Bipy

Distribution by Scientific Domains
Distribution within Chemistry

Terms modified by Bipy

  • bipy ligand

  • Selected Abstracts


    Synthesis and Photophysical Properties of LnIII,DOTA,Bipy Complexes and LnIII,DOTA,Bipy,RuII Coordination Conjugates

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2010
    Miguel Vzquez Lpez
    Abstract The synthesis and the systematic and comparative photophysical study of a series of visible (EuIII, TbIII) and NIR-emitting (NdIII, YbIII) lanthanide complexes (Ln2L) and ruthenium,lanthanide coordination conjugates (Ln2LRu) are reported. The GdIII complex, the GdIII,RuII coordination conjugate, as well as the RuII complex of the ligand H6L have also been synthesized and photophysically studied as control systems. The ligand H6L, composed of a central bipyridine binding unit and functionalized on each 5,-position with a DOTA macrocycle, has been successfully synthesized from cyclen, 5,5,-dimethyl-2,2,-bipyridine and 1,2-ethylendiamine in a nine-step process. Detailed luminescence studies of all complexes, including the determination of the quantum yield and lifetime, were carried out on finely powdered microcrystalline samples as well as in water, deuterated water and [D6]DMSO at ambient (295 K) and low temperature (77 K). The photophysical data corroborate the existence of energy transfer in the Ln2L complexes and in the Nd2LRu coordination conjugate. However, no (or at most, very little) energy transfer is takes place from the Ru(bipy)3 chromophore to the LnIII ion in the other Ln2LRu heteropolymetallic complexes. Moreover, the photophysical studies reveal that all the complexes and coordination conjugates adopt different conformations and hydration states in solution and in the solid state, which influences the efficiency of the energy transfer between the bipy and/or Ru(bipy)3 antennae and the LnIII ions. [source]


    Transformation of a zinc inclusion complex to wurtzite ZnS microflowers under solvothermal conditions

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2010
    Liwei Mi
    Abstract Wurtzite zinc sulfide (ZnS) microflowers were synthesized successfully by a convenient solvothermal route in ethylene glycol (EG) and ethylenediamine (EN) using thiourea and zinc inclusion complex as starting materials. The inclusion complex {[Zn(bipy)2(H2O)2](4-Cl-3-NH2 -C6H3SO3)2(bipy) (H2O)2}n was achieved by the reaction of zinc oxide (ZnO) and 4-Cl-3-NH2 -C6H3SO3 with the bridging ligand bipy under moderate conditions, in which bipy is 4,4,-bipyridine and 4-Cl-3-NH2C6H3SO3NH is 4-Chloro-3-aminobenzene sulfonic acid. The phase purity of bulk products was confirmed by powder X-ray diffraction and element analysis. The factors that might affect the purity of the ZnS product during the synthesis were discussed in detail. It was found that the products were significantly affected by the mixed solvents and the starting materials. X-ray single crystal diffraction, scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), and X-ray diffraction (XRD) were used to characterize the products. ( 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Synthesis and crystal strcucture of two zinc inclusion complexes

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2008
    Min-Le Han
    Abstract X-ray single crystals of these two inclusion complexes, [Zn(H2O)4L2](4-amino-1-naphthalene sulfonate)2 (L = 1,3-bis(4-pyridyl) propane), 1, and [Zn(H2O)(bipy)2](4-amino-1-naphthalene sulfonate)(NO3) (bipy = 4,4'-bipyridine), 2 were achieved by the reaction of Zn(NO3)2 and 4-amino-1-naphthalene sulfonate to 1,3-bis(4-pyridyl) propane and 4,4'-bipyridine, respectively. As inclusion complexes, the cationic components of 1 and 2 were formed by two infinite zigzag chains, while, 4-amino-1-naphthalene sulfonate made up the anionic parts of these two complexes. Thus, the whole molecules of these two complexes are neuter. Numous hydrogen bonds could be found in these two inclusion complexes, which help them to form three-dimensional solid-state packing structure architectures. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Two-Surface Strategy in Electrochemical DNA Hybridization Assays: Detection of Osmium-Labeled Target DNA at Carbon Electrodes

    ELECTROANALYSIS, Issue 5-6 2003
    Miroslav Fojta
    Abstract Target DNAs, including a 71-mer oligonucleotide, a PCR product and a plasmid DNA, all containing oligo(A) stretches, were hybridized at magnetic Dynabeads oligo(dT)25 (DBT). The hybridization events were detected using a technique based on chemical modification of the target DNA with a complex of osmium tetroxide with 2,2,-bipyridine (Os,,bipy) and voltammetric detection at carbon electrodes. DNA was modified with Os,,bipy prior to capture at DBT, at the beads, or after release from the beads. In the latter case, DNA-Os,,bipy was detected in the reaction mixture using adsorptive transfer stripping voltammetry involving extraction of unreacted Os,,bipy from the electrode by organic solvents. Pre-labeling of the target plasmid DNA and the PCR product with Os,,bipy significantly increased the yield of DNA captured at the beads. Tens of femtomoles of both short (the 71-mer oligonucleotide) and long (the 3-kilobase plasmid) target DNAs in a 20-microliter hybridization sample can be easily detected by means of these techniques. Various carbon electrode materials, including pyrolytic graphite (PGE), highly oriented pyrolytic graphite (HOPGE), carbon paste (CPE), glassy carbon and pencil graphite, were tested regarding their suitability for the detection of osmium-labeled DNA. Among them, PGE and HOPGE appeared usable in the measurements of both purified DNA-Os,,bipy and its mixtures with unreacted Os,,bipy while CPE was suitable for the detection purified osmium-labeled DNA. [source]


    Synthesis and Photophysical Properties of LnIII,DOTA,Bipy Complexes and LnIII,DOTA,Bipy,RuII Coordination Conjugates

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2010
    Miguel Vzquez Lpez
    Abstract The synthesis and the systematic and comparative photophysical study of a series of visible (EuIII, TbIII) and NIR-emitting (NdIII, YbIII) lanthanide complexes (Ln2L) and ruthenium,lanthanide coordination conjugates (Ln2LRu) are reported. The GdIII complex, the GdIII,RuII coordination conjugate, as well as the RuII complex of the ligand H6L have also been synthesized and photophysically studied as control systems. The ligand H6L, composed of a central bipyridine binding unit and functionalized on each 5,-position with a DOTA macrocycle, has been successfully synthesized from cyclen, 5,5,-dimethyl-2,2,-bipyridine and 1,2-ethylendiamine in a nine-step process. Detailed luminescence studies of all complexes, including the determination of the quantum yield and lifetime, were carried out on finely powdered microcrystalline samples as well as in water, deuterated water and [D6]DMSO at ambient (295 K) and low temperature (77 K). The photophysical data corroborate the existence of energy transfer in the Ln2L complexes and in the Nd2LRu coordination conjugate. However, no (or at most, very little) energy transfer is takes place from the Ru(bipy)3 chromophore to the LnIII ion in the other Ln2LRu heteropolymetallic complexes. Moreover, the photophysical studies reveal that all the complexes and coordination conjugates adopt different conformations and hydration states in solution and in the solid state, which influences the efficiency of the energy transfer between the bipy and/or Ru(bipy)3 antennae and the LnIII ions. [source]


    Thermal Decomposition Reactions as a Tool for the Synthesis of New Thermodynamic Metastable Modifications: Synthesis, Structures, and Properties of (Formato)nickel(II) Coordination Polymers Based on 4,4,-Bipyridine

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2010
    Jan Boeckmann
    Abstract The reaction of nickel formate with 4,4,-bipyridine (bipy) in aqueous solution at room temperature leads to the formation of the hydrated compound [Ni(HCO2)2(H2O)(bipy)4H2O]n (1) reported recently. On heating, compound 1 decomposes into the new anhydrous compound of composition [Ni(HCO2)2(bipy)]n (2II), which decomposes on further heating. Interestingly, if the anhydrous compound is prepared from solution, a new modification 2I is obtained. Investigations on the stability of both forms show that modification 2I presents the thermodynamically most stable form between room and decomposition temperature, whereas modification 2II, which can only be prepared by thermal decomposition, is metastable. In the crystal structure of 2I, the Ni2+ cations are coordinated by four ,2 - anti,anti bridging formato anions and two bridging ,2 -bipy ligands in a slightly distorted octahedralgeometry. The formato anions bridge the metal cations in zigzag chains, which are further connected by ,2 - anti,anti formato anions and bipy ligands to give a three-dimensional coordination network. IR spectroscopic investigations on the metastable form 2II also indicate that all formato anions act as bridging ligands. Magnetic measurements of the hydrated and anhydrous compounds reveal different behavior with a ferromagnetic ordering for compound 2I and an antiferromagnetic ordering for compound 1. For form 2II, only Curie,Weiss paramagnetism was found. [source]


    Nucleophilic Addition of Water and Alcohols to Dicyanonitrosomethanide: Ligands with Diverse Bonding Modes in Magnetically Coupled d-Block Complexes

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2010
    Anthony S. R. Chesman
    Abstract Ligands resulting from the transition-metal-promoted nucleophilic addition of water or an alcohol to dicyanonitrosomethanide ions (dcnm) have been utilised in the formation of a large series of polynuclear complexes. Addition of water to dcnm results in formation of carbamoylcyanonitrosomethanide (ccnm); deprotonation of this ligand gives amidocarbonyl(cyano)nitrosomethanide (acnm), which has been incorporated into the trinuclear complex [Cu3(acnm)2(dmae)2(H2O)2] [dmae = 2-(dimethylamino)ethoxide] (1) which shows strong antiferromagnetic coupling with an exchange coupling constant, J = ,500 cm,1. [Cu(acnm)(NH3)2], (2) marks the first instance of acnm facilitating the formation of a coordination polymer, namely a 1D chain with intramolecular hydrogen bonding. Attempts to synthesise 2 through different reaction conditions instead resulted in the mononuclear [Cu(acnm)(NH3)2(py)] (py = pyridine) (3). The addition of ethanol to dcnm results in cyano[imino(ethoxy)methyl]nitrosomethanide (cenm) which features in the mononuclear [Cu(cenm)2(H2O)2] (4) and polymeric {[Cu(cenm)2]2H2O}, (5). The latter is the first example of the cenm ligand in a coordination polymer and has a highly unusual coordination mode through the nitrile groups and extremely weak antiferromagnetic coupling. {[Mn3(ccnm)2(EtOH)2(OAc)4]2EtOH}, (6) and (Et4N)2[Cu(ccnm)4] (7) contain previously unobserved coordination modes of the ccnm ligand while the complex [Mn(cmnm)3Mn(bipy)(MeOH)](ClO4) (8) {cmnm = cyano[imino(methoxy)methyl]nitrosomethanide, bipy = 2,2,-bipyridine} displays weak antiferromagnetic coupling between manganese atoms with J = ,1.44 cm,1. A change in the solvent systems used in the synthesis of 7 results in the formation of the mononuclear complexes [Mn(bipy)2(dcnm)2] (9) or [Mn(bipy)2(H2O)(dcnm)](dcnm)H2O (10) and [Mn(bipy)2(dcnm)(H2O)](dcnm) (11). The addition of ethlyene glycol monomethyl ether to dcnm gives cyano[imino(2-methoxyethoxy)methyl]nitrosomethanide (cgnm) and the formation of [Cu(cgnm)2(H2O)2] (12). [source]


    Reactions of [Et4N][Tp*W(,3 -S)(,-S)2(CuSCN)2] with Nitrogen Donor Ligands: Syntheses, Structures, and Third-Order Nonlinear Optical Properties

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2009
    Zhen-Hong Wei
    Abstract Reactions of the preformed cluster [Et4N][Tp*W(,3 -S)(,-S)2(CuSCN)2] (1) with pyridine (py), 4,4,-bipyridine (4,4,-bipy), or 1,3-bis(4-pyridyl)propane (bpp) led to the formation of three neutral [Tp*W(,3 -S)(,-S)2Cu2]-based compounds [Tp*W(,3 -S)(,-S)2Cu2(SCN)(py)2] (2), [{Tp*W(,3 -S)(,-S)2Cu2(SCN)}2(4,4,-bipy)]3.5H2O (33.5H2O), and [Tp*W(,3 -S)(,-S)2Cu2(SCN)(bpp)]2 (4), respectively. Compounds 2,4 were characterized by elemental analysis, IR spectra, UV/Vis spectra, 1H NMR, and X-ray analysis. There are two linkage isomers [Tp*W(,3 -S)(,-S)2Cu2(SCN)(py)2] and [Tp*W(,3 -S)(,-S)2Cu2(NCS)(py)2], each of which has its own enantiomeric pair in the crystal of 2. Compound 3 has a double butterfly-shaped structure in which two [Tp*W(,3 -S)(,-S)2Cu2(SCN)] fragments are linked with a single 4,4,-bipy bridge. For 4, the two butterfly-shaped [Tp*W(,3 -S)(,-S)2Cu2(SCN)] fragments are interconnected by a pair of bpp bridges. The third-order nonlinear optical (NLO) performances of 2,4 in DMF were also investigated by Z -scan techniques.( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Self-Assembly from Discrete Clusters to 2D Network Based on [Fe(phen)(CN)4], and [Fe(bipy)(CN)4],: Synthesis, Structures and Magnetic Properties

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2009
    Hua Xiang
    Abstract A series of cyanido-bridged complexes {[FeIII(phen) (CN)4]2[NiL1]}4H2O (1), {[FeIII(bipy)(CN)4]2[NiL1]}4H2O (2), [FeIII(bipy)(CN)4]2[NiL2] (3), {[FeIII(phen)(CN)4]2[CuL3]}5H2O (4), {[FeII(phen)(CN)4][Ni(ea)2]}22H2O (5), {[FeII(phen)(CN)4] [NiL2]2H2O}n (6), {[FeIII(bipy)(CN)4]2[Ni(H2O)2]}6.5H2O}n (7) and {[FeII(bipy)(CN)4][Ni(ea)2]H2O}n (8) were synthesized using H[Fe(phen)(CN)4]2H2O and H[Fe(bipy)(CN)4]2H2O as precursors [L1 = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, L2 = 3,10-bis(2-phenylethyl)-1,3,5,8, 10,12-hexaazacyclotetradecane, L3 = 3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, phen = 1,10-phenanthroline, bipy = 2,2,-bipyridine, ea = ethanolamine). Complexes 1,4 are trinuclear clusters, and 5 is a tetranuclear square. In 6, the [FeII(phen)(CN)4]2, anions alternately bridge the [NiL2]2+ cations to generate a 1D wavy chain. The structure of 7 possesses a 4,2-ribbonlike chain, which contains a NiII2(CN)4FeIII2 square with each NiII atom shared by two adjacent squares. Each FeII and NiII atom in 8 acts as a three-connected node through the cyanido-bridges to generate a 2D network with a 4,82 topological net. Ferromagnetic couplings are found between the low-spin FeIII ions and the NiII ions through the cyanido groups in 1,3 and 7, and a metamagnetic behavior and a frequency dependence of the out-of-phase ac susceptibility are observed in 7. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Highly Efficient Visible-Light-Induced Photocleavage of DNA by a Ruthenium-Substituted Fluorinated Porphyrin

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 11 2009
    Michelle Cunningham
    Abstract A new porphyrin, meso -5-(pentafluorophenyl)-10,15,20-tris(4-pyridyl)porphyrin, has been synthesized. Coordination of two [Ru(bipy)2Cl]+ moieties (where bipy = 2,2,-bipyridine) to the pyridyl nitrogen atoms in the 10,15-positions gives the target complex. Electronic transitions associated with the ruthenium,porphyrin include an intense Soret band and four less intense Q-bands in the visible region of the spectrum. An intense ,,,* transition in the UV region associated with the bipyridyl groups and a metal-to-ligand charge-transfer (MLCT) band appearing as a shoulder to the Soret band are also observed. Electrochemical properties associated with the complex include a redox couple in the cathodic region with E1/2 = ,0.84 V vs. Ag/AgCl attributed to the porphyrin and a redox couple in the anodic region at E1/2 = 0.79 V vs. Ag/AgCl due to the RuIII/II couple. DNA titrations and ethidium bromide displacement experiments indicate the ruthenium porphyrin interacts with DNA potentially through a partial intercalation mechanism. Irradiation of aqueous solutions of the ruthenated complex and supercoiled DNA at a 100:1 base pair/complex ratio with visible light above 400 nm indicates that the complex causes double-strand breaks of the DNA.( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Quenching the Hysteresis in Single Crystals of a 1D Chain Iron(II) Spin Crossover Complex

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2008
    Birgit Weber
    Abstract The unusual grinding effects observed in the 1D spin crossover polymer [FeL(bipy)]n (1), with L being a tetradentate N2O22, coordinating Schiff base type ligand {(3,3,)-[1,2-phenylenebis(iminomethylidyne)]bis(2,4-pentanedionato)(2,)- N,N,,O2,O2,} and bipy = 4,4,-bipyridine, are investigated using magnetic measurements, X-ray powder diffraction and optical reflectivity studies. The observed behaviour can be explained when solvent effects are taken into account. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


    Synthesis, Structure and Magnetic Behaviour of Manganese(II) Selenolate Complexes ,1[Mn(SePh)2], [Mn(SePh)2(bipy)2] and [Mn(SePh)2(phen)2] (bipy = bipyridyl, phen = phenanthroline)

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 30 2007
    Andreas Eichhfer
    Abstract The manganese selenolate complex ,1[Mn(SePh)2] has been prepared by reaction of Mn(OOCCH3)2 with 2 equiv.PhSeSiMe3 in thf. In the crystal structure, the compound forms one-dimensional chains, and the bridging selenolate ligands result in relatively short metal,metal contacts of about 3 . Reaction with two equivalents of the Lewis bases 2,2,-bipyridine and 1,10-phenanthroline yielded the monomeric octahedral complexes [Mn(SePh)2(2,2,-bipy)2] and [Mn(SePh)2(1,10-phen)2], respectively. The magnetic and optical properties of these complexes have been investigated. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    The First Heterohexametallic Transition-Metal Complex

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 24 2007
    Rico Packheiser
    Abstract The synthesis and characterisation of a first heteromultimetallic transition metal complex with six different metal atoms (Fe, Ru, Re, Au, Cu and Ti), connected through carbon-rich bridging units, are reported. Complex {1-[(,2 -dppf)(,5 -C5H5)RuC,C]-3-[(bipy*)(CO)3ReC,C]-5-[PPh2AuC,C-bipy({[Ti](,-,,,-C,CSiMe3)2}Cu)]C6H3}PF6 is accessible in a consecutive reaction sequence by applying building blocks from a ligand and coordination complex library. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    Three Novel Functional CdII Dicarboxylates with Nanometer Channels: Hydrothermal Synthesis, Crystal Structures, and Luminescence Properties

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2007
    Yu-Peng Tian
    Abstract Three novel functional transition-metal complexes with H2A (H2A = 9-ethylcarbazole-3,6-dicarboxylic acid), Cd(HA)2(H2O)2 (1), [Cd(A)(phen)]1.5H2O (2) (phen = 1,10-phenanthroline), and Cd(HA)2(bipy) (3) (bipy = 4,4,-bipyridine), have been successfully synthesized by a hydrothermal synthetic method and characterized by single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, thermogravimetric analysis, and photoluminescence. The results show that all of the complexes contain nanometer channels, while the coordination modes were changed by the addition of the mixed ligands. The 2D supramolecular open-framework 1 is constructed through hydrogen-bond and aromatic ,,, interactions. 2D coordination polymer 2 is constructed by ,,, interactions between adjacent metal-organic polymeric coordination chains. Interestingly, the 3D supramolecular architecture of 3 first formed 2D grid layers from 1D chains by intermolecular hydrogen bonds and then extended into a 3D structure through aromatic ,,, interactions. Furthermore, strong emissions from these complexes were also changed by the coordination modes in the solid state. However, complexes 1,3 show high thermal stability.( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


    A Novel Copper(I) Halide Framework Templated by Organic,Inorganic Hybrid Polyoxometalate Chains Formed In Situ: A New Route for the Design and Synthesis of Porous Frameworks

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2006
    Hua Jin
    Abstract A 1D organic,inorganic hybrid polyoxometalate chain has been used as a non-coordinating anionic template for the construction of a novel 3D copper halide 4,4,-bipy framework, namely [Cu3ICl(4,4,-bipy)4][CuII(1,10-phen)2Mo8O26]. X-ray diffraction experiments revealed that the title compound consists of chloride-bridged trinuclear CuI units linked by neutral organic 4,4,-bipy groups into a 3D framework with hexagon-like channels in which 1D organic,inorganic hybrid polyoxometalate chains reside. This is the first example of a 1D organic,inorganic hybrid polyoxometalate chain functioning as a novel anionic template for the construction of a 3D framework. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


    Pressure Effect Investigations on the Spin Crossover Systems{Fe[H2B(pz)2]2(bipy)} and {Fe[H2B(pz)2]2(phen)}

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2006
    Ana Galet
    Abstract Pressure effect studies on the spin crossover behaviour of the mononuclear compounds {Fe[H2B(pz)2]2(bipy)}(1) and {Fe[H2B(pz)2]2(phen)}(2) have been performed in the range of 105 Pa,1.02 GPa at variable temperatures (100,310 K). Continuous spin transitions and displacement of its characteristic temperature has been observed for 1 with increasing pressure. Meanwhile the response of 2 under applied pressures is quite unexpected, and can only be understood in terms of a crystallographic phase transition or change in the bulk modulus of the compound. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


    Syntheses, Crystal Structures and Magnetic Properties of Carboxylato-Bridged Polymeric Networks of MnII

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2006
    Subal Chandra Manna
    Abstract Three new carboxylato-bridged polymeric networks of MnII having,molecular formula [Mn(ox)(dpyo)]n (1), {[Mn2(mal)2(bpee)(H2O)2]0.5(bpee)0.5(CH3OH)}n (2) and {[Mn3(btc)2(2,2,-bipy)2(H2O)6]4H2O}n (3) [dpyo, 4,4,-bipyridine N,N,-dioxide; bpee, trans -1,2 bis(4-pyridyl)ethylene; 2,2,-bipy, 2,2,-bipyridine; ox = oxalate dianion; mal = malonate dianion; btc = 1,3,5-benzenetricarboxylate trianion] have been synthesized and characterized by single-crystal X-ray diffraction studies and low temperature magnetic measurements. Structure determination of complex 1 reveals a covalent bonded 2D network containing bischelating oxalate and bridging dpyo; complex 2 is a covalent bonded 3D polymeric architecture, formed by bridging malonate and bpee ligands, resulting in an open framework with channels filled by uncoordinated disordered bpee and methanol molecules. Whereas complex 3, comprising btc anions bound to three metal centers, is a 1D chain which further extends its dimensionality to 3D via - and H-bonding interactions. Low temperature magnetic measurements reveal the existence of weak antiferromagnetic interaction in all these complexes. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


    The Reaction of (Bipyridyl)palladium(II) Complexes with Thiourea , Influence of DNA and Other Polyanions on the Rate of Reaction

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2005
    Matteo Cusumano
    Abstract [Pd(bipy)(py)2](PF6)2 reacts stepwise with excess thiourea to give [Pd(tu)4](PF6)2. The kinetics of the second step, which refers to the replacement of bipyridyl in [Pd(bipy)(tu)2](PF6)2, have been studied in water and in the presence of calf thymus DNA, sodium polyriboadenylate, sodium polyvinylsulfonate or sodium polymetaphosphate at 25 C and pH = 7 and a fixed sodium chloride concentration. The reaction follows a first order course and a plot of kobs against [thiourea]2 affords a straight line with a small intercept. DNA inhibits the process without altering the rate law. The kobs values decrease systematically on increasing the DNA concentration eventually tending to a limiting value. The values are larger at higher ionic strengths and the other polyanions show similar behaviour. The influence of DNA on the kinetics can be related to steric inhibition caused by noncovalent binding with the complex. Upon interaction with DNA, [Pd(bipy)(tu)2]2+ gives rise to immediate spectroscopic changes in the UV/Vis region as well as induced circular dichroism suggesting that the complex, like similar platinum(II) and palladium(II) species of bipyridyl, intercalates with the double helix. Such a type of interaction hampers the attack of the nucleophile at the metal centre inhibiting the reaction. The decrease in the rate of ligand substitution upon decreasing salt concentration but at a given DNA concentration is due to the influence of ionic strength on the complex,DNA interaction. The reactivity inhibition by single-stranded poly(A), polyvinylsulfonate or polymetaphosphate can be accounted for in terms of self-aggregation of the complex induced by the polyanion. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]


    NMR Study of L-Shaped (Quinoxaline)platinum(II) Complexes , Crystal Structure of [Pt(DMeDPQ)(bipy)](PF6)2

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2004
    Enrico Rotondo
    Abstract A 1H and 13C NMR study of nine PtII complexes of DMeDPQ [6,7-dimethyl-2,3-bis(2-pyridyl)quinoxaline] and BDPQ [2,3-bis(2-pyridyl)benzo[g]quinoxaline], and the crystal structure of one of them, are reported. The results are consistent with Cs symmetry of "L-shaped square-planar complexes". The rigid seven-membered chelated quinoxaline ligand holds the fused aromatic rings nearly perpendicular to the PtII coordination plane, generating the peculiar L-shaped structure. Ancillary ligands in the residual coordination sites are: a) bidentate flexible-planar 2,2,-bipyridine (bipy; complexes 1 and 2); b) bidentate rigid-planar dipyrido[3,2- a:2,3,- c]phenazine (dppz) or benzo[b]dipyrido[3,2- h:2,,3,- j]phenazine (bdppz; complexes 3,6); or c) 3-substituted monodentate pyridines (3-Rpy; complexes 7,9). The L-shaped geometry has been exploited to gain insight into the steric and dynamic features that regulate the noncovalent interactions of these square-planar complexes with DNA. We have shown previously, for [Pt(bipy)(n -Rpy)2]2+, that bipy twisting can be frozen out on the NMR timescale below 260 K. Preservation of the Cs symmetry at low temperature indicates a lack of bipy fluxionality within these L-shaped structures. The static butterfly-like symmetric orientation of the quinoxaline pyridyl rings accounts for the hampered twisting of Pt(bipy), which is otherwise assisted by the synchronous "windscreen wiper" conrotatory rocking of the ancillary pyridine rings. The L-geometry can also be used to monitor the ancillary n -Rpy rotation by NMR spectroscopy. The quasi-vertical quinoxaline pyridyl rings alignment leave room in the coordination plane for the crossing of the opposite pyridine rings, thereby reducing their rotational barriers about the Pt,N bond. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


    Novel Cadmium(II) Adipate Coordination Polymers with Structural Transformation via Oxalate Ligand: Syntheses, Structures and Fluorescence Properties

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 20 2004
    Na Hao
    Abstract Two novel cadmium adipate coordination polymers [Cd{O2C(CH2)4CO2}{1,10-phen}]n (1) and [Cd2(C2O4){O2C(CH2)4CO2(OH2)2}{2,2,-bipy}]H2O (2) [adipic acid = HO2C(CH2)4CO2H] have been hydrothermally synthesized and characterized by elemental analyses, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. Crystallographic data for 1: monoclinic, C2/c, a = 16.186(3) , b = 15.487(3) , c = 14.052(3) , , = 112.73(3), Z = 8. Crystal data for 2: monoclinic, Cc, a = 23.448(5) , b = 11.826(2) , c = 8.3163(17) , , = 99.08(3), Z = 4. The structural analysis reveals that 1 forms a novel one-dimensional chain in which the binuclear Cd centers are linked by adipate anions. Compound 2 is the first example in which both a 2,2,-bipy ligand and an oxalate group are found in the {M/adipate} system. Compound 2 possesses one-dimensional sine- or cosine-type chains, which are alternately connected together by the oxalate group to form a three-dimensional framework. The structural determination reveals that the introduction of the oxalate ligand causes the dimensional transformation of the compounds. Compounds 1 and 2 show strong fluorescent properties at room temperature. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


    Mono- and Dimetallic Cyano Complexes with {Mo(,3 -allyl)(CO)2(N,N)} Fragments

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2003
    Julio Prez
    Abstract Treatment of [MoCl(,3 -allyl)(CO)2(phen)] with NaCN in CH2Cl2/MeOH afforded [Mo(CN)(,3 -allyl)(CO)2(phen)] [allyl = C3H5 (1a); 2-MeC3H4 (1b)] as the sole products (no products of cyanide attack on the allyl group were detected). Treatment of 1a,b with [Mo(OTf)(,3 -C3H5)(CO)2(phen)] and NaBAr,4 in CH2Cl2 yielded the compounds [{Mo(,3allyl)(CO)2(phen)}(,-CN){Mo(,3 -C3H5)(CO)2(phen)}]BAr,4 (2a,b). Analogous treatment of 1a with fac -[M(OTf)(CO)3(bipy)] (M = Mn, Re) and NaBAr,4 resulted in the synthesis of [{Mo(,3 -C3H5)(CO)2(phen)}(,-CN){M(CO)3(bipy)}]BAr,4 (3, 4), in which the C and N atoms of the cyano bridge are bonded to Mo and M (M = Mn, Re), respectively. The linkage isomer of 4 (C and N atoms of the cyano group bonded to Re and Mo, respectively) (6) was prepared by treatment of [Re(CN)(CO)3(bipy)] (5) with [Mo(OTf)(,3 -C3H5)(CO)2(phen)] and NaBAr,4. Compounds 1a, 2b, 3, and 6 were characterized by X-ray diffraction. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]


    Enhancement of crystalline perfection by organic dopants in ZTS, ADP and KHP crystals as investigated by high-resolution XRD and SEM

    JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2006
    S. Parthiban
    To reveal the influence of complexing agents on crystalline perfection, tristhiourea zinc(II) sulfate (ZTS), ammonium dihydrogen phosphate (ADP) and potassium hydrogen phthalate (KHP) crystals grown by slow-evaporation solution growth technique using low concentrations (5 10,3M) of dopants like ethylenediamminetetraacetic acid (EDTA) and 1,10-phenanthroline (phen) were characterized by high-resolution X-ray diffractometry (XRD) and scanning electron microscopy (SEM). High-resolution diffraction curves (DCs) recorded for ZTS and ADP crystals doped with EDTA show that the specimen contains an epilayer, as observed by the additional peak in the DC, whereas undoped specimens do not have such additional peaks. On etching the surface layer, the additional peak due to the epilayer disappears and a very sharp DC is obtained, with full width at half-maximum (FWHM) of less than 10,arcsec, as expected from the plane wave dynamical theory of X-ray diffraction for an ideally perfect crystal. SEM micrographs also confirm the existence of an epilayer in doped specimens. The ZTS specimen has a layer with a rough surface morphology, having randomly oriented needles, whereas the ADP specimen contains a layer with dendric structure. In contrast to ADP and ZTS crystals, the DC of phen-doped KHP shows no additional peak, but it is quite broad (FWHM = 28,arcsec) with a high value of integrated intensity, , (area under the DC). The broadness of the DC and the high value of , indicate the formation of a mosaic layer on the surface of the crystal. However, similar to ADP and ZTS, the DC recorded after etching the surface layer of the KHP specimen shows a very sharp peak with an FWHM of 8 arcsec. An SEM photograph of phen-doped KHP shows deep cracks on the surface, confirming the mosaicity. After removing the surface layer, the SEM pictures reveal a smooth surface. A similar trend is observed with other complexing agents, like oxalic acid, bipy and picolinic acid. However, only typical examples are described in the present article where the effects were observed prominently. The investigations on ZTS, ADP and KHP crystals, employing high-resolution XRD and SEM studies, revealed that some organic dopants added to the solution during the growth lead to the formation of a surface layer, due to complexation of these dopants with the trace metal ion impurities present in the solution, which prevents the entry of impurities, including the solvent, into the crystal, thereby assisting crystal growth with high crystalline perfection. The influence of organic dopants on the second harmonic generation efficiency is also investigated. [source]


    Poly[[[aqua(2,2,-bipyridine-,2N,N,)manganese(II)]-,-croconato-,4O,O,:O,,,O,,,] monohydrate]: a one-dimensional coordination polymer connected by hydrophilic,hydrophilic and lipophilic,lipophilic interactions at 135,K

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
    Hong-Feng Chen
    In the title one-dimensional coordination polymer, {[Mn(C5O5)(C10H8N2)(H2O)]H2O}n, each MnII ion is seven-coordinated by four O atoms from two croconate ligands, two N atoms from a 2,2,-bipyridine (2,2,-bipy) ligand and one O atom from an aqua ligand. The croconate ligand bridges the MnII ions in a bis-bidentate chelation mode, forming an extended [Mn(C5O5)]n chain running parallel to the [001] direction, with the lipophilic 2,2,-bipy ligands lying along one side and the hydrophilic water molecules along the opposite side. Coordinated water and solvent water molecules are arranged in the hydrophilic layer, which is characterized by O,H...O hydrogen bonds between croconate ligands. Meanwhile, 2,2,-bipy ligands from adjacent chains partially overlap and exhibit ,,, interactions to form a lipophilic layer. The hydrophilic and lipophilic layers are arranged alternately to build a layer structure. [source]


    Ammine(2,2,-bipyridine-,2N,N,)silver(I) nitrate: a dimer formed by ,,, stacking and ligand-unsupported Ag...Ag interactions

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
    Di Sun
    Reaction of AgNO3 and 2,2,-bipyridine (bipy) under ultrasonic treatment gave the title compound, [Ag(C10H8N2)(NH3)]NO3. The crystal structure consists of dimers formed by two symmetry-related AgI,bipy monomers connected through intra-dimer ,,, stacking and ligand-unsupported Ag...Ag interactions. A crystallographic C2 axis passes through the mid-point of and is perpendicular to the Ag...Agi(,x + 1, y, ,z + ) axis. In addition, each AgI cation is coordinated by one chelating bipy ligand and one ammine ligand, giving a trigonal coordination environment capped by the symmetry-equivalent Ag atom. Molecules are assembled by Ag...Ag, ,,,, hydrogen-bond (N,H...O and C,H...O) and weak Ag..., interactions into a three-dimensional framework. Comparing the products synthesized under different mechanical treatments, we found that reaction conditions have a significant influence on the resulting structures. The luminescence properties of the title compound are also discussed. [source]


    catena -Poly[bis[silver(I)-,2 -4,4,-bipyridine-,2N:N,] naphthalene-2,6-dicarboxylate tetrahydrate]: self-assembly of a supramolecular framework via coordination bonds and supramolecular interactions

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009
    Di Sun
    The ultrasonic reaction of AgNO3, 4,4,-bipyridine (bipy) and naphthalene-2,6-dicarboxylic acid (H2NDC) gives rise to the title compound, {[Ag2(C10H8N2)2](C12H6O4)4H2O}n. The NDC dianion is located on an inversion centre. The AgI centre is coordinated in a linear manner by two N atoms from two bipy ligands. The crystal structure consists of one-dimensional AgI,bipy cationic chains and two-dimensional NDC,H2O anionic sheets, constructed by coordination bonds and supramolecular interactions, respectively. [source]


    catena -Poly[silver(I)-,2 -4,4,-bipyridine-,2N:N,-,3 -chlorido]: self-assembly of a two-dimensional bilayer silver(I) coordination polymer from AgCl and a bipodal spacer

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009
    Di Sun
    The title compound, [AgCl(C10H8N2)]n, was synthesized by reaction of silver(I) chloride with 4,4,-bipyridine (bipy) under ammoniacal conditions. The crystal structure reveals that the Ag and Cl atoms lie on twofold axes, while the bipy ligands also sit across twofold axes. The AgI center is five-coordinated by three Cl atoms and two N atoms from two symmetry-related bipy ligands in a distorted square-pyramidal geometry. The complex contains one-dimensional AgI,bipy chains, which are further linked by rarely formed T-frame ,3 -Cl to form a two-dimensional bilayer structure. [source]


    4,4,-Methylenediphenol,4,4,-bipyridine (2/3): decarboxylation of 5,5,-methylenedisalicylic acid under hydrothermal conditions

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009
    Zhi-Hui Zhang
    Reaction of 5,5,-methylenedisalicylic acid (5,5,-H4mdsa) with 4,4,-bipyridine (4,4,-bipy) and manganese(II) acetate under hydrothermal conditions led to the unexpected 2:3 binary cocrystal 4,4,-methylenediphenol,4,4,-bipyridine (2/3), C13H12O21.5C10H8N2 or (4,4,-H2dhdp)(4,4,-bipy)1.5, which is formed with a concomitant decarboxylation. The asymmetric unit contains one and a half 4,4,-bipy molecules, one of which straddles a centre of inversion, and one 4,4,-H2dhdp molecule. O,H...N interactions between the hydroxy and pyridyl groups lead to a discrete ribbon motif with an unusual 2:3 stoichiometric ratio of strong hydrogen-bonding donors and acceptors. One of the pyridyl N-atom donors is not involved in hydrogen-bond formation. Additional weak C,H...O interactions between 4,4,-bipy and 4,4,-H2dhdp molecules complete a two-dimensional bilayer supramolecular structure. [source]


    A cyanide-bridged FeII,NdIII bimetallic assembly with a one-dimensional ladder-like chain structure

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2009
    Yan Xu
    The title complex, catena -poly[[[(2,2,-bipyridine-1,2N,N,)tris(methanol-2,O)(nitrato-2,2O,O,)-,-cyanido-1:2C:N -cyanido-1,C -iron(II)neodymium(III)]-di-,-cyanido-1:2,C:N;2:1,N:C] methanol solvate], {[FeIINdIII(CN)4(NO3)(C10H8N2)(CH3OH)3]CH3OH}n, is made up of ladder-like one-dimensional chains oriented along the c axis. Each ladder consists of two strands based on alternating FeII and NdIII centers connected by cyanide bridges. Furthermore, two such parallel chains are connected by additional cyanide cross-pieces (the `rungs' of the ladder), which likewise connect FeII and NdIII centers, such that each [Fe(CN)4(bipy)]2, unit (bipy is 2,2,-bipyridine) coordinates with three NdIII centers and each NdIII center connects with three different [Fe(CN)4(bipy)]2, units. In the complex, the iron(II) cation is six-coordinated with a distorted octahedral geometry and the neodymium(III) cation is eight-coordinated with a distorted dodecahedral environment. [source]


    Poly[[diaqua-,-4,4,-bipyridine-dinitratodi-,- l -tyrosinato-dicopper(II)]: a chiral two-dimensional coordination polymer

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2009
    Shuo Zhang
    The title compound, [Cu2(C9H10NO3)2(NO3)2(C10H8N2)(H2O)2]n, contains CuII atoms and l -tyrosinate (l -tyr) and 4,4,-bipyridine (4,4,-bipy) ligands in a 2:2:1 ratio. Each Cu atom is coordinated by one amino N atom and two carboxylate O atoms from two l -tyr ligands, one N atom from a 4,4,-bipy ligand, a monodentate nitrate ion and a water molecule in an elongated octahedral geometry. Adjacent Cu atoms are bridged by the bidentate carboxylate groups into a chain. These chains are further linked by the bridging 4,4,-bipy ligands, forming an undulated chiral two-dimensional sheet. O,H...O and N,H...O hydrogen bonds connect the sheets in the [100] direction. This study offers useful information for the engineering of chiral coordination polymers with amino acids and 4,4,-bipy ligands by considering the ratios of the metal ion and organic components. [source]


    An unusual chain cadmium(II) coordination polymer: catena -poly[[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-chlorido-[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-thiocyanato-,2N:S;,2S:N]

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2007
    Min Chen
    The title complex, [CdCl(NCS)(C10H8N2)]n, represents an unusual CdII coordination polymer constructed by two types of anionic bridges and 2,2,-bipyridyl (bipy) terminal ligands. These two types of bridges are arranged around inversion centers. The distorted octahedral coordination of the CdII center is provided by two chloride ions, one N- and one S-donor atom from two thiocyanate ions, and a pair of N atoms from the chelating bipy ligand. Interestingly, adjacent CdII ions are interconnected alternately by paired chloride [Cd...Cd = 3.916,(1),] and thiocyanate bridges [Cd...Cd = 5.936,(1),] to generate an infinite one-dimensional coordination chain. Furthermore, weak interchain C,H...S interactions between the bipy components and thiocyanate ions lead to the formation of a layered supramolecular structure. [source]