. 1D ferrimagnetism in homometallic chains

    OpenAIRE

    Coronado Miralles, Eugenio; Gómez García, Carlos José; Borrás Almenar, Juan José

    1990-01-01

    The magnetic properties of the cobalt zigzag chain Co(bpy)(NCS)2 (bpy=2,2′‐bipyridine) are discussed on the basis of an Ising‐chain model that takes into account alternating Landé factors. It is emphasized, for the first time, that a homometallic chain containing only one type of site can give rise to a 1D ferrimagneticlike behavior. ,

  9. Modulation in selectivity and allosteric properties of small-molecule ligands for CC-chemokine receptors

    DEFF Research Database (Denmark)

    Thiele, Stefanie; Malmgaard-Clausen, Mikkel; Engel-Andreasen, Jens;

    2012-01-01

    Among 18 human chemokine receptors, CCR1, CCR4, CCR5, and CCR8 were activated by metal ion Zn(II) or Cu(II) in complex with 2,2'-bipyridine or 1,10-phenanthroline with similar potencies (EC(50) from 3.9 to 172 μM). Besides being agonists, they acted as selective allosteric enhancers of CCL3...... exploration of chemokine receptors as possible targets for therapeutic intervention....

  10. Crystal structure of poly[[(2,2′-bipyridinemanganese(II]-di-μ-thiocyanato

    Directory of Open Access Journals (Sweden)

    Stefan Suckert

    2014-12-01

    Full Text Available In the crystal structure of the polymeric title compound, [Mn(NCS2(C10H8N2]n, the MnII cations are coordinated by one chelating 2,2′-bipyridine ligand and four thiocyanate anions (two N- and two S-coordinating, forming a distorted [MnN4S2] octahedron. The asymmetric unit consists of one manganese cation located on a twofold rotation axis and half of a 2,2′-bipyridine ligand, the other half being generated by the same twofold rotation axis, as well as one thiocyanate anion in a general position. The MnII cations are linked by two pairs of μ1,3-bridging thiocyanate ligands into chains along the c axis; because the N atoms of the 2,2′-bipyridine ligands, as well as the N and the S atoms of the thiocyanate anions, are each cis-coordinating, these chains show a zigzag arrangement.

  11. Amphiphilic nanocapsules entangled with organometallic coordination polymers for controlled cargo release.

    Science.gov (United States)

    Liang, Guodong; Ni, Huan; Bao, Suping; Zhu, Fangming; Gao, Haiyang; Wu, Qing; Tang, Ben Zhong

    2014-06-01

    A class of new amphiphilic nanocapsules entangled with organometallic coordination polymers has been developed for the first time. Poly(2-(N,N-dimethyl amino)ethyl methacrylate)-b-polystyrene capped with β-cyclodextrin (β-CD) (CD-PDMAEMA-b-PS) is first synthesized using sequent RAFT polymerization of styrene and 2-(N,N-dimethyl amino)ethyl methacrylate with xanthate modified β-CD as chain transfer agent. The end group of β-CD is allowed to include 4,4'-bipyridine through host-guest inclusion to yield PDMAEMA-b-PS terminated with an inclusion complex of β-CD and bipyridine (bpy-PDMAEMA-b-PS), which is then used as surfactant to prepare emulsion droplets in toluene/water mixture. Upon addition of Ni(II), bipyridine coordinates with Ni(II) to form coordination polymers in the periphery of emulsion droplets, affording amphiphilic capsules entangled with organometallic coordination polymers, as confirmed by GPC, (1)H NMR, SEM, TEM, DLS, and so on. The organometallic coordination polymer capsules are capable of encapsulating organic cargoes. Interestingly, encapsulated cargoes can be extracted from the capsules without damaging the capsules. Such capsules are potential candidates for encapsulating and controlled release of organic cargoes. PMID:24828951

  12. Synthesis and Crystal Structure of a 1-D Chain Coordination Complex {[Mn2(HCAM)3(H2bipy)]·5H2O}n

    Institute of Scientific and Technical Information of China (English)

    SUN Ya-Guang; RONG Shu-Ting; WU Yong-Li; YU Wan; WANG Chuan-Sheng; ZHANO Wan-Zhong; GAO En-Jun

    2009-01-01

    The 1-D chain coordination complex of {[Mn2(HCAM)3(H2bipy)]·5H2O}n (H3CAM = 4-hydroxypyridine-2,6-dicarboxylic acid, bipy = 4,4'-bipyridine) has been synthesized by the reaction of 4-hydroxypyridine-2,6-dicarboxylic acid, 4,4'-bipyridine and manganese carbonate under hydrothermal conditions, and its crystal structure was determined by X-ray diffraction method. The crystal belongs to the monoclinie system, space group P21/n with a = 10.110(2), b = 20.159(4), c = 17.861(4) A, β = 99.67(3)°, V= 3.5884(12) nm3, Mr= 901.47, Z = 4, Dc= 1.669 g·cm-3, μ= 0.798 mm-1, F(000) = 1840, the final R = 0.0713 and wR = 0.1853. The complex forms a 1-D chain bridged by HCAM, protonated 4,4-bipyridines link the 1-D chains to construct 2-D networks via N-H…O hydrogen bonds, and networks are further extended via π-π stacking and hydrogen bonds into 3-D supramolecular framework.

  13. Synthesis, characterization, and photophysics of oxadiazole- and diphenylaniline-substituted Re(I) and Cu(I) complexes.

    Science.gov (United States)

    Horvath, Raphael; Fraser, Michael G; Cameron, Scott A; Blackman, Allan G; Wagner, Pawel; Officer, David L; Gordon, Keith C

    2013-02-01

    Transition-metal complexes of the types [Re(CO)(3)Cl(NN)], [Re(CO)(3)py(NN)](+), and [Cu(PPh(3))(2)(NN)](+), where NN = 4,4'-bis(5-phenyl-1,3,4-oxadiazol-2-yl)-2,2'-bipyridine (OX) and 4,4'-bis(N,N-diphenyl-4-[ethen-1-yl]-aniline)-2,2'-bipyridine (DPA), have been synthesized and characterized. Crystal structures for [Re(CO)(3)Cl(DPA)] and [Cu(PPh(3))(2)(OX)]BF(4) are presented. The crystal structure of the rhenium complex shows a trans arrangement of the ethylene groups, in agreement with density functional theory calculations. The structure of the copper complex displays the planar aromatic nature of the bpy-oxadiazole ligand. Density functional theory modeling of the complexes was supported by comparison of calculated and experimental normalized Raman spectra; the mean absolute deviations of the complexes were computational techniques. It was shown that the lowest energy absorption peaks are metal to ligand charge transfer and ligand-centered charge transfer for the oxadiazole- and diphenylaniline-substituted bipyridine ligands, respectively. The lowest energy excited states were characterized using transient emission and absorption spectroscopic techniques in conjunction with density functional theory calculations. These showed that the DPA complexes had ligand-centered nonemissive "dark" states with lifetimes ranging from 300 to 2000 ns. PMID:23311357

  14. Dye-sensitization of nanocrystalline semiconductor electrodes

    Science.gov (United States)

    Stipkala, Jeremy M.

    Electron transfer from excited sensitizer molecules into colloidal titanium dioxide thin film electrodes in the absence of an intimate covalent bond has been exploited to convert light into electricity. A brief review of research reported in the literature is given, which focuses on the kinetics of interfacial charge transfer events at sensitized sol-gel processed semiconductor particles. It was found that forward electron transfer from the sensitizer to the semiconductor is several orders of magnitude faster than the energy wasting recombination in the most successful systems. The novel results included here detail two new approaches to the problem of immobilizing sensitizers on the surface of the semiconductor. First, linkage ligands 4-methyl-4sp'-R-2,2sp'-bipyridine, where R = -COOH, -(CHsb2)sb3COOH, and -(CHsb2)sb3COCHsb2COOCsb2Hsb5 were synthesized. These ligands were incorporated into the sensitizer RuspII(dmb)sb2LL(PFsb6)sb2, where dmb = 4,4sp'-dimethyl-2,2sp'-bipyridine, and LL is the linkage ligand. The performance of these ruthenium sensitizers in regenerative solar cells was measured. It was found that the presence of the propylene spacer slows the recombination of the injected electron in the semiconductor with the oxidized sensitizer by a factor of 3-4. Second, electropolymerization of RuspII(vbpy) compounds, where vbpy is 4-methyl-4sp'-vinyl-2,2sp'-bipyridine, is explained. If the polymerization conditions are kept within narrow parameters, it is possible to add polymeric sensitizer to the semiconductor electrode and improve the cell performance. It was often observed, however, that the addition of polymer increased the dye surface coverage but lowered light-to-electricity conversion efficiencies. Evidence for self-quenching and iodide diffusion inhibition as mechanistic explanations for the reduced efficiencies from polymeric samples is given.

  15. Flexible sorption and transformation behavior in a microporous metal-organic framework.

    Science.gov (United States)

    Cussen, Edmund J; Claridge, John B; Rosseinsky, Matthew J; Kepert, Cameron J

    2002-08-14

    Crystals of the metal-organic framework material Ni(2)(4,4'-bipyridine)(3)(NO(3))(4) (A) have been grown by reaction of Ni(NO(3))(2).6H(2)O and 4,4'-bipyridine in methanol solution. Single-crystal X-ray diffraction experiments show that the ladder structure of the framework is maintained after desolvation of the material, resulting in the production of a porous solid stable to 215(4) degrees C. Powder X-ray diffraction has been employed to confirm the bulk purity and temperature stability of this material. The crystal structure indicates that the pore window has an area of 12.3 A(2). However, sorption experiments show these windows will admit toluene, which has a minimum cross-sectional area of 26.6 A(2), with no significant change in the structure. Monte Carlo docking calculations show that toluene can be accommodated within the large pores of the structure. Exposure of the related microporous material Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH (B) to methanol vapor causes a guest-driven solid-state transformation to A which is observed using powder X-ray diffraction. This structural rearrangement proceeds directly from crystalline B to crystalline A and is complete in less than 1 day. Mechanisms for the transformation are proposed which require breaking of at least one in six of the covalent bonds that confer rigidity on the framework. PMID:12167052

  16. Improved electrochemiluminescence labels for heterogeneous microbead immunoassay.

    Science.gov (United States)

    Yu, Linpo; Liu, Yang; Zhou, Ming

    2016-10-01

    Ruthenium(II) complexes with carboxylic acid as a bioconjugatable group, i.e., [Ru(bathophenanthroline disulfonate)(2,2'-bipyridine)(4-methyl-4'-(3-carboxypropyl)-2,2'-bipyridine)](0), (C49H38N6O8S2Ru), and [Ru(bathophenanthroline disulfonate)2(4-methyl-4'-(3-carboxypropyl)-2,2'-bipyridine)](2-) · 2Na(+), (C63H44N6O14S4RuNa2) were characterized spectroscopically and electrochemically. As potential labels for electrochemiluminescence (ECL) immunoassays, the ECL intensities of the free labels in homogenous aqueous buffer solutions were compared under a condition that is similar to the one employed by a commercial clinical immunoassay system. The two labels were found to be more emissive and, thus, can be detected at 10(- 12) pM compared with 5× 10(-12) pM of the label currently used in the commercial ECL system. Furthermore, the improved ECL emission of the free labels in homogenous solutions was proven to be translated into more intense ECL signal in heterogeneous sandwich immunoassay and, thus, leading to a lower limit of detection in immunoassay. The data obtained from these ECL labels shed light on the further development of ECL-based clinical immunoassay technology. Graphical abstract Electrochemiluminescence immunoassays were carried out with three different ruthenium(II) complex labels. It was proved that the higher signal intensities found with the novel labels in homogeneous solutions were maintained in heterogeneous sandwich format. PMID:27178555

  17. Fully Enzymatic Membraneless Glucose|Oxygen Fuel Cell That Provides 0.275 mA cm(-2) in 5 mM Glucose, Operates in Human Physiological Solutions, and Powers Transmission of Sensing Data.

    Science.gov (United States)

    Ó Conghaile, Peter; Falk, Magnus; MacAodha, Domhnall; Yakovleva, Maria E; Gonaus, Christoph; Peterbauer, Clemens K; Gorton, Lo; Shleev, Sergey; Leech, Dónal

    2016-02-16

    Coimmobilization of pyranose dehydrogenase as an enzyme catalyst, osmium redox polymers [Os(4,4'-dimethoxy-2,2'-bipyridine)2(poly(vinylimidazole))10Cl](+) or [Os(4,4'-dimethyl-2,2'-bipyridine)2(poly(vinylimidazole))10Cl](+) as mediators, and carbon nanotube conductive scaffolds in films on graphite electrodes provides enzyme electrodes for glucose oxidation. The recombinant enzyme and a deglycosylated form, both expressed in Pichia pastoris, are investigated and compared as biocatalysts for glucose oxidation using flow injection amperometry and voltammetry. In the presence of 5 mM glucose in phosphate-buffered saline (PBS) (50 mM phosphate buffer solution, pH 7.4, with 150 mM NaCl), higher glucose oxidation current densities, 0.41 mA cm(-2), are obtained from enzyme electrodes containing the deglycosylated form of the enzyme. The optimized glucose-oxidizing anode, prepared using deglycosylated enzyme coimmobilized with [Os(4,4'-dimethyl-2,2'-bipyridine)2(poly(vinylimidazole))10Cl](+) and carbon nanotubes, was coupled with an oxygen-reducing bilirubin oxidase on gold nanoparticle dispersed on gold electrode as a biocathode to provide a membraneless fully enzymatic fuel cell. A maximum power density of 275 μW cm(-2) is obtained in 5 mM glucose in PBS, the highest to date under these conditions, providing sufficient power to enable wireless transmission of a signal to a data logger. When tested in whole human blood and unstimulated human saliva maximum power densities of 73 and 6 μW cm(-2) are obtained for the same fuel cell configuration, respectively. PMID:26750758

  18. Synthesis, photophysical and preliminary investigation of the dye-sensitized solar cells properties of functionalized anthracenyl-based bipyridyl and phenanthrolyl Ru(II) complexes

    Indian Academy of Sciences (India)

    Adewale O Adeloye; Peter A Ajibade; Frances R Cummings; Lukas J Le Roux; Sampson N Mamphweli; Edson L Meyer

    2013-01-01

    Four new amphiphilic ligands: 4-(2,3-dimethylacrylic acid)-2,2'-bipyridine (L1), 4-(9-anthracenyl-10-(2,3-dimethylacrylic acid)-2,2'-bipyridine (L2), 5-(2,3-dimethylacrylic acid)-1,10-phenanthroline (L3) and 5-(9-anthracenyl-10-(2,3-dimethylacrylic acid)-1,10-phenanthroline (L4), with their corresponding homonuclear ruthenium(II) complexes formulated as cis-[Ru-(L1)3(PF6)2] (C1), cis-[Ru-(L2)3(PF6)2] (C2), cis-[Ru-(L3)3(PF6)2] (C3) and cis-[Ru-(L4)3(PF6)2] (C4), have been synthesized and characterized by elemental analysis, 1H- and 13C- NMR, FT-IR, UV-Vis and photoluminescence spectroscopy. The complexes exhibit broad and intense metal-to-ligand charge transfer (MLCT) transition bands in the visible region (400-700 nm), and red light emitting properties at room temperature. By comparison however, complexes C1 and C2 bipyridine moiety gave lower molar absorptivity coefficient at relatively similar wavelength characteristics (410-520 nm) when compared to C3 and C4 with phenanthroline based molecules. Cyclic voltammograms of the complexes revealed complex C4 with most reduction potential which might be due to increase in the conjugation of the anthracene functionalized units. Preliminary investigation of the solar cell efficiency of the complexes on TiO2 nanocrystalline films gave the best result with efficiency of 0.103% for C1 under illumination at 1000 W/m2 AM 1.5. Electrochemical impedance spectroscopy (EIS) technique however, revealed the charge transfer resistances (Rct) of the electrons on the TiO2 semiconductor.

  19. Post-Synthetic Shaping of Porosity and Crystal Structure of Ln-Bipy-MOFs by Thermal Treatment

    Directory of Open Access Journals (Sweden)

    Philipp R. Matthes

    2015-07-01

    Full Text Available The reaction of anhydrous lanthanide chlorides together with 4,4′-bipyridine yields the MOFs 2∞[Ln2Cl6(bipy3]·2bipy, with Ln = Pr − Yb, bipy = 4,4′-bipyridine, and 3∞[La2Cl6(bipy5]·4bipy. Post-synthetic thermal treatment in combination with different vacuum conditions was successfully used to shape the porosity of the MOFs. In addition to the MOFs microporosity, a tuneable mesoporosity can be implemented depending on the treatment conditions as a surface morphological modification. Furthermore, thermal treatment without vacuum results in several identifiable crystalline high-temperature phases. Instead of collapse of the frameworks upon heating, further aggregation under release of bipy is observed. 3∞[LaCl3(bipy] and 2∞[Ln3Cl9(bipy3], with Ln = La, Pr, Sm, and 1∞[Ho2Cl6(bipy2] were identified and characterized, which can also exhibit luminescence. Besides being released upon heating, the linker 4,4′-bipyridine can undergo activation of C-C bonding in ortho-position leading to the in-situ formation of 4,4′:2′,2′′:4′′,4′′′-quaterpyridine (qtpy. qtpy can thereby function as linker itself, as shown for the formation of the network 2∞[Gd2Cl6(qtpy2(bipy2]·bipy. Altogether, the manuscript elaborates the influence of thermal treatment beyond the usual activation procedures reported for MOFs.

  20. Structural archetypes in nickel(II) hybrid vanadates. Towards a directed hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Luis, R. Fernandez de; Urtiaga, M.K. [Dpto. Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); Mesa, J.L.; Rojo, T. [Dpto. Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); Arriortua, M.I. [Dpto. Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/UPV/EHU, Apdo. 644, 48080 Bilbao (Spain)], E-mail: maribel.arriortua@ehu.es

    2009-07-01

    In the present work, we relate the modifications of the initial synthesis parameters (pH value, stoichiometry and concentration) with the different structural archetypes obtained in the {l_brace}Ni/Bpy/VO{r_brace} and {l_brace}Ni/Bpe/VO{r_brace} systems (4,4'-bipyridine (Bpy), 1,2-di(4-pyridyl) ethylene (Bpe)). The vanadium coordination is partially controlled by the hydrothermal synthesis conditions, and the final crystal structures depend on the synergetic interaction between the metal-organic subnets and the vanadium oxide subunits.

  1. Poly[[bis­(μ-4,4′-bipyridyl-κ2 N:N′)bis­(thio­cyanato-κN)manganese(II)] diethyl ether disolvate

    OpenAIRE

    Mario Wriedt; Inke Jess; Christian Näther

    2010-01-01

    In the title compound, {[Mn(NCS)2(C10H8N2)2]·2C4H10O}n, the MnII ion is coordinated by four N-bonded 4,4′-bipyridine (bipy) ligands and two N-bonded thiocyanate anions in a distorted octahedral coordination geometry. The asymmetric unit consists of one MnII ion and two bipy ligands each located on a twofold rotation axis, as well as one thiocyanate anion and one diethyl ether molecule in general positions. In the crystal structure, the metal centers with terminally bonded t...

  2. Synthesis and Crystal Structure of a New Manganese Complex

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; LIU Ping; CHEN Yun

    2003-01-01

    @@ In order to study the relationship between the manganese ion and the biological coordination agent, the role ofmanganese ion in the active sites and the structure of the active sites in the manganese enzymes, small molecule complexes are often applied to modeling the structure and the properties of reaction in the active centers. In this pa per, we will report the synthesis and crystal structure of a new manganese(Ⅱ) complex, catena[ aqua-(p-methoxybenzoato- O, O′ ) - (p-methoxybenzoato- O )- (2,2′-bipyridine)-manganese (Ⅱ) ] (p-methoxybenzoic acid). The crystal structure was confirmeded by X-ray crystallography analysis.

  3. Nickel-Catalyzed Carbon–Carbon Bond-Forming Reactions of Unactivated Tertiary Alkyl Halides: Suzuki Arylations

    OpenAIRE

    Zultanski, Susan L.; Fu, Gregory C.

    2013-01-01

    The first Suzuki cross-couplings of unactivated tertiary alkyl electrophiles are described. The method employs a readily accessible catalyst (NiBr[subscript 2]·diglyme/4,4′-di-tert-butyl-2,2′-bipyridine, both commercially available) and represents the initial example of the use of a group 10 catalyst to cross-couple unactivated tertiary electrophiles to form C–C bonds. This approach to the synthesis of all-carbon quaternary carbon centers does not suffer from isomerization of the alkyl group,...

  4. Synthesis, Spectral study of Ni (II) and CU (II) metal ions with Heterocyclic Ligands

    OpenAIRE

    Sachin R Joshi; Seema I. Habib

    2014-01-01

    Four Complexes of Cu (II) and Ni (II) Schiff bases have been prepared. The Schiff bases are derived by the reaction of Salisylaldoxime primary ligand with heterocyclic compounds such as 2-aminopyridine (S-L2), 2-2- bipyridine (S-L4) to form the secondary ligand, which than react with the metal halides to form corresponding complexes. The elemental analysis data shows that the metal to ligand ratio in all Ni(II) and Cu(II) simple complexes are 1:2 while for mixed ligand complexes having ratio ...

  5. Microwave synthesis of mixed ligand diimine–thiosemicarbazone complexes of ruthenium(ii): biophysical reactivity and cytotoxicity†

    OpenAIRE

    Beckford, Floyd A.; Shaloski, Michael; LeBlanc, Gabriel; Thessing, Jeffrey; Lewis-Alleyne, Lesley C.; Holder, Alvin A.; LI, LIYA; Seeram, Navindra P.

    2009-01-01

    A novel microwave-assisted synthetic method has been used to synthesise a series of mixed ligand ruthenium(ii) compounds containing diimine as well as bidentate thiosemicarbazone ligands. The compounds contain the diimine 1,10-phenanthroline (phen) or 2,2′-bipyridine (bpy) and the thiosemicarbazone is derived from 9-anthraldehyde. Based on elemental analyses and spectroscopic data, the compounds are best formulated as [(phen)2Ru(thiosemicarbazone)](PF6)2 and [(phen)2Ru(thiosemicarbazone)](PF6...

  6. Comparison of physical and photophysical properties of monometallic and bimetallic ruthenium(II) complexes containing structurally altered diimine ligands

    Energy Technology Data Exchange (ETDEWEB)

    Macatangay, A.; Jackman, D.C.; Merkert, J.W. [Univ. of North Carolina, Charlotte, NC (United States)] [and others

    1996-11-06

    The physical and photophysical properties of a series of monometallic, [Ru(bpy){sub 2}(dmb)]{sup 2+}, [Ru(bpy){sub 2}(BPY)]{sup 2+}, [Ru(bpy)(Obpy)]{sup 2+} and [Ru(bpy){sub 2}(Obpy)] {sup 2+}, and bimetallic, [(Ru(bpy){sub 2}){sub 2}(BPY)]{sup 4+} and [(Ru(bpy){sub 2}){sub 2}(Obpy)]{sup 4+}, complexes are examined, where bpy is 2,2{prime}-bipyridine, dmb is 4,4{prime}-dimethyl-2,2{prime}-bipyridine, BPY is 1,2-bis(4-methyl-2,2{prime}-bipyridin-4{prime}-yl)ethane, and Obpy is 1,2-bis(2,2{prime}-bipyridin-6-yl)ethane. The complexes display metal-to-ligand charge transfer transitions in the 450 nmn region, intraligand {pi}{yields}{pi}* transitions at energies greater than 300 nm, a reversible oxidation of the ruthenium(II) center in the 1.25-1.40 V vs SSCE region, a series of three reductions associated with each coordinated ligand commencing at {minus}1.3 V and ending at {approximately}{minus}1.9 V, and emission from a {sup 3}MLCT state having energy maxima between 598 and 610 nm. The Ru{sup III}/Ru{sup II} oxidation of the two bimetallic complexes is a single, two one-electron process. Relative to [Ru(bpy){sub 2}(BPY)]{sup 2+}, the Ru{sup III}/Ru{sup II} potential for [Ru-(bpy){sub 2}(Obpy)]{sup 2+} increases from 1.24 to 1.35 V, the room temperature emission lifetime decreases from 740 to 3ns, and the emission quantum yield decreases from 0.078 to 0.000 23. Similarly, relative to [(Ru(bpy){sub 2}){sub 2}(BPY)]{sup 4+}, the Ru{sup III}/Ru{sup II} potential for [(Ru(bpy){sub 2}){sub 2}(Obpy)]{sup 4+} increases from 1.28 to 1.32 V, the room temperature emission lifetime decreases from 770 to 3 ns, and the room temperature emission quantum yield decreases from 0.079 to 0.000 26.

  7. Cationic zinc (II) dimers and one dimensional coordination polymer from ionic carboxylic acid

    Indian Academy of Sciences (India)

    Paladugu Suresh; Ganesan Prabusankar

    2014-09-01

    A rare example of chelating two tetra cationic paddle-wheel zinc dimers were synthesized from the reaction between flexible imidazolium carboxylate (LH2Br2) and corresponding zinc precursors. A zinc coordination polymer was synthesised by treating in situ generation of 2 in the presence of 4,4′-bipyridine. These new molecules, dimers and polymer, were characterized by FT-IR, NMR, UV-vis, fluorescent and single crystal X-ray diffraction techniques. Zinc polymer is the first example of 1D coordination polymer constructed by tetra cationic zinc dimer as a secondary building unit in coordination polymer.

  8. Cobalt (Ⅱ) Complexes of Dibenzoylmethane (Hdbm): Crystal Structures and Axial Metathetical Reaction of the Complexes with Pyridine or its Derivatives%钴的二苯甲酰甲烷配合物:晶体结构及其轴向置换反应

    Institute of Scientific and Technical Information of China (English)

    卢会杰; 高洁; 杜晨霞; 樊耀亭; 侯红卫; 丁德刚; 翟俊玲

    2003-01-01

    Cobalt (Ⅱ) can form complexes with Hdbm in different environments. Hdbm reacted with cobalt nitrate to give complex 1 [Co(dbm)2 @ 2H2O]. When complex 1 reacted with pyridine, α-stilbazole or 4, 4'-bipyridine respectively, complex 2 [Co(DBM)2Py2] (Py= pyridine), 3 [Co(DBM)2Sbz2] (Sbz =α-stilbazole) or 4 [Co(DBM)2BPy] n was obtained in turn through metathetical reaction. The coordination modes are octahedral polyhedrons. In the crystal structures, the two dbms take the plane position and two other donor molecules take the axial position. CCDC: 196070 for complex 2; 186859 for complex 3.

  9. Linear homobimetallic 4-thioacetyl-substituted NCN pincer palladium(II) and platinum(II) complexes with N-bidentate connecting units (NCN = [C6H2(CH2NMe2)2-2,6-R-4]−)

    NARCIS (Netherlands)

    Döring, K.; Taher, D.; Walfort, B.; Lutz, M.; Spek, A.L.; van Klink, G.P.M.; van Koten, G.; Lang, H.

    2008-01-01

    The synthesis and characterization of homobimetallic palladium and platinum complexes of type [(Me(O)CS-4-NCN–M ← N∩N → M–NCN-4-SC(O)Me](OTf)2 (Me(O)CS-4-NCN = [C6H2(CH2NMe2)2-2,6-SC(O)Me-4]−; N∩N = 4,4′-bipyridine (bipy); M = Pd, 12; M = Pt, 13) is reported. The required bifunctional thio-acetyl NC

  10. Luminescence quenching of Ru(phen)$^{2+}_{3}$ by some polymer-cobalt(III) complexes - Effect of micelles and DNA

    Indian Academy of Sciences (India)

    R Senthil Kumar; K Sasikala; S Arunachalam

    2007-05-01

    Studies on the luminescence quenching of Ru(phen)$^{2+}_{3}$ (phen = 1,10-phenanthroline) by the polymer-cobalt(III) complex ions, cis-[Co(phen)2(BPEI)Cl]2+ and cis-[Co(bpy)2(BPEI)Cl]2+ (bpy = 2,2'-bipyridine, BPEI = branched polyethyleneimine) in DNA as well as in various micellar media by steadystate emission spectroscopic technique have been reported. The quenching rate constants were arrived through Stern-Volmer equation. The results have been analysed based on hydrophobic as well as electrostatic binding between polymer-cobalt(III) complexes and DNA/micelles.

  11. Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting

    Directory of Open Access Journals (Sweden)

    Christian Benkhäuser

    2015-05-01

    Full Text Available A Tröger's base-derived racemic bis(1,10-phenanthroline ligand (rac-1 and a bis(2,2'-bipyridine ligand with a central 1,3-diethynylbenzene unit 2 were synthesized. Each of these ligands acts as a multivalent entity for the binding of two copper(I ions. Upon coordination to the metal ions these two ligands undergo selective self-assembly into heteroleptic dinuclear metallosupramolecular kites in a high-fidelity social self-sorting manner as evidenced by NMR spectroscopy and mass spectrometry.

  12. A Heteroleptic Ferrous Complex with Mesoionic Bis(1,2,3-triazol-5-ylidene) Ligands: Taming the MLCT Excited State of Iron(II)

    DEFF Research Database (Denmark)

    Liu, Yizhu; Kjær, Kasper Skov; Fredin, Lisa A.;

    2015-01-01

    Strongly sigma-donating N-heterocyclic carbenes (NHCs) have revived research interest in the catalytic chemistry of iron, and are now also starting to bring the photochemistry and photophysics of this abundant element into a new era. In this work, a heteroleptic Fe-II complex (1) was synthesized...... based on sequentially furnishing the Fe-II center with the benchmark 2,2-bipyridine (bpy) ligand and the more strongly sigma-donating mesoionic ligand, 4,4-bis(1,2,3-triazol-5-ylidene) (btz). Complex1 was comprehensively characterized by electrochemistry, static and ultrafast spectroscopy, and quantum...

  13. Synthesis of asymmetric supramolecular compounds using a Ni(0) catalysed homo-coupling approach

    OpenAIRE

    Cassidy, Lynda; Horn, Sabine; Cleary, Laura; Halpin, Yvonne; Browne, Wesley R.; Vos, Johannes G.

    2009-01-01

    The synthesis and characterisation of a series of dinuclear ruthenium and osmium polypyridyl metal complexes based on the bridging ligands [5-(5'-bipyridin-2',2 ''-yl)-3-(pyridin-2-yl)]-1,2,4-triazole (Hpytr-bipy), 2,2 ''-bis(pyridin-2 '' yl)-5,5 ''-bis(pyridin-3 ''-yl) (bipy-bipy) and 5,5'-bis(pyridin-2 ''-yl)-3,3'-bis(1,2,4-triazole) (Hpytr-Hpytr) are reported. The dinuclear complexes have been synthesised via a Ni(0) catalysed cross-coupling reaction from brominated precursors. With this a...

  14. Synthesis, characterization and DNA-binding studies of ruthenium(II) mixed-ligand complexes containing dipyrido[1,2,5]oxadiazolo[3,4-b]quinoxaline

    Science.gov (United States)

    Peng, Bin; Chen, Xiang; Du, Ke-Jie; Yu, Bo-Le; Chao, Hui; Ji, Liang-Nian

    2009-11-01

    A novel ligand dipyrido[1,2,5]oxadiazolo[3,4-b]quinoxaline (dpoq) and its complexes [Ru(bpy) 2(dpoq)] 2+ and [Ru(phen) 2(dpoq)] 2+ (bpy = 2,2'-bipyridine; phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, electrospray mass spectra and 1H NMR. The interaction of Ru(II) complexes with calf thymus DNA (CT-DNA) was investigated by absorption spectroscopy, fluorescence spectroscopy, thermal denaturation and viscosity measurements. Results suggest that two Ru(II) complexes bind to DNA via an intercalative mode.

  15. 4,4′-Bipyridine–3-(thiophen-3-ylacrylic acid (1/2

    Directory of Open Access Journals (Sweden)

    Malaichamy Sathiyendiran

    2011-10-01

    Full Text Available In the title 1/2 adduct, C10H8N2·2C7H6O2S, the dihedral angle between the pyridine rings is 18.41 (11°. In the thiopheneacrylic acid molecules, the dihedral angles between the respective thiophene and acrylic acid units are 5.52 (17° and 23.92 (9°. In the crystal, the components are linked via O—H...N hydrogen-bonding interactions, forming units of two 3-thiopheneacrylic acid molecules and one 4,4′-bipyridine molecule.

  16. Two Zn(II) coordination complexes assembled by trithiocyanuric acid and two different N-donor auxiliary ligands.

    Science.gov (United States)

    He, Xiao Xiao; Guo, Ya Mei

    2014-08-01

    The dipyridyl-type building blocks 4-amino-3,5-bis(pyridin-3-yl)-1,2,4-triazole (3-bpt) and 4,4'-bipyridine (bpy) have been used to assemble with Zn(II) in the presence of trithiocyanuric acid (ttcH3) to afford two coordination compounds, namely bis[4-amino-3,5-bis(pyridin-3-yl)-1,2,4-triazole-κN(3)]bis(trithiocyanurato-κ(2)N,S)zinc(II), [Zn(C3H2N3S3)2(C12H10N6)2]·2H2O, (1), and catena-poly[[[bis(trithiocyanurato-κ(2)N,S)zinc(II)]-μ-4,4'-bipyridine-κ(2)N:N'] 4,4'-bipyridine monosolvate], {[Zn2(C3H2N3S3)4(C10H8N2)3]·C10H8N2}n, (2). Single-crystal X-ray analysis indicates that complex (1) is a mononuclear structure, while complex (2) presents a one-dimensional chain coordination motif. In both complexes, the central Zn(II) cation adopts an octahedral geometry, coordinated by four N- and two S-donor atoms. Notably, trithiocyanurate (ttcH2(-)) adopts the same bidentate chelating coordination mode in each complex and exists in the thione tautomeric form. The 3-bpt co-ligand in (1) adopts a monodentate coordination mode and serves as a terminal pendant ligand, whereas the 4,4'-bipyridine (bpy) ligand in (2) adopts a bidentate-bridging coordination mode. The different coordination characters of the different N-donor auxiliary ligands lead to structural diversity for complexes (1) and (2). Further analysis indicates that the resultant three-dimensional supramolecular networks for (1) and (2) arise through intermolecular N-H...S and N-H...N hydrogen bonds. Both complexes have been further characterized by FT-IR spectroscopy and elemental analyses.

  17. Epoxidation of Alkenes with Molecular Oxygen Catalyzed by Immobilized Co(acac)2 and Co(bpy)2Cl2 Complexes within Nanoreactors of Al-MCM-41

    OpenAIRE

    Farzaneh, F; Jalalian, M; Tayebi, L.

    2012-01-01

    Cobalt complexes with different ligands such as bipyridine, and acetylacetonate were immobilized within nanoreactors of Al-MCM-41, designated as Co(acac)2/Al-MCM-41 and Co(bipy)22+/Al-MCM41. The immobilized complexes were characterized by XRD, N2-adsorption desorption, FT-IR and UV-Vis techniques. It was found that Co(bipy)22+/Al-MCM41 and Co(acac)2/Al-MCM-41 successfully catalyze the oxidation of norbornene, styrene, cis-stilbene, trans-stilbene, and cyclohexene with 68% to 100% conversion a...

  18. The azido ligand: a useful tool in designing chain compounds exhibiting alternating ferro- and antiferro-magnetic interactions

    OpenAIRE

    Viau, Guillaume; Lombardi, Maria Grazia; De Munno, Giovanni; Julve Olcina, Miguel; Lloret Pastor, Francisco; Faus, Juan; Caneschi, Andrea; Clemente Juan, Juan Modesto

    1997-01-01

    A one-pot reaction of NiII 1, CoII 2, FeII 3 and MnII 4 with 2,2A-bipyridine (bipy) and azide in water leads to [M(bipy)(N3)2]n chains where the metal ion is alternatively bridged by double end-on (EO) and end-to-end (EE) azido bridges; theoretical analysis of the variable-temperature magnetic susceptibility data of 1 and 4 reveals the occurrence of intrachain alternating ferro- (through EO) and antiferro-magnetic (through EE) interactions. Julve Olcina, Miguel, ; Lloret...

  19. Crossbar nanoarchitectonics of the crosslinked self-assembled monolayer

    OpenAIRE

    Hamoudi, Hicham

    2014-01-01

    A bottom-up approach was devised to build a crossbar device using the crosslinked SAM of the 5,5′-bis (mercaptomethyl)-2,2′-bipyridine-Ni2+ (BPD- Ni2+) on a gold surface. To avoid metal diffusion through the organic film, the author used (i) nanoscale bottom electrodes to reduce the probability of defects on the bottom electrodes and (ii) molecular crosslinked technology to avoid metal diffusion through the SAMs. The properties of the crosslinked self-assembled monolayer were determined by XP...

  20. Multifunctional sensing ability of a new Pt/Zn-based luminescent coordination polymer

    OpenAIRE

    Kobayashi, Atsushi; Hara, Hirofumi; Noro, Shin-ichiro; Kato, Masako

    2010-01-01

    We synthesized a new Pt/Zn-based coordination polymer, {Zn[Pt(CN)2(5,5'-dcbpy)]・4H2O}n, (5,5'-H2dcbpy = 5,5'-dicarboxy-2,2'-bipyridine), which exhibits reversible colour changes in response to temperature change or exposure to chemical vapours and liquids. Such chromic behaviour shows promise for sensing not only changes in temperature but also for detecting chemical solvents and vapours. The single crystal X-ray structure indicates that one-dimensional coordination polymeric chains formed by...

  1. Substitution of Carbazole Modified Fluorenes as π-Extension in Ru(II Complex-Influence on Performance of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Malapaka Chandrasekharam

    2011-01-01

    Full Text Available A new high molar extinction coefficient ruthenium(II bipyridyl complex “cis-Ru(4,4-bis(9,9-dibutyl-7-(3,6-di-tert-butyl-9H-carbazol-9-yl-9H-fluoren-2-yl-2,2-bipyridine(2,2-bipyridine-4,4-dicarboxylic acid(NCS2, BPFC” has been synthesized and characterized by FT-IR, 1H-NMR, and ESI-MASS spectroscopes. The sensitizer showed molar extinction coefficient of 18.5×103 M−1cm−1, larger as compared to the reference N719, which showed 14.4×103 M−1cm−1. The test cells fabricated using BPFC sensitizer employing high performance volatile electrolyte, (E01 containing 0.05 M I2, 0.1 M LiI, 0.6 M 1,2-dimethyl-3-n-propylimidazolium iodide, 0.5 M 4-tert-butylpyridine in acetonitrile solvent, exhibited solar-to-electric energy conversion efficiency (η of 4.65% (short-circuit current density (SC = 11.52 mA/cm2, open-circuit voltage (OC = 566 mV, fill factor = 0.72 under Air Mass 1.5 sunlight, lower as compared to the reference N719 sensitized solar cell, fabricated under similar conditions, which exhibited η-value of 6.5% (SC = 14.3 mA/cm2, OC = 640 mV, fill factor = 0.71. UV-Vis measurements conducted on TiO2 films showed decreased film absorption ratios for BPFC as compared to those of reference N719. Staining TiO2 electrodes immediately after sonication of dye solutions enhanced film absorption ratios of BPFC relative to those of N719. Time-dependent density functional theory (TD-DFT calculations show higher oscillation strengths for 4,4-bis(9,9-dibutyl-7-(3,6-di-tert-butyl-9H-carbazol-9-yl-9H-fluoren-2-yl-2,2-bipyridine relative to 2,2-bipyridine-4,4-dicarboxylic acid and increased spectral response for the corresponding BPFC complex.

  2. Single-Molecule Electrochemical Transistor Utilizing a Nickel-Pyridyl Spinterface

    OpenAIRE

    Brooke, Richard J.; Jin, Chengjun; Szumski, Douglas S; Nichols, Richard J; Mao, Bing-Wei; Thygesen, Kristian S.; Schwarzacher, Walther

    2015-01-01

    Using a scanning tunnelling microscope break-junction technique, we produce 4,4′-bipyridine (44BP) single-molecule junctions with Ni and Au contacts. Electrochemical control is used to prevent Ni oxidation and to modulate the conductance of the devices via nonredox gating—the first time this has been shown using non-Au contacts. Remarkably the conductance and gain of the resulting Ni-44BP-Ni electrochemical transistors is significantly higher than analogous Au-based devices. Ab-initio calcula...

  3. Metal ion controlled self-assembly of a chemically reengineered protein drug studied by small-angle X-ray scattering

    DEFF Research Database (Denmark)

    Jesper, Nygaard; Munch, Henrik K.; Thulstrup, Peter W.;

    2012-01-01

    Precise control of the oligomeric state of proteins is of central importance for biological function and for the properties of biopharmaceutical drugs. Here, the self-assembly of 2,2′-bipyridine conjugated monomeric insulin analogues, induced through coordination to divalent metal ions, was studied....... This protein drug system was designed to form non-native homo-oligomers through selective coordination of two divalent metal ions, Fe(II) and Zn(II), respectively. The insulin type chosen for this study is a variant designed for a reduced tendency toward native dimer formation at physiological concentrations...

  4. 4,4′-Bipyridine–4-(p-toluene­sulfonamido)­benzoic acid (1/2)

    Science.gov (United States)

    Huang, Miao-Ling

    2011-01-01

    In the title compound, C14H13NO4S·0.5C10H8N2, the two benzene rings are nearly perpendicular to each other [dihedral angle = 83.21 (10)°]. The bipyridine mol­ecule is centrosymmetric, the mid-point of the C—C bond linking the pyridine rings being located on an inversion center. Inter­molecular N—H⋯O and O—H⋯N hydrogen bonds and weak inter­molecular C—H⋯O hydrogen bonds are present in the crystal structure. PMID:22059045

  5. 4,4′-Bipyridine–4-(p-toluene­sulfonamido)­benzoic acid (1/2)

    OpenAIRE

    Huang, Miao-Ling

    2011-01-01

    In the title compound, C14H13NO4S·0.5C10H8N2, the two benzene rings are nearly perpendicular to each other [dihedral angle = 83.21 (10)°]. The bipyridine mol­ecule is centrosymmetric, the mid-point of the C—C bond linking the pyridine rings being located on an inversion center. Inter­molecular N—H⋯O and O—H⋯N hydrogen bonds and weak inter­molecular C—H⋯O hydrogen bonds are present in the crystal structure.

  6. Sensitization of n-type Ti O{sub 2} electrode by a novel isoquinoline ruthenium (II) poly pyridyl complex

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Christian Graziani; Iha, Neyde Yukie Murakami [Sao Paulo Univ., SP (Brazil). Inst. de Quimica; Argazzi, Roberto; Bignozzi, Carlo Alberto [Ferrara Univ. (Italy). Dipt. di Chimica

    1998-02-01

    The effective sensitization of Ti O{sub 2} to visible light by cis-[(dcbH{sub 2})2 Ru (isq)2](Cl O{sub 4}){sub 2}, where dcb H{sub 2} = 4,4'-(C O{sub 2}H){sub 2}-2,2'- bipyridine and isq = isoquinoline, is reported. The photocurrent action spectrum obtained for the regenerative cell with dye coated nanocrystalline Ti O{sub 2} films resulted in IPCE values up to 40%. This novel compound acts as an efficient Ti O{sub 2} photoanode sensitizer in thin-layer sandwich solar cells. (author)

  7. Dielectric and magnetic anisotropy of a nematic ytterbium complex

    International Nuclear Information System (INIS)

    The sign and the magnitude of the dielectric anisotropy of an ytterbium-based paramagnetic nematic liquid crystal complex, namely, tris[1-(4-(4-propylcyclohexyl)phenyl)octane-1,3-dione]-[5,5'-di (heptadecile)-2,2'-bipyridine]ytterbium, are determined. The temperature dependence of the permittivity components of the complex is obtained in the temperature range of a nematic phase. The sign of the anisotropy of the magnetic susceptibility of this compound is experimentally determined

  8. Dielectric and magnetic anisotropy of a nematic ytterbium complex

    Energy Technology Data Exchange (ETDEWEB)

    Dobrun, L. A., E-mail: l.dobrun@spbu.ru; Sakhatskii, A. S.; Kovshik, A. P.; Ryumtsev, E. I.; Kolomiets, I. P. [St. Petersburg State University (Russian Federation); Knyazev, A. A.; Galyametdinov, Yu. G. [Kazan National Research Technological University (Russian Federation)

    2015-05-15

    The sign and the magnitude of the dielectric anisotropy of an ytterbium-based paramagnetic nematic liquid crystal complex, namely, tris[1-(4-(4-propylcyclohexyl)phenyl)octane-1,3-dione]-[5,5'-di (heptadecile)-2,2'-bipyridine]ytterbium, are determined. The temperature dependence of the permittivity components of the complex is obtained in the temperature range of a nematic phase. The sign of the anisotropy of the magnetic susceptibility of this compound is experimentally determined.

  9. Electron Transfer Mediators for Photoelectrochemical Cells Based on Cu(I Metal Complexes

    Directory of Open Access Journals (Sweden)

    Michele Brugnati

    2007-01-01

    Full Text Available The preparation and the photoelectrochemical characterization of a series of bipyridine and pyridyl-quinoline Cu(I complexes, used as electron transfer mediators in regenerative photoelectrochemical cells, are reported. The best performing mediators produced maximum IPCEs of the order of 35–40%. The J-V curves recorded under monochromatic light showed that the selected Cu(I/(II couples generated higher Vocs and fill factors compared to an equivalent I-/I3- cell, due to a decreased dark current.

  10. Light induced electron transfer reactions of metal complexes

    International Nuclear Information System (INIS)

    Properties of the excited states of tris(2,2'-bipyridine) and tris(1,10-phenanthroline) complexes of chromium(III), iron(II), ruthenium(II), osmium(II), rhodium(III), and iridium(III) are described. The electron transfer reactions of the ground and excited states are discussed and interpreted in terms of the driving force for the reaction and the distortions of the excited states relative to the corresponding ground states. General considerations relevant to the conversion of light into chemical energy are presented and progress in the use of polypyridine complexes to effect the light decomposition of water into hydrogen and oxygen is reviewed

  11. Synthesis and Preliminary Characterization of a PPE-Type Polymer Containing Substituted Fullerenes and Transition Metal Ligation Sites

    Directory of Open Access Journals (Sweden)

    Corinne A. Basinger

    2015-01-01

    Full Text Available A substituted fullerene was incorporated into a PPE-conjugated polymer repeat unit. This subunit was then polymerized via Sonogashira coupling with other repeat units to create polymeric systems approaching 50 repeat units (based on GPC characterization. Bipyridine ligands were incorporated into some of these repeat units to provide sites for transition metal coordination. Photophysical characterization of the absorption and emission properties of these systems shows excited states located on both the fullerene and aromatic backbone of the polymers that exist in a thermally controlled equilibrium. Future work will explore other substituted polyaromatic systems using similar methodologies.

  12. Ferrocene and cobaltocene derivatives for non-aqueous redox flow batteries.

    Science.gov (United States)

    Hwang, Byunghyun; Park, Min-Sik; Kim, Ketack

    2015-01-01

    Ferrocene and cobaltocene and their derivatives are studied as new redox materials for redox flow cells. Their high reaction rates and moderate solubility are attractive properties for their use as active materials. The cyclability experiments are carried out in a static cell; the results showed that these materials exhibit stable capacity retention and predictable discharge potentials, which agree with the potential values from the cyclic voltammograms. The diffusion coefficients of these materials are 2 to 7 times higher than those of other non-aqueous materials such as vanadium acetylacetonate, iron tris(2,2'-bipyridine) complexes, and an organic benzene derivative. PMID:25428116

  13. Accessibility studies of ionic and non-ionic fluorophores embedded in sol-gel materials and new functionalised polyhedral silsesquioxanes

    OpenAIRE

    Ruiz Abad, David

    2009-01-01

    The knowledge about the diffusion of products and educts into and out of porous materials is of high importance for the development of new porous sol-gel processed hybrid catalysts. Therefore the accessibility of active centers embedded in sol-gel materials was studied by luminescence spectroscopy. Modified tris(2,2’- bipyridine)ruthenium(II) and pyrenemethanol were co-condensed with tetramethoxysilane (TMOS) in a buffer system. The buffer enforces the pH to remain constant during the sol-gel...

  14. Star polymers by ATRP of styrene and acrylates employing multifunctional initiators

    DEFF Research Database (Denmark)

    Jankova, Katja Atanassova; Bednarek, Melania; Hvilsted, Søren

    2005-01-01

    Multifunctional initiators for atom transfer radical polymerization (ATRP) are prepared by converting ditrimethylolpropane with four hydroxyl groups, dipentaerythritol with six hydroxyl groups, and poly(3-ethyl-3-hydroxymethyl-oxetane) with similar to 11 hydroxyl groups to the corresponding 2......-bromoisobutyrates or 2-bromopropionates as obtained by reaction with acid bromides. Star polystyrene (PS) is produced by using these macroinitiators and neat styrene in a controlled manner by ATRP at 110 degrees C, employing the catalytic system CuBr and bipyridine. M. up to 51,000 associated with narrow molecular...

  15. Iron and zinc availability in maize lines

    OpenAIRE

    Valéria Aparecida Vieira Queiroz; Paulo Evaristo de Oliveira Guimarães; Luciano Rodrigues Queiroz; Estefânia de Oliveira Guedes; Vanessa Diniz Barcelos Vasconcelos; Lauro José Guimarães; Paulo Eduardo de Aquino Ribeiro; Robert Eugene Schaffert

    2011-01-01

    The aim of this study was to characterize the Zn and Fe availability by phytic acid/Zn and phytic acid/Fe molar ratios, in 22 tropical maize inbred lines with different genetic backgrounds. The Zn and Fe levels were determined by atomic absorption spectrophotometry and the P through colorimetry method. Three screening methods for phytic acid (Phy) analysis were tested and one, based on the 2,2'-bipyridine reaction, was select. There was significant variability in the contents of zinc (17.5 to...

  16. Single-Molecule Electrochemical Transistor Utilizing a Nickel-Pyridyl Spinterface

    DEFF Research Database (Denmark)

    Brooke, Richard J.; Jin, Chengjun; Szumski, Doug S.;

    2015-01-01

    Using a scanning tunnelling microscope break-junction technique, we produce 4,4′-bipyridine (44BP) single-molecule junctions with Ni and Au contacts. Electrochemical control is used to prevent Ni oxidation and to modulate the conductance of the devices via nonredox gating - the first time this has...... been shown using non-Au contacts. Remarkably the conductance and gain of the resulting Ni-44BP-Ni electrochemical transistors is significantly higher than analogous Au-based devices. Ab-initio calculations reveal that this behavior arises because charge transport is mediated by spin-polarized Ni d...

  17. POLYMER—SUPPORTED RHODIUM CATALYSTS FOR CARBONYLATION OF METHYL ACETATE TO ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    CHENDean; HUANGShizhuan; 等

    1993-01-01

    Two kinds of rhodium catalysts supported on cross-linked styrene-divinylbenzene copolymers containing bipyridine or o-phenylene diamine have been prepared and found to display high activity for methyl acetate carbonylation to form acetic anhydride,the activities are even higher than their homogeneous counterparts. XPS analysis was used to characterize the synthetic catalysts.The apparent activation parameters were determined to be Eα=73.3KJ/mol,ΔH≠=66.3KJ/mol,ΔS≠=-28.6eu.These parameters are very close to those in methanol carbonylation and imply to have analogous mechanism in both cases.

  18. Rectangular Coordination Polymer Nanoplates: Large-Scale, Rapid Synthesis and Their Application as a Fluorescent Sensing Platform for DNA Detection

    OpenAIRE

    Yingwei Zhang; Yonglan Luo; Jingqi Tian; Asiri, Abdullah M.; Al-Youbi, Abdulrahman O.; Xuping Sun

    2012-01-01

    In this paper, we report on the large-scale, rapid synthesis of uniform rectangular coordination polymer nanoplates (RCPNs) assembled from Cu(II) and 4,4'-bipyridine for the first time. We further demonstrate that such RCPNs can be used as a very effective fluorescent sensing platform for multiple DNA detection with a detection limit as low as 30 pM and a high selectivity down to single-base mismatch. The DNA detection is accomplished by the following two steps: (1) RCPN binds dye-labeled sin...

  19. Ferrocene and cobaltocene derivatives for non-aqueous redox flow batteries.

    Science.gov (United States)

    Hwang, Byunghyun; Park, Min-Sik; Kim, Ketack

    2015-01-01

    Ferrocene and cobaltocene and their derivatives are studied as new redox materials for redox flow cells. Their high reaction rates and moderate solubility are attractive properties for their use as active materials. The cyclability experiments are carried out in a static cell; the results showed that these materials exhibit stable capacity retention and predictable discharge potentials, which agree with the potential values from the cyclic voltammograms. The diffusion coefficients of these materials are 2 to 7 times higher than those of other non-aqueous materials such as vanadium acetylacetonate, iron tris(2,2'-bipyridine) complexes, and an organic benzene derivative.

  20. 4,4′-Bipyridine–4-(p-toluenesulfonamidobenzoic acid (1/2

    Directory of Open Access Journals (Sweden)

    Miao-Ling Huang

    2011-09-01

    Full Text Available In the title compound, C14H13NO4S·0.5C10H8N2, the two benzene rings are nearly perpendicular to each other [dihedral angle = 83.21 (10°]. The bipyridine molecule is centrosymmetric, the mid-point of the C—C bond linking the pyridine rings being located on an inversion center. Intermolecular N—H...O and O—H...N hydrogen bonds and weak intermolecular C—H...O hydrogen bonds are present in the crystal structure.

  1. Tuning the Solubility of Copper Complex in Atom Transfer Radical Self-Condensing Vinyl Polymerizations to Control Polymer Topology via One-Pot to the Synthesis of Hyperbranched Core Star Polymers

    OpenAIRE

    Zong-Cheng Chen; Chia-Ling Chiu; Chih-Feng Huang

    2014-01-01

    In this paper, we propose a simple one-pot methodology for proceeding from atom transfer reaction-induced conventional free radical polymerization (AT-FRP) to atom transfer self-condensing vinyl polymerization (AT-SCVP) through manipulation of the catalyst phase homogeneity (i.e., CuBr/2,2'-bipyridine (CuBr/Bpy)) in a mixture of styrene (St), 4-vinyl benzyl chloride (VBC), and ethyl 2-bromoisobutyrate. Tests of the solubilities of CuBr/Bpy and CuBr2/Bpy under various conditions revealed that ...

  2. Single Walled Carbon Nanohorns as Catalytic Counter Electrodes for Co(III)/(II) Electron Mediators in Dye Sensitized Cells.

    Science.gov (United States)

    Carli, Stefano; Casarin, Laura; Syrgiannis, Zois; Boaretto, Rita; Benazzi, Elisabetta; Caramori, Stefano; Prato, Maurizio; Bignozzi, Carlo Alberto

    2016-06-15

    The electrochemical properties of both pristine single walled carbon nanohorns (SWCNHS) and their chemically oxidized form (ox-SWCNHS) spray coated onto fluorine doped SnO2 (FTO) were investigated in the framework of the fabrication of cobalt based transparent dye sensitized solar cells (DSSCs). These new nanocarbon substrates, evaluated in conjunction with the Co(bpy)3(2+/3+) (bpy = 2,2'-bipyridine) redox mediator, are endowed with excellent electrocatalytic properties, ease of fabrication, and very promising stability and display a great potential for replacing the best noble metal and conductive polymer catalytic materials in the building of semitransparent counter electrodes in new generation photoelectrochemical devices. PMID:27227738

  3. Electron and proton transfer assemblies and new porous materials from nanometer-scale building blocks

    Science.gov (United States)

    Johnson, Stacy Ann

    Elegant examples of molecular engineering are found in nature that make our current small devices seem primitive. By using naturally occurring examples we can better imagine how to construct useful three dimensional nanoscaled devices. Electron and proton transfer composites were prepared using a multilayer film growth technique, in which single anionic sheets derived from inorganic solids are interleaved with cationic polyelectrolytes. This method allows for the growth of concentric monolayers of redox-active polymers on high-surface-area silica supports, and for vectorial electron transfer reactions through the layers of the "onion." Photoinduced charge separation has been observed in composites consisting of an inner polycationic layer of poly(styrene- co-N-vinylbenzyl-N'-methyl-4,4 '-bipyridine), and an outer polycationic layer of poly[Ru(bpy) 2(vbpy)]2+, vbpy = 4-vinyl-4'-methyl- 2,2'-bipyridine, bpy = 2,2' -bipyridine, which are separated by a thin inorganic sheet of Zr(HOPO 3)2·H2O. Following the logic of the proton transport mechanism found in biological membranes, a photosensitive proton pump was constructed using the same electrostatic adsorption technique. This composite was prepared with a polymeric form of a luminescent ruthenium complex, poly[Ru(bpy) 2(bpm)]2+, bpy = 2,2'-bipyridine bpm = 2,2'-bipyrimidine. The pH of a solution in which the composites were suspended changed reversibly when irradiated with visible light. A series of microporous polymer replicas were synthesized using inorganic templates. Zeolites were used as templates to prepare microporous polymer replicas with nanometer sized pore networks. Phenol-formaldehyde polymers were synthesized and cured within the channel networks of zeolites Y, beta, and L. Dissolution of the aluminosilicate framework in aqueous IHF yields an organic replica. The zeolite template exerts important topological effects on the structure and physical properties of the replica. A similar process is described

  4. Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free Electron Laser

    DEFF Research Database (Denmark)

    Lemke, Henrik T.; Bressler, Christian; Chen, Lin X.;

    2013-01-01

    X-ray free electron lasers (XFELs) deliver short (time-resolved studies. Here we show that, despite the inherent instabilities of current (SASE based) XFELs, they can be used for measuring high......-quality X-ray absorption data and we report femtosecond time-resolved X-ray absorption near-edge spectroscopy (XANES) measurements of a spin-crossover system, iron(II) tris(2,2'-bipyridine) in water. The data indicate that the low-spin to high-spin transition can be modeled by single-exponential kinetics...

  5. Fluorinated Boronic Acid-Appended Bipyridinium Salts for Diol Recognition and Discrimination via (19)F NMR Barcodes.

    Science.gov (United States)

    Axthelm, Jörg; Görls, Helmar; Schubert, Ulrich S; Schiller, Alexander

    2015-12-16

    Fluorinated boronic acid-appended benzyl bipyridinium salts, derived from 4,4'-, 3,4'-, and 3,3'-bipyridines, were synthesized and used to detect and differentiate diol-containing analytes at physiological conditions via (19)F NMR spectroscopy. An array of three water-soluble boronic acid receptors in combination with (19)F NMR spectroscopy discriminates nine diol-containing bioanalytes--catechol, dopamine, fructose, glucose, glucose-1-phosphate, glucose-6-phosphate, galactose, lactose, and sucrose--at low mM concentrations. Characteristic (19)F NMR fingerprints are interpreted as two-dimensional barcodes without the need of multivariate analysis techniques.

  6. Synthesis of new pyrrole–pyridine-based ligands using an in situ Suzuki coupling method

    Directory of Open Access Journals (Sweden)

    Matthias Böttger

    2012-07-01

    Full Text Available The compounds 6-(pyrrol-2-yl-2,2‘-bipyridine, 2-(pyrrol-2-yl-1,10-phenanthroline and 2-(2-(N-methylbenz[d,e]imidazole-6-(pyrrol-2-yl-pyridine were synthesized by using an in situ generated boronic acid for the Suzuki coupling. Crystals of the products could be grown and exhibited interesting structures by X-ray analysis, one of them showing a chain-like network with the adjacent molecules linked to each other via intermolecular N–H…N hydrogen bonds.

  7. Synthesis, Crystal Structure and Thermal Stability of a One-dimensional Chain Cobalt Coordination Polymer [ Co( 4,4 '-bipy)( 2,4,6- TMBA)2( CH3CH2OH)2]n

    Institute of Scientific and Technical Information of China (English)

    LI Wei; LI Chang-Hong; YANG Ying-Qun; CHEN Zhi-Min; KUANG Dai-Zhi; ZHANG Chun-Hua; KANG Yun-Fei

    2006-01-01

    A one-dimensional chain cobalt(Ⅱ) coordination polymer with 2,4,6-trimethylbenzoic acid, 4,4'-bipyridine and cobalt perchlorate anhydrous has been synthesized and characterized in the mixture solvent of water and alcohol. Crystal data for this complex: monoclinic, space group C2/c, a = 2.3805(8), b = 1.1464(4), c = 1.5807(5) nm, γ = 128.435(4)°, V= 3.3791(18) nm3,Dc = 1.246 g/cm3, Z = 4, F(000) = 1340, final GooF = 1.009, R = 0.0504 and wR = 0.1287.Structural analysis shows that the cobalt ion is coordinated with two nitrogen atoms of one 4,4'-bipyridine molecule and four oxygen atoms from two 2,4,6-trimethylbenzoic acid molecules and two alcohol molecules, giving a distorted octahedral coordination geometry. The result of TG analysis indicates that the title complex is stable till 200 ℃.

  8. Synthesis of New Ruthenium(Ⅱ)Bipyridyl Complexes and Studies on Their Photophysical and Photoelectrochemical Properties

    Institute of Scientific and Technical Information of China (English)

    宋林青; 刘普会; 王雪松; 侯原军; 张宝文; 曹怡; 李维盈; 张敬波; 肖绪瑞; 林原

    2003-01-01

    Two new mixed-ligand ruthenium(Ⅱ) complexes,Ru(dcbpy)-(LL)NCS)2[where dcbpy=4,4'-dicarboxyl-2,2''-bipyridine,LL=4,4'-bis(N-methyl-anilinomethyl)-2,2''-bipyridine(2)],were synthesized,and the tphotophysical properties of these complexes were studied.The metal-to-ligand charge transfer (MLCT) transitions of these complexes exhibited solvatochromic effect due to the existence of NCS ligands.The MLCT energies also strongly depend on the pH values of the solutions because of protonation and deprotonation of the carboxyl groups.The pKa values of the ground state,4.0 for 1 and 3.8 for 2,were obtained from the titration curves.The photoelectrochemical properties of 1 and 2 as sensitizers in sandwich-type solar cells have been studied.Complex 1 exhibited better photoelectrochemical behavior than complex 2 as expected.It was proved that the design of mixed-ligand complex by introducing electron donating group in one of the ligands should be a promising approach.

  9. The induction of apoptosis in HepG-2 cells by ruthenium(II) complexes through an intrinsic ROS-mediated mitochondrial dysfunction pathway.

    Science.gov (United States)

    Zeng, Chuan-Chuan; Lai, Shang-Hai; Yao, Jun-Hua; Zhang, Cheng; Yin, Hui; Li, Wei; Han, Bing-Jie; Liu, Yun-Jun

    2016-10-21

    Four new ruthenium(II) polypyridyl complexes [Ru(N-N)2(dhbn)](ClO4)2 (N-N = dmb: 4,4'-dimethyl-2,2'-bipyridine 1; bpy = 2,2'-bipyridine 2; phen = 1,10-phenanthroline 3; dmp = 2,9-dimethyl-1,10-phenanthroline 4) were synthesized and characterized. The cytotoxicity in vitro of the ligand and complexes toward HepG-2, HeLa, MG-63 and A549 were assayed by MTT method. The IC50 values of the complexes against the above cells range from 17.7 ± 1.1 to 45.1 ± 2.8 μM. The cytotoxic activity of the complexes against HepG-2 cells follows the order of 4 > 2 > 3 > 1. Ligand shows no cytotoxic activity against the selected cell lines. Cellular uptake, apoptosis, comet assay, reactive oxygen species, mitochondrial membrane potential, cell cycle arrest, and the expression of proteins involved in apoptosis pathway induced by the complexes were investigated. The results indicate that complexes 1-4 induce apoptosis in HepG-2 cells through an intrinsic ROS-mediated mitochondrial dysfunction pathway. PMID:27344489

  10. Development of redox-labeled electrochemical immunoassay for polycyclic aromatic hydrocarbons with controlled surface modification and catalytic voltammetric detection.

    Science.gov (United States)

    Wei, Ming-Yuan; Wen, Shou-Dong; Yang, Xi-Qiang; Guo, Liang-Hong

    2009-05-15

    A redox-labeled direct competitive electrochemical immunoassay for polycyclic aromatic hydrocarbons (PAHs) was developed. A ruthenium tris(bipyridine)-pyrenebutyric acid conjugate was synthesized as the redox-labeled tracer. Its recognition by an anti-PAH monoclonal antibody was confirmed by surface plasmon resonance. In the immunoassay, the antibody was immobilized on (3-glycidoxypropyl)-trimethoxysilane (GPTMS)-modified indium tin oxide (ITO) electrodes. The assay was quantified by measuring the electro-catalytic current of the redox label in an oxalate-containing electrolyte which served as a sacrificial electron donor to amplify the current signal. Formation of GPTMS film on ITO and subsequent antibody immobilization were characterized by X-ray photoelectron spectroscopy (XPS) and electrochemistry. Using a ruthenium tris(bipyridine)-conjugated IgG (IgG-Ru) as the surface-bound redox probe, the highest electrochemical signal was obtained on GPTMS electrodes with 1 h modification. Under the optimized conditions for ITO modification, antibody immobilization and tracer concentration, competition curves for benzo[a]pyrene and pyrenebutyric acid were obtained with a detection limit of 2.4 and 10 ng mL(-1), respectively. The redox-labeled electrochemical immunoassay with signal amplification mechanism offers a potential analytical method for the simultaneous detection of multiple environmental organic pollutants on antibody biochips. PMID:19321333

  11. Mixed ligand complex formation of FeIII with boric acid and typical N-donor multidentate ligands

    Indian Academy of Sciences (India)

    G N Mukherjee; Ansuman Das

    2002-06-01

    Equilibrium study of the mixed ligand complex formation of FeIII with boric acid in the absence and in the presence of 2,2'-bipyridine, 1,10-phenanthroline, diethylenetriamine and triethylenetetramine (L) in different molar ratios provides evidence of formation of Fe(OH)2+, Fe(OH)$^{+}_{2}$, Fe(L)3+, Fe(H2BO4), Fe(OH)(H2BO4)-, Fe(OH)2(H2BO4)2-, Fe(L)(H2BO4) and Fe2(L)2(BO4)+ complexes. Fe(L)$^{3+}_{2}$, Fe(L)2(H2BO4) and Fe2(L)4(BO4)+ complexes are also indicated with 2,2'-bipyridine and 1,10-phenanthroline. Complex formation equilibria and stability constants of the complexes at 25 ± 0 × 1° C in aqueous solution at a fixed ionic strength, = 0.1 mol -3 (NaNO3) have been determined by potentiometric method.

  12. The effect of ligand substituent on crystal packing: Structural and theoretical studies of two Ga(III) supramolecular compounds

    Science.gov (United States)

    Soleimannejad, Janet; Nazarnia, Esfandiar

    2016-07-01

    A new Ga(III) supramolecular compound (4,4‧-bipyH2)[Ga(hpydc)2]2·7H2O (2) (where H2hpydc = 4-hydroxy-pyridine-2,6-dicarboxylic acid and 4,4‧-bipy = 4,4‧-bipyridine) was synthesized using the proton transfer reaction. Compound 2 was structurally characterized using single crystal X-ray diffraction, and it was shown that its asymmetric unit consists of two independent anionic Ga(III) complexes, one fully protonated 4,4‧-bipyridine and seven uncoordinated water molecules. In order to understand the effect of pyridine OH substituent on supramolecular interactions and crystal packing, compound 2 was compared with (bipyH2)[Ga(pydc)2]·(H2pydc)·4H2O (1) (where H2pydc = pyridine-2,6-dicarboxylic acid), that does not have an OH group on the pyridine ligand. The Density Functional Theory (DFT) and Natural Bond Orbital (NBO) calculations and also Atoms in Molecules (AIM) analysis were used to analyze the non-covalent interactions in both complexes. The calculation of non-covalent interactions' energy provides a useful means to investigate their effects in the crystal packing.

  13. On the viability of cyclometalated Ru(II) complexes as dyes in DSSC regulated by COOH group, a DFT study.

    Science.gov (United States)

    Wang, Jian; Bai, Fu-Quan; Xia, Bao-Hui; Feng, Lu; Zhang, Hong-Xing; Pan, Qing-Jiang

    2011-02-14

    The Ru(II) complexes [Ru(bpp)(dcbpy)Cl](+) (1), [Ru(tcbpp)(bpy)Cl](+) (2), and [Ru(tc'bpp)(bpy)Cl](+) (3) (bpp = 2,6-bis(N-pyrazolyl)pyridine, dcbpy = 4,4'-dicarboxyl-bipyridine, bpy = bipyridine, tcbpp = 4-carboxyl-2,6-bis(2-carboxyl-N-pyrazolyl)pyridine, tc'bpp = 4-carboxyl-2,6-bis(4-carboxyl-N-pyrazolyl)pyridine) are studied theoretically using density functional theory (DFT) techniques to explore their properties as dye in a solar cell. The calculated geometry structure and absorption spectrum of 1 are consistent with its experimental results. The calculation results indicate which sites the COOH groups attach to can significantly influence the electronic structure of the complex. By migrating the COOH groups from the bpy ligand in 1 to bpp ligand in 2 and 3, the nature of LUMO changes from bpy-localized to bpp dominated. The calculated low-lying absorptions at λ > 370 nm of the three complexes are categorized as metal-to-ligand charge-transfer (MLCT) transitions and the transition terminates at the orbital populated by the COOH appended ligand. The atomic spin density analysis also indicates that the ligand which is modified by the COOH groups is the ideal spot for the captured electron to situate. It can be predicted that the performance of 2 and 3 in the dye-sensitized solar cell can be enhanced as compared with 1.

  14. Photochemical Stereospecific Hydrogenation of a Ru Complex with an

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, K.; Fujita, E.; Fukushima, T.; Muckerman, J.T.; Polyansky, D.E.; Wada, T.

    2009-12-21

    A polypyridylruthenium complex with an NAD{sup +}/NADH model ligand, [Ru(bpy){sub 2}(pbn)]{sup 2+} [bpy = 2,2'-bipyridine; pbn = 2-(2-pyridyl)benzo[b]-1,5-naphthyridine] in a D{sub 2}O/CH{sub 3}CN/triethylamine solution, undergoes stereospecific hydrogenation to give {Delta}-(S)- and {Lambda}-(R)-[Ru(bpy){sub 2}(pbnDD)]{sup 2+} [pbnDD = 5,10-dideutero-2-(2-pyridyl)benzo[b]-1,5-naphthyridine] upon visible-light irradiation. This result clearly indicates the pathway via the {pi}-stacked dimer of the deuterated one-electron-reduced species. The reduction of [Ru(bpy){sub 2}(pbn)]{sup 2+} with Na{sub 2}S{sub 2}O{sub 4} in D{sub 2}O did not afford any stereospecific products. Furthermore, the more sterically crowded Ru complex, [Ru(dmb){sub 2}(pbn)]{sup 2+} (dmb = 6,6'-dimethyl-2,2'-bipyridine), did not produce the corresponding pbnDD species upon irradiation.

  15. Deep red to near-infrared emitting rhenium(I) complexes: synthesis, characterization, electrochemistry, photophysics, and electroluminescence studies.

    Science.gov (United States)

    Yu, Tao; Tsang, Daniel Ping-Kuen; Au, Vonika Ka-Man; Lam, Wai Han; Chan, Mei-Yee; Yam, Vivian Wing-Wah

    2013-09-27

    A series of triarylamine-containing tricarbonyl rhenium(I) complexes, [BrRe(CO)3 (N^N)] (N^N=5,5'-bis(N,N-diaryl-4-[ethen-1-yl]-aniline)-2,2'-bipyridine), has been designed and synthesized by introducing a rhenium(I) metal center into a donor-π-acceptor-π-donor structure. All of the complexes showed an intense broad structureless emission band in dichloromethane at around 680-708 nm, which originated from an excited state of intraligand charge transfer ((3)ILCT) character from the triarylamine to the bipyridine moiety. Upon introduction of the bulky and electron-donating pentaphenylbenzene units attached to the aniline groups, the emission bands were found to be red shifted. The nanosecond transient absorption spectra of two selected complexes were studied, which were suggestive of the formation of an initial charge-separated state. Computational studies have been performed to provide further insight into the origin of the absorption and emission. One of the rhenium(I) complexes has been utilized in the fabrication of organic light-emitting diodes (OLEDs), representing the first example of the realization of deep red to near-infrared rhenium(I)-based OLEDs with an emission extending up to 800 nm. PMID:23959682

  16. Considering the chemical energy requirements of the tri-n-propylamine co-reactant pathways for the judicious design of new electrogenerated chemiluminescence detection systems.

    Science.gov (United States)

    Kerr, Emily; Doeven, Egan H; Wilson, David J D; Hogan, Conor F; Francis, Paul S

    2016-01-01

    The introduction of a 'co-reactant' was a critical step in the evolution of electrogenerated chemiluminescence (ECL) from a laboratory curiosity to a widely utilised detection system. In conjunction with a suitable electrochemiluminophore, the co-reactant enables generation of both the oxidised and reduced precursors to the emitting species at a single electrode potential, under the aqueous conditions required for most analytical applications. The most commonly used co-reactant is tri-n-propylamine (TPrA), which was developed for the classic tris(2,2'-bipyridine)ruthenium(II) ECL reagent. New electrochemiluminophores such as cyclometalated iridium(III) complexes are also evaluated with this co-reactant. However, attaining the excited states in these systems can require much greater energy than that of tris(2,2'-bipyridine)ruthenium(II), which has implications for the co-reactant reaction pathways. In this tutorial review, we describe a simple graphical approach to characterise the energetically feasible ECL pathways with TPrA, as a useful tool for the development of new ECL detection systems. PMID:26525583

  17. A functional ruthenium(ii) complex for imaging biothiols in living bodies.

    Science.gov (United States)

    Ye, Zhiqiang; Gao, Quankun; An, Xin; Song, Bo; Yuan, Jingli

    2015-05-01

    A unique ruthenium(ii) complex, [Ru(bpy)2(DNS-bpy)](PF6)2 [bpy: 2,2'-bipyridine, DNS-bpy: 4-(2,4-dinitrophenylthio)-2,2'-bipyridine], that can act as a probe for the recognition and luminescence sensing of biothiols has been designed and synthesized. Due to the presence of effective photo-induced electron transfer (PET) from the potent electron donor (Ru-bpy centre) to the strong electron acceptor (2,4-dinitrophenyl moiety), the Ru(ii) complex itself is weakly luminescent. Reaction of [Ru(bpy)2(DNS-bpy)](PF6)2 with biothiols leads to the replacement of the 2,4-dinitrophenyl moiety by biothiols, which results in the loss of PET within the complex, to allow recovery of the MLCT-based emission of the Ru(ii) complex with an 80-fold increase in luminescence intensity. Taking advantage of the high specificity and sensitivity, and the excellent photophysical properties of Ru(ii) complexes, [Ru(bpy)2(DNS-bpy)](PF6)2 was successfully applied to the luminescence imaging of biothiols in living Daphnia magna. The results demonstrated the practical applicability of [Ru(bpy)2(DNS-bpy)](PF6)2 as a luminescent probe for the monitoring of biothiols in living bodies. PMID:25851565

  18. Catalytic water oxidation by mononuclear Ru complexes with an anionic ancillary ligand.

    Science.gov (United States)

    Tong, Lianpeng; Inge, A Ken; Duan, Lele; Wang, Lei; Zou, Xiaodong; Sun, Licheng

    2013-03-01

    Mononuclear Ru-based water oxidation catalysts containing anionic ancillary ligands have shown promising catalytic efficiency and intriguing properties. However, their insolubility in water restricts a detailed mechanism investigation. In order to overcome this disadvantage, complexes [Ru(II)(bpc)(bpy)OH2](+) (1(+), bpc = 2,2'-bipyridine-6-carboxylate, bpy = 2,2'-bipyridine) and [Ru(II)(bpc)(pic)3](+) (2(+), pic = 4-picoline) were prepared and fully characterized, which features an anionic tridentate ligand and has enough solubility for spectroscopic study in water. Using Ce(IV) as an electron acceptor, both complexes are able to catalyze O2-evolving reaction with an impressive rate constant. On the basis of the electrochemical and kinetic studies, a water nucleophilic attack pathway was proposed as the dominant catalytic cycle of the catalytic water oxidation by 1(+), within which several intermediates were detected by MS. Meanwhile, an auxiliary pathway that is related to the concentration of Ce(IV) was also revealed. The effect of anionic ligand regarding catalytic water oxidation was discussed explicitly in comparison with previously reported mononuclear Ru catalysts carrying neutral tridentate ligands, for example, 2,2':6',2″-terpyridine (tpy). When 2(+) was oxidized to the trivalent state, one of its picoline ligands dissociated from the Ru center. The rate constant of picoline dissociation was evaluated from time-resolved UV-vis spectra.

  19. Terpyridine and Quaterpyridine Complexes as Sensitizers for Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Davide Saccone

    2016-02-01

    Full Text Available Terpyridine and quaterpyridine-based complexes allow wide light harvesting of the solar spectrum. Terpyridines, with respect to bipyridines, allow for achieving metal-complexes with lower band gaps in the metal-to-ligand transition (MLCT, thus providing a better absorption at lower energy wavelengths resulting in an enhancement of the solar light-harvesting ability. Despite the wider absorption of the first tricarboxylate terpyridyl ligand-based complex, Black Dye (BD, dye-sensitized solar cell (DSC performances are lower if compared with N719 or other optimized bipyridine-based complexes. To further improve BD performances several modifications have been carried out in recent years affecting each component of the complexes: terpyridines have been replaced by quaterpyridines; other metals were used instead of ruthenium, and thiocyanates have been replaced by different pinchers in order to achieve cyclometalated or heteroleptic complexes. The review provides a summary on design strategies, main synthetic routes, optical and photovoltaic properties of terpyridine and quaterpyridine ligands applied to photovoltaic, and focuses on n-type DSCs.

  20. Surface-enhanced Raman scattering active gold nanostructure fabricated by photochemical reaction of synchrotron radiation

    International Nuclear Information System (INIS)

    The deposition of gold nanoparticles in an electroplating solution containing gold (I) trisodium disulphite under synchrotron X-ray radiation was investigated. The nanoparticles grew and aggregated into clusters with increasing radiation time. This behavior is explained by evaluating the effect of Derjaguin-Landau-Verweyand-Overbeek (DLVO) interactions combining repulsive electrostatic and attractive van der Waals forces on the particle deposition process. The surface-enhanced Raman scattering (SERS) of 4,4′ -bipyridine (4bpy) in aqueous solution was measured using gold nanoparticles immobilized on silicon substrates under systematically-varied X-ray exposure. The substrates provided an in situ SERS spectrum for 1 nM 4bpy. This demonstration creates new opportunities for chemical and environmental analyses through simple SERS measurements. - Highlights: • Gold nanoparticles were produced by photochemical reaction of synchrotron radiation. • The gold nanoparticles grew and aggregated into the higher-order nanostructure. • The behavior is qualitatively explained by analytical estimation. • The surface-enhanced Raman spectroscopy of 4,4′-bipyridine (4bpy) was demonstrated. • The substrate fabricated in a suitable condition provides in situ SERS for 1 nM 4bpy

  1. Synthesis and Crystal Structure of Cu2 (pba) (bpy) 2 Cl2·4H2O

    Institute of Scientific and Technical Information of China (English)

    朱志成; 毛新平; 徐正; 黄小荥

    2000-01-01

    A new copper complex, Cu2 (pba)(bpy)2Cl2·4H2O (here pba was pro-pylenebis (oxamic acid), bpy was bipyridine), was synthesized. Crystal structure of thetitle complex was determined. It belongs to the tetragonal system, molecular formulaCu2Cl2Oi0N6C27H32, Mr = 798. 58, space group P4t212, a = b = 9. 484(4), c =35.918(9) A, V = 3235(2) A3, Dx = 1. 64gcm-3 and F(000) = 1568, μ =1. 546mm 1 for Z = 4. The crystal structure was solved by direct methods for final R =0.048 and Rω, = 0.060 for 1992 observed reflections with I >3a (I). The complex hasa C2 symmetry. A chloride anion, two nitrogen atoms from bipyridine and two oxygenatoms from the oxamide carbonyl and carboxyl coordinated to the CuⅡ ion forming asquare pyramidal geometry. In each molecule, two bpy are almost parallel.

  2. Reactions of the excited state of polypyridyl chromium(III) ion

    Energy Technology Data Exchange (ETDEWEB)

    Steffan, C.

    1990-09-21

    There has been much recent interest in the photochemistry and photophysics of transition metal polypyridine complexes due to the possibility of their use in solar energy conversion systems. The excited state of these compounds are known to undergo useful electron transfer and energy transfer reactions. This work attempts to elucidate the mechanism of the quenching of *CrL{sub 3}{sup 3+} (where L = 2,2{prime}-bipyridine, 4,4{prime}-dimethyl-2,2{prime}-bipyridine, 1,10-phenanthroline, 5-chloro-1,10-phenanthroline, 5-methyl-1,10-phenanthroline) by oxalate ions in neutral pH. Evidence suggests an ion-pairing pre-equilibrium followed by rate limiting electron transfer to produce CrL{sub 3}{sup 2+} and CO{sub 2}{sup {minus}} can then react with ground state chromium(III) species to produce another mole of the reduced product or it can produce a secondary transient as in the case of phenanthroline and substituted phenanthroline complexes. The secondary transient reacts to produce CrL{sub 3}{sup 2+} in a subsequent reaction. 85 refs., 24 figs., 7 tabs.

  3. Surface-enhanced Raman scattering active gold nanostructure fabricated by photochemical reaction of synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Akinobu, E-mail: yamaguti@lasti.u-hyogo.ac.jp [Laboratory of Advance Science and Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori, Ako, Hyogo 678-1205 (Japan); Matsumoto, Takeshi [Laboratory of Advance Science and Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori, Ako, Hyogo 678-1205 (Japan); Okada, Ikuo; Sakurai, Ikuya [Synchrotoron Radiation Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Utsumi, Yuichi [Laboratory of Advance Science and Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori, Ako, Hyogo 678-1205 (Japan)

    2015-06-15

    The deposition of gold nanoparticles in an electroplating solution containing gold (I) trisodium disulphite under synchrotron X-ray radiation was investigated. The nanoparticles grew and aggregated into clusters with increasing radiation time. This behavior is explained by evaluating the effect of Derjaguin-Landau-Verweyand-Overbeek (DLVO) interactions combining repulsive electrostatic and attractive van der Waals forces on the particle deposition process. The surface-enhanced Raman scattering (SERS) of 4,4′ -bipyridine (4bpy) in aqueous solution was measured using gold nanoparticles immobilized on silicon substrates under systematically-varied X-ray exposure. The substrates provided an in situ SERS spectrum for 1 nM 4bpy. This demonstration creates new opportunities for chemical and environmental analyses through simple SERS measurements. - Highlights: • Gold nanoparticles were produced by photochemical reaction of synchrotron radiation. • The gold nanoparticles grew and aggregated into the higher-order nanostructure. • The behavior is qualitatively explained by analytical estimation. • The surface-enhanced Raman spectroscopy of 4,4′-bipyridine (4bpy) was demonstrated. • The substrate fabricated in a suitable condition provides in situ SERS for 1 nM 4bpy.

  4. Ultraviolet spectrophotometric characterization of copper(II) complexes with imidazole N-methyl derivatives of ?-histidine in aqueous solution

    Science.gov (United States)

    Prenesti, Enrico; Berto, Silvia; Daniele, Pier Giuseppe

    2003-01-01

    In this study we considered π-methyl- L-histidine (π-methis) and τ-methyl- L-histidine (τ-methis) as ligands for copper(II) ion, in order to clarify, by means of ultraviolet (UV) spectroscopy in aqueous solution ( T=25 °C, I=0.1 M), some aspects of the co-ordination mode with respect to other ligands of a previous study in which copper(II) complexes of L-histidine, N-acetyl- L-histidine, histamine, L-histidine methyl ester or carnosine were investigated. Particularly, UV spectra (300-400 nm) were recorded on solutions at various pH values, containing each binary system Cu-L; afterwards, an UV absorption spectrum for single complexes was calculated, taking into account the chemical model previously assessed, in order to fulfil a correct spectrum-structure correlation. The problem related to the eventual superimposition of the CT shoulder (≈330 nm) to copper(II) of OH - and imidazole pyridine nitrogen groups were now solved by means of a comparison of the UV spectra of dimer species formed by both π-methis or τ-methis. Finally, copper(II) complex formation with 2,2'-bipyridine was taken into account to compare the behaviour of pyridine (from 2,2'-bipyridine) and pyridine imidazole nitrogens (from π-methis or τ-methis) with respect to the UV charge transfer process to copper(II) ion.

  5. Osmium-Based Pyrimidine Contrast Tags for Enhanced Nanopore-Based DNA Base Discrimination.

    Directory of Open Access Journals (Sweden)

    Robert Y Henley

    Full Text Available Nanopores are a promising platform in next generation DNA sequencing. In this platform, an individual DNA strand is threaded into nanopore using an electric field, and enzyme-based ratcheting is used to move the strand through the detector. During this process the residual ion current through the pore is measured, which exhibits unique levels for different base combinations inside the pore. While this approach has shown great promise, accuracy is not optimal because the four bases are chemically comparable to one another, leading to small differences in current obstruction. Nucleobase-specific chemical tagging can be a viable approach to enhancing the contrast between different bases in the sequence. Herein we show that covalent modification of one or both of the pyrimidine bases by an osmium bipyridine complex leads to measureable differences in the blockade amplitudes of DNA molecules. We qualitatively determine the degree of osmylation of a DNA strand by passing it through a solid-state nanopore, and are thus able to gauge T and C base content. In addition, we show that osmium bipyridine reacts with dsDNA, leading to substantially different current blockade levels than exhibited for bare dsDNA. This work serves as a proof of principle for nanopore sequencing and mapping via base-specific DNA osmylation.

  6. Determinação espectrofotométrica simultânea de cobre e ferro em álcool etílico combustível com reagentes derivados da ferroína Simultaneous spectrophotometric determination of iron and copper using ferroin reagents

    Directory of Open Access Journals (Sweden)

    Leonardo S. G. Teixeira

    2006-07-01

    Full Text Available In the present work three ferroin reagents were studied for the simultaneous spectrophotometric determination of iron and copper: 1,10-phenanthroline, 2,2'-bipyridine and 2,4,6-tri(2-pyridyl-1,3,5-triazine. Effect of pH, conditions, order reagent addition, interferences, amount of reagents, lineal range, sensitivity and stability of each system were compared. The 2,4,6-tri(2-pyridyl-1,3,5-triazine can be used for determination of iron in the presence of copper with a detection limit of 5 µg L-1 and coefficient of variation of 2.0%; However it was not possible to determine directly copper in the presence of iron with this reagent. 1,10-phenanthroline can be used for simultaneous determination of the metallic ions with detection limits of 7 and 8 mg L-1 and coefficients of variation of 1.8 and 2.3% in the determination of iron and copper, respectively. The results showed also that 2,2'-bipyridine can be used for simultaneous determination of the metallic ions with detection limits of 11 and 32 µg L-1 and coefficients of variation of 1.9 and 2.5% in the determination of iron and copper, respectively. The reagents were used for spectrophotometric determination of iron and copper in ethanol fuel.

  7. The First Molybdenum(VI) and Tungsten(VI) Oxoazides MO2(N3)2, MO2(N3)2⋅2 CH3CN, (bipy)MO2(N3)2, and [MO2(N3)4](2-) (M=Mo, W).

    Science.gov (United States)

    Haiges, Ralf; Skotnitzki, Juri; Fang, Zongtang; Dixon, David A; Christe, Karl O

    2015-08-10

    Molybdenum(VI) and tungsten(VI) dioxodiazide, MO2(N3)2 (M=Mo, W), were prepared through fluoride-azide exchange reactions between MO2F2 and Me3SiN3 in SO2 solution. In acetonitrile solution, the fluoride-azide exchange resulted in the isolation of the adducts MO2(N3)2⋅2 CH3CN. The subsequent reaction of MO2(N3)2 with 2,2'-bipyridine (bipy) gave the bipyridine adducts (bipy)MO2(N3)2. The hydrolysis of (bipy)MoO2(N3)2 resulted in the formation and isolation of [(bipy)MoO2N3]2O. The tetraazido anions [MO2(N3)4](2-) were obtained by the reaction of MO2(N3)2 with two equivalents of ionic azide. Most molybdenum(VI) and tungsten(VI) dioxoazides were fully characterized by their vibrational spectra, impact, friction, and thermal sensitivity data and, in the case of (bipy)MoO2(N3)2, (bipy)WO2(N3)2, [PPh4]2[MoO2(N3)4], [PPh4]2[WO2(N3)4], and [(bipy)MoO2N3]2O by their X-ray crystal structures. PMID:26178877

  8. Synthesis, structure, terahertz spectroscopy and luminescent properties of copper (I) complexes with bis(diphenylphosphino)methane and N-donor ligands

    Science.gov (United States)

    Fan, Wei-Wei; Li, Zhong-Feng; Li, Jiao-Bao; Yang, Yu-Ping; Yuan, Yuan; Tang, Han-Qin; Gao, Ling-Xiao; Jin, Qiong-Hua; Zhang, Zhen-Wei; Zhang, Cun-Lin

    2015-11-01

    The reactions of copper(I) salts CuX [X = Cl, OTf (OTf = CF3SO3) and ClO4] and bis(diphenylphosphino)methane (dppm) with 4,4-bipyridine (4,4-bipy), 2,2-bipyridine (2,2-bipy), isoquinoline (i-C9H7N) and 1,10-phenanthroline (phen) lead to five new copper(I) complexes: [CuCl(dppm)(i-C9H7N)]2 (1), {[CuCl(dppm)(phen)]2•5H2O}n (2), [Cu2Cl2(dppm)2(4,4-bipy)]•4CH3CN (3), [Cu(dppm)(2,2-bipy)]2(OTf)2 (4), {[Cu2Cl(dppm)2(4,4-bipy)](ClO4)}n (5). Complexes 1, 3 and 4 are of dinuclear structure with eight-membered Cu2P4C2 rings. The structure of compound 2 can be simplified as three-dimensional topology. Complex 5 is of infinite chain structure linked by 4,4-bipy. All these complexes are characterized by IR, elemental analyses, single-crystal X-ray diffraction analysis, luminescence, NMR and terahertz time-domain spectroscopy.

  9. Synthesis and Structure of a Manganese(Ⅱ) Complex [Mn·(p-Methoxybenzoato)2·(2,2'- bipy)·H2O]·(p-methoxybenzoic Acid)

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; HUANG Mei-Hua; CHENG Wen-Dan; LIU Ping

    2007-01-01

    The title compound,{[MnL2·(2,2'-bipy)·H2O]·(HL)},has been synthesized (HL =p-methoxybenzoic acid,2,2'-bipy = 2,2'-bipyridine) by the reaction of MnCl2·6H2O with p-methoxybenzoic and 2,2'-bipyridine in an alcohol-water solution.It crystallizes in the triclinic system,space group P1 with a = 10.1138(5),b = 11.2811(5),c = 16.2210(8)(A),a = 77.5920(10),β= 72.1890(10),γ = 66.2320(10)°,Mr = 683.56,V= 1603.65(13) (A)3,Z= 2,Dc = 1.416 g/cm3,F(000)= 710,μ =0.473 mm-1,the final R = 0.0619 and wR = 0.1571 for 4724 observed reflections with I > 2σ(I).The structure determined demonstrated that it is an isomeric modification of the structure reported before.The Mn atom is six-coordinated by two N and four O atoms,forming a distorted octahedral geometry.All Mn-O and Mn-N distances range from 2.113(3)~2.410(3) (A).There also.exists a dissociative p-methoxybenzoic acid beside the octahedron.

  10. Reversible, Selective Trapping of Perchlorate from Water in Record Capacity by a Cationic Metal-Organic Framework.

    Science.gov (United States)

    Colinas, Ian R; Silva, Rachel C; Oliver, Scott R J

    2016-02-16

    We report the capture of ppm-level aqueous perchlorate in record capacity and kinetics via the complete anion exchange of a cationic metal-organic framework. Ambient conditions were used for both the synthesis of silver 4,4'-bipyridine nitrate (SBN) and the exchange, forming silver 4,4'-bipyridine perchlorate (SBP). The exchange was complete within 90 min, and the capacity was 354 mg/g, representing 99% removal. These values are greater than current anion exchangers such as the resins Amberlite IRA-400 (249 mg/g), Purolite A530E (104 mg/g), and layered double hydroxides (28 mg/g). Moreover, unlike resins and layered double hydroxides, SBN is fully reusable and displays 96% regeneration to SBN in nitrate solution, with new crystal formation allowing the indefinite cycling for perchlorate. We show seven cycles as proof of concept. Perchlorate contamination of water represents a serious health threat because it is a thyroid endocrine disruptor. This noncomplexing anionic pollutant is significantly mobile and environmentally persistent. Removal of other anionic pollutants from water such as chromate, pertechnetate, or arsenate may be possible by this methodology. PMID:26765213

  11. Hybrid compounds of Keggin polyoxotungstate with transition metal ion as the central atom. Synthesis, structure and properties

    Science.gov (United States)

    Li, Xiao-Min; Chen, Ya-Guang; Shi, Tian

    2016-02-01

    The compounds (Hbipy)2[Co(bipy)2(H2O)4]2(CoW12O40)·2bipy·7H2O (1) and [Ni2(Hbipy)2(bipy)(H2O)4(H2W12O40)]·5H2O (2) (bipy = 4,4-bipyridine) were synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy, TG analyses, solid ultraviolet diffuse spectroscopy and single crystal X-ray diffraction method. In 1 the complex ions, [Co(bipy)2(H2O)4]2+, construct a supramolecular layer through π-π stacking interaction. The heteropolyanions with central Co atom and supramolecular layers are linked by hydrogen bonds. In 2 a 2D structure is formed from metatungstate anions and binuclear Ni-bipy complexes through the coordination of metatungstate anions and bipy to Ni ions. Between the layers and bipyridine molecules are the hydrogen bond interactions. The formation of 1 and 2 shows that the solution acidity and metal ions influence greatly the structure of the compounds. Solid ultraviolet diffusion results indicate that the compounds 1 and 2 are potential semiconductor materials. In 1 and 2 there exists a weak antiferromagnetic interaction.

  12. Copper-mediated C-H activation/C-S cross-coupling of heterocycles with thiols

    KAUST Repository

    Ranjit, Sadananda

    2011-11-04

    We report the synthesis of a series of aryl- or alkyl-substituted 2-mercaptobenzothiazoles by direct thiolation of benzothiazoles with aryl or alkyl thiols via copper-mediated aerobic C-H bond activation in the presence of stoichiometric CuI, 2,2′-bipyridine and Na 2CO 3. We also show that the approach can be extended to thiazole, benzimidazole, and indole substrates. In addition, we present detailed mechanistic investigations on the Cu(I)-mediated direct thiolation reactions. Both computational studies and experimental results reveal that the copper-thiolate complex [(L)Cu(SR)] (L: nitrogen-based bidentate ligand such as 2,2′-bipyridine; R: aryl or alkyl group) is the first reactive intermediate responsible for the observed organic transformation. Furthermore, our computational studies suggest a stepwise reaction mechanism based on a hydrogen atom abstraction pathway, which is more energetically feasible than many other possible pathways including β-hydride elimination, single electron transfer, hydrogen atom transfer, oxidative addition/reductive elimination, and σ-bond metathesis. © 2011 American Chemical Society.

  13. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane

    Directory of Open Access Journals (Sweden)

    A. G. Gaikwad

    2012-06-01

    Full Text Available Transport of carbonate ions was explored through fiber supported solid membrane. A novel fiber supported solid membrane was prepared by chemical modification of cellulose fiber with citric acid, 2′2-bipyridine and magnesium carbonate. The factors affecting the permeability of carbonate ions such as immobilization of citric acid-magnesium metal ion -2′2-bipyridine complex (0 to 2.5 mmol/g range over cellulose fiber, carbon-ate ion concentration in source phase and NaOH concentration in receiving phase were investigated. Ki-netic of carbonate, sulfate, and nitrate ions was investigated through fiber supported solid membrane. Transport of carbonate ions with/without bubbling of CO2 (0 to 10 ml/min in source phase was explored from source to receiving phase. The novel idea is to explore the adsorptive transport of CO2 from source to receiving phase through cellulose fiber containing magnesium metal ion organic framework. Copyright © 2012 BCREC UNDIP. All rights reserved.Received: 25th November 2011; Revised: 17th December 2011; Accepted: 19th December 2011[How to Cite: A.G. Gaikwad. (2012. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1: 49– 57.  doi:10.9767/bcrec.7.1.1225.49-57][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.1225.49-57 ] | View in 

  14. Turn-On Fluorescent Chemosensor for Fluoride Based on Pyreneamide Derivative

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Nam Joong; Hong, Sung Won; Hong, Ju Hyun; Jeong, Ju Mi; Nam, Kye Chun [Seoul National University, Seoul (Korea, Republic of)

    2012-01-15

    A new chemosensor with pyreneamide derivative of bipyridine is synthesized. In the free ligand, pyreneamide derivative has nearly no fluorescence in acetonitrile solution. However, in the presence of fluoride ion, a 'turn-on' fluorescence was observed. Simultaneously, the colorless ligand solution became markedly orange when fluoride ion was added to pyreneamide derivative in acetonitrile. This phenomenon suggest that the PET (photoinduced electron transfer) between anion electron and pyrene unit was changed the π-π interaction between bipyridine and pyrene that was modified structure by deprotonation. On account of the important roles of anion in biological, clinical, environmental, catalysis, and chemical processes, the selective and efficient recognition of anion is an area of growing interest in supramolecular chemistry. In particular, the studies of chemosensors toward F{sup -} anion are quite intriguing because of its beneficial effects in human physiology. Also, fluoride is interest due to its established role in dental care and osteoporosis. However, an excess of fluoride ion can lead to fluorosis. Therefore, the development of reliable sensors for F{sup -} is needed for environment and human health care. Color changes that can be detected by the naked eye are widely used as signals for events owing to the inexpensive equipment required or no equipment at all.

  15. Luminescent host–guest materials of electrostatically adsorbed Eu3+(tta)3-tpyIL on zeolite L crystals

    International Nuclear Information System (INIS)

    Graphical abstract: Luminescent host–guest materials exhibiting tunable emission colors by changing the excitation wavelength are obtained by surface modification of terbium(III) bipyridine-loaded zeolite L crystals with the ionic europium(III) complexes. - Highlights: • Luminescent ionic europium(III) complex was synthesized. • Outer surface of zeolite L was modified by electrostatic adsorption of the ionic complex. • Luminescent host–guest material with tunable emission color was obtained. - Abstract: The surface modification of zeolite L crystals with lanthanide complexes was achieved by electrostatic adsorption of ionic europium(III) complexes that are prepared by the reaction of tris(2-thenoyltrifluoroacetonate) europium(III) dehydrate with an organic salt containing terpyridine moieties on the negative charge-bearing surfaces of zeolite L crystals. Luminescent host–guest materials exhibiting tunable emission colors by changing the excitation wavelength are obtained by surface modification of terbium(III) bipyridine-loaded zeolite L crystals with the ionic europium(III) complexes

  16. Luminescent host–guest materials of electrostatically adsorbed Eu{sup 3+}(tta){sub 3}-tpyIL on zeolite L crystals

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peng; Wang, Dongyue [Hebei Provincial Key Lab of Green Chemical Technology and High Efficient Energy Saving, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China); Liang, Dong [Tangshan Zhonghao chemical co. Ltd., Hebei 300130 (China); Zhang, Li; Zhang, Shuming [Hebei Provincial Key Lab of Green Chemical Technology and High Efficient Energy Saving, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China); Wang, Yige, E-mail: wangyige@hebut.edu.cn [Hebei Provincial Key Lab of Green Chemical Technology and High Efficient Energy Saving, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China)

    2014-07-01

    Graphical abstract: Luminescent host–guest materials exhibiting tunable emission colors by changing the excitation wavelength are obtained by surface modification of terbium(III) bipyridine-loaded zeolite L crystals with the ionic europium(III) complexes. - Highlights: • Luminescent ionic europium(III) complex was synthesized. • Outer surface of zeolite L was modified by electrostatic adsorption of the ionic complex. • Luminescent host–guest material with tunable emission color was obtained. - Abstract: The surface modification of zeolite L crystals with lanthanide complexes was achieved by electrostatic adsorption of ionic europium(III) complexes that are prepared by the reaction of tris(2-thenoyltrifluoroacetonate) europium(III) dehydrate with an organic salt containing terpyridine moieties on the negative charge-bearing surfaces of zeolite L crystals. Luminescent host–guest materials exhibiting tunable emission colors by changing the excitation wavelength are obtained by surface modification of terbium(III) bipyridine-loaded zeolite L crystals with the ionic europium(III) complexes.

  17. Development of a ruthenium(II) complex based luminescent probe for imaging nitric oxide production in living cells.

    Science.gov (United States)

    Zhang, Run; Ye, Zhiqiang; Wang, Guilan; Zhang, Wenzhu; Yuan, Jingli

    2010-06-18

    A unique ruthenium(II) complex, bis(2,2'-bipyridine)(4-(3,4-diaminophenoxy)-2,2'-bipyridine)ruthenium(II) hexafluorophosphate ([(Ru(bpy)(2)(dabpy)][PF(6)](2)), has been designed and synthesized as a highly sensitive and selective luminescence probe for the imaging of nitric oxide (NO) production in living cells. The complex can specifically react with NO in aqueous buffers under aerobic conditions to yield its triazole derivative with a high reaction rate constant at the 10(10) M(-1) s(-1) level; this reaction is accompanied by a remarkable increase of the luminescence quantum yield from 0.13 to 2.2 %. Compared with organic probes, the new Ru(II) complex probe shows the advantages of a large Stokes shift (>150 nm), water solubility, and a wide pH-availability range (pH independent at pH>5). In addition, it was found that the new probe could be easily transferred into both living animal cells and plant cells by the coincubation method, whereas the triazole derivative was cell-membrane impermeable. The probe was successfully used for luminescence-imaging detection of the exogenous NO in mouse macrophage cells and endogenous NO in gardenia cells. The results demonstrated the efficacy and advantages of the new probe for NO detection in living cells. PMID:20458707

  18. Synthesis, crystal structure and properties of a new organic-inorganic hybrid Dawson-like polyoxotungstate [Co(2,2'-bpy)3]2[Co(2,2'-bpy)2Cl][Co(2,2'-bpy)2]H2-[SbW18O60]·4H2O

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new organic-inorganic hybrid polyoxometalate based on Dawson-like polyoxotungstate anion [SbW18O60]9-, formulated [Co(2,2'-bpy)3]2[Co(2,2'-bpy)2Cl][Co(2,2'-bpy)2]H2[SbW18O60]·4H2O (2,2'-bpy= 2,2(-bipyridine) has been synthesized from Sb2O3, Na2WO4, CoCl2, and 2,2'-bipyridine materials by hydrothermal method, and which was characterized by elemental analyses, IR, XPS, EPR, TG, and X-ray single crystal diffraction. Structure analysis shows that the polyoxoanion self-assembled under hydrothermal conditions consists of a Dawson-like polyoxotungstate cluster anion [SbW18O60]9- encapsulating a pyramidal {SbO3} group within the {W18} cluster cage. EPR spectra show that the high-spin octahedral CoⅡ and low-spin CoⅡ ions coexist in the title compound. Magnetic properties indicate that the compound is antiferromagnetic.

  19. Synthesis of Fe–Li–Cr Multinuclear Complexes as Molecular Magnet Materials

    Directory of Open Access Journals (Sweden)

    Iis Siti Jahro

    2008-03-01

    Full Text Available Multinuclear complexes have received considerable interest as molecular magnet materials. Up to now, several complex compounds based on bidentate ligand 2,2’ bipyridine have been synthesized. In this research, the Fe-Li-Cr multinuclear complexes with derivative 2’2- bipyridine ligands: 2-(2’-pyridylquinoline(pq, 2,2’-Pyridil(pdl have been synthesized. The oxalate (ox ligand has also been used as a bridging ligand in these multinuclear complexes. The chemical formula of Li[FeCr(ox2(pq(BF42(H2O2] and [Fe(pdln][LiCr(ox3] complexes have been verified using metal and C, H, N elemental analysis data. The IR spectra in 350 – 4000 cm-1 range exhibit characteristic absorptions, which support the proposed structure of complex. The plausible structure of the compounds has been drawn based on complex formation mechanism. The magnetic susceptibility at room temperature of the pq-complex is about 5.7 BM and of the pdl- complexes are 4.8 and 5.5 BM. These indicated that both spin states of iron(II exist in the multinuclear complexes.

  20. Study of DNA light switch Ru(II) complexes: synthesis, characterization, photocleavage and antimicrobial activity.

    Science.gov (United States)

    Yata, Praveen Kumar; Shilpa, M; Nagababu, P; Reddy, M Rajender; Kotha, Laxma Reddy; Gabra, Nazar Md; Satyanarayana, S

    2012-05-01

    The three Ru(II) complexes of [Ru(phen)(2)dppca](2+) (1) [Ru(bpy)(2)dppca](2+) (2) and [Ru(dmb)(2)dppca](2+) (3) (where phen = 1,10 phenanthroline, bpy = 2,2-bipyridine, dmb = 2 ,2-dimethyl 2',2'-bipyridine and polypyridyl ligand containing a single carboxylate functionality dppca ligand (dipyridophenazine-11-carboxylic acid) have been synthesized and characterized. These complexes have been shown to act as promising calf thymus DNA intercalators and a new class of DNA light switches, as evidenced by UV-visible and luminescence titrations with Co(2+) and EDTA, steady-state emission quenching by [Fe(CN)(6)](4-) and KI, DNA competitive binding with ethidium bromide, viscosity measurements, and DNA melting experiments. The results suggest that 1, 2, and 3 complexes bind to CT-DNA through intercalation and follows the order 1 > 2 > 3. Under irradiation at 365 nm, the three complexes have also been found to promote the photocleavage of plasmid pBR322 DNA. PMID:22194001

  1. Synthesis, characterization; DNA binding and antitumor activity of ruthenium(II) polypyridyl complexes.

    Science.gov (United States)

    Srishailam, A; Gabra, Nazar Mohammed; Kumar, Yata Praveen; Reddy, Kotha Laxma; Devi, C Shobha; Anil Kumar, D; Singh, Surya S; Satyanarayana, S

    2014-12-01

    Three new ruthenium(II) polypyridyl complexes [Ru(phen)2BrIPC](2+) (1), [Ru(bpy)2 BrIPC](2+) (2) and [Ru(dmb)2BrIPC](2+) (3) where, BrIPC = (6-bromo-3-(1H-imidazo[4,5-f] [1,10]-phenanthroline, phen = 1,10-phenanthroline, bpy = 2,2' bipyridine, dmb = 4,4'-dimethyl 2,2' bipyridine, were synthesised and characterised. DNA-binding nature was investigated by spectroscopic titrations and mode of binding was assessed by viscosity measurements. The DNA-binding constants Kb of complexes 1, 2 and 3 were determined to be in the order of 10(5). Experimental results showed that these complexes interact with CT-DNA by intercalative mode. Photocleavage and antimicrobial activities were complex concentration dependent, at high concentration, high activity and vice versa. MTT assay was performed on HeLa cell lines, IC50 values of complexes in the order of 3 > 2 > 1 > cisplatin. From comet assay, cellular uptake studies, we observed that complexes could enter into the cell membrane and accumulate inside the nucleus. Molecular docking studies support the DNA binding affinity with hydrogen bonding and van der Waals attractions between base pairs and phosphate backbone of DNA with metal complexes. PMID:25318017

  2. Synthesis, DNA-binding, cytotoxicity, photo cleavage, antimicrobial and docking studies of Ru(II) polypyridyl complexes.

    Science.gov (United States)

    Srishailam, A; Kumar, Yata Praveen; Gabra, Nazar M D; Reddy, P Venkat; Deepika, N; Veerababu, Nageti; Satyanarayana, S

    2013-09-01

    Three Ruthenium(II) polypyridine complexes, [Ru(phen)2(mipc)](2+)(1), [Ru(bpy)2(mipc)](2+) (2) and [Ru(dmb)2(mipc)](2+)(3) [mipc = 2-(6-methyl-3-(1H-imidazo[4, 5-f][1,10]-phenanthroline-2-yl)-4H-chromene-4-one, phen = 1,10-phenanthroline,bpy = 2, 2'bipyridine,dmb = 4, 4'-dimethyl-2, 2'-bipyridine] have been synthesized and characterized by elemental analysis, IR, UV-Vis, (1)H& (13)C NMR and mass spectra. The DNA-binding properties of the Ruthenium(II) complexes were investigated by spectrophotometric methods, viscosity measurements and light switch studies. These three complexes have been focused on photo activated cleavage studies with pBR-322 and antimicrobial studies. Experimental results indicate that the three complexes intercalate into DNA base pairs and follows the order of 1 > 2 > 3 respectively. Molecular docking studies also support the DNA interactions with complexes through hydrogen bonding and vander Waal's interactions. Cytotoxicity studies with Hela cell lines has been revealing about anti tumor activity of these complexes. PMID:23553642

  3. Two supramolecular architectures constructed from dinuclear zinc(II) unit

    Science.gov (United States)

    Lou, Ben-Yong; Yuan, Da-Qiang; Wang, Rui-Hu; Xu, Ying; Wu, Ben-Lai; Han, Lei; Hong, Mao-Chun

    2004-07-01

    Two supramolecular architectures, [Zn 2( D, L-sala) 2(4-H 2Npy) 2·2H 2O] n ( 1) (4-H 2Npy=4-aminopyridine) and [Zn 2( D, L-sala) 2(4,4'-bpy)·0.5H 2O] n ( 2) (4,4'-bpy=4,4'-bipyridine), have been constructed from dinuclear zinc(II) unit [Zn 2( D, L-sala) 2] (sala= N-(2-hydroxybenzyl)-alanine anion). For 1, four dimmers link together through N-H⋯O hydrogen bonds to give rise to a square ring that is extended into two-dimensional supramolecular network. For 2, dinuclear units are connected by 4,4'-bipyridine to generate a one-dimensional chain with ladder structure, which is connected through hydrogen bonds into three-dimensional supramolecular framework. Complex 1 exhibits intense photoluminescence at 402 nm upon photo-excitation at 348 nm, while complex 2 gives two intense photoluminescent peaks at 464 and 613 nm upon photo-excitation at 350 nm.

  4. Stretchable Self-Healing Polymeric Dielectrics Cross-Linked Through Metal-Ligand Coordination.

    Science.gov (United States)

    Rao, Ying-Li; Chortos, Alex; Pfattner, Raphael; Lissel, Franziska; Chiu, Yu-Cheng; Feig, Vivian; Xu, Jie; Kurosawa, Tadanori; Gu, Xiaodan; Wang, Chao; He, Mingqian; Chung, Jong Won; Bao, Zhenan

    2016-05-11

    A self-healing dielectric elastomer is achieved by the incorporation of metal-ligand coordination as cross-linking sites in nonpolar polydimethylsiloxane (PDMS) polymers. The ligand is 2,2'-bipyridine-5,5'-dicarboxylic amide, while the metal salts investigated here are Fe(2+) and Zn(2+) with various counteranions. The kinetically labile coordination between Zn(2+) and bipyridine endows the polymer fast self-healing ability at ambient condition. When integrated into organic field-effect transistors (OFETs) as gate dielectrics, transistors with FeCl2 and ZnCl2 salts cross-linked PDMS exhibited increased dielectric constants compared to PDMS and demonstrated hysteresis-free transfer characteristics, owing to the low ion conductivity in PDMS and the strong columbic interaction between metal cations and the small Cl(-) anions which can prevent mobile anions drifting under gate bias. Fully stretchable transistors with FeCl2-PDMS dielectrics were fabricated and exhibited ideal transfer characteristics. The gate leakage current remained low even after 1000 cycles at 100% strain. The mechanical robustness and stable electrical performance proved its suitability for applications in stretchable electronics. On the other hand, transistors with gate dielectrics containing large-sized anions (BF4(-), ClO4(-), CF3SO3(-)) displayed prominent hysteresis due to mobile anions drifting under gate bias voltage. This work provides insights on future design of self-healing stretchable dielectric materials based on metal-ligand cross-linked polymers. PMID:27099162

  5. Effect of methylene spacers on the spectral, electrochemical, and structural properties of bis(4,4'-disubstituted-2,2'-bipyridyl) ruthenium(II) dye analogues.

    Science.gov (United States)

    Lense, Sheri; Hardcastle, Kenneth I; MacBeth, Cora E

    2009-09-28

    Two new ruthenium complexes, [Ru(L1OMe)2(NCS)2] and [Ru(L2OMe)2(NCS)2] (where L1OMe = 2,2'-bipyridine-4,4'-di(methyl ethanoate) and L2OMe = 2,2'-bipyridine-4,4'-di(methyl propionate)), have been synthesized and characterized using spectroscopic and electrochemical techniques. The [Ru(L2OMe)2(NCS)2] complex has also been characterized by X-ray diffraction studies and reveals a distorted octahedral coordination geometry about the ruthenium center. Cyclic voltammetry studies of both complexes exhibit quasi-reversible Ru(II/III) couples and a number of ligand reduction events. The complex with one methylene spacer between the bipyridyl ligand and the methyl ester functional group, [Ru(L1OMe)2(NCS)2], was particularly unstable under reducing conditions. The properties of these complexes are compared with the ethyl ester analogue of the N3 photosensitizer [Ru(L0OEt)2(NCS)2].

  6. Chromophore-immobilized luminescent metal-organic frameworks as potential lighting phosphors and chemical sensors.

    Science.gov (United States)

    Wang, Fangming; Liu, Wei; Teat, Simon J; Xu, Feng; Wang, Hao; Wang, Xinlong; An, Litao; Li, Jing

    2016-08-11

    An organic chromophore H4tcbpe-F was synthesized and immobilized into metal-organic frameworks along with two bipyridine derivatives as co-ligands to generate two strongly luminescent materials [Zn2(tcbpe-F)(4,4'-bpy)·xDMA] (1) and [Zn2(tcbpe-F)(bpee)·xDMA] (2) [4,4'-bpy = 4,4'-bipyridine, bpee = 4,4'-bipyridyl-ethylene, tcbpe-F = 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(3-fluoro-[1,1'-biphenyl]-4-carboxylic acid), DMA = N,N-dimethylacetamide]. Compounds 1 and 2 are isoreticular and feature a 2-fold interpenetrated three-dimensional porous structure. Both compounds give green-yellow emission under blue light excitation. Compound 1 has a high internal quantum yield of ∼51% when excited at 455 nm and shows selective luminescence signal change (e.g. emission energy and/or intensity) towards different solvents, including both aromatic and nonaromatic volatile organic species. These properties make it potentially useful as a lighting phosphor and a chemical sensor. PMID:27465685

  7. The niobium oxoazides [NbO(N3)3], [NbO(N3)3·2CH3CN], [(bipy)NbO(N3)3], Cs2[NbO(N3)5] and [PPh4]2[NbO(N3)5].

    Science.gov (United States)

    Haiges, Ralf; Vasiliu, Monica; Dixon, David A; Christe, Karl O

    2016-06-28

    Niobium oxotriazide, [NbO(N3)3], was prepared in a fluoride-azide exchange reaction between [NbOF3] and an excess of Me3SiN3 in SO2 solution. In acetonitrile solution, the fluoride-azide exchange resulted in the isolation of the adduct [NbO(N3)3·2CH3CN]. The subsequent reaction of [NbO(N3)3] with 2,2'-bipyridine (bipy) resulted in the isolation of the bipyridine adduct [(bipy)NbO(N3)3]. The pentaazido anion [NbO(N3)5](2-) was obtained by the reaction of [NbO(N3)3] with two equivalents of ionic azide. The novel niobium oxoazides were fully characterized by their vibrational spectra, impact, friction and thermal sensitivity data and, in the case of [(bipy)NbO(N3)3], Cs2[NbO(N3)5], and [PPh4]2[NbO2(N3)5] by their X-ray crystal structures. PMID:27198621

  8. Human Collagen Prolyl 4-Hydroxylase Is Activated by Ligands for Its Iron Center.

    Science.gov (United States)

    Vasta, James D; Raines, Ronald T

    2016-06-14

    Collagen is the most abundant protein in animals. The posttranslational hydroxylation of proline residues in collagen contributes greatly to its conformational stability. Deficient hydroxylation is associated with a variety of disease states, including scurvy. The hydroxylation of proline residues in collagen is catalyzed by an Fe(II)- and α-ketoglutarate-dependent dioxygenase, collagen prolyl 4-hydroxylase (CP4H). CP4H has long been known to suffer oxidative inactivation during catalysis, and the cofactor ascorbate (vitamin C) is required to reactivate the enzyme by reducing its iron center from Fe(III) to Fe(II). Herein, we report on the discovery of the first synthetic activators of CP4H. Specifically, we find that 2,2'-bipyridine-4-carboxylate and 2,2'-bipyridine-5-carboxylate serve as ligands for the iron center in human CP4H that enhance the rate of ascorbate-dependent reactivation. This new mode of CP4H activation is available to other biheteroaryl compounds but does not necessarily extend to other prolyl 4-hydroxylases. As collagen is weakened in many indications, analogous activators of CP4H could have therapeutic benefits. PMID:27183028

  9. Luminescent lanthanide complexes with 4-acetamidobenzoate: Synthesis, supramolecular assembly via hydrogen bonds, crystal structures and photoluminescence

    Science.gov (United States)

    Yin, Xia; Fan, Jun; Wang, Zhi Hong; Zheng, Sheng Run; Tan, Jing Bo; Zhang, Wei Guang

    2011-07-01

    Four new luminescent complexes, namely, [Eu(aba) 2(NO 3)(C 2H 5OH) 2] ( 1), [Eu(aba) 3(H 2O) 2]·0.5 (4, 4'-bpy)·2H 2O ( 2), [Eu 2(aba) 4(2, 2'-bpy) 2(NO 3) 2]·4H 2O ( 3) and [Tb 2(aba) 4(phen) 2(NO 3) 2]·2C 2H 5OH ( 4) were obtained by treating Ln(NO 3) 3·6H 2O and 4-acetamidobenzoic acid (Haba) with different coligands (4, 4'-bpy=4, 4'-bipyridine, 2, 2'-bpy=2, 2'-bipyridine, and phen=1, 10-phenanthroline). They exhibit 1D chains ( 1- 2) and dimeric structures ( 3- 4), respectively. This structural variation is mainly attributed to the change of coligands and various coordination modes of aba molecules. Moreover, the coordination units are further connected via hydrogen bonds to form 2D even 3D supramolecular networks. These complexes show characteristic emissions in the visible region at room temperature. In addition, thermal behaviors of four complexes have been investigated under air atmosphere. The relationship between the structures and physical properties has been discussed.

  10. Coupling of metal-based light-harvesting antennas and electron-donor subunits: Trinuclear Ruthenium(II) complexes containing tetrathiafulvalene-substituted polypyridine ligands

    DEFF Research Database (Denmark)

    Campagna, Sebastiano; Serroni, Scolastica; Puntoriero, Fausto;

    2002-01-01

    +) (4,4'-Mebpy = 4,4'-dimethyl-2,2'-bipyridine) and [{(bpy)(2)Ru(mu-2,3-dpp)}(2)Ru(bpy)](6+). The absorption spectra and redox behavior of all the new metal compounds can be interpreted by a multicomponent approach, in which specific absorption features and redox processes can be assigned to specific......Three new tetrathiafulvalene-substituted 2,2'-bipyridine ligands, cis-bpy-TTF1, trans-bpy-TTF1, and cis-bpy-TTF2 have been prepared and characterized. X-ray analysis of trans-bpy-TTF1, is also reported. Such ligands have been used to prepare two new trinuclear Ru-II complexes, namely, [{(bpy)(2)Ru...... as light-harvesting antennas and the tetrathiafulvalene electron donors can induce charge separation. The absorption spectra, redox behavior, and luminescence properties (both at room temperature in acetonitrile and at 77 K in a rigid matrix of butyronitrile) of the trinuclear metal complexes have been...

  11. Tetranuclear polybipyridyl complexes of Ru(II) and Mn(II), their electro- and photo-induced transformation into di-mu-oxo Mn(III)Mn(IV) hexanuclear complexes.

    Science.gov (United States)

    Romain, Sophie; Baffert, Carole; Dumas, Stéphane; Chauvin, Jérôme; Leprêtre, Jean-Claude; Daveloose, Denis; Deronzier, Alain; Collomb, Marie-Noëlle

    2006-12-28

    Three heterotetranuclear complexes, [{Ru(II)(bpy)(2)(L(n))}(3)Mn(II)](8+) (bpy = 2,2'-bipyridine, n = 2, 4, 6), in which a Mn(II)-tris-bipyridine-like centre is covalently linked to three Ru(II)-tris-bipyridine-like moieties using bridging bis-bipyridine L(n) ligands, have been synthesised and characterised. The electrochemical, photophysical and photochemical properties of these complexes have been investigated in CH(3)CN. The cyclic voltammograms of the three complexes exhibit two successive very close one-electron metal-centred oxidation processes in the positive potential region. The first, which is irreversible, corresponds to the Mn(II)/Mn(III) redox system (E(pa) approximately 0.82 V vs Ag/Ag(+) 0.01 M in CH(3)CN-0.1 M Bu(4)NClO(4)), whereas the second which is, reversible, is associated with the Ru(II)/Ru(III) redox couple (E(1/2) approximately 0.91 V). In the negative potential region, three successive reversible four electron systems are observed, corresponding to ligand-based reduction processes. The three stable dimeric oxidized forms of the complexes, [Mn(2)(III,IV)O(2){Ru(II)(bpy)(2)(L(n))}(4)](11+), [Mn(2)(IV,IV)O(2){Ru(II)(bpy)(2)(L(n))}(4)](12+) and [Mn(2)(IV,IV)O(2){Ru(III)(bpy)(2)(L(n))}(4)](16+) are obtained in fairly good yields by sequential electrolyses after consumption of respectively 1.5, 0.5 and 3 electrons per molecule of initial tetranuclear complexes. The formation of the di-micro-oxo binuclear complexes are the result of the instability of the {[Ru(II)(bpy)(2)(L(n))](3)Mn(III)}(9+) species, which react with residual water, via a disproportionation reaction and the release of one ligand, [Ru(II)(bpy)(2)(L(n))](2+). A quantitative yield can be obtained for these reactions if the electrochemical oxidations are performed in the presence of an added external base like 2,6-dimethylpyridine. Photophysical properties of these compounds have been investigated showing that the luminescence of the Ru(II)-tris-bipyridine-like moieties is little

  12. Influence of selenocyanate ligands on the transition temperature and cooperativity of bapbpy-based Fe(II) spin-crossover compounds.

    Science.gov (United States)

    Zheng, Sipeng; Siegler, Maxime A; Roubeau, Olivier; Bonnet, Sylvestre

    2014-12-15

    Coordination of the ligand bapbpy (1, bapbpy = N,N'-di(pyrid-2-yl)-2,2'-bipyridine-6,6'-diamine), of one of its four dimethyl-substituted analogues 2-5 (R2bapbpy = N,N'-di(methylpyrid-2-yl)-2,2'-bipyridine-6,6'-diamine), or of one of its three bis(iso)quinoline analogues 6-8 (R2bapbpy= N,N'-di(quinolyl)-2,2'-bipyridine-6,6'-diamine), to Fe(NCSe)2, afforded eight new iron(II) compounds of the type [Fe(R2bapbpy)(NCSe)2] (9-16). Three of these compounds (11, 13, and 16) were structurally characterized by single crystal X-ray diffraction, which showed similar molecular geometry and packing compared to their thiocyanate analogues. Magnetic susceptibility measurements were carried out for all iron compounds and revealed thermal spin-crossover (SCO) behavior for compounds 9, 11, 13, 15, and 16. Compounds 11, 13, 15, and 16 show an increased transition temperature compared to the thiocyanate analogues. [Fe(bapbpy)(NCSe)2] (9) shows a gradual, one-step SCO, whereas its thiocyanate analogue [Fe(bapbpy)(NCS)2] is known for its cooperative two-step SCO. To discuss the influence of S-to-Se substitution on the cooperativity of the SCO, heat capacity measurements were carried out for compounds 9, 11, 13, 15, and 16, and fitted to the Sorai domain model. The number n of like-spin SCO centers per interacting domain, which is a quantitative measure of the cooperativity of the spin transition, was found to be high for compounds 11 and 15, and low for compounds 9, 11, and 13. Compound 15 is one of the few known SCO compounds that is more cooperative than its thiocyanate analogue. Altogether, X-ray diffraction, calorimetry, and magnetic data give a consistent structure-property relationship for this family of compounds: hydrogen-bonding networks made of intermolecular N-H···Se interactions are of paramount importance for the cooperativity of the SCO. PMID:25411921

  13. Cytotoxicity of Ru(II) piano-stool complexes with chloroquine and chelating ligands against breast and lung tumor cells: Interactions with DNA and BSA.

    Science.gov (United States)

    Colina-Vegas, Legna; Villarreal, Wilmer; Navarro, Maribel; de Oliveira, Clayton Rodrigues; Graminha, Angélica E; Maia, Pedro Ivo da S; Deflon, Victor M; Ferreira, Antonio G; Cominetti, Marcia Regina; Batista, Alzir A

    2015-12-01

    The synthesis and spectroscopic characterization of nine π-arene piano-stool ruthenium (II) complexes with aromatic dinitrogen chelating ligands or containing chloroquine (CQ), are described in this study: [Ru(η(6)-C10H14)(phen)Cl]PF6 (1), [Ru(η(6)-C10H14)(dphphen)Cl]PF6 (2), [Ru(η(6)-C10H14)(bipy)Cl]PF6 (3), [Ru(η(6)-C10H14)(dmebipy)Cl]PF6 (4) and [Ru(η(6)-C10H14)(bdutbipy)Cl]PF6 (5), [Ru(η(6)-C10H14)(phen)CQ](PF6)2 (6), [Ru(η(6)-C10H14)(dphphen)CQ](PF6)2 (7), [Ru(η(6)-C10H14)(bipy)CQ](PF6)2 (8), [Ru(η(6)-C10H14)(dmebipy)CQ](PF6)2 (9): [1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (dphphen), 2,2'-bipyridine (bipy), 5,5'-dimethyl-2,2'-bipyridine (dmebipy), and 4,4'-di-t-butyl-2,2'-bipyridine (dbutbipy)]. The solid state structures of five ruthenium complexes (1-5) were determined by X-ray crystallography. Electrochemical experiments were performed by cyclic voltammetry to estimate the redox potential of the Ru(II)/Ru(III) couple in each case. Their interactions with DNA and BSA, and activity against four cell lines (L929, A549, MDA-MB-231 and MCF-7) were evaluated. Compounds 2, 6 through 9, interact with DNA which was comparable to the one observed for free chloroquine. The results of fluorescence titration revealed that these complexes strongly quenched the intrinsic fluorescence of BSA following a static quenching procedure. Binding constants (Kb) and the number of binding sites (n~1) were calculated using modified Stern-Volmer equations. The thermodynamic parameters ΔG at different temperatures were calculated and subsequently the values of ΔH and ΔS were also calculated, which revealed that hydrophobic and electrostatic interactions play a major role in the BSA-complex association. The MTT assay results indicated that complexes 2, 5 and 7 showed cytostatic effects at appreciably lower concentrations than those needed for cisplatin, chloroquine and doxorubicin.

  14. Cytotoxicity of Ru(II) piano-stool complexes with chloroquine and chelating ligands against breast and lung tumor cells: Interactions with DNA and BSA.

    Science.gov (United States)

    Colina-Vegas, Legna; Villarreal, Wilmer; Navarro, Maribel; de Oliveira, Clayton Rodrigues; Graminha, Angélica E; Maia, Pedro Ivo da S; Deflon, Victor M; Ferreira, Antonio G; Cominetti, Marcia Regina; Batista, Alzir A

    2015-12-01

    The synthesis and spectroscopic characterization of nine π-arene piano-stool ruthenium (II) complexes with aromatic dinitrogen chelating ligands or containing chloroquine (CQ), are described in this study: [Ru(η(6)-C10H14)(phen)Cl]PF6 (1), [Ru(η(6)-C10H14)(dphphen)Cl]PF6 (2), [Ru(η(6)-C10H14)(bipy)Cl]PF6 (3), [Ru(η(6)-C10H14)(dmebipy)Cl]PF6 (4) and [Ru(η(6)-C10H14)(bdutbipy)Cl]PF6 (5), [Ru(η(6)-C10H14)(phen)CQ](PF6)2 (6), [Ru(η(6)-C10H14)(dphphen)CQ](PF6)2 (7), [Ru(η(6)-C10H14)(bipy)CQ](PF6)2 (8), [Ru(η(6)-C10H14)(dmebipy)CQ](PF6)2 (9): [1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (dphphen), 2,2'-bipyridine (bipy), 5,5'-dimethyl-2,2'-bipyridine (dmebipy), and 4,4'-di-t-butyl-2,2'-bipyridine (dbutbipy)]. The solid state structures of five ruthenium complexes (1-5) were determined by X-ray crystallography. Electrochemical experiments were performed by cyclic voltammetry to estimate the redox potential of the Ru(II)/Ru(III) couple in each case. Their interactions with DNA and BSA, and activity against four cell lines (L929, A549, MDA-MB-231 and MCF-7) were evaluated. Compounds 2, 6 through 9, interact with DNA which was comparable to the one observed for free chloroquine. The results of fluorescence titration revealed that these complexes strongly quenched the intrinsic fluorescence of BSA following a static quenching procedure. Binding constants (Kb) and the number of binding sites (n~1) were calculated using modified Stern-Volmer equations. The thermodynamic parameters ΔG at different temperatures were calculated and subsequently the values of ΔH and ΔS were also calculated, which revealed that hydrophobic and electrostatic interactions play a major role in the BSA-complex association. The MTT assay results indicated that complexes 2, 5 and 7 showed cytostatic effects at appreciably lower concentrations than those needed for cisplatin, chloroquine and doxorubicin. PMID:26277415

  15. Synthesis and Crystal Structure of Zinc Complex [Zn(bipy)3][Zn(SCN)4

    Institute of Scientific and Technical Information of China (English)

    何翔; 卢灿忠; 张全争

    2005-01-01

    The hydrothermal reaction of thiocyanate, 2,2'-bipyridine and ZnⅡ in basified aqueous solutions gave rise to complex [Zn(bipy)3][Zn(SCN)4] 1 (C34H24N1oS4Zn2) which was characterized by X-ray diffraction analysis. Crystal data for 1: monoclinic, space group P21/n, Mr= 831.61, Z= 4, a = 15.920(3), b = 13.5201(17), c = 17.362(3) (A), β= 99.467(9)°, V= 3686.1(10) (A)3, Dc= 1.499 g/cm3, μ = 1.568 mm-1, F(000) = 1688, R = 0.0586 and wR = 0.1354 for 5604 observed reflections (I > 2σ(I)). The photoluminescence spectrum for the title compound has also been studied.

  16. Synthesis, Characterization, and Crystal Structure Determination of a New Indium (III) Complex: [In(5,5’-DiMeBiPy)Cl3(DMSO)].2(DMSO)

    OpenAIRE

    Sadif A. Shirvan; Fereydoon Khazali; Sara Haydari Dezfuli

    2014-01-01

    [In(5,5’-DiMeBiPy)Cl3(DMSO)].2(DMSO) complex (5,5’-DiMeBiPy is 5,5’-Dimethyl-2,2’-bipyridine) was prepared from reaction of InCl3.4H2O with 5,5’-DiMeBiPy in 1.1 molar ratio in DMSO. This compound has been characterized by IR, 1H NMR, UV-Vis spectroscopy as well as X-ray crystallography. This compound crystallizes in the space group Pī of the triclinic system. The unit cell dimensions is: a = 8.6695(8) Å, b = 12.8456(14) Å, c = 13.0877(12) Å, a = 78.258(8)º, β = 85.270(8)º, g = 74.932(8)º. Acc...

  17. Fluoride Bridges as Structure-Directing Motifs in 3d-4f Cluster Chemistry

    DEFF Research Database (Denmark)

    Birk, Torben; Pedersen, Kasper; Thuesen, Christian Aa.;

    2012-01-01

    ,2′-bipyridine (“bpy”)) with Ln(NO3)3·xH2O produces isostructural series of molecular {Ln2Cr2} squares (1–9) with linear fluoride bridges. In a parallel fashion, fac-[CrIIIF3L], where L = N,N′,N″-trimethyl-1,4,7-triazacyclononane (“Me3tacn”), reacts with Nd(NO3)3·6H2O to form a fluoride-centered penta...... by a partial solvolysis of the Cr(III) precursor but without formation of insoluble LnF3. The magnetic properties of the gadolinium containing clusters allow quantification of fluoride-mediated, antiferromagnetic Gd–Cr exchange interactions of magnitude between 0.14 cm–1 and 0.71 cm–1 (Ĥ = J12Ŝ1·Ŝ2...

  18. Ruthenium(ii) complexes with dppz: from molecular photoswitch to biological applications.

    Science.gov (United States)

    Li, Guanying; Sun, Lingli; Ji, Liangnian; Chao, Hui

    2016-09-14

    The DNA photoswitch [Ru(bpy)2dppz](2+) (bpy = 2,2'-bipyridine, dppz = dipyrido[3,2-a:2',3'-c]phenazine) has attracted much attention and become a powerful tool for studying the interaction of metal polypyridyl complexes with DNA. A large number of Ru-dppz complexes have been designed for a wide range of uses in many fields. In this perspective, we first introduce the latest results of Ru-dppz complexes that bind with DNA. The mechanisms of the light-switch effect and the structural modifications of Ru-dppz systems are also briefly introduced. We also review the recent advances in biological applications of the Ru-dppz system in DNA binders, cellular imaging, anticancer drugs, protein aggregation detection and chemosensors. PMID:27426487

  19. Chemisorption of a thiol-functionalized ruthenium dye on zinc oxide nanoparticles: Implications for dye-sensitized solar cells

    Science.gov (United States)

    Singh, Jagdeep; Im, Jisun; Whitten, James E.; Soares, Jason W.; Steeves, Diane M.

    2010-09-01

    ZnO is an alternative to TiO 2-based dye-sensitized solar cells (DSSCs). Adsorption of cis-ruthenium-bis[2,2'-bipyridine]-bis[4-thiopyridine] onto ZnO nanorods has been studied using X-ray and ultraviolet photoelectron spectroscopies (XPS and UPS). XPS indicates chemisorption with a surface density of ca. 1 × 10 15 molecules/cm 2, confirming the possibility of using thiol-terminated dyes for ZnO-based DSSC devices. The energy level diagram, based on UPS and absorbance spectroscopy, indicates that the LUMO of this dye is lower in energy than the ZnO conduction band edge, providing minimal enthalpic driving force for photovoltaic electron injection. However, optimization of thiol-functionalized Ru dyes could result in competitive ZnO-based DSSCs.

  20. Titania modification with a ruthenium(II) complex and gold nanoparticles for photocatalytic degradation of organic compounds

    OpenAIRE

    Zheng, Shuaizhi; Wei, Zhishun; Yoshiiri, Kenta; Braumueller, Markus; Ohtani, Bunsho; Rau, Sven; Kowalska, Ewa

    2016-01-01

    Titania of fine anatase nanoparticles (ST01) was modified successively with two components, i.e., a ruthenium(II) complex with phosphonic anchoring groups [Ru(bpy)(2)(4,4'-(CH2PO3H2)(2)bpy)](2+) bpy = 2,2'-bipyridine ((RuCP)-C-II) and gold nanoparticles (Au). Various compositions of two titania modifiers were investigated, i.e., Au, Au + (RuCP)-C-II, Au + 0.5Ru(II)CP, (RuCP)-C-II, 0.5Ru(II)CP and 0.25Ru(II)CP, where Au and (RuCP)-C-II correspond to 0.81 mol% and 0.34 mol% (with respect to tit...

  1. Electroreduction of O{sub 2} at a mediated Melanocarpus albomyces laccase cathode in a physiological buffer

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, Paul; Jenkins, Peter; Leech, Donal [Department of Chemistry, National University of Ireland, Galway (Ireland)

    2008-07-15

    We report on oxygen reduction in a physiological buffer solution (0.05 M phosphate buffer containing dissolved O{sub 2}, 0.1 M NaCl, pH 7.4, 37 C) by Melanocarpus albomyces laccase, co-immobilized with [Os(2,2'-bipyridine){sub 2}(polyvinylimidazole){sub 10}Cl]{sup +/2+} as a mediator, on glassy carbon electrodes. Such oxygen cathodes yielded current densities of 3.8 mA cm{sup -2} at 0.2 V vs. Ag/AgCl, the largest current density reported to date for a mediated laccase cathode in physiological buffer solutions, showing promise for development of biocatalytic fuel cell prototypes. (author)

  2. Fluorescence quenching effect of metal ions for α,α'-diamine containing conjugated polymers in solid films

    Institute of Scientific and Technical Information of China (English)

    TIAN Leilei; ZHANG Ming; LU Ping; ZHANG Wu; YANG Bing; MA Yuguang

    2004-01-01

    The fluorescence quenching effect of the conjugated polymers P1 and P2 (the molecular recognitions are twisted 2,2′-bipyridine (bpy) and planar 1,10-phenanthrolin (phen), respectively) films upon the addition of metal ions has been studied. And the results showed that P2 exhibited stronger fluorescence quenching ability upon the addition of both transition metal ions and main group metal ions compared with that of P1. The 20° twist angle between the two consecutive pyridine rings of bpy unit in the P1 main chain is the reason for the weaker fluorescence quenching ability compared with P2, in which the planar phen unit can chelate with metal ions relatively freely without the conformational transition. So P2 is a kind of material with better properties for solid film devices, such as sensors for metal ions recognition.

  3. Effect of particle size and alloying with different metals on {sup 57}Fe Moessbauer spectra

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Rabia; Mazhar, Muhammad, E-mail: mazhar42pk@yahoo.com [Quaid-i-Azam University, Department of Chemistry (Pakistan); Siddique, Muhammad [PINSTECH, Physics Division (Pakistan); Hussain, S. Tajammul [Quaid-i-Azam University, Department of Chemistry (Pakistan)

    2009-02-15

    Iron nanoparticles of various sizes have been synthesized using the chemical route which involves the preparation of iron bipyridine complexes in presence of different capping agents followed by thermal decomposition at 450 deg. C in inert atmosphere. The bimetallic nanoalloys of Fe with Mg and Pd have also been prepared by following the same route. The resulting nanoparticles have been characterized by EDX-RF, XRD, AFM and {sup 57}Fe Moessbauer spectroscopy. The appearance of quadrupole doublets in the Moessbauer spectra of Fe nanoparticles indicates the absence of magnetic interaction and variation in parameters is due to the varying particle size. The Moessbauer spectrum of Fe-Mg{sub 2} bimetallic nanoalloy shows two doublets indicating the presence of superparamagnetism. The two doublets can be attributed to change in s-electron density of iron resulting from its two neighboring magnesium atoms. Fe-Pd nanoalloy Moessbauer spectrum is characterized by having a superparamagnetic doublet and a ferromagnetic sextet.

  4. Gradients of Rectification: Tuning Molecular Electronic Devices by the Controlled Use of Different-Sized Diluents in Heterogeneous Self-Assembled Monolayers.

    Science.gov (United States)

    Kong, Gyu Don; Kim, Miso; Cho, Soo Jin; Yoon, Hyo Jae

    2016-08-22

    Molecular electronics has received significant attention in the last decades. To hone performance of devices, eliminating structural defects in molecular components inside devices is usually needed. We herein demonstrate this problem can be turned into a strength for modulating the performance of devices. We show the systematic dilution of a monolayer of an organic rectifier (2,2'-bipyridine-terminated n-undecanethiolate) with electronically inactive diluents (n-alkanethiolates of different lengths), gives remarkable gradients of rectification. Rectification is finely tunable in a range of approximately two orders of magnitude, retaining its polarity. Trends of rectification against the length of the diluent indicate the gradient of rectification is extremely sensitive to the molecular structure of the diluent. Further studies reveal that noncovalent intermolecular interactions within monolayers likely leads to gradients of structural defect and rectification. PMID:27443577

  5. SYNTHESIS, CRYSTAL STRUCTURE AND LUMINESCENT PROPERTY OF A DINUCLEAR Tb(II COMPLEX WITH HOMOPHTHALIC ACID AND 2,2’-BIPYRIDYL

    Directory of Open Access Journals (Sweden)

    LI-HUA WANG

    2015-07-01

    Full Text Available A novel dinuclear Tb(III complex, [Tb(bpy2L2] (bpy = 2,2’-bipyridine, H2L = homophthalic acid, has been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Tb(III complex is monoclinic, space group P21/c with a = 9.368(2 Å, b = 15.948(4 Å, c = 12.216(3 Å, β = 103.023(4º, V= 1778.2(7 Å3, Z = 2, Dc = 1.910 mg·m-3, μ = 4.011 mm-1, F(000 = 996, and final R1 = 0.0602, ωR2 = 0.2192. The result shows that the Tb(III center is seven-coordination with a N2O5 distorted pengonal bipyramidal geometry. The luminescent property of Tb(III complex was investigated.

  6. Role of substituents on the reactivity and electron density profile of diimine ligands: A density functional theory based study

    Indian Academy of Sciences (India)

    Bhakti S Kulkarni; Deepti Mishra; Sourav Pal

    2013-09-01

    In this paper, we study the reactivity of diimines like 2, 2'-bipyridine, 1, l0-phenanthroline and 1, 2, 4-triazines using density-based reactivity descriptors. We discuss the enhancement or diminution in the reactivity of these ligands as a function of two substituent groups, namely methyl (-CH3) group and phenyl (-C6H5) group. The global reactivity descriptors explain the global affinity and philicity of these ligands, whereas the local softness depicts the particular site selectivity. The inter-molecular reactivity trends for the same systems are analysed through the philicity and group philicity indices. The -donor character of these ligands is quantified with the help of electron density profile. In addition, the possible strength of interaction of these ligands with metal ions is supported with actual reaction energies of Ru-L complexes.

  7. Synthesis and Crystal Structure of the First Hybrid Manganese Phosphate with 1-D Framework of Dinuclear Structure

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel hybrid manganese phosphate, [(bipy)Mn(H2PO4)2] (bipy = 2,2'-bipyridine) 1, was synthesized, and its structure is characteristic of 1-D framework involving a dinuclear structure made up of edge-sharing Mn(II) octahedra. 1 crystallizes in the monoclinic system, space group C2/c with a = 12.230(2), b = 17.800(4), c = 13.530(3)(A), β = 105.00(3)o, V = 2845.0(10)(A)3, Z = 8. Dc = 1.892 g/cm3, F(000) = 1640, Mr = 405.10, μ(MoKα) = 1.198 mm-1, R = 0.0306 and wR = 0.0657 for 2093 observed reflections (I > 2σ(I)).

  8. Electronic Spectra of Bare and Solvated Ruthenium Polypyridine Complexes

    Science.gov (United States)

    Xu, Shuang; Smith, James E. T.; Weber, J. Mathias

    2016-06-01

    We present work on a prototypical water oxidation catalyst, namely the aqua-complex [(bpy)(tpy)Ru-OH_2]2+ (2,2'-bpy = bipyridine, tpy = 2,2':6',2"-terpyridine), and its hydrated clusters [(bpy)(tpy)Ru-OH_2]2+ ·(H2O)_n, with n = 1 - 4. This complex is the starting species in a catalytic cycle for water oxidation. We couple electrospray ionization mass spectrometry with laser spectroscopy to circumvent challenges that arise in reactive solutions from speciation. Here, we report the electronic spectrum of [(bpy)(tpy)Ru-OH_2]2+ by photodissociation spectroscopy of mass selected, cryogenically prepared ions, and we examine effects of its microhydration environment on its electronic structure. In particular, we investigate the solvatochromic shift of the spectral envelope upon sequential addition of water molecules up to the tetrahydrate.

  9. A quantum chemical study from a molecular perspective: ionization and electron attachment energies for species often used to fabricate single-molecule junctions

    CERN Document Server

    Baldea, Ioan

    2015-01-01

    The accurate determination of the lowest electron attachment ($EA$) and ionization ($IP$) energies for molecules embedded in molecular junctions is important for correctly estimating, \\emph{e.g.}, the magnitude of the currents ($I$) or the biases ($V$) where an $I-V$-curve exhibits a significant non-Ohmic behavior. Benchmark calculations for the lowest electron attachment and ionization energies of several typical molecules utilized to fabricate single-molecule junctions characterized by n-type conduction (4,4'-bipyridine, 1,4-dicyanobenzene, and 4,4'-dicyano-1,1'-biphenyl) and p-type conduction (benzenedithiol, biphenyldithiol, hexanemonothiol, and hexanedithiol] based on the EOM-CCSD (equation-of-motion coupled-cluster singles and doubles) state-of-the-art method of quantum chemistry are presented. They indicate significant differences from the results obtained within current approaches to molecular transport. The present study emphasizes that, in addition to a reliable quantum chemical method, basis sets m...

  10. Allosteric Regulation of Unidirectional Spring-like Motion of Double-Stranded Helicates.

    Science.gov (United States)

    Suzuki, Yoshimasa; Nakamura, Taiki; Iida, Hiroki; Ousaka, Naoki; Yashima, Eiji

    2016-04-13

    We report the unprecedented allosteric regulation of the extension and contraction motions of double-stranded spiroborate helicates composed of 4,4'-linked 2,2'-bipyridine (bpy) and its N,N'-dioxide units in the middle of ortho-linked tetraphenol strands. NMR and circular dichroism measurements and an X-ray crystallographic analysis along with theoretical calculations revealed that enantiomeric helicates contract and extend upon the binding and release of protons and/or metal ions at the covalently linked two binding bpy or N,N'-dioxide moieties without racemization, respectively, regulated by a cooperative anti-syn conformational change of the two bpy or N,N'-dioxide moieties. These anti-syn conformational changes that occurred at the linkages are amplified into a large-scale molecular motion of the helicates leading to reversible spring-like motions coupled with twisting in one direction in a highly homotropic allosteric fashion. PMID:26910831

  11. Theoretical oxidation state analysis of Ru-(bpy)3: Influence of water solvation and Hubbard correction in first-principles calculations

    International Nuclear Information System (INIS)

    Oxidation state is a powerful concept that is widely used in chemistry and materials physics, although the concept itself is arguably ill-defined quantum mechanically. In this work, we present impartial comparison of four, well-recognized theoretical approaches based on Lowdin atomic orbital projection, Bader decomposition, maximally localized Wannier function, and occupation matrix diagonalization, for assessing how well transition metal oxidation states can be characterized. Here, we study a representative molecular complex, tris(bipyridine)ruthenium. We also consider the influence of water solvation through first-principles molecular dynamics as well as the improved electronic structure description for strongly correlated d-electrons by including Hubbard correction in density functional theory calculations

  12. A trinuclear ruthenium complex as a highly efficient molecular catalyst for water oxidation.

    Science.gov (United States)

    Zhang, L L; Gao, Y; Liu, Z; Ding, X; Yu, Z; Sun, L C

    2016-03-01

    A trinuclear ruthenium complex, 3, was designed and synthesized with the ligand 2,2'-bipyridine-6,6'-dicarboxylic acid (bda) and we found that this complex could function as a highly efficient molecular catalyst for water oxidation in homogeneous systems. This trinuclear molecular water oxidation catalyst, 3, displayed much higher efficiencies in terms of turnover numbers and initial oxygen evolution rate than its counterparts, a binuclear catalyst, 2, and a mononuclear catalyst, 1, in both chemically driven and photochemically driven water oxidation based on either the whole catalytic molecules or just the active Ru centers. The reasons for the superior performance of catalyst 3 were discussed and we believe that multiple Ru centers in a single molecule are indeed beneficial for increasing the probability of the formation of O-O bonds through an intramolecular radical coupling pathway.

  13. Molecular orientation of hydrogen-bonded liquid crystal (6BA){sub 2}-(BPy){sub x} as Studied by {sup 2}H NMR

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, M., E-mail: mizuno@se.kanazawa-u.ac.jp; Higashima, Y.; Yamashita, A.; Ishida, Y.; Miyatou, T.; Kumagai, Y.; Ohashi, R.; Ida, T. [Kanazawa University, Kakuma, Department of Chemistry, Graduate School of Natural Science & Technology (Japan)

    2015-04-15

    The thermal properties of hydrogen-bonded liquid crystal (6BA){sub 2}-(BPy){sub x} (6BA: 4-n-hexylbenzoicacid, BPy: 4,4’-bipyridine) were investigated by DSC. Two liquid crystal phases (LC{sub I}, LC{sub II}) were found for (6BA){sub 2}-(BPy){sub 0.5}. In LC{sub II}, the distribution of the orientation of molecules was larger than in LC{sub I}. The order parameter S of molecular orientation in the liquid crystal phase was estimated from a {sup 2}H NMR spectrum. S decreased rapidly around the LC{sub I}-LC{sub II} phase transition. The increase in orientational fluctuation of the 6BA dimer with an open dimer structure is predicted to cause the rapid decrease of S.

  14. Electrostatic-assembly-driven formation of supramolecular rhombus microparticles and their application for fluorescent nucleic acid detection.

    Directory of Open Access Journals (Sweden)

    Hailong Li

    Full Text Available In this paper, we report on the large-scale formation of supramolecular rhombus microparticles (SRMs driven by electrostatic assembly, carried out by direct mixing of an aqueous HAuCl(4 solution and an ethanol solution of 4,4'-bipyridine at room temperature. We further demonstrate their use as an effective fluorescent sensing platform for nucleic acid detection with a high selectivity down to single-base mismatch. The general concept used in this approach is based on adsorption of the fluorescently labeled single-stranded DNA (ssDNA probe by SRM, which is accompanied by substantial fluorescence quenching. In the following assay, specific hybridization with its target to form double-stranded DNA (dsDNA results in desorption of ssDNA from SRM surface and subsequent fluorescence recovery.

  15. Pair-distribution function analysis of the structural valence transition in Cp{sub 2}{sup *}Yb(4,4'-Me{sub 2}-bipy)

    Energy Technology Data Exchange (ETDEWEB)

    Booth, C H; Bauer, E D; Bozin, E S; Billinge, S J L; Walter, M D

    2010-07-20

    The Cp{sup *}{sub 2} Yb(L) class of compounds, where Cp{sup *}=pentamethylcyclopentadienyl = C{sub 5}Me{sub 5} and L is either a 1,4-diazabutadiene or bipy = 2,2'bipyridine related ligand, have provided excellent analogies to the Kondo state on the nanoscale. Cp{sup *}{sub 2} Yb(4,4'-Me{sub 2}-bipy) furthers this analogy by demonstrating a valence transition as the sample is cooled below 200 K. Here, pair-distribution function (PDF) analysis of x-ray powder diffraction data demonstrate that the Cp{sup *}{sub 2}Yb(4,4'Me{sub 2}-bipy) molecule is virtually unchanged through the valence transition. However, the molecule’s stacking arrangement is altered through the valence transition.

  16. Gradients of Rectification: Tuning Molecular Electronic Devices by the Controlled Use of Different-Sized Diluents in Heterogeneous Self-Assembled Monolayers.

    Science.gov (United States)

    Kong, Gyu Don; Kim, Miso; Cho, Soo Jin; Yoon, Hyo Jae

    2016-08-22

    Molecular electronics has received significant attention in the last decades. To hone performance of devices, eliminating structural defects in molecular components inside devices is usually needed. We herein demonstrate this problem can be turned into a strength for modulating the performance of devices. We show the systematic dilution of a monolayer of an organic rectifier (2,2'-bipyridine-terminated n-undecanethiolate) with electronically inactive diluents (n-alkanethiolates of different lengths), gives remarkable gradients of rectification. Rectification is finely tunable in a range of approximately two orders of magnitude, retaining its polarity. Trends of rectification against the length of the diluent indicate the gradient of rectification is extremely sensitive to the molecular structure of the diluent. Further studies reveal that noncovalent intermolecular interactions within monolayers likely leads to gradients of structural defect and rectification.

  17. Conversion of agonist site to metal-ion chelator site in the beta(2)-adrenergic receptor

    DEFF Research Database (Denmark)

    Elling, C E; Thirstrup, K; Holst, Birgitte;

    1999-01-01

    in the mutant receptors not by normal catecholamine ligands but instead either by free zinc ions or by zinc or copper ions in complex with small hydrophobic metal-ion chelators. Chelation of the metal ions by small hydrophobic chelators such as phenanthroline or bipyridine protected the cells from the toxic...... effect of, for example Cu(2+), and in several cases increased the affinity of the ions for the agonistic site. Wash-out experiments and structure-activity analysis indicated, that the high-affinity chelators and the metal ions bind and activate the mutant receptor as metal ion guided ligand complexes....... Because of the well-understood binding geometry of the small metal ions, an important distance constraint has here been imposed between TM-III and -VII in the active, signaling conformation of 7TM receptors. It is suggested that atoxic metal-ion chelator complexes could possibly in the future be used...

  18. Synthesis, Bonding, and Reactivity of Vanadium(IV) Oxido-Fluorido Compounds with Neutral Chelate Ligands of the General Formula cis-[V(IV)(═O)(F)(L(N-N))2](+).

    Science.gov (United States)

    Passadis, Stamatis S; Tsiafoulis, Constantinos; Drouza, Chryssoula; Tsipis, Athanassios C; Miras, Haralampos N; Keramidas, Anastasios D; Kabanos, Themistoklis A

    2016-02-15

    Reaction of the oxidovanadium(IV)-L(N-N) species (L(N-N) is bipy = 2,2'-bipyridine or bipy-like molecules) with either BF4(-) or HF and/or KF results in the formation of compounds of the general formula cis-[V(IV)(═O)(F)(L(N-N))2](+). Structural and spectroscopic (electron paramagnetic resonance) characterization shows that these compounds are in the tetravalent oxidation state containing a terminal fluorido ligand. Density functional theory calculations reveal that the V(IV)-F bond is mainly electrostatic, which is reinforced by reactivity studies that demonstrate the nucleophilicity of the fluoride ligand in a halogen exchange reaction and in fluorination of various organic substrates.

  19. Luminescence of a conjugated polymer containing europium (III) chelate

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Hao; Xie, Fang, E-mail: xiefang4498@126.com

    2013-12-15

    A europium (III) chelate has been incorporated in a conjugated polymer, poly-[2,2′-bipyridine-5,5′-diyl-(2,5-dihexyl-1,4-phenylene)]. From the absorbance and emission spectra measurement and using the Judd–Ofelt theory, an efficient energy transfer between the conjugated polymer and the europium (III) chelate has been confirmed. The luminescence lifetime of Eu{sup 3+} ion in the conjugated polymer is 0.352 ms and the emission cross section of this material is 3.11×10{sup −21} cm{sup 2}. -- Highlights: • A europium chelate has been incorporated in a conjugated polymer. • Energy transfer in the conjugated polymer containing europium chelate is efficient. • The conjugated polymer containing europium chelate is a promising optical material.

  20. Activation of the CXCR3 chemokine receptor through anchoring of a small molecule chelator ligand between TM-III, -IV, and -VI

    DEFF Research Database (Denmark)

    Rosenkilde, Mette M; Andersen, Michael B; Nygaard, Rie;

    2006-01-01

    between the extracellular ends of transmembrane (TM) III and TM-IV to anchor aromatic chelators at a location corresponding to the presumed binding pocket for adrenergic receptor agonists. In this construct, free metal ions had no agonistic effect in accordance with the optimal geometry of the metal ion...... site in molecular models built over the inactive form of rhodopsin. In contrast, the aromatic chelators bipyridine or phenanthrolene in complex with Zn(II) or Cu(II) acted as potent agonists displaying signaling efficacies similar to or even better than the endogenous chemokine agonists. Molecular...... modeling and molecular simulations combined with mutational analysis indicated that the metal ion site-anchored chelators act as agonists by establishing an aromatic-aromatic, second-site interaction with TyrVI:16 on the inner face of TM-VI. It is noteworthy that this interaction required...

  1. In Vitro Polarized Resonance Raman Study of N719 and N719-TBP in Dye Sensitized Solar Cells

    DEFF Research Database (Denmark)

    Hassing, Søren; Jernshøj, Kit Drescher; Nguyen, Phuong Tuyet;

    2016-01-01

    Abstract: The working efficiency of dye-sensitized solar cells (DSCs) depends on the long-term stability of the dye itself and on the microscopic structure of the dye-semiconductor interface. Previous experimental studies of DSCs based on ruthenium dye with bipyridine ligands (N719) adsorbed...... of the scattered light is generally different from the polarization of the laser light. When the excitation is chosen within the visible absorption band of N719 only the skeleton ring-modes in N719 are enhanced and are observed as the most intense bands in the RRS spectra. We demonstrate by experimental results...... the adsorption of the dye on TiO2 can be obtained. Furthermore it is found that the polarization fluorescence anisotropy is very different for adsorbed and non-adsorbed dye molecules. This information is automatically obtained when processing the Raman data. The conclusion is that if the polarization properties...

  2. An investigation of the photosubstitution reaction between N719-dyed nanocrystalline TiO2 particles and 4-tert-butylpyridine

    DEFF Research Database (Denmark)

    Nour-Mohammadi, Farahnaz; Nguyen, Thai Hoang; Boschloo, Gerrit;

    2007-01-01

    The effect of high concentrations of the solar cell additive 4-tert-butylpyridine (4-TBP) on the stability and lifetime of the sensitizer [Ru(Hdcbpy)2(NCS)2]2-, 2(n-C4H9)4N+, (H2dcbpy=2,2′-bipyridine-4,4′-dicarboxylic acid), known as N719, has been evaluated based on kinetic data obtained from si......s-1, of the reaction between TiO2|N719+ and iodide. We conclude that the addition of 4-TBP to dye-sensitized solar cells (DSSC) does not decrease the lifetime of the N719 dye during normal solar cell operation at room temperature. © 2007 Elsevier B.V. All rights reserved...

  3. Synthesis of asymmetric supramolecular compounds using a Ni(0) catalysed homo-coupling approach.

    Science.gov (United States)

    Cassidy, Lynda; Horn, Sabine; Cleary, Laura; Halpin, Yvonne; Browne, Wesley R; Vos, Johannes G

    2009-05-28

    The synthesis and characterisation of a series of dinuclear ruthenium and osmium polypyridyl metal complexes based on the bridging ligands [5-(5'-bipyridin-2',2''-yl)-3-(pyridin-2-yl)]-1,2,4-triazole (Hpytr-bipy), 2,2'-bis(pyridin-2''yl)-5,5'-bis(pyridin-3''-yl) (bipy-bipy) and 5,5'-bis(pyridin-2''-yl)-3,3'-bis(1,2,4-triazole) (Hpytr-Hpytr) are reported. The dinuclear complexes have been synthesised via a Ni(0) catalysed cross-coupling reaction from brominated precursors. With this approach a mixture of three products is obtained, which are separated by chromatographic methods. The compounds obtained are characterised by elemental analysis, (1)H NMR, absorption and emission spectroscopy. The synthetic approach developed offers a new route to asymmetric multinuclear supramolecular structures that is complimentary to the complexes as ligands/complexes as metal approaches. PMID:19440590

  4. The first one-pot synthesis of metal-organic frameworks functionalised with two transition-metal complexes.

    Science.gov (United States)

    Platero-Prats, Ana E; Bermejo Gómez, Antonio; Samain, Louise; Zou, Xiaodong; Martín-Matute, Belén

    2015-01-01

    The synthesis of a metal-organic framework (UiO-67) functionalised simultaneously with two different transition metal complexes (Ir and Pd or Rh) through a one-pot procedure is reported for the first time. This has been achieved by an iterative modification of the synthesis parameters combined with characterisation of the resulting materials using different techniques, including X-ray absorption spectroscopy (XAS). The method also allows the first synthesis of UiO-67 with a very wide range of loadings (from 4 to 43 mol %) of an iridium complex ([IrCp*(bpydc)(Cl)Cl](2-) ; bpydc=2,2'-bipyridine-5,5'-dicarboxylate, Cp*=pentamethylcyclopentadienyl) through a pre-functionalisation methodology.

  5. Bis(μ-bis{[4-(2-pyridylpyrimidin-2-yl]sulfanyl}methanedisilver(I bis(perchlorate

    Directory of Open Access Journals (Sweden)

    Hai-Bin Zhu

    2010-12-01

    Full Text Available In the macrocyclic centrosymmetric dinuclear complex, [Ag2(C19H14N6S22](ClO42, the AgI atom, bis{[4-(2-pyridylpyrimidin-2-yl]sulfanyl}methane (2-bppt ligand and perchlorate anion each lie on a twofold rotation axis. The 2-bppt ligand chelates two four-coordinated AgI atoms through its two bipyridine-like arms. The O atoms of the perchlorate anion are disordered each over two positions of equal occupancy. Adjacent complex molecules are linked by π–π interactions between the pyridine and pyrimidine rings [centroid–centroid distance = 3.663 (8 Å].

  6. A solid-state electrochemiluminescence biosensing switch for detection of DNA hybridization based on ferrocene-labeled molecular beacon

    International Nuclear Information System (INIS)

    A solid-state electrochemiluminescence (ECL) biosensing switch incorporating quenching of ECL of ruthenium(II) tris-(bipyridine) (Ru(bpy)32+) by ferrocene (Fc) has been successfully developed for DNA hybridization detection. The important issue for this biosensing system is based on the ferrocene-labeled molecular beacon (Fc-MB), i.e. using the special Fc-MB to react with the target DNA and then change its structure, resulting in an ECL intensity change. Under the optimal conditions, the difference of ECL intensity before and after the hybridization reaction (ΔIECL) was linearly related to the concentration of the complementary sequence in the range of 10 fM-10 pM and the detection limit was down to 1.0 fM.

  7. Allosteric activation of membrane-bound glutamate receptors using coordination chemistry within living cells

    Science.gov (United States)

    Kiyonaka, Shigeki; Kubota, Ryou; Michibata, Yukiko; Sakakura, Masayoshi; Takahashi, Hideo; Numata, Tomohiro; Inoue, Ryuji; Yuzaki, Michisuke; Hamachi, Itaru

    2016-10-01

    The controlled activation of proteins in living cells is an important goal in protein-design research, but to introduce an artificial activation switch into membrane proteins through rational design is a significant challenge because of the structural and functional complexity of such proteins. Here we report the allosteric activation of two types of membrane-bound neurotransmitter receptors, the ion-channel type and the G-protein-coupled glutamate receptors, using coordination chemistry in living cells. The high programmability of coordination chemistry enabled two His mutations, which act as an artificial allosteric site, to be semirationally incorporated in the vicinity of the ligand-binding pockets. Binding of Pd(2,2‧-bipyridine) at the allosteric site enabled the active conformations of the glutamate receptors to be stabilized. Using this approach, we were able to activate selectively a mutant glutamate receptor in live neurons, which initiated a subsequent signal-transduction pathway.

  8. Poly[[bis(μ-4,4′-bipyridyl-κ2N:N′bis(thiocyanato-κNmanganese(II] diethyl ether disolvate

    Directory of Open Access Journals (Sweden)

    Mario Wriedt

    2010-07-01

    Full Text Available In the title compound, {[Mn(NCS2(C10H8N22]·2C4H10O}n, the MnII ion is coordinated by four N-bonded 4,4′-bipyridine (bipy ligands and two N-bonded thiocyanate anions in a distorted octahedral coordination geometry. The asymmetric unit consists of one MnII ion and two bipy ligands each located on a twofold rotation axis, as well as one thiocyanate anion and one diethyl ether molecule in general positions. In the crystal structure, the metal centers with terminally bonded thicyanate anions are bridged by the bipy ligands into layers parallel to (001. The diethyl ether solvent molecules occupy the voids of the structure.

  9. Synthesis, structure and fluorescence properties of a novel 3D Sr(II) coordination polymer

    Science.gov (United States)

    Tan, Yu-Hui; Xu, Qing; Gu, Zhi-Feng; Gao, Ji-Xing; Wang, Bin; Liu, Yi; Yang, Chang-Shan; Tang, Yun-Zhi

    2016-09-01

    Solvothermal reaction of 2,2‧-bipyridine-5,5‧-dicarboxylic acid (H2bpdc) and SrCl2 affords a novel coordination polymer [Sr(Hbpdc)2]n1. X-ray structure determination shows that 1 exhibits a novel three-dimensional network. The unique Sr II cation sits on a two-fold axis and coordinated by four O-atom donors from four Hbptc- ligands and four N-atom donors from two Hbptc- ligands in distorted dodecahedral geometry. In 1 each Sr II cation connects to six different Hbptc- ligands and each Hbptc- ligand bridges three different Sr II cations which results in the formation of a three-dimensional polymeric structure. Corresponding to the free ligand, the fluorescent emission of complex 1 display remarkable "Einstain" shifts, which may be attributed to the coordination interaction of Sr atoms, thus reduce the rigidity of pyridyl rings.

  10. Coordination behavior of N-benzoylamino acids: Synthesis and structure of mixed-ligand complexes of palladium(Ⅱ) with N-benzoylamino acid dianion and diamine

    Institute of Scientific and Technical Information of China (English)

    龚钰秋; 陈耀峰; 顾建明; 胡秀荣

    1997-01-01

    Four new mixed-ligand complexes of pailadiumt(Ⅱ) with L1(N-benzoyl-α-amino acid dianion) and L2[ethyldiamine (en),2,2’-bipyridine (Bpy) and 1,10-phenanthroline (Phen)] were synthesized.Ail the complexes have been characterized by elemental analyses,molar conductance,infrared and 1H NMR spectra and therme-gravimetric analyses.Crystal structures of [Pd(Bpy)(Bzval-N,O)] and [Pd(en) (Bzphe-N,O)] H2O have been do termmed by X-ray diffraction analysis.The results indicate that in all the complexes hgand L1 coordinates to palladium (Ⅱ) through deprotonated amide nitrogen and carboxylic oxygen,and there are some intramolecular nonrovalent in teractions in the complexes.

  11. Iodide Recognition and Sensing in Water by a Halogen-Bonding Ruthenium(II)-Based Rotaxane.

    Science.gov (United States)

    Langton, Matthew J; Marques, Igor; Robinson, Sean W; Félix, Vítor; Beer, Paul D

    2016-01-01

    The synthesis and anion-recognition properties of the first halogen-bonding rotaxane host to sense anions in water is described. The rotaxane features a halogen-bonding axle component, which is stoppered with water-solubilizing permethylated β-cyclodextrin motifs, and a luminescent tris(bipyridine)ruthenium(II)-based macrocycle component. (1) H NMR anion-binding titrations in D2 O reveal the halogen-bonding rotaxane to bind iodide with high affinity and with selectively over the smaller halide anions and sulfate. The binding affinity trend was explained through molecular dynamics simulations and free-energy calculations. Photo-physical investigations demonstrate the ability of the interlocked halogen-bonding host to sense iodide in water, through enhancement of the macrocycle component's Ru(II) metal-ligand charge transfer (MLCT) emission. PMID:26626866

  12. Selective Alcohol Oxidation by a Copper TEMPO Catalyst: Mechanistic Insights by Simultaneously Coupled Operando EPR/UV-Vis/ATR-IR Spectroscopy.

    Science.gov (United States)

    Rabeah, Jabor; Bentrup, Ursula; Stößer, Reinhard; Brückner, Angelika

    2015-09-28

    The first coupled operando EPR/UV-Vis/ATR-IR spectroscopy setup for mechanistic studies of gas-liquid phase reactions is presented and exemplarily applied to the well-known copper/TEMPO-catalyzed (TEMPO=(2,2,6,6-tetramethylpiperidin-1-yl)oxyl) oxidation of benzyl alcohol. In contrast to previous proposals, no direct redox reaction between TEMPO and Cu(I) /Cu(II) has been detected. Instead, the role of TEMPO is postulated to be the stabilization of a (bpy)(NMI)Cu(II) -O2 (⋅-) -TEMPO (bpy=2,2'-bipyridine, NMI=N-methylimidazole) intermediate formed by electron transfer from Cu(I) to molecular O2 . PMID:26174141

  13. The synthesis and unexpected solution chemistry of thermochromic carborane-containing osmium half-sandwich complexes.

    Science.gov (United States)

    Pitto-Barry, Anaïs; South, Amy; Rodger, Alison; Barry, Nicolas P E

    2016-01-28

    The functionalisation of the 16-electron complex [Os(η(6)-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)] (1) with a series of Lewis bases to give the 18-electron complexes of general formula [Os(η(6)-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)(L)] (L = pyridine (2), 4-dimethylaminopyridine (3), 4-cyanopyridine (4), 4-methoxypyridine (5), pyrazine (6), pyridazine (7), 4,4'-bipyridine (8) and triphenylphosphine (9)) is reported. All 18-electron complexes are in equilibrium in solution with the 16-electron precursor, and thermochromic properties are observed in some cases (2, 3, 5, 8, and 9). The binding constants and Gibbs free energies of the equilibria are determined using UV-visible titrations and their stabilities investigated. Synthetic routes for forcing the formation of the 18-electron species are proposed, and analytical methods to characterise the equilibria are described. PMID:26700880

  14. Septipyridines as conformationally controlled substitutes for inaccessible bis(terpyridine-derived oligopyridines in two-dimensional self-assembly

    Directory of Open Access Journals (Sweden)

    Daniel Caterbow

    2011-07-01

    Full Text Available The position of the peripheral nitrogen atoms in bis(terpyridine-derived oligopyridines (BTPs has a strong impact on their self-assembly behavior at the liquid/HOPG (highly oriented pyrolytic graphite interface. The intermolecular hydrogen bonding interactions in these peripheral pyridine units show specific 2D structures for each BTP isomer. From nine possible constitutional isomers only four have been described in the literature. The synthesis and self-assembling behavior of an additional isomer is presented here, but the remaining four members of the series are synthetically inaccessible. The self-assembling properties of three of the missing four BTP isomers can be mimicked by making use of the energetically preferred N–C–C–N transoid conformation between 2,2'-bipyridine subunits in a new class of so-called septipyridines. The structures are investigated by scanning tunneling microscopy (STM and a combination of force-field and first-principles electronic structure calculations.

  15. 4,4′-Bipyridine–2-hydroxy­propane-1,2,3-tricarboxylic acid (3/2)

    OpenAIRE

    Soleimannejad, Janet; Aghabozorg, Hossein; Najafi, Shokoh; Nasibipour, Mina; Attar Gharamaleki, Jafar

    2009-01-01

    The combination of 2-hydroxy­propane-1,2,3-tricarboxylic acid (H3hypta, also called citric acid) and 4,4′-bipyridine (4,4′-bipy) in a 1:1.5 molar ratio leads to the formation of the title mol­ecular cocrystal, 1.5C10H8N2·C6H8O7. The asymmetric unit contains one and a half 4,4′-bipy units, with one lying across a centre of inversion, and one H3hypta mol­ecule. The significant differences in the C—O bond distances support the existence of the un-ionized acid mol­ecule and confirm the formation ...

  16. A Star of David catenane

    Science.gov (United States)

    Leigh, David A.; Pritchard, Robin G.; Stephens, Alexander J.

    2014-11-01

    We describe the synthesis of a [2]catenane that consists of two triply entwined 114-membered rings, a molecular link. The woven scaffold is a hexameric circular helicate generated by the assembly of six tris(bipyridine) ligands with six iron(II) cations, with the size of the helicate promoted by the use of sulfate counterions. The structure of the ligand extension directs subsequent covalent capture of the catenane by ring-closing olefin metathesis. Confirmation of the Star of David topology (two rings, six crossings) is provided by NMR spectroscopy, mass spectrometry and X-ray crystallography. Extraction of the iron(II) ions with tetrasodium ethylenediaminetetraacetate affords the wholly organic molecular link. The self-assembly of interwoven circular frameworks of controlled size, and their subsequent closure by multiple directed covalent bond-forming reactions, provides a powerful strategy for the synthesis of molecular topologies of ever-increasing complexity.

  17. Synthesis, DNA-binding and photocleavage studies of Ru(II) complexes of phenyl-(4,5,9,14-tetraaza-benzo[]triphenylen-1,1-)-methanone

    Indian Academy of Sciences (India)

    Li-Feng Tan; Xue-Jiao Chen; Jian-Liang Shen; Xi-Ling Liang

    2009-07-01

    A novel polypyridyl ligand phenyl-(4,5,9,14-tetraaza-benzo[]triphenylen-1,1-)-methanone (PTBM) and its complexes [Ru(phen)2(PTBM)]2+ (1) (phen = 1,10-phenanthroline) and [Ru(bpy)2 (PTBM)]2+ (2) (bpy = 2,2'-bipyridine) have been synthesized and characterized by elemental analysis, mass spectroscopy, and 1H NMR. The DNA-binding properties of the two complexes were investigated by spectroscopic and viscosity measurements. The results indicate that both complexes bind to DNA via an intercalative mode and the DNA-binding affinity of complex 1 is greater than that of complex 2. When irradiated at 365 nm, complex 1 was found to be a more-effective DNA-cleaving agent than complex 2.

  18. Lanthanide and actinide complexation studies with tetradentate 'N' donor ligands

    International Nuclear Information System (INIS)

    Because of their similar charge and chemical behaviour separation of trivalent actinides and lanthanides is an important and challenging task in nuclear fuel cycle. Soft (S,N) donor ligands show selectivity towards the trivalent actinides over the lanthanides. Out of various 'N' donor ligands studied, bis(1,2,4)triazinyl bipyridine (BTBP) and bis(1,2,4)triazinyl phenanthroline (BTPhen) were found to be most promising. In order to understand the separation behaviour of these ligands, their complexation studies with these 'f' block elements are essential. In the present work, complexation studies of various lanthanide ions (La3+, Eu3+ and Er3+) was studied with ethyl derivatives of BTBP (C2BTBP) and BTBPhen (C2BTPhen) and pentyl derivative of BTBP (C5BTBP) in acetonitrile medium using UV-Vis spectrophotometry, fluorescence spectroscopy and solution calorimetry. Computational studies were also carried out to understand the experimental results

  19. Control of excitation and quenching in multi-colour electrogenerated chemiluminescence systems through choice of co-reactant.

    Science.gov (United States)

    Barbante, Gregory J; Kebede, Noah; Hindson, Christopher M; Doeven, Egan H; Zammit, Elizabeth M; Hanson, Graeme R; Hogan, Conor F; Francis, Paul S

    2014-10-20

    We demonstrate a new approach to manipulate the selective emission in mixed electrogenerated chemiluminescence (ECL) systems, where subtle changes in co-reactant properties are exploited to control the relative electron-transfer processes of excitation and quenching. Two closely related tertiary-amine co-reactants, tri-n-propylamine and N,N-diisopropylethylamine, generate remarkably different emission profiles: one provides distinct green and red ECL from [Ir(ppy)3] (ppy=2-phenylpyridinato-C2,N) and a [Ru(bpy)3](2+) (bpy=2,2'-bipyridine) derivative at different applied potentials, whereas the other generates both emissions simultaneously across a wide potential range. These phenomena can be rationalized through the relative exergonicities of electron-transfer quenching of the excited states, in conjunction with the change in concentration of the quenchers over the applied potential range. PMID:25204830

  20. Spectroscopic, solvent influence and thermal studies of ternary copper(II) complexes of diester and dinitrogen base ligands.

    Science.gov (United States)

    Emara, Adel A A; Abu-Hussein, Azza A A; Taha, Ahmed A; Mahmoud, Nelly H

    2010-10-15

    New mixed-ligand copper(II) complexes containing the bidentate dinitrogen ligands [N,N,N',N'-tetramethylethylenediamine (tmen), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)] and the bidentate dioxygen ligands [diethylmalonate (DEM), ethylacetoacetate (EAA) and ethylbenzoylacetate (EBA)] were prepared. The complexes were characterized by elemental analysis, infrared, mass and ESR spectral data, magnetic and molar conductance measurements and thermal gravimetric analysis. From the investigation, the geometries of the complexes are square planar for perchlorate complexes and a square pyramid or octahedral for the nitrate complexes. Solvatochromic behavior of the Cu(II) complexes indicates strong solvatochromism of their solutions in polar and non-polar solvents. The observed solvatochromism is due to the solute-solvent interaction between the chelate cation and the solvent molecules. PMID:20688561

  1. A New Luminescent Ruthenium(Ⅱ) Polypyridine-derived Dipicolylamine Complex as a Sensor for Cu2+ Ions%A New Luminescent Ruthenium(Ⅱ) Polypyridine-derived Dipicolylamine Complex as a Sensor for Cu2+ Ions

    Institute of Scientific and Technical Information of China (English)

    Li, Xianghong; Chen, Yuanbing; Meng, Jiahe; Lu, Kangle; Zhang, Aiqing; Zhang, Bingguang

    2011-01-01

    A chemo-sensor [Ru(bpy)2(bpy-DPF)](PF6)2 (1) (bpy = 2,2'-bipyridine, bpy-DPF = 2,2'-bipyridyl-4,4'- bis(N,N-di(2-picolyl))formylamide) for Cu2+ using di(2-picolyl)amine (DPA) as the recognition group and a ruthe- nium(II) complex as the reporting group was synthesized and characterized successfully. It demonstrates a high se- lectivity and efficient signaling behavior only for Cu2+ with obvious red-shifted MLCT (metal-to-ligand charge transfer transitions) absorptions and dramatic fluorescence quenching compared with Zn2+ and other metal ions.

  2. Design, synthesis, and characterization of a novel class of tunable chromophores for second- and third-order NLO applications

    Science.gov (United States)

    Attias, Andre-Jean; Leclerc, Nicolas; Chen, Qiying; Sargent, Edward H.; Schull, Guillaume; Charra, Fabrice

    2004-10-01

    We describe a general approach for the synthesis of 6,6'-(disubstituted)-3,3'-bipyridine based chromophores. This combinatorial type strategy is based on (i) the synthesis of a library of conjugated building blocks end-capped with electron donor or acceptor groups, and (ii) their homo- or cross-coupling. The compounds are either dipolar (push-pull molecules) or apolar (symmetric D-A-A-D) molecules. Depending on the building blocks, we are able to tune both the structural and NLO properties of the chromophores. For example, the D-A-A-D structure possesses ultrafast nonresonant nonlinearity around 1550 nm with excellent figures of merit, as well as TPA in the visible and NIR ranges.

  3. Scanning electrochemical microscopy. 36. A combined scanning electrochemical microscope-quartz crystal microbalance instrument for studying thin films.

    Science.gov (United States)

    Cliffel, D E; Bard, A J

    1998-05-01

    The design of a combined scanning electrochemical microscope-quartz crystal microbalance (SECM-QCM) with separate potential control of the tip and substrate is described. Both lateral and vertical tip movements near the substrate affect the QCM resonant frequency because of perturbations of the longitudinal and shear waves of the quartz crystal (QC) acoustic wave sensor. The SECM-QCM was used to study etching of a thin Ag layer deposited on the QC contact by generating an etchant, iron(III) tris(bipyridine), at the tip near the surface. The SECM-QCM was also used to monitor film mass and surrounding electrolyte composition during potential cycling of a film of C(60) on an electrode. PMID:21651290

  4. Direct electrochemical measurements inside a 2000 angstrom thick polymer film by scanning electrochemical microscopy.

    Science.gov (United States)

    Mirkin, M V; Fan, F R; Bard, A J

    1992-07-17

    An extremely small, conically shaped Pt microelectrode tip (with a radius of 30 nanometers) and the precise positioning capabilities of the scanning electrochemical microscope were used to penetrate a thin (200 nanometers) polymer film and obtain directly the standard potential and kinetic parameters of an electrode reaction within the film. The thickness of the film was determined while it was immersed in and swollen by an electrolyte solution. The film studied was the perfluorosulfonate Nafion containing Os(bpy)(3)(2+) (bpy, 2,2'-bipyridine) cast on an indium tin oxide surface. The steady-state response at the ultramicroelectrode allowed direct determination of the rate constant for heterogeneous electron transfer K(o) and the diffusion coefficient D without complications caused by transport in the liquid phase, charge exchange at the liquid-polymer interface, and resistive drop. PMID:17832832

  5. Is copper(I) really soft? Probing the hardness of Cu(I) with pyridinecarboxaldehyde ligands

    Indian Academy of Sciences (India)

    D Saravanabharathi; M Nethaji; A G Samuelson

    2002-08-01

    Cu(I) complexes of formula Cu(PPh3)2LClO4 [L = 2 or 3 pyridine carboxaldehyde] are synthesised and characterised to explore the coordination of an aldehyde, a hard and neutral oxygen donor to a soft Cu(I) centre. The structural and spectroscopic results illustrate that only in 2-pyridinecarboxaldehyde, the `C=O' group coordinates to soft Cu(I) centres due to a favourable chelate effect, while in 3-pyridinecarboxaldehyde, it remains uncoordinated. Upon chelation via N and O donors, 2-pyridinecarboxaldehyde resembles bipyridine or phenanthroline in terms of its bite angle and spectroscopic features. Such chelation can be easily challenged with coordinating anions like bromide, or more basic pyridines. A drastic change in the MLCT absorption signals the decomplexation of the `C=O’ group. The observed results point out that the Cu(I) centre can readily exchange the hard `O’ donor for softer ligands.

  6. Characterization of screen printed carbon counter electrodes for Co(II)/(III) mediated photoelectrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghamouss, Fouad [CEISAM, Universite de Nantes, CNRS, 2 rue de la Houssiniere, B.P. 92208, 44322, Nantes cedex 3 (France); Pitson, Robbin [Gwent Electronics Materials Ltd, Monmouth House, Mamhilad Park, Pontypool, NP4 0HZ (United Kingdom); Odobel, Fabrice [CEISAM, Universite de Nantes, CNRS, 2 rue de la Houssiniere, B.P. 92208, 44322, Nantes cedex 3 (France); Boujtita, Mohammed, E-mail: mohammed.boujtita@univ-nantes.f [CEISAM, Universite de Nantes, CNRS, 2 rue de la Houssiniere, B.P. 92208, 44322, Nantes cedex 3 (France); Caramori, Stefano [Dipartmento di Chimica, Universita di Ferrara, Via L.Borsari, 46, 44100 Ferrara (Italy); Bignozzi, Carlo A., E-mail: g4s@unife.i [Dipartmento di Chimica, Universita di Ferrara, Via L.Borsari, 46, 44100 Ferrara (Italy)

    2010-09-01

    A screen printed carbon electrode associated with Tris(4,4'-di-tert-butyl-2,2'-bipyridine)Cobalt(II) as redox mediator was investigated as possible alternative to the volatile and corrosive iodide/triodide system in dye sensitized solar cells (DSSCs). We report here a first study on the screen printing technology for the manufacturing of an advanced and stable carbon cathode for dye sensitized solar cell. The electrode surface was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) while the electrochemical response towards the cobalt complex was evaluated by using cyclic voltammetry. Photocurrent-voltage characteristics of DSSCs based on the new cathode/Cobalt complex system were 30% lower than those recorded with Pt/iodide.

  7. Microwave Irradiated Reactions of N-Phenacylpyridinium Chloride with Aromatic Aldehydes and Ketones

    Institute of Scientific and Technical Information of China (English)

    Ping WU; Xi Mei CAI; Rong YAO; Chao Guo YAN

    2006-01-01

    In the system of ammonium acetate and acetic acid and under microwave irradiation,N-phenacylpyridinium chloride 1 reacted with chalcone 2 to give 2,4,6-triarylpyrididnes 3a-g in high yields. 3a-g can also be prepared from one-pot reaction of 1 with aromatic aldehydes 4 and substituted acetophenones 5. Under the same conditions 1 can also react with pyridinecar boxaldehyde 6a-c and acetophenone to yield bipyridine derivatives 7a-c. 1 reacted with aromatic aldehyde and cyclohexanone 6 to yield 2,4-diaryltetrahydroquinolines 8a-d. At last 1 reacted with aromatic aldehydes to give 2,4,6-triarylpyrimidine 9a-i. The structure of the products was characterized with 1H NMR and IR and mass spectroscopy.

  8. Dearomatization Reactions of N-Heterocycles Mediated by Group 3 Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Kevin L [Univ. of California, Los Angeles, CA (United States); Williams, Bryan N [Univ. of California, Los Angeles, CA (United States); Benitez, Diego [California Inst. of Technology (CalTech), Pasadena, CA (United States); Carver, Colin T [Univ. of California, Los Angeles, CA (United States); Ogilby, Kevin R [Univ. of California, Los Angeles, CA (United States); Tkatchouk, Ekaterina [California Inst. of Technology (CalTech), Pasadena, CA (United States); Goddard, William A [California Inst. of Technology (CalTech), Pasadena, CA (United States); Diaconescu, Paula L [Univ. of California, Los Angeles, CA (United States)

    2010-01-13

    Group 3 (Sc, Y, Lu, La) benzyl complexes supported by a ferrocene diamide ligand are reactive toward aromatic N-heterocycles by mediating their coupling and, in a few cases, the cleavage of their C-N bonds. When these complexes reacted with 2,2'-bipyridine or isoquinoline, they facilitated the alkyl migration of the benzyl ligand onto the pyridine ring, a process accompanied by the dearomatization of the N-heterocycle. The products of the alkyl-transfer reactions act as hydrogen donors in the presence of aromatic N-heterocycles, ketones, and azobenzene. Experimental and computational studies suggest that the hydrogen transfer takes place through a concerted mechanism. An interesting disproportionation reaction of the dearomatized, alkyl-substituted isoquinoline complexes is also reported.

  9. A mercuric ensemble based on a cycloruthenated complex as a visual probe for iodide in aqueous solution

    Science.gov (United States)

    Su, Xianlong; Guo, Lieping; Ma, Yajuan; Li, Xianghong

    2016-01-01

    A new water-soluble cycloruthenated complex Ru(bthiq)(dcbpy)2+ (1, Hbthiq = 1-(2-benzo[b]thiophenyl)isoquinoline, dcbpy = 4,4‧-dicarboxylate-2,2‧-bipyridine) was designed and synthesized to form its mercuric ensemble (1-Hg2+) to achieve visual detection of iodide anions. The binding constant of 1-Hg2+ is calculated to be 2.40 × 104 M-1, which is lower than that of HgI2. Therefore, the addition of I- to the aqueous solution of 1-Hg2+lead to significant color changes from yellow to deep-red by the release of 1. The results showed that iodide anions could be easily detected by the naked eyes. The detection limit of iodide anion is calculated as 0.77 μM. In addition, an easily-prepared test strip of 1-Hg2+ was obtained successfully to detect iodide anions.

  10. Synthesis,crystal structures,electrochemical and spectroscopic properties of ruthenium(Ⅱ) complexes containing diamino-1,3,5-triazine derivatives

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Three Ru(Ⅱ) complexes [Ru(bpy)2(1-IQTNH)](ClO4)2 (1), [Ru(bpy)2(2-QTNH)](ClO4)2 (2) and [Ru(bpy)2(3-IQTNH)](ClO4)2 (3) (bpy = 2,2′-bipyridine, 1-IQTNH = 6-(isoquinolin-1-yl)-1,3,5-triazine-2,4-diamine, 2-QTNH = 6-(quinolin-2-yl)-1,3,5-triazine-2,4-diamine, 3-IQTNH = 6-(isoquinolin-3-yl)-1,3,5-triazine-2,4-diamine) have been synthesized and characterized by elemental analysis, 1H NMR spectroscopy, electrospray ionization mass spectrometry and X-ray crystallography. The electrochemical and spectroscopic properties of the complexes differ from those of [Ru(bpy)3]2+ owing to the structural differences between the ligands and their complexes.

  11. Ruthenium-Immobilized Periodic Mesoporous Organosilica: Synthesis, Characterization, and Catalytic Application for Selective Oxidation of Alkanes.

    Science.gov (United States)

    Ishito, Nobuhiro; Kobayashi, Hirokazu; Nakajima, Kiyotaka; Maegawa, Yoshifumi; Inagaki, Shinji; Hara, Kenji; Fukuoka, Atsushi

    2015-10-26

    Periodic mesoporous organosilica (PMO) is a unique material that has a crystal-like wall structure with coordination sites for metal complexes. A Ru complex, [RuCl2 (CO)3 ]2 , is successfully immobilized onto 2,2'-bipyridine (BPy) units of PMO to form a single-site catalyst, which has been confirmed by various physicochemical analyses. Using NaClO as an oxidant, the Ru-immobilized PMO oxidizes the tertiary C-H bonds of adamantane to the corresponding alcohols at 57 times faster than the secondary C-H bonds, thereby exhibiting remarkably high regioselectivity. Moreover, the catalyst converts cis-decalin to cis-9-decalol in a 63 % yield with complete retention of the substrate stereochemistry. The Ru catalyst can be separated by simple filtration and reused without loss of the original activity and selectivity for the oxidation reactions. PMID:26330333

  12. Control of excitation and quenching in multi-colour electrogenerated chemiluminescence systems through choice of co-reactant.

    Science.gov (United States)

    Barbante, Gregory J; Kebede, Noah; Hindson, Christopher M; Doeven, Egan H; Zammit, Elizabeth M; Hanson, Graeme R; Hogan, Conor F; Francis, Paul S

    2014-10-20

    We demonstrate a new approach to manipulate the selective emission in mixed electrogenerated chemiluminescence (ECL) systems, where subtle changes in co-reactant properties are exploited to control the relative electron-transfer processes of excitation and quenching. Two closely related tertiary-amine co-reactants, tri-n-propylamine and N,N-diisopropylethylamine, generate remarkably different emission profiles: one provides distinct green and red ECL from [Ir(ppy)3] (ppy=2-phenylpyridinato-C2,N) and a [Ru(bpy)3](2+) (bpy=2,2'-bipyridine) derivative at different applied potentials, whereas the other generates both emissions simultaneously across a wide potential range. These phenomena can be rationalized through the relative exergonicities of electron-transfer quenching of the excited states, in conjunction with the change in concentration of the quenchers over the applied potential range.

  13. Sheet-like of MoV-SmIII assembly containing [MoV(CN)8]3- and Sm3+ ions as building blocks

    Indian Academy of Sciences (India)

    Shu-Lin Ma; Shi Ren; Yue Ma; Dai-Zheng Liao

    2009-07-01

    The reaction of [Mo(CN)8]3- with Sm3+ and 2,2'-bipyridine (bpy) lead to a sheet-like bimetallic complex, {Sm(H2O)9[Sm2(bpy)2(OH)2.75(NO3)0.25][Mo(CN)8]2} (1) in EtOH/H2O mixture solvent. The complex 1 crystallizes in monoclinic, space group 2/. The structural investigation denotes that the layers interaction with each other by - stacks and hydrogen bonds result in a 3D network, containing Sm(H2O)$^{3+}_{9}$ as guest molecules in the holes. The magnetic behaviour of the complex 1 has been studied.

  14. Self-assembly of a Co(II) dimer through H-bonding of water molecules to a 3D open-framework structure

    Indian Academy of Sciences (India)

    Sujit K Ghosh; Parimal K Bharadwaj

    2005-01-01

    Reaction of pyridine-2,4,6-tricarboxylic acid (ptcH3) with Co(NO3)2.6H2O in presence of 4,4'-bipyridine (4,4'-bpy) in water at room temperature results in the formation of {[Co2(ptcH)2(4,4'-bpy)(H2O)4].2H2O}, (1). The solid-state structure reveals that the compound is a dimeric Co(II) complex assembled to a 3D architecture via an intricate intra- and inter-molecular hydrogen-bonding interactions involving water molecules and carboxylate oxygens of the ligand ptcH2-. Crystal data: monoclinic, space group 21/, = 11.441(5) Å, = 20.212(2) Å, = 7.020(5) Å, = 103.77(5)°, = 1576.7(1) Å3, = 2, 1 = 0.0363, 2 = 0.0856, = 1.000.

  15. [U(TpMe2)2(bipy)]+: A cationic uranium(III) complex with single molecule magnet behavior

    International Nuclear Information System (INIS)

    The addition of 2,2'-bipyridine to [U(TpMe2)2I] (1) results in the displacement of the iodide and the formation of the cationic uranium(III) complex [U(TpMe2)2(bipy)]I (2). This compound was isolated as a dark-green solid in good yield and characterized by IR and NMR spectroscopies, and its molecular structure was determined by single-crystal X-ray diffraction. Studies of its magnetic properties revealed a frequency dependence of magnetization with a blocking temperature of 4.5 K and, at lower temperatures, a slow relaxation of magnetization with an energy barrier of 18.2 cm-1, characteristic of single-molecule-magnet behavior. (authors)

  16. Cyclic Water Clusters in Tape-Like and Cage-Like Structures

    Directory of Open Access Journals (Sweden)

    Fuhou Lei

    2011-04-01

    Full Text Available Controlling the ratio of 2,2′-bpy to benzene-1,3,5-tricarboxylic acid produces two interesting complexes, namely [Co(2,2′-bpy3] (SO4 8.5H2O (1 and [Cu2(BTCA (2,2′-bpy4] (OH (2,2′-bpy0.5·14H2O (2 (H3BTCA = benzene-1,3,5-tricarboxylic acid, 2,2′-bpy = 2,2′-bipyridine. We report the structural evidence in the solid state of discrete lamellar water cluster conformations. These units are found to act as supramolecular glue in the aggregation of cobalt (II or copper (II complexes to give three dimensional cage-like networks through hydrogen-bonding. It is interesting that the structure of complex 1 contains a 3D negatively charged cage.

  17. Determination of Ultratrace Silver Using Surfactant as Sensitizer by Catalytic Near Field Laser Thermal Lens Spectrometry

    Institute of Scientific and Technical Information of China (English)

    HAN,Quan(韩权); YAN,Hong-Tao(阎宏涛); QIAN,Zhen-Jie(钱振杰)

    2004-01-01

    A new method for the determination of ultratrace silver(Ⅰ) by near field laser thermal lens spectrometry has been developed. This method is based on the silver(Ⅰ) catalyzed discoloring reaction of bromcresol green oxidized by sodium persulfate in the presence of α,α′-bipyridine as an activator and TritonX-100 as a sensitizer. The reaction mechanism was discussed. The linear range of the method is 0-1.6 ng·mL-1 and the detection limit is 2 × 10-2ng·mL i for silver. The method has been applied to the determination of silver in lead powder and photographic paper with satisfactory results.

  18. Integration of [(Co(bpy)₃]²⁺ electron mediator with heterogeneous photocatalysts for CO₂ conversion.

    Science.gov (United States)

    Lin, Jinliang; Hou, Yidong; Zheng, Yun; Wang, Xinchen

    2014-09-01

    An efficient chemical system for electron generation and transfer is constructed by the integration of an electron mediator ([Co(bpy)3](2+); bpy=2,2'-bipyridine) with semiconductor photocatalysts. The introduction of [Co(bpy)3](2+) remarkably enhances the photocatalytic activity of pristine semiconductor photocatalysts for heterogeneous CO2 conversion; this is attributable to the acceleration of charge separation. Of particular interest is that the excellent photocatalytic activity of heterogeneous catalysts can be developed as a universal photocatalytic CO2 reduction system. The present findings clearly demonstrate that the integration of an electron mediator with semiconductors is a feasible process for the design and development of efficient photochemical systems for CO2 conversion.

  19. Ultrasensitive gaseous NH3 sensor based on ionic liquid-mediated signal-on electrochemiluminescence.

    Science.gov (United States)

    Chen, Lichan; Huang, Danjun; Zhang, Yuanjin; Dong, Tongqing; Zhou, Chen; Ren, Shuyan; Chi, Yuwu; Chen, Guonan

    2012-08-01

    This work reports that ammonia (NH(3)) can be used as an efficient co-reactant for tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)(3)(2+)) electrochemiluminescence (ECL) in ionic liquids (ILs), on the basis of which a signal-on ECL sensor for directly detecting gaseous NH(3) has been developed. The NH(3) ECL sensor has a very high sensitivity, with a detection limit of 10 ppt NH(3) (at signal-to-noise ratio of 3) without any preconcentration. The high sensitivity is mainly due to the zero ECL background of Ru(bpy)(3)(2+) in the ILs, strong co-reactant ECL activity of NH(3), and high solubility of NH(3) in imidazolium-based ILs. Additionally, the ECL sensor shows an excellent selectivity against common interfering gases and a wide linear response range from 10 ppt to 10 ppm. PMID:22728516

  20. Highly stable gelatin layer-protected gold nanoparticles as surface-enhanced Raman scattering substrates.

    Science.gov (United States)

    Lee, Changwon; Zhang, Peng

    2014-06-01

    Amine and carboxylic groups rich gelatin was used as reducing and stabilizing agent to form highly stable gold nanoparticles for surface-enhanced Raman scattering (SERS) applications. The size of the particle was determined to be 13 nm by TEM with mono-dispersity. The size of the gold nanoparticles was little affected by the initial gelatin concentration. The gelatin-gold nanoparticles show strong SERS activity with Rhodamine 6G and Ruthenium bipyridine as reporter molecules. Both carboxylic acid groups and amine groups were identified by FT-IR to be present on the gelatin-gold nanoparticle surface, providing the possibility of further conjugation with other molecules. The gelatin-protected gold nanoparticles prepared by this simple, green, method displayed very good solubility and stability in many solvents, and good monodispersity, all desirable features as good SERS substrates. PMID:24738391