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Sample records for ccaat-binding complex coordinates

  1. Coordination Approaches for Complex Software Systems

    NARCIS (Netherlands)

    Bosse, T.; Hoogendoorn, M.; Treur, J.

    2006-01-01

    This document presents the results of a collaboration between the Vrije Universiteit Amsterdam, Department of Artificial Intelligence and Force Vision to investigate coordination approaches for complex software systems. The project was funded by Force Vision.

  2. Deriving force field parameters for coordination complexes

    DEFF Research Database (Denmark)

    Norrby, Per-Ola; Brandt, Peter

    2001-01-01

    The process of deriving molecular mechanics force fields for coordination complexes is outlined. Force field basics are introduced with an emphasis on special requirements for metal complexes. The review is then focused on how to set up the initial model, define the target, refine the parameters......, and validate the final force field, Alternatives to force field derivation are discussed briefly....

  3. Encoding of coordination complexes with XML.

    Science.gov (United States)

    Vinoth, P; Sankar, P

    2017-09-01

    An in-silico system to encode structure, bonding and properties of coordination complexes is developed. The encoding is achieved through a semantic XML markup frame. Composition of the coordination complexes is captured in terms of central atom and ligands. Structural information of central atom is detailed in terms of electron status of valence electron orbitals. The ligands are encoded with specific reference to the electron environment of ligand centre atoms. Behaviour of ligands to form low or high spin complexes is accomplished by assigning a Ligand Centre Value to every ligand based on the electronic environment of ligand centre atom. Chemical ontologies are used for categorization purpose and to control different hybridization schemes. Complexes formed by the central atoms of transition metal, non-transition elements belonging to s-block, p-block and f-block are encoded with a generic encoding platform. Complexes of homoleptic, heteroleptic and bridged types are also covered by this encoding system. Utility of the encoded system to predict redox electron transfer reaction in the coordination complexes is demonstrated with a simple application. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Seventeen-coordinate actinide helium complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kaltsoyannis, Nikolas [School of Chemistry, The University of Manchester (United Kingdom)

    2017-06-12

    The geometries and electronic structures of molecular ions featuring He atoms complexed to actinide cations are explored computationally using density functional and coupled cluster theories. A new record coordination number is established, as AcHe{sub 17}{sup 3+}, ThHe{sub 17}{sup 4+}, and PaHe{sub 17}{sup 4+} are all found to be true geometric minima, with the He atoms clearly located in the first shell around the actinide. Analysis of AcHe{sub n}{sup 3+} (n=1-17) using the quantum theory of atoms in molecules (QTAIM) confirms these systems as having closed shell, charge-induced dipole bonding. Excellent correlations (R{sup 2}>0.95) are found between QTAIM metrics (bond critical point electron densities and delocalization indices) and the average Ac-He distances, and also with the incremental He binding energies. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Transition Metal Complexes Coordinated by Water Soluble Phosphane Ligands: How Cyclodextrins Can Alter the Coordination Sphere?

    Directory of Open Access Journals (Sweden)

    Michel Ferreira

    2017-01-01

    Full Text Available The behaviour of platinum(II and palladium(0 complexes coordinated by various hydrosoluble monodentate phosphane ligands has been investigated by 31P{1H} NMR spectroscopy in the presence of randomly methylated β-cyclodextrin (RAME-β-CD. This molecular receptor can have no impact on the organometallic complexes, induce the formation of phosphane low-coordinated complexes or form coordination second sphere species. These three behaviours are under thermodynamic control and are governed not only by the affinity of RAME-β-CD for the phosphane but also by the phosphane stereoelectronic properties. When observed, the low-coordinated complexes may be formed either via a preliminary decoordination of the phosphane followed by a complexation of the free ligand by the CD or via the generation of organometallic species complexed by CD which then lead to expulsion of ligands to decrease their internal steric hindrance.

  6. Fluorescent zinc–terpyridine complex containing coordinated ...

    Indian Academy of Sciences (India)

    Unknown

    Keywords. Zinc peroxo complex; terpyridine complexes; fluorescence ... structure determination 3. Zinc is an essential element for normal function of most .... 63 179; (d) De Silva A P, Gunaratna H Q N, Gunnlaugsson T, Huxley A J M, Mcloy C.

  7. An EPR Monitoring of Isomerism and coordination sphere dynamics in five-coordinated pincer nickel complexes

    OpenAIRE

    Kozhanov, K.; Bubnov, M.; Cherkasov, V.; Fukin, G.; Vavilina, N.; Efremova, L.; Abakumov, G.

    2006-01-01

    A number of five-coordinated paramagnetic pincer nickel complexes have been obtained and investigated by X-band EPR spectroscopy. In general, these complexes can exist in solution as a pair of interconverting structure isomers. Activation parameters of this interconversion were estimated for several complexes.

  8. Metallacyclopentadienes: structural features and coordination in transition metal complexes

    International Nuclear Information System (INIS)

    Dolgushin, Fedor M; Yanovsky, Aleksandr I; Antipin, Mikhail Yu

    2004-01-01

    Results of structural studies of polynuclear transition metal complexes containing the metallacyclopentadiene fragment are overviewed. The structural features of the complexes in relation to the nature of the substituents in the organic moiety of the metallacycles, the nature of the transition metals and their ligand environment are analysed. The main structural characteristics corresponding to different modes of coordination of metallacyclopentadienes to one or two additional metal centres are revealed.

  9. A simple coordination complex exhibiting colour change on slight ...

    Indian Academy of Sciences (India)

    Administrator

    structure analysis. In 1979, Grenthe and co-worker. reported thermochromism of bis(NN-diethylethane-. 1,2-diamine) copper(II) perchlorate on the basis of ... ture was allowed to cool when white solid KCl sepa- rated out and it was .... A simple coordination complex exhibits colour change on slight structural modification. 733.

  10. Memory for Negation in Coordinate and Complex Sentences

    Science.gov (United States)

    Harris, Richard J.

    1976-01-01

    Two experiments were run to test memory for the negation morpheme "not" in coordinate sentences (e.g., The ballerina had twins and the policewoman did not have triplets) and complex sentences (e.g., The ghost scared Hamlet into not murdering Shakespeare). (Editor)

  11. Six-Coordinate Ln(III Complexes with Various Coordination Geometries Showing Distinct Magnetic Properties

    Directory of Open Access Journals (Sweden)

    Mei Guo

    2018-01-01

    Full Text Available The syntheses, structural characterization, and magnetic properties of three lanthanide complexes with formulas [Ln(L13] (Ln = Dy (1Dy; Er (1Er; and [Dy(L22] (2Dy were reported. Complexes 1Dy and 1Er are isostructural with the metal ion in distorted trigonal-prismatic coordination geometry, but exhibit distinct magnetic properties due to the different shapes of electron density for DyIII (oblate and ErIII (prolate ions. Complex 1Dy shows obvious SMM behavior under a zero direct current (dc field with an effective energy barrier of 31.4 K, while complex 1Er only features SMM behavior under a 400 Oe external field with an effective energy barrier of 23.96 K. In stark contrast, complex 2Dy with the octahedral geometry only exhibits the frequency dependence of alternating current (ac susceptibility signals without χ″ peaks under a zero dc field.

  12. Energetic lanthanide complexes: coordination chemistry and explosives applications

    International Nuclear Information System (INIS)

    Manner, V W; Barker, B J; Sanders, V E; Laintz, K E; Scott, B L; Preston, D N; Sandstrom, M; Reardon, B L

    2014-01-01

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  13. Prospective Vigilance: Assessing Complex Coordinated Attack Preparedness Programs

    Science.gov (United States)

    2017-12-01

    INTENTIONALLY LEFT BLANK xiii LIST OF ACRONYMS AND ABBREVIATIONS CCA complex coordinate attack EMS emergency medical services FBI Federal Bureau...the Bombings in London on 7th July 2005, vol. HC 1087 (London: The Stationery Office, 2006), https://www.gov.uk/government/uploads/system/uploads...School Center for Homeland Defense and Security Mobile Education Team, DHS Office of Bombing Prevention, and DHS Active Shooter training. 55 NCTC, DHS

  14. STABILIZATION OF UNUSUAL SUBSTRATE COORDINATION MODES IN DINUCLEAR MACROCYCLIC COMPLEXES

    Directory of Open Access Journals (Sweden)

    Vasile Lozan

    2010-06-01

    Full Text Available The steric protection offered by the macrobinucleating hexaazaditiophenolate ligand (L allows for the preparation of the first stable dinuclear nickel(II borohydride bridged complex, which reacts rapidly with elemental sulphur producing a tetranuclear nickel(II complex [{(LNi2}2(μ-S6]2+ bearing a helical μ4-hexa- sulfide ligand. The [(LCoII 2]2+ fragment have been able to trap a monomethyl orthomolybdate in the binding pocket. Unusual coordination modes of substrate in dinuclear macrocyclic compounds was demonstrated.

  15. Facile Preparation of Hybrid Zinc Porphyrin Dendrimer Using Coordination Complex

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Go-Eun; Shin, Eun Ju [Sunchon National University, Suncheon (Korea, Republic of)

    2016-03-15

    Porphyrins and metalloporphyrins have been investigated extensively due to their important role in natural photosynthesis, strong absorption in visible region, good light-harvesting properties, unique photophysical and electrochemical properties, and the development of simple synthetic routes for various derivatives. Dendrimers have globular structure with branches of repeating units and wide diversity of the architecture because their size, shape, and functionalities can be tailored. Numerous dendrimers have been designed and synthesized for various applications ranging from catalyst to drug delivery. Both pyridine dendrons Py-PD and Py-AD were successfully coordinated at axial position on central zinc metal cation in zinc porphyrin dendrimers ZnP-AD, ZnP-AD2, or ZnP-AD4. Therefore, it was proven that the formation of axial coordination complex between metal-centered dendrimer and ligand-containing dendron provides another facile method for the preparation of new hybrid dendrimer.

  16. Design of magnetic coordination complexes for quantum computing.

    Science.gov (United States)

    Aromí, Guillem; Aguilà, David; Gamez, Patrick; Luis, Fernando; Roubeau, Olivier

    2012-01-21

    A very exciting prospect in coordination chemistry is to manipulate spins within magnetic complexes for the realization of quantum logic operations. An introduction to the requirements for a paramagnetic molecule to act as a 2-qubit quantum gate is provided in this tutorial review. We propose synthetic methods aimed at accessing such type of functional molecules, based on ligand design and inorganic synthesis. Two strategies are presented: (i) the first consists in targeting molecules containing a pair of well-defined and weakly coupled paramagnetic metal aggregates, each acting as a carrier of one potential qubit, (ii) the second is the design of dinuclear complexes of anisotropic metal ions, exhibiting dissimilar environments and feeble magnetic coupling. The first systems obtained from this synthetic program are presented here and their properties are discussed.

  17. Coordination phenomena of cationic uranium(iv) complexes

    International Nuclear Information System (INIS)

    Rohwer, H.E.

    1974-12-01

    The coordination properties of the cationic uranium(IV) complexes UCl 3 + , UCl 2 2+ , UCl 3+ , and U 4+ were studied in a non-aqueous medium in the presence of perchlorate as counterion which, however, proved to coordinate to a much greater extent than expected. The strong neutral ligand, HMPA, could successively displace some of the perchlorates. An electrostatic model for the U(CIO 4 ) 4 -HMPA-acetone system compared favourably with the actual results. This emphasized the high ionic content in the bonding with actenoid cations, even with such a high charge as +4 . These conclusions are in agreement with studies 75 in which nitrate acts as counter ion. Correspondingly the uranium (IV) chemistry is characterized by the absence of typical 3d-organometallic chemistry, for example, strong bonding with CO, P(Phi) 3 etc, which strongly depends on covalent bonding. This stresses the fact that the d and f orbitals are not readily available for strong bond formation with the actenoids. 76

  18. Complex Interdependence Regulates Heterotypic Transcription Factor Distribution and Coordinates Cardiogenesis.

    Science.gov (United States)

    Luna-Zurita, Luis; Stirnimann, Christian U; Glatt, Sebastian; Kaynak, Bogac L; Thomas, Sean; Baudin, Florence; Samee, Md Abul Hassan; He, Daniel; Small, Eric M; Mileikovsky, Maria; Nagy, Andras; Holloway, Alisha K; Pollard, Katherine S; Müller, Christoph W; Bruneau, Benoit G

    2016-02-25

    Transcription factors (TFs) are thought to function with partners to achieve specificity and precise quantitative outputs. In the developing heart, heterotypic TF interactions, such as between the T-box TF TBX5 and the homeodomain TF NKX2-5, have been proposed as a mechanism for human congenital heart defects. We report extensive and complex interdependent genomic occupancy of TBX5, NKX2-5, and the zinc finger TF GATA4 coordinately controlling cardiac gene expression, differentiation, and morphogenesis. Interdependent binding serves not only to co-regulate gene expression but also to prevent TFs from distributing to ectopic loci and activate lineage-inappropriate genes. We define preferential motif arrangements for TBX5 and NKX2-5 cooperative binding sites, supported at the atomic level by their co-crystal structure bound to DNA, revealing a direct interaction between the two factors and induced DNA bending. Complex interdependent binding mechanisms reveal tightly regulated TF genomic distribution and define a combinatorial logic for heterotypic TF regulation of differentiation. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Micro practices of coordination based on complex adaptive systems: user needs and strategies for coordinating public health in Denmark

    Directory of Open Access Journals (Sweden)

    Morten Deleuran Terkildsen

    2015-09-01

    Full Text Available Introduction: Many highly formalised approaches to coordination poorly fit public health and recent studies call for coordination based on complex adaptive systems. Our contribution is two-fold. Empirically, we focus on public health, and theoretically we build on the patient perspective and treat coordination as a process of contingent, two-level negotiations of user needs.Theory and Methods: The paper draws on the concept of user needs-based coordination and sees coordination as a process, whereby needs emerging from the life world of the user are made amenable to the health system through negotiations. The analysis is based on an explorative case study of a health promotion initiative in Denmark. It adopts an anthropological qualitative approach and uses a range of qualitative data.Results: The analysis identifies four strategies of coordination: the coordinator focusing on the individual user or on relations with other professionals; and the manager coaching the coordinator or providing structural support. Crucially, the coordination strategies by management remain weak as they do not directly relate to specific user needs.Discussion: In process of bottom-up negotiations user needs become blurred and this is especially a challenge for management. The study therefore calls for an increased focus on the level nature of negotiations to bridge the gap that currently weakens coordination strategies by management.

  20. Micro practices of coordination based on complex adaptive systems: user needs and strategies for coordinating public health in Denmark.

    Science.gov (United States)

    Terkildsen, Morten Deleuran; Wittrup, Inge; Burau, Viola

    2015-01-01

    Many highly formalised approaches to coordination poorly fit public health and recent studies call for coordination based on complex adaptive systems. Our contribution is two-fold. Empirically, we focus on public health, and theoretically we build on the patient perspective and treat coordination as a process of contingent, two-level negotiations of user needs. The paper draws on the concept of user needs-based coordination and sees coordination as a process, whereby needs emerging from the life world of the user are made amenable to the health system through negotiations. The analysis is based on an explorative case study of a health promotion initiative in Denmark. It adopts an anthropological qualitative approach and uses a range of qualitative data. The analysis identifies four strategies of coordination: the coordinator focusing on the individual user or on relations with other professionals; and the manager coaching the coordinator or providing structural support. Crucially, the coordination strategies by management remain weak as they do not directly relate to specific user needs. In process of bottom-up negotiations user needs become blurred and this is especially a challenge for management. The study therefore calls for an increased focus on the level nature of negotiations to bridge the gap that currently weakens coordination strategies by management.

  1. Mathematical model and coordination algorithms for ensuring complex security of an organization

    Science.gov (United States)

    Novoseltsev, V. I.; Orlova, D. E.; Dubrovin, A. S.; Irkhin, V. P.

    2018-03-01

    The mathematical model of coordination when ensuring complex security of the organization is considered. On the basis of use of a method of casual search three types of algorithms of effective coordination adequate to mismatch level concerning security are developed: a coordination algorithm at domination of instructions of the coordinator; a coordination algorithm at domination of decisions of performers; a coordination algorithm at parity of interests of the coordinator and performers. Assessment of convergence of the algorithms considered above it was made by carrying out a computing experiment. The described algorithms of coordination have property of convergence in the sense stated above. And, the following regularity is revealed: than more simply in the structural relation the algorithm, for the smaller number of iterations is provided to those its convergence.

  2. Osmium and cobalt complexes incorporating facially coordinated N ...

    Indian Academy of Sciences (India)

    Administrator

    coordinated N,N,O donor azo-imine ligands: Redox and catalytic properties. Poulami Pattanayak, a. Debprasad Patra, a. Jahar Lal Pratihar, a. Andrew Burrows,. Mary F. Mahon b and Surajit Chattopadhyay* a a. Department of Chemistry, University of Kalyani, Kalyani-741235, India b. Department of Inorganic Chemistry, ...

  3. Distributed detection of communities in complex networks using synthetic coordinates

    International Nuclear Information System (INIS)

    Papadakis, H; Fragopoulou, P; Panagiotakis, C

    2014-01-01

    Various applications like finding Web communities, detecting the structure of social networks, and even analyzing a graph’s structure to uncover Internet attacks are just some of the applications for which community detection is important. In this paper, we propose an algorithm that finds the entire community structure of a network, on the basis of local interactions between neighboring nodes and an unsupervised distributed hierarchical clustering algorithm. The novelty of the proposed approach, named SCCD (standing for synthetic coordinate community detection), lies in the fact that the algorithm is based on the use of Vivaldi synthetic network coordinates computed by a distributed algorithm. The current paper not only presents an efficient distributed community finding algorithm, but also demonstrates that synthetic network coordinates could be used to derive efficient solutions to a variety of problems. Experimental results and comparisons with other methods from the literature are presented for a variety of benchmark graphs with known community structure, derived from varying a number of graph parameters and real data set graphs. The experimental results and comparisons to existing methods with similar computation cost on real and synthetic data sets demonstrate the high performance and robustness of the proposed scheme. (paper)

  4. Coordinating complex decision support activities across distributed applications

    Science.gov (United States)

    Adler, Richard M.

    1994-01-01

    Knowledge-based technologies have been applied successfully to automate planning and scheduling in many problem domains. Automation of decision support can be increased further by integrating task-specific applications with supporting database systems, and by coordinating interactions between such tools to facilitate collaborative activities. Unfortunately, the technical obstacles that must be overcome to achieve this vision of transparent, cooperative problem-solving are daunting. Intelligent decision support tools are typically developed for standalone use, rely on incompatible, task-specific representational models and application programming interfaces (API's), and run on heterogeneous computing platforms. Getting such applications to interact freely calls for platform independent capabilities for distributed communication, as well as tools for mapping information across disparate representations. Symbiotics is developing a layered set of software tools (called NetWorks! for integrating and coordinating heterogeneous distributed applications. he top layer of tools consists of an extensible set of generic, programmable coordination services. Developers access these services via high-level API's to implement the desired interactions between distributed applications.

  5. Identification of different coordination geometries by XAFS in copper(II) complexes with trimesic acid

    Science.gov (United States)

    Gaur, A.; Klysubun, W.; Soni, Balram; Shrivastava, B. D.; Prasad, J.; Srivastava, K.

    2016-10-01

    X-ray absorption spectroscopy (XAS) is very useful in revealing the information about geometric and electronic structure of a transition-metal absorber and thus commonly used for determination of metal-ligand coordination. But XAFS analysis becomes difficult if differently coordinated metal centers are present in a system. In the present investigation, existence of distinct coordination geometries around metal centres have been studied by XAFS in a series of trimesic acid Cu(II) complexes. The complexes studied are: Cu3(tma)2(im)6 8H2O (1), Cu3(tma)2(mim)6 17H2O (2), Cu3(tma)2(tmen)3 8.5H2O (3), Cu3(tma) (pmd)3 6H2O (ClO4)3 (4) and Cu3(tma)2 3H2O (5). These complexes have not only Cu metal centres with different coordination but in complexes 1-3, there are multiple coordination geometries present around Cu centres. Using XANES spectra, different coordination geometries present in these complexes have been identified. The variation observed in the pre-edge features and edge features have been correlated with the distortion of the specific coordination environment around Cu centres in the complexes. XANES spectra have been calculated for the distinct metal centres present in the complexes by employing ab-initio calculations. These individual spectra have been used to resolve the spectral contribution of the Cu centres to the particular XANES features exhibited by the experimental spectra of the multinuclear complexes. Also, the variation in the 4p density of states have been calculated for the different Cu centres and then correlated with the features originated from corresponding coordination of Cu. Thus, these spectral features have been successfully utilized to detect the presence of the discrete metal centres in a system. The inferences about the coordination geometry have been supported by EXAFS analysis which has been used to determine the structural parameters for these complexes.

  6. [Coordinating complex nursing care: building a guidance tool for cancer patients, to direct them towards the coordination nurse].

    Science.gov (United States)

    Froger, Raphael; Allenet, Benoit; Guillem, Pascale

    2017-03-01

    Introduction : following the 2009-2013 Cancer Plan, the experimental oncology nursing coordination (IDEC) showed a positive impact on the fluidity of care pathways. The 2014-2019 cancer plan guides their mission to complex cases. The objective of this study is to build a tool to facilitate the recruitment of patients likely to experience a complex path. Method : two phases have formed this research. The first one collected the elements of the dimensions that can predict the complexity of the care path, by focus group. The second consisted of reduction and selection of priority items and to estimate their importance by the Delphi method. Results : from the 12 selected items, two are recognized as a significant risk scoring, seven probably correlated with a complex pathway and three unrelated to the complexity of the pathways. Discussion : later this instrument would be validated by a test sample to evaluate its psychometric properties, metrological and feasibility.

  7. Osmium and cobalt complexes incorporating facially coordinated N ...

    Indian Academy of Sciences (India)

    The ligands which bind the transition metal ion in a predictable way play ... was purified by thin-layer chromatography on silica gel. A green band ..... gands, L. −. , (X-ray structure). The unipositive charge of the complex cation, [(L)2Co]. +. , 7, was satisfied by one. ClO. −. 4 ion. These complexes are soluble in common ...

  8. Equilibrium between Different Coordination Geometries in Oxidovanadium(IV) Complexes

    Science.gov (United States)

    Ugone, Valeria; Garribba, Eugenio; Micera, Giovanni; Sanna, Daniele

    2015-01-01

    In this laboratory activity, the equilibrium between square pyramidal and octahedral V(IV)O[superscript 2+] complexes is described. We propose a set of experiments to synthesize and characterize two types of V(IV)O[superscript 2+] complexes. The experiment allows great flexibility and may be effectively used at a variety of levels and the activity…

  9. Structure of Coordination Complexes: The Synergy between NMR ...

    African Journals Online (AJOL)

    NICO

    determined by density functional theory (DFT) methods and the application of the Boltzmann equation, are in ... single crystals suitable for crystallography can be obtained, ...... NMR analysis of bonding in transition metal olefin complexes.

  10. Proton exchange in acid–base complexes induced by reaction coordinates with heavy atom motions

    International Nuclear Information System (INIS)

    Alavi, Saman; Taghikhani, Mahdi

    2012-01-01

    Highlights: ► Proton exchange in acid–base complexes is studied. ► The structures, binding energies, and normal mode vibrations are calculated. ► Transition state structures of proton exchange mechanism are determined. ► In the complexes studied, the reaction coordinate involves heavy atom rocking. ► The reaction coordinate is not simply localized in the proton movements. - Abstract: We extend previous work on nitric acid–ammonia and nitric acid–alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid–strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are −1 . This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm −1 . Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

  11. Enantioselective cellular localisation of europium(iii) coordination complexes.

    Science.gov (United States)

    Frawley, Andrew T; Linford, Holly V; Starck, Matthieu; Pal, Robert; Parker, David

    2018-01-28

    The selective mitochondrial localisation of the Λ enantiomer of three different emissive europium(iii) complexes in NIH 3T3 and MCF7 cells contrasts with the behaviour of the Δ enantiomer, for which a predominant lysosomal localisation was observed by confocal microscopy. In each case, cell uptake occurs via macropinocytosis.

  12. The coordination and atom transfer chemistry of titanium porphyrin complexes

    Energy Technology Data Exchange (ETDEWEB)

    Hays, James Allen [Iowa State Univ., Ames, IA (United States)

    1993-11-05

    Preparation, characterization, and reactivity of (η2- alkyne)(meso-tetratolylpoprphrinato)titanium(II) complexes are described, along with inetermetal oxygen atom transfer reactions involving Ti(IV) and Ti(III) porphyrin complexes. The η2- alkyne complexes are prepared by reaction of (TTP)TiCl2 with LiAlH4 in presence of alkyne. Structure of (OEP)Ti(η2-Ph-C≡C-Ph) (OEP=octaethylporphryin) was determined by XRD. The compounds undergo simple substitution to displace the alkyne and produce doubly substituted complexes. Structure of (TTP)Ti(4-picoline)2 was also determined by XRD. Reaction of (TTP)Ti=O with (OEP)Ti-Cl yields intermetal O/Cl exchange, which is a one-electron redox process mediated by O atom transfer. Also a zero-electron redox process mediated by atom transfer is observed when (TTP)TiCl2 is reacted with (OEP)Ti=O.

  13. Biphenolate Iron (II) Complexes with Intramolecularly Coordinating Nitrogen Lewis Bases

    NARCIS (Netherlands)

    Koten, G. van; Brandts, J.A.M.; Janssen, M.D.; Hogerheide, M.P.; Boersma, J.; Spek, A.L.

    1999-01-01

    The synthesis and characterisation of a novel Fe(II) bisphenolate complex [Fe(OC{6}H{4}CH{2}NMe{2}-2){2}]{2} (1) from [Na(OC{6}H{4}CH{2}NMe{2}-2)] and anhydrous FeCl{2} is reported. The solid state structure has been elucidated by single crystal X-ray analysis and shows a dimeric structure with two

  14. Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

    KAUST Repository

    Lamberti, Marina; Fortman, George C.; Poater, Albert; Broggi, Julie; Slawin, Alexandra M. Z.; Cavallo, Luigi; Nolan, Steven P.

    2012-01-01

    The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

  15. Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

    KAUST Repository

    Lamberti, Marina

    2012-01-23

    The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

  16. Variable Denticity in Carboxylate Binding to the Uranyl Coordination Complexes

    International Nuclear Information System (INIS)

    Groenewold, G.S.; De Jong, Wibe A.; Oomens, Jos; Van Stipdonk, Michael J.

    2010-01-01

    Tris-carboxylate complexes of the uranyl (UO2)2+ cation with acetate and benzoate were generated using electrospray ionization mass spectrometry, and then isolated in a Fourier transformion cyclotron resonance mass spectrometer. Wavelength-selective infrared multiple photon dissociation (IRMPD) of the tris-acetatouranyl anion resulted in a redox elimination of an acetate radical, which was used to generate an IR spectrum that consisted of six prominent absorption bands. These were interpreted with the aid of density functional theory calculations in terms of symmetric and antisymmetric -CO2 stretches of both the monodentate and bidentate acetate, CH3 bending and umbrella vibrations, and a uranyl O-U-O asymmetric stretch. The comparison of the calculated and measured IR spectra indicated that the tris-acetate complex contained two acetate ligands bound in a bidentate fashion, while the third acetate was monodentate. In similar fashion, the tris-benzoate uranyl anion was formed and photodissociated by loss of a benzoate radical, enabling measurement of the infrared spectrum that was in close agreement with that calculated for a structure containing one monodentate, and two bidentate benzoate ligands.

  17. Plutonium(IV) complexation by diglycolamide ligands - coordination chemistry insight into TODGA-based actinide separations

    NARCIS (Netherlands)

    Reilly, S.D.; Gaunt, A.J.; Scott, B.L.; Modolo, G.; Iqbal, M.; Verboom, Willem; Sarsfield, M.J.

    2012-01-01

    Complexation of Pu(IV) with TMDGA, TEDGA, and TODGA diglycolamide ligands was followed by vis-NIR spectroscopy. A crystal structure determination reveals that TMDGA forms a 1:3 homoleptic Pu(IV) complex with the nitrate anions forced into the outer coordination sphere

  18. Coordination of a complex welfare system case: rehabilitation entity in Finland.

    Science.gov (United States)

    Miettinen, Sari; Ashorn, Ulla; Lehto, Juhani; Viitanen, Elina

    2011-01-01

    The main purpose of this article is to analyse the institutional and political structures of the Finnish rehabilitation entity and the governmental efforts to improve the governance of the rehabilitation policy. Rehabilitation in Finland is a complex welfare system which has undergone several coordination attempts during the last two decades. The centrality of the coordination of this welfare system is obvious. Based on the content analysis of three Government's rehabilitation reports from 1994 to 2002 and their background papers, this article provides two main findings. First, the rehabilitation entity seems to be based on different funding strategies, different governing and different coordination models between the rehabilitation subsystems. Second, the governance discourse in the reports seems to be unchanging with a predominantly hierarchical mode. The article concludes with a discussion on the challenges to coordinate this kind of a complex welfare system as an entity and also how to overcome those challenges. Copyright © 2010 John Wiley & Sons, Ltd.

  19. Information Design for Synchronization and Co-ordination of Modern, Complex, Multi-National Operations

    Science.gov (United States)

    2011-06-01

    1 16th ICCRTS Information design for synchronization and co-ordination of modern, complex, multi- national operations “Collective C2 in...REPORT DATE JUN 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Information design for synchronization and co...at 11th ICCRTS) who emphasise that information needs to be designed, not merely found or catalogued, to achieve synchronizations and co-ordinations

  20. Parent Perspective on Care Coordination Services for Their Child with Medical Complexity.

    Science.gov (United States)

    Cady, Rhonda G; Belew, John L

    2017-06-06

    The overarching goal of care coordination is communication and co-management across settings. Children with medical complexity require care from multiple services and providers, and the many benefits of care coordination on health and patient experience outcomes have been documented. Despite these findings, parents still report their greatest challenge is communication gaps. When this occurs, parents assume responsibility for aggregating and sharing health information across providers and settings. A new primary-specialty care coordination partnership model for children with medical complexity works to address these challenges and bridge communication gaps. During the first year of the new partnership, parents participated in focus groups to better understand how they perceive communication and collaboration between the providers and services delivering care for their medically complex child. Our findings from these sessions reflect the current literature and highlight additional challenges of rural families, as seen from the perspective of the parents. We found that parents appreciate when professional care coordination is provided, but this is often the exception and not the norm. Additionally, parents feel that the local health system's inability to care for their medically complex child results in unnecessary trips to urban-based specialty care. These gaps require a system-level approach to care coordination and, consequently, new paradigms for delivery are urgently needed.

  1. Parent Perspective on Care Coordination Services for Their Child with Medical Complexity

    Directory of Open Access Journals (Sweden)

    Rhonda G. Cady

    2017-06-01

    Full Text Available The overarching goal of care coordination is communication and co-management across settings. Children with medical complexity require care from multiple services and providers, and the many benefits of care coordination on health and patient experience outcomes have been documented. Despite these findings, parents still report their greatest challenge is communication gaps. When this occurs, parents assume responsibility for aggregating and sharing health information across providers and settings. A new primary-specialty care coordination partnership model for children with medical complexity works to address these challenges and bridge communication gaps. During the first year of the new partnership, parents participated in focus groups to better understand how they perceive communication and collaboration between the providers and services delivering care for their medically complex child. Our findings from these sessions reflect the current literature and highlight additional challenges of rural families, as seen from the perspective of the parents. We found that parents appreciate when professional care coordination is provided, but this is often the exception and not the norm. Additionally, parents feel that the local health system’s inability to care for their medically complex child results in unnecessary trips to urban-based specialty care. These gaps require a system-level approach to care coordination and, consequently, new paradigms for delivery are urgently needed.

  2. Talking about the institutional complexity of the integrated rehabilitation system – the importance of coordination

    OpenAIRE

    Miettinen, Sari; Ashorn, Ulla; Lehto, Juhani

    2013-01-01

    Rehabilitation in Finland is a good example of functions divided among several welfare sectors, such as health services and social services.  The rehabilitation system in Finland is a complex one and there have been many efforts to create a coordinated entity. The purpose of this study is to open up a complex welfare system at the upper policy level and to understand the meaning of coordination at the level of service delivery. We shed light in particular on the national rehabilitation policy...

  3. Mechanics of metal-catecholate complexes: The roles of coordination state and metal types

    Science.gov (United States)

    Xu, Zhiping

    2013-01-01

    There have been growing evidences for the critical roles of metal-coordination complexes in defining structural and mechanical properties of unmineralized biological materials, including hardness, toughness, and abrasion resistance. Their dynamic (e.g. pH-responsive, self-healable, reversible) properties inspire promising applications of synthetic materials following this concept. However, mechanics of these coordination crosslinks, which lays the ground for predictive and rational material design, has not yet been well addressed. Here we present a first-principles study of representative coordination complexes between metals and catechols. The results show that these crosslinks offer stiffness and strength near a covalent bond, which strongly depend on the coordination state and type of metals. This dependence is discussed by analyzing the nature of bonding between metals and catechols. The responsive mechanics of metal-coordination is further mapped from the single-molecule level to a networked material. The results presented here provide fundamental understanding and principles for material selection in metal-coordination-based applications. PMID:24107799

  4. Detecting coordinated regulation of multi-protein complexes using logic analysis of gene expression

    Directory of Open Access Journals (Sweden)

    Yeates Todd O

    2009-12-01

    Full Text Available Abstract Background Many of the functional units in cells are multi-protein complexes such as RNA polymerase, the ribosome, and the proteasome. For such units to work together, one might expect a high level of regulation to enable co-appearance or repression of sets of complexes at the required time. However, this type of coordinated regulation between whole complexes is difficult to detect by existing methods for analyzing mRNA co-expression. We propose a new methodology that is able to detect such higher order relationships. Results We detect coordinated regulation of multiple protein complexes using logic analysis of gene expression data. Specifically, we identify gene triplets composed of genes whose expression profiles are found to be related by various types of logic functions. In order to focus on complexes, we associate the members of a gene triplet with the distinct protein complexes to which they belong. In this way, we identify complexes related by specific kinds of regulatory relationships. For example, we may find that the transcription of complex C is increased only if the transcription of both complex A AND complex B is repressed. We identify hundreds of examples of coordinated regulation among complexes under various stress conditions. Many of these examples involve the ribosome. Some of our examples have been previously identified in the literature, while others are novel. One notable example is the relationship between the transcription of the ribosome, RNA polymerase and mannosyltransferase II, which is involved in N-linked glycan processing in the Golgi. Conclusions The analysis proposed here focuses on relationships among triplets of genes that are not evident when genes are examined in a pairwise fashion as in typical clustering methods. By grouping gene triplets, we are able to decipher coordinated regulation among sets of three complexes. Moreover, using all triplets that involve coordinated regulation with the ribosome

  5. Attributes of advanced practice registered nurse care coordination for children with medical complexity.

    Science.gov (United States)

    Cady, Rhonda G; Kelly, Anne M; Finkelstein, Stanley M; Looman, Wendy S; Garwick, Ann W

    2014-01-01

    Care coordination is an essential component of the pediatric health care home. This study investigated the attributes of relationship-based advanced practice registered nurse care coordination for children with medical complexity enrolled in a tertiary hospital-based health care home. Retrospective review of 2,628 care coordination episodes conducted by telehealth over a consecutive 3-year time period for 27 children indicated that parents initiated the majority of episodes and the most frequent reason was acute and chronic condition management. During this period, care coordination episodes tripled, with a significant increase (p < .001) between years 1 and 2. The increased episodes could explain previously reported reductions in hospitalizations for this group of children. Descriptive analysis of a program-specific survey showed that parents valued having a single place to call and assistance in managing their child's complex needs. The advanced practice registered nurse care coordination model has potential for changing the health management processes for children with medical complexity. Copyright © 2014 National Association of Pediatric Nurse Practitioners. Published by Mosby, Inc. All rights reserved.

  6. Electrochemically fabricated polypyrrole-cobalt-oxygen coordination complex as high-performance lithium-storage materials.

    Science.gov (United States)

    Guo, Bingkun; Kong, Qingyu; Zhu, Ying; Mao, Ya; Wang, Zhaoxiang; Wan, Meixiang; Chen, Liquan

    2011-12-23

    Current lithium-ion battery (LIB) technologies are all based on inorganic electrode materials, though organic materials have been used as electrodes for years. Disadvantages such as limited thermal stability and low specific capacity hinder their applications. On the other hand, the transition metal oxides that provide high lithium-storage capacity by way of electrochemical conversion reaction suffer from poor cycling stability. Here we report a novel high-performance, organic, lithium-storage material, a polypyrrole-cobalt-oxygen (PPy-Co-O) coordination complex, with high lithium-storage capacity and excellent cycling stability. Extended X-ray absorption fine structure and Raman spectroscopy and other physical and electrochemical characterizations demonstrate that this coordination complex can be electrochemically fabricated by cycling PPy-coated Co(3)O(4) between 0.0 V and 3.0 V versus Li(+)/Li. Density functional theory (DFT) calculations indicate that each cobalt atom coordinates with two nitrogen atoms within the PPy-Co coordination layer and the layers are connected with oxygen atoms between them. Coordination weakens the C-H bonds on PPy and makes the complex a novel lithium-storage material with high capacity and high cycling stability. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Study by magnetic resonance and relaxation of carbon 13 of some paramagnetic coordination complexes

    International Nuclear Information System (INIS)

    Ronfard-Haret, Jean-Claude

    1977-01-01

    This research thesis reports the study of coordination complexes by using NMR. After a brief recall of the theoretical background required for the processing of experimental data (hyper-fine coupling and magnetic resonance, spin density distribution, chemical displacement, dipolar, scalar and electronic relaxation), the author describes the conditions in which experiments have been performed and presents measurement methods (pulsed nuclear magnetic resonance, relaxation time measurement, determination of hyper-fine coupling constants, spectrometers and reactants). The next chapters address the study of different coordination complexes: [(pyridine-N-oxide) 2 Ni(acetylacetonate) 2 ], carbon 13 in alkyl-anilines-Ni II, complexation of 1- and 2-aminonaphthalene by transition ions, complexation of pyridine-N-oxide by the nickel Ni ++ ion in presence of water

  8. XAFS study of copper(II) complexes with square planar and square pyramidal coordination geometries

    Science.gov (United States)

    Gaur, A.; Klysubun, W.; Nitin Nair, N.; Shrivastava, B. D.; Prasad, J.; Srivastava, K.

    2016-08-01

    X-ray absorption fine structure of six Cu(II) complexes, Cu2(Clna)4 2H2O (1), Cu2(ac)4 2H2O (2), Cu2(phac)4 (pyz) (3), Cu2(bpy)2(na)2 H2O (ClO4) (4), Cu2(teen)4(OH)2(ClO4)2 (5) and Cu2(tmen)4(OH)2(ClO4)2 (6) (where ac, phac, pyz, bpy, na, teen, tmen = acetate, phenyl acetate, pyrazole, bipyridine, nicotinic acid, tetraethyethylenediamine, tetramethylethylenediamine, respectively), which were supposed to have square pyramidal and square planar coordination geometries have been investigated. The differences observed in the X-ray absorption near edge structure (XANES) features of the standard compounds having four, five and six coordination geometry points towards presence of square planar and square pyramidal geometry around Cu centre in the studied complexes. The presence of intense pre-edge feature in the spectra of four complexes, 1-4, indicates square pyramidal coordination. Another important XANES feature, present in complexes 5 and 6, is prominent shoulder in the rising part of edge whose intensity decreases in the presence of axial ligands and thus indicates four coordination in these complexes. Ab initio calculations were carried out for square planar and square pyramidal Cu centres to observe the variation of 4p density of states in the presence and absence of axial ligands. To determine the number and distance of scattering atoms around Cu centre in the complexes, EXAFS analysis has been done using the paths obtained from Cu(II) oxide model and an axial Cu-O path from model of a square pyramidal complex. The results obtained from EXAFS analysis have been reported which confirmed the inference drawn from XANES features. Thus, it has been shown that these paths from model of a standard compound can be used to determine the structural parameters for complexes having unknown structure.

  9. Chiral phosphites as ligands in asymmetric metal complex catalysis and synthesis of coordination compounds

    International Nuclear Information System (INIS)

    Gavrilov, Konstantin N; Bondarev, Oleg G; Polosukhin, Aleksei I

    2004-01-01

    The data published during the last five years on the application of chiral derivatives of phosphorous acid in coordination chemistry and enantioselective catalysis are summarised and discussed. The effect of the nature of these ligands on the structure of metal complexes and on the efficiency of catalytic organic syntheses is shown. Hydroformylation, hydrogenation, allylic substitution and conjugate addition catalysed by transition metal complexes with optically active phosphites and hydrophosphoranes are considered. The prospects for the development of this field of research are demonstrated.

  10. Coordination symmetry determination of some lanthanide complexes by x-ray diffraction

    International Nuclear Information System (INIS)

    Oliveira Paiva Santos, C. de.

    1983-01-01

    The x-ray determination of the crystal and molecular structures of three lanthanide complexes is described. The work is a contribution to the study of the coordination chemistry of lanthanide ions with organic ligands and in particular, it aims to compare the observed point symmetry of the ion environment with spectroscopic predictions. (author)

  11. Experimental investigation of some coordination complexes using the sup(151)Eu Moessbauer resonance

    International Nuclear Information System (INIS)

    Lal, Asharfi; Rama Reddy, A.; Arvind; Ahmad, Naseer

    1979-01-01

    Several Schiff base complexes containing Eu 151 metal ions have been synthesized and their Moessbauer spectra are recorded using the constant acceleration velocity spectrometer. The least-square analysis method for the evaluation of the hyperfine field coupling constants is adopted using the computer dec system-10. From the systematic analysis of the quadrupole coupling constants (q.c.c.) and isomer shifts it has been established that the coordination number of the metal ion of Bis(acetylacetone) benzidine and thiourea complexes is five, that of bis-vanillin benzidine and bis-salicylaldehyde-o-dianisidine is six, and that of bis-vanillin-o-phenylene diamine is seven. It is also found that the q.c.c. being negative in all these complexes decreases monotonically as the coordination number increases. One unusual aspect of this experimental data is that most of the coordination complexes have very low f-factors whereas the Schiff base complexes studied here have a fairly high recoilless fractions. Attempts are in progress to synthesize and study the Fe Schiff base complexes in place of Eu. (auth.)

  12. The Role of Care Coordinator for Children with Complex Care Needs: A Systematic Review

    Science.gov (United States)

    Hillis, Rowan; Larkin, Philip J; Cawley, Des; Connolly, Michael

    2016-01-01

    Introduction: This systematic review seeks to identify the intended components of the role of care coordinator for children with complex care needs and the factors that determine its composition in practice. Theory and methods: The initial search identified 1,157 articles, of which 37 met the inclusion criteria. They were quality assessed using the SIGN hierarchy of evidence structure. Results: Core components of the role include: coordination of care needs, planning and assessment, specialist support, emotional support, administration and logistics and continuing professional development. Influencing factors on the role include the external environment (political and socio-economic), the internal environment (organisational structure and funding protocols), the skills, qualifications and experience of the coordinator, the family circumstances and the nature of the interaction between the care coordinator and the family. Discussion: The lack of consistent terminology creates challenges and there is a need for greater consensus on this issue. Organisations and healthcare professionals need to recognise the extent to which contextual factors influence the role of a care coordinator in practice and plan accordingly. Despite evidence that suggests that the role is pivotal in ensuring that care needs are sustained, there remains great variability in the understanding of the role of a care coordinator for this population. Conclusions: As the provision of care increasingly moves closer to home there is a need for greater understanding of the nature and composition of the interaction between care coordinators and families to determine the extent to which appropriate services are being provided. Further work in this area should take into consideration any potential variance in service provision, for example any potential inequity arising due to geographic location. It is also imperative, where appropriate, to seek the views of children with complex care needs and their

  13. The Role of Care Coordinator for Children with Complex Care Needs: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Rowan Hillis

    2016-05-01

    Full Text Available Introduction: This systematic review seeks to identify the intended components of the role of care coordinator for children with complex care needs and the factors that determine its composition in practice. Theory and methods: The initial search identified 1,157 articles, of which 37 met the inclusion criteria. They were quality assessed using the SIGN hierarchy of evidence structure. Results: Core components of the role include: coordination of care needs, planning and assessment, specialist support, emotional support, administration and logistics and continuing professional development. Influencing factors on the role include the external environment (political and socio-economic, the internal environment (organisational structure and funding protocols, the skills, qualifications and experience of the coordinator, the family circumstances and the nature of the interaction between the care coordinator and the family. Discussion: The lack of consistent terminology creates challenges and there is a need for greater consensus on this issue. Organisations and healthcare professionals need to recognise the extent to which contextual factors influence the role of a care coordinator in practice and plan accordingly. Despite evidence that suggests that the role is pivotal in ensuring that care needs are sustained, there remains great variability in the understanding of the role of a care coordinator for this population. Conclusions: As the provision of care increasingly moves closer to home there is a need for greater understanding of the nature and composition of the interaction between care coordinators and families to determine the extent to which appropriate services are being provided. Further work in this area should take into consideration any potential variance in service provision, for example any potential inequity arising due to geographic location. It is also imperative, where appropriate, to seek the views of children with complex care

  14. ACTIVATION OF ACETYLENE BY COORDINATION TO BIS-TRIPHENYLPHOSPHINE COMPLEX OF Pt(0: DFT STUDY

    Directory of Open Access Journals (Sweden)

    N. N. Gorinchoy

    2009-06-01

    Full Text Available The present work is devoted to the theoretical study of the activation of the acetylene molecule coordinated in the [Pt(PPh32C2H2] complex. By means of DFT calculations it is shown that the geometrical and electronic characteristics of the C2H2 are essentially changed due to its coordination. The subsequent detailed analysis of the molecular orbitals (MO of the active valence zone of this complex allows one to make important conclusion that this activation is being realized mainly due to the orbital back donation of 5d-electronic density from one of the occupied MOs of the complex [Pt(PPh32] to the unoccupied antibonding π*-MO of C2H2.

  15. Low complexity non-iterative coordinated beamforming in 2-user broadcast channels

    KAUST Repository

    Park, Kihong

    2010-10-01

    We propose a new non-iterative coordinated beamforming scheme to obtain full multiplexing gain in 2-user MIMO systems. In order to find the beamforming and combining matrices, we solve a generalized eigenvector problem and describe how to find generalized eigenvectors according to the Gaussian broadcast channels. Selected simulation results show that the proposed method yields the same sum-rate performance as the iterative coordinated beamforming method, while maintaining lower complexity by non-iterative computation of the beamforming and combining matrices. We also show that the proposed method can easily exploit selective gain by choosing the best combination of generalized eigenvectors. © 2006 IEEE.

  16. A Stable Coordination Complex of Rh(IV) in an N,O-Donor Environment

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Shashi B. [Department of Chemistry, Yale University, 225 Prospect; Shopov, Dimitar Y. [Department of Chemistry, Yale University, 225 Prospect; Sharninghausen, Liam S. [Department of Chemistry, Yale University, 225 Prospect; Vinyard, David J. [Department of Chemistry, Yale University, 225 Prospect; Mercado, Brandon Q. [Department of Chemistry, Yale University, 225 Prospect; Brudvig, Gary W. [Department of Chemistry, Yale University, 225 Prospect; Crabtree, Robert H. [Department of Chemistry, Yale University, 225 Prospect

    2015-12-10

    We describe facial and meridional isomers of [RhIII(pyalk)3], as well as meridional [RhIV(pyalk)3]+ {pyalk =2-(2-pyridyl)-2-propanoate}, the first coordination complex in an N,O-donor environment to show a clean, reversible RhIII/IV redox couple and to have a stable Rh(IV) form, which we characterize by EPR and UV–visible spectroscopy as well as X-ray crystallography. The unprecedented stability of the Rh(IV) species is ascribed to the exceptional donor strength of the ligands, their oxidation resistance, and the meridional coordination geometry.

  17. Direct measurement and modulation of single-molecule coordinative bonding forces in a transition metal complex

    DEFF Research Database (Denmark)

    Hao, Xian; Zhu, Nan; Gschneidtner, Tina

    2013-01-01

    remain a daunting challenge. Here we demonstrate an interdisciplinary and systematic approach that enables measurement and modulation of the coordinative bonding forces in a transition metal complex. Terpyridine is derived with a thiol linker, facilitating covalent attachment of this ligand on both gold...... substrate surfaces and gold-coated atomic force microscopy tips. The coordination and bond breaking between terpyridine and osmium are followed in situ by electrochemically controlled atomic force microscopy at the single-molecule level. The redox state of the central metal atom is found to have...

  18. Low complexity non-iterative coordinated beamforming in 2-user broadcast channels

    KAUST Repository

    Park, Kihong; Ko, Youngchai; Alouini, Mohamed-Slim

    2010-01-01

    We propose a new non-iterative coordinated beamforming scheme to obtain full multiplexing gain in 2-user MIMO systems. In order to find the beamforming and combining matrices, we solve a generalized eigenvector problem and describe how to find generalized eigenvectors according to the Gaussian broadcast channels. Selected simulation results show that the proposed method yields the same sum-rate performance as the iterative coordinated beamforming method, while maintaining lower complexity by non-iterative computation of the beamforming and combining matrices. We also show that the proposed method can easily exploit selective gain by choosing the best combination of generalized eigenvectors. © 2006 IEEE.

  19. Polynuclear complexes of copper(I) halides: coordination chemistry and catalytic transformations of alkynes

    International Nuclear Information System (INIS)

    Mykhalichko, B M; Mys'kiv, M G; Temkin, Oleg N

    2000-01-01

    Characteristic features of the coordination chemistry of Cu(I) and mechanisms of catalytic conversions of alkynes in the CuCl-MCl-H 2 O-HC≡CR system (MCl is alkali metal or ammonium chloride or amine hydrochloride; R=H, CH 2 OH, CH=CH 2 , etc.) are analysed based on studies of the compositions and structures of copper(I) chloride (bromide) complexes, alkyne π-complexes and ethynyl organometallic polynuclear compounds formed in this system in solutions and in the crystalline state. The role of polynuclear complexes in various reactions of alkynes is discussed. The bibliography includes 149 references.

  20. Emission properties of Sm(III) complex having ten-coordination structure

    International Nuclear Information System (INIS)

    Hasegawa, Yasuchika; Tsuruoka, Shin-ichi; Yoshida, Takahiko; Kawai, Hideki; Kawai, Tsuyoshi

    2008-01-01

    Sammarium(III) complex having ten-coordination structure, bis-(1,10-phenanthroline)tris-(hexafluoroacetylacetonato)samarium(III) (Sm(hfa) 3 (phen) 2 ) was prepared by chelation of tris-(hexafluoroacetylacetonato) samarium(III) (Sm(hfa) 3 (H 2 O) 2 ) with 1,10-phenantroline (phen). The characteristic ten-coordination structure of Sm(hfa) 3 (phen) 2 was determined by 1 H NMR and elemental analyses. Strong deep-red emission (λ max =643 nm) and narrow emission band (FWHM=5 nm) of Sm(hfa) 3 (phen) 2 originated from electronic allowed transition from characteristics ten coordinate structure. The emission quantum yields Sm(hfa) 3 (phen) 2 excited at absorption bands of ligands and Sm(III) ion were found to be 0.36 and 1.4%, respectively

  1. Coordination functionalization of graphene oxide with tetraazamacrocyclic complexes of nickel(II): Generation of paramagnetic centers

    Energy Technology Data Exchange (ETDEWEB)

    Basiuk, Vladimir A., E-mail: basiuk@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510 México D.F. (Mexico); Department of Chemistry,Tufts University, 62 Talbot Avenue, Medford, MA 02155 (United States); Alzate-Carvajal, Natalia [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510 México D.F. (Mexico); Henao-Holguín, Laura V. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510 México D.F. (Mexico); Rybak-Akimova, Elena V. [Department of Chemistry,Tufts University, 62 Talbot Avenue, Medford, MA 02155 (United States); Basiuk, Elena V., E-mail: elbg1111@gmail.com [Department of Chemistry,Tufts University, 62 Talbot Avenue, Medford, MA 02155 (United States); Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510 México D.F. (Mexico)

    2016-05-15

    Highlights: • [Ni(cyclam)]{sup 2+} and [Ni(tet b)]{sup 2+} cations coordinate to carboxylic groups of GO. • The coordination takes place under basic conditions in aqueous-based medium. • The coordination results in the conversion from low-spin to high-spin Ni(II). • Functionalized GO samples were characterized by various instrumental techniques. - Abstract: We describe a novel approach to functionalization of graphene oxide (GO) which allows for a facile generation of paramagnetic centers from two diamagnetic components. Coordination attachment of [Ni(cyclam)]{sup 2+} or [Ni(tet b)]{sup 2+} tetraazamacrocyclic cations to carboxylic groups of GO takes place under basic conditions in aqueous-based reaction medium. The procedure is very straightforward and does not require high temperatures or other harsh conditions. Changing the coordination geometry of Ni(II) from square-planar tetracoordinated to pseudooctahedral hexacoordinated brings about the conversion from low-spin to high-spin state of the metal centers. Even though the content of tetraazamacrocyclic complexes in functionalized GO samples was found to be relatively low (nickel content of ca. 1 wt%, as determined by thermogravimetric analysis, elemental analysis and energy dispersive X-ray spectroscopy), room temperature magnetic susceptibility measurements easily detected the appearance of paramagnetic properties in GO + [Ni(cyclam)] and GO + [Ni(tet b)] nanohybrids, with effective magnetic moments of 1.95 BM and 2.2 BM for, respectively. According to density functional theory calculations, the main spin density is localized at the macrocyclic complexes, without considerable extension to graphene sheet, which suggests insignificant ferromagnetic coupling in the nanohybrids, in agreement with the results of magnetic susceptibility measurements. The coordination attachment of Ni(II) tetraazamacrocycles to GO results in considerable changes in Fourier-transform infrared and X-ray photoelectron spectra

  2. Social dilemmas and individual/group coordination strategies in a complex rural land-use game

    Directory of Open Access Journals (Sweden)

    Luis García-Barrios

    2011-09-01

    Full Text Available Strengthening ongoing bottom-up capacity building processes for local and sustainable landscape-level governance is a multi-dimensional social endeavor. One of the tasks involved – participatory rural land use planning – requires more understanding and more awareness among all stakeholders regarding the social dilemmas local people confront when responding to each other’s land-use decisions. In this paper we will analyze and discuss a version of our game SIERRA SPRINGS that is simple to play for any stakeholder that can count to 24, yet entails a complex-coordination land use game – with an extensive and yet finite set of solutions – which can mimic in a stylized form some of the dilemmas landowners could confront in a landscape planning process where there livelihoods are at stake. The game has helped researchers and players observe and reflect on the individual coordination strategies that emerge within a group in response to these stylized dilemmas. This paper (1 develops a game-theoretical approach to cooperation, competition and coordination of land uses in small rural watersheds, (2 describe the goal, rules and mechanics of the game, (3 analyzes the structure of each farms’ solution set vs. the whole watershed’s solution set, (4 derives from them the coordination dilemmas and the risk of coordination failure, (5 describes four individual coordination strategies consistently displayed by players; mapping them in a plane we have called Group-Level Coordination Space, and (6 discusses the strengths, limitations and actual and potential uses of the game both for research and as an introductory tool for stakeholders involved in participatory land use planning.

  3. Investigation of the complex reaction coordinate of acid catalyzed amide hydrolysis from molecular dynamics simulations

    International Nuclear Information System (INIS)

    Zahn, Dirk

    2004-01-01

    The rate-determining step of acid catalyzed peptide hydrolysis is the nucleophilic attack of a water molecule to the carbon atom of the amide group. Therein the addition of the hydroxyl group to the amide carbon atom involves the association of a water molecule transferring one of its protons to an adjacent water molecule. The protonation of the amide nitrogen atom follows as a separate reaction step. Since the nucleophilic attack involves the breaking and formation of several bonds, the underlying reaction coordinate is rather complex. We investigate this reaction step from path sampling Car-Parrinello molecular dynamics simulations. This approach does not require the predefinition of reaction coordinates and is thus particularly suited for investigating reaction mechanisms. From our simulations the most relevant components of the reaction coordinate are elaborated. Though the C···O distance of the oxygen atom of the water molecule performing the nucleophilic attack and the corresponding amide carbon atom is a descriptor of the reaction progress, a complete picture of the reaction coordinate must include all three molecules taking part in the reaction. Moreover, the proton transfer is found to depend on favorable solvent configurations. Thus, also the arrangement of non-reacting, i.e. solvent water molecules needs to be considered in the reaction coordinate

  4. A Rac1--GDP trimer complex binds zinc with tetrahedral and octahedral coordination, displacing magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Prehna, G.; Stebbins, C

    2007-01-01

    The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3221 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

  5. A Rac1-GDP Trimer Complex Binds Zinc with Tetrahedral and Octahedral Coordination, Displacing Magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Prehna,G.; Stebbins, E.

    2007-01-01

    The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3{sub 2}21 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

  6. Coordination diversity of new mononucleating hydrazone in 3d metal complexes: Synthesis, characterization and structural studies

    Directory of Open Access Journals (Sweden)

    RAJESH S. BALIGAR

    2006-12-01

    Full Text Available The mononucleating hydrazone ligand LH3, a condensation product of salicyloylhydrazine and (2-formylphenoxyacetic acid, was synthesized and its coordination behavior with first row transition metal(II ions was investigated by isolating and elucidating the structure of the complexes using elemental analysis, conductivity and magnetic susceptibility measurements, as well as IR, 1H-NMR, electronic and EPR spectral techniques. The ligand forms mononuclear metal(II complexes of the type [CoLH(H2O2], [NiLH(H2O2, [CuLH] and [ZnLH]. The ligand field parameters, Dq, B and b values, in the case of the cobalt and nickel complexes support not only the octahedral geometry around the metal ion, but also imply the covalent nature of the bonding in the complexes. The EPR study revealed the presence of a spin exchange interaction in the solid copper complex and the covalent nature of the bonding. The 1H-NMR study of the zinc(II complex indicated the non-involvement of the COOH group in the coordination. The physico-chemical study supports for the presence of octahedral geometry around cobalt(II, nickel(II and tetrahedral geometry around copper(II and zinc(II ions.

  7. Tetraphenylborate as a non - coordinating anion in hexamethyphosphoramine (HMPA) and tetramethylurea (TMU) lanthanide complexes

    International Nuclear Information System (INIS)

    Kuya, M.K.; Serra, O.A.

    1979-01-01

    The synthesis of the HMPA and TMU complexes of rare earth ions using tetraphenylborate, a non-coordinating anion, as a precipitating agent is reported. The compounds obtained conform to the general formula LnL 6 (B PHI 4 ) 3 (Ln=Ce-Lu,Y, whe L=HMPA and Ln=nd, Sm,Eu,Er,Y when L=TMU). The characterization by conductance, infrared and visible measurements is consistent with the lack of donor capacity of tetraphenylborate ion, and with a coordination number six in a nearly octahedral site symmetry for both type of compounds. The TMU complexes seem to be more stable than the corresponding HMPA ones, indicating that the steric factor can be more important than the donor capacity of the ligands in this type of lanthanide compounds. (author) [pt

  8. Ligand influences on properties of uranium coordination complexes. Structure, reactivity, and spectroscopy

    International Nuclear Information System (INIS)

    Kosog, Boris

    2012-01-01

    In this thesis several different aspects of uranium chemistry are presented. It was shown that terminal uranium(V) oxo and imido complexes [(( R ArO) 3 tacn)U V (O)] and [(( R ArO) 3 tacn)U V (NSiMe 3 )] (R = t Bu, Ad) can be oxidized by silver(I) hexafluoro-antimonate to the uranium(VI) oxo and imido complexes [(( R ArO) 3 tacn)U VI (O)]SbF 6 and [(( R ArO) 3 tacn)U VI (NSiMe 3 )]SbF 6 . While for the t Bu-derivative of the oxo complex an equatorial coordination is observed due to stabilization by the inverse trans-influence, normal axial coordination is observed for the Ad-derivative and both imido complexes. The inverse trans-influence was thus proven to be a key factor for the coordination mode of a terminal ligand on high valent uranium complexes. L III XANES was shown to be a great tool for the determination of oxidation states of uranium complexes. Therefore, a series of uranium complexes in all stable oxidation states for uranium, +III to +VI was prepared, and their spectra analyzed. All compounds bear only O-donor ligands in addition to the chlating trisaryloxide-tacn-ligand. A separation of 1.5 to 3 eV in the white line energy is observed between the different oxidation states. This series can be used as reference for compounds, where oxidation state assignment is not obvious, such as a ketyl radical complex [(( t-Bu Ar)O 3 tacn)U(O-C( t-Bu Ph) 2 .- )]. For this complex, the oxidation state of +IV could be assigned. Moreover, a series of isostructural uranium(IV) complexes was prepared. The influence of different ligands according to the spectrochemical series on the electronic and magnetic properties could be shown using UV/vis/NIR spectroscopy and variable temperature SQUID measurements. Calculations of uranium L III XANES spectra show a variation in the shape of the spectra and thus high resolution PFY-XANES would be a great tool to determine the electronic influence of these different axial ligands. Using the single N-anchored ligand system, the first

  9. Copper-based metal coordination complexes with Voriconazole ligand: Syntheses, structures and antimicrobial properties

    Science.gov (United States)

    Zhao, Yan-Ming; Tang, Gui-Mei; Wang, Yong-Tao; Cui, Yue-Zhi; Ng, Seik Weng

    2018-03-01

    Three new chiral metal coordination complexes, namely, [Cu(FZ)2(CH3COO)2(H2O)]·2H2O (1), [Cu(FZ)2(NO3)2] (2), and [Cu2(FZ)2 (H2O)8](SO4)2·4H2O (3) [FZ = (2R,3S)-2-(2,4-difluorophenyl)-3-(5-fluoro-4-pyrimidiny)-1-(1H-1,2,4-triazol-1-yl)-2-butanol) (Voriconazole)] have been obtained by the reaction of Cu(II) salts and the free ligand FZ at room temperature. Complexes 1-3 were structurally characterized by X-ray single-crystal diffraction, IR, UV-vis, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). Complex 1 crystallizes in the chiral space group C2, which exhibits a mono-nuclear structure. Both complexes 2 and 3 display a one-dimensional (1D) tape structure, which crystallize in chiral space group P21212 and P212121, respectively. Among these complexes, there exist a variety of hydrogen bonds and stacking interactions, through which a three-dimensional supramolecular architecture will be generated. Compared with the standard (Voriconazole), these Cu-based complexes show the more potent inhibiting efficiency against the species of Candida and Aspergillus. Moreover, among these complexes, complex 1 shows the most excellent efficiency.

  10. Coordination chemistry of gadolinium complexes having pyridine carboxylate units in relation with the medical imagery

    International Nuclear Information System (INIS)

    Gateau, C.; Chatterton, N.; Nonat, A.; Mazzanti, M.; Pecaut, J.; Borel, A.; Merbach, A.; Heim, L.

    2005-01-01

    In order to study the influence of the coordination sphere on the properties which govern the relaxivity, ligands containing pyridine carboxylates units have been particularly studied. It has been shown that the tripodal ligand tpaa forms with gadolinium (III) a neutral complex having a relaxivity (r1p=13.3 mM -1 at 298 K and 60 MHz) which is three times superior to the contrast agents currently used in NMR Imaging. To explain this remarkably relaxivity, two new ligands analogous to the tpaa: the tpatcn and the bpeda containing pyridine carboxylate units bound to one or several aliphatic nitrogen have been studied in modulating the number of coordination sites and the symmetry degree. The study of the relaxivity of the corresponding gadolinium (III) complexes gives precious data on the understanding of the results in the case of the complex [Gd(tpaa)]. The synthesis and the properties of these gadolinium (III) complexes will be presented during this conference. (O.M.)

  11. Investigating the pharmacodynamic and magnetic properties of pyrophosphate-bridged coordination complexes

    Science.gov (United States)

    Ikotun, Oluwatayo (Tayo) F.

    The multidentate nature of pyrophosphate makes it an attractive ligand for complexation of metal cations. The participation of pyrophosphate in a variety of biological pathways and its metal catalyzed hydrolysis has driven our investigation into its coordination chemistry. We have successfully synthesized a library of binuclear pyrophosphate bridge coordination complexes. The problem of pyrophosphate hydrolysis to phosphate in the presence of divalent metal ions was overcome by incorporating capping ligands such as 1,10-phenanthroline and 2,2'-bipyridine prior to the addition of the pyrophosphate. The magnetic properties of these complexes was investigated and magneto-structural analysis was conducted. The biological abundance of pyrophosphate and the success of metal based drugs such as cisplatin, prompted our investigation of the cytotoxic properties of M(II) pyrophosphate dimeric complexes (where M(II) is CoII, CuII, and NiII) in adriamycin resistant human ovarian cancer cells. Thess compounds were found to exhibit toxicity in the nanomolar to picomolar range. We conducted in vitro stability studies and the mechanism of cytoxicity was elucidated by performing DNA mobility and binding assays, enzyme inhibition assays, and in vitro oxidative stress studies.

  12. Heterobimetallic coordination polymers involving 3d metal complexes and heavier transition metals cyanometallates

    Energy Technology Data Exchange (ETDEWEB)

    Peresypkina, Eugenia V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Samsonenko, Denis G. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Vostrikova, Kira E., E-mail: vosk@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); LMI, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France)

    2015-04-15

    The results of the first steps in the design of coordination polymers based on penta- and heptacyanometallates of heavier d transitions metals are presented. The 2D structure of the coordination polymers: [(Mn(acacen)){sub 2}Ru(NO)(CN){sub 5}]{sub n} and two complexes composed of different cyanorhenates, [Ni(cyclam)]{sub 2}[ReO(OH)(CN){sub 4}](ClO{sub 4}){sub 2}(H{sub 2}O){sub 1.25} and [Cu(cyclam)]{sub 2}[Re(CN){sub 7}](H{sub 2}O){sub 12}, was confirmed by single crystal XRD study, the rhenium oxidation state having been proved by the magnetic measurements. An amorphism of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} (M=Ni, Cu) polymers does not allow to define strictly their dimensionality and to model anisotropic magnetic behavior of the compounds. However, with high probability a honey-comb like layer structure could be expected for [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2} complexes, studied in this work, because such an arrangement is the most common among the bimetallic assemblies of hexa- and octacyanometallates with a ratio [M(cyclam)]/[M(CN){sub n}]=3/2. For the first time was prepared and fully characterized a precursor (n-Bu{sub 4}N){sub 2}[Ru(NO)(CN){sub 5}], soluble in organic media. - Graphical abstract: The very first results in the design of 2D coordination polymers based on penta- and heptacyanometallates of 4d and5d transitions metals are presented. - Highlights: • Design of coordination polymers based on penta- and heptacyanometallates. • New Ru and Re cyanide based heterobimetallic coordination complexes. • Hydrolysis and ox/red processes involving [Re(CN){sub 7}]{sup 3+} during crystallization. • High magnetic anisotropy of [M(cyclam)]{sub 3}[Re(CN){sub 7}]{sub 2}(H{sub 2}O){sub n}, M=Cu, Ni, complexes.

  13. Coordination Nature of 4-Mercaptoaniline to Sn(II Ion: Formation of a One Dimensional Coordination Polymer and Its Decomposition to a Mono Nuclear Sn(IV Complex

    Directory of Open Access Journals (Sweden)

    Eon S. Burkett

    2014-12-01

    Full Text Available The coordination of the bifunctional ligand 4-mercaptoaniline with aqueo us tin(II metal ion was studied. A coordination polymer was synthesized when an aqueous solution of SnCl2 was treated with 4-MA. The crystalline material is stable under atmospheric conditions retaining its oxidation state. However, when submerged in a solution saturated with oxygen, the compound oxidizes to a mononuclear tin(IV complex. Both the compounds were characterized by single crystal X-ray diffraction studies. Although the structure of the tin(IV complex was previously reported, crystal structure of this compound was redetermined.

  14. Correlation of Solid State and Solution Coordination Numbers with Infrared Spectroscopy in Five-, Six-, and Eight-Coordinate Transition Metal Complexes of DOTAM.

    Science.gov (United States)

    Nagata, Maika K C T; Brauchle, Paul S; Wang, Sen; Briggs, Sarah K; Hong, Young Soo; Laorenza, Daniel W; Lee, Andrea G; Westmoreland, T David

    2016-08-16

    Three new DOTAM (1,4,7,10-tetrakis(acetamido)-1,4,7,10-tetraazacyclododecane) complexes have been synthesized and characterized by X-ray crystallography: [Co(DOTAM)]Cl 2 •3H 2 O, [Ni(DOTAM)]Cl 2 •4H 2 O, and [Cu(DOTAM)](ClO 4 ) 2 •H 2 O. Solid state and solution IR spectroscopic features for a series of [M(DOTAM)] 2+ complexes (M=Mn, Co, Cu, Ni, Ca, Zn) correlate with solid state and solution coordination numbers. [Co(DOTAM)] 2+ , [Ni(DOTAM)] 2+ , and [Zn(DOTAM)] 2+ are demonstrated to be six-coordinate in both the solid state and in solution, while [Mn(DOTAM)] 2+ and [Ca(DOTAM)] 2+ are eight-coordinate in the solid state and remain so in solution. [Cu(DOTAM)] 2+ , which is five-coordinate by X-ray crystallography, is shown to increase its coordination number in solution to six-coordinate.

  15. Hardware Implementation of a Modified Delay-Coordinate Mapping-Based QRS Complex Detection Algorithm

    Directory of Open Access Journals (Sweden)

    Andrej Zemva

    2007-01-01

    Full Text Available We present a modified delay-coordinate mapping-based QRS complex detection algorithm, suitable for hardware implementation. In the original algorithm, the phase-space portrait of an electrocardiogram signal is reconstructed in a two-dimensional plane using the method of delays. Geometrical properties of the obtained phase-space portrait are exploited for QRS complex detection. In our solution, a bandpass filter is used for ECG signal prefiltering and an improved method for detection threshold-level calculation is utilized. We developed the algorithm on the MIT-BIH Arrhythmia Database (sensitivity of 99.82% and positive predictivity of 99.82% and tested it on the long-term ST database (sensitivity of 99.72% and positive predictivity of 99.37%. Our algorithm outperforms several well-known QRS complex detection algorithms, including the original algorithm.

  16. Ligand Influences on Properties of Uranium Coordination Complexes - Structure, Reactivity, and Spectroscopy

    OpenAIRE

    Kosog, Boris

    2012-01-01

    In this thesis several different aspects of uranium chemistry are presented. It was shown that terminal uranium(V) oxo and imido complexes [((RArO)3tacn)UV(O)] and [((RArO)3tacn)UV(NSiMe3)] (R = t Bu, Ad) can be oxidized by silver(I) hexafluoro-antimonate to the uranium(VI) oxo and imido complexes [((RArO)3tacn)UVI(O)]SbF6 and [((RArO)3tacn)UVI(NSiMe3)]SbF6. While for the t Bu-derivative of the oxo complex an equatorial coordination is observed due to stabilization by the inverse trans-influe...

  17. Ligand design for site-selective metal coordination: synthesis of transition-metal complexes with η{sup 6}-coordination of the central ring of anthracene

    Energy Technology Data Exchange (ETDEWEB)

    Karslyan, Eduard E.; Borissova, Alexandra O.; Perekalin, Dmitry S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow (Russian Federation)

    2017-05-08

    A polycyclic aromatic ligand for site-selective metal coordination was designed by using DFT calculations. The computational prediction was confirmed by experiments: 2,3,6,7-tetramethoxy-9,10-dimethylanthracene initially reacts with [(C{sub 5}H{sub 5})Ru(MeCN){sub 3}]BF{sub 4} to give the kinetic product with a [(C{sub 5}H{sub 5})Ru]{sup +} fragment coordinated at the terminal ring, which is then transformed into the thermodynamic product with coordination through the central ring. These isomeric complexes have markedly different UV/Vis spectra, which was explained by analysis of the frontier orbitals. At the same time, the calculations suggest that electrostatic interactions are mainly responsible for the site selectivity of the coordination. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Functional cooperation between FACT and MCM is coordinated with cell cycle and differential complex formation

    Directory of Open Access Journals (Sweden)

    Lin Chih-Li

    2010-02-01

    Full Text Available Abstract Background Functional cooperation between FACT and the MCM helicase complex constitutes an integral step during DNA replication initiation. However, mode of regulation that underlies the proper functional interaction of FACT and MCM is poorly understood. Methods & Results Here we present evidence indicating that such interaction is coordinated with cell cycle progression and differential complex formation. We first demonstrate the existence of two distinct FACT-MCM subassemblies, FACT-MCM2/4/6/7 and FACT-MCM2/3/4/5. Both complexes possess DNA unwinding activity and are subject to cell cycle-dependent enzymatic regulation. Interestingly, analysis of functional attributes further suggests that they act at distinct, and possibly sequential, steps during origin establishment and replication initiation. Moreover, we show that the phosphorylation profile of the FACT-associated MCM4 undergoes a cell cycle-dependent change, which is directly correlated with the catalytic activity of the FACT-MCM helicase complexes. Finally, at the quaternary structure level, physical interaction between FACT and MCM complexes is generally dependent on persistent cell cycle and further stabilized upon S phase entry. Cessation of mitotic cycle destabilizes the complex formation and likely leads to compromised coordination and activities. Conclusions Together, our results correlate FACT-MCM functionally and temporally with S phase and DNA replication. They further demonstrate that enzymatic activities intrinsically important for DNA replication are tightly controlled at various levels, thereby ensuring proper progression of, as well as exit from, the cell cycle and ultimately euploid gene balance.

  19. Talking about the institutional complexity of the integrated rehabilitation system – the importance of coordination

    Directory of Open Access Journals (Sweden)

    Sari Miettinen

    2013-03-01

    Full Text Available Rehabilitation in Finland is a good example of functions divided among several welfare sectors, such as health services and social services.  The rehabilitation system in Finland is a complex one and there have been many efforts to create a coordinated entity. The purpose of this study is to open up a complex welfare system at the upper policy level and to understand the meaning of coordination at the level of service delivery. We shed light in particular on the national rehabilitation policy in Finland and how the policy has tried to overcome the negative effects of institutional complexity. In this study we used qualitative content analysis and frame analysis. As a result we identified four different welfare state frames with distinct features of policy problems, policy alternatives and institutional failure. The rehabilitation policy in Finland seems to be divided into different components which may cause problems at the level of service delivery and thus in the integration of services. Bringing these components together could at policy level enable a shared view of the rights of different population groups, effective management of integration at the level of service delivery and also an opportunity for change throughout the rehabilitation system.

  20. Hydrothermal synthesis and characterization of a binuclear complex and a coordination

    Directory of Open Access Journals (Sweden)

    Reza Mohamadinasab

    2010-06-01

    Full Text Available Two new copper complexes [(bipy(pydcCu(μ-OCO-pydcCu(bipy(H2O].3.5H¬2O (1 and {[(μ2-C2O4(2,2'-bipyCu].2H2O}n (2 (pydcH2 = pyridine-2,6-dicarboxylilic acid, bipy = 2,2'-bipyridine have been hydrothermally synthesized. Both complexes were characterized by IR spectroscopy, elemental analysis and single crystal X-ray diffraction studies. Complex 1 consists of two independent neutral molecules. In every moiety, metal ion center is in a distorted octahedral geometry. Coordination polymer (2 has been prepared from the reaction of bis-(cyclohexanone-oxal-dihydrazone,2,2'-bipyridine and Cu(NO32 in basic solution and under hydrothermal condition. The results showed that the bis-(cyclohexanone-oxal-dihydrazone was converted to oxalate ion under heating and basic pH. Each metal ion center in 2 is in a distorted octahedral geometry and is coordinated by four oxygen atoms of two bridged oxalate ions and two nitrogen atoms of 2,2'-bipyridine molecules. In the crystal structure of 2, some H-bonds and π-π interaction cause formation of a 3D network.

  1. Talking about the institutional complexity of the integrated rehabilitation system-the importance of coordination.

    Science.gov (United States)

    Miettinen, Sari; Ashorn, Ulla; Lehto, Juhani

    2013-01-01

    Rehabilitation in Finland is a good example of functions divided among several welfare sectors, such as health services and social services. The rehabilitation system in Finland is a complex one and there have been many efforts to create a coordinated entity. The purpose of this study is to open up a complex welfare system at the upper policy level and to understand the meaning of coordination at the level of service delivery. We shed light in particular on the national rehabilitation policy in Finland and how the policy has tried to overcome the negative effects of institutional complexity. In this study we used qualitative content analysis and frame analysis. As a result we identified four different welfare state frames with distinct features of policy problems, policy alternatives and institutional failure. The rehabilitation policy in Finland seems to be divided into different components which may cause problems at the level of service delivery and thus in the integration of services. Bringing these components together could at policy level enable a shared view of the rights of different population groups, effective management of integration at the level of service delivery and also an opportunity for change throughout the rehabilitation system.

  2. Silver(i) complexes with 1'-(diphenylphosphino)-1-cyanoferrocene: the art of improvisation in coordination.

    Science.gov (United States)

    Škoch, Karel; Uhlík, Filip; Císařová, Ivana; Štěpnička, Petr

    2016-06-28

    1'-(Diphenylphosphino)-1-cyanoferrocene () reacts with silver(i) halides at a 1 : 1 metal-to-ligand ratio to afford the heterocubane complexes [Ag(μ3-X)(-κP)]4, where X = Cl (), Br (), and I (). In addition, the reaction with AgCl with 2 equiv. of leads to chloride-bridged dimer [(μ-Cl)2{Ag(-κP)2}2] () and, presumably, also to [(μ(P,N)-){AgCl(-κP)}]2 (). While similar reactions with AgCN furnished only the insoluble coordination polymer [(-κP)2Ag(NC)Ag(CN)]n (), those with AgSCN afforded the heterocubane [Ag(-κP)(μ-SCN-S,S,N)]4 () and the thiocyanato-bridged disilver(i) complex [Ag(-κP)2(μ-SCN-S,N)]2 (), thereby resembling reactions in the AgCl- system. Attempted reactions with AgF led to ill-defined products, among which [Ag(-κP)2(μ-HF2)]2 () and [(μ-SiF6){Ag(-κP)2}2] () could be identified. The latter compound was prepared also from Ag2[SiF6] and . Reactions between and AgClO4 or Ag[BF4] afforded disilver complexes [(μ(P,N)-)Ag(ClO4-κO)]2 () and [(μ(P,N)-)Ag(BF4-κF)]2 () featuring pseudolinear Ag(i) centers that are weakly coordinated by the counter anions. A similar reaction with Ag[SbF6] followed by crystallization from ethyl acetate produced an analogous complex, albeit with coordinated solvent, [(μ(P,N)-)Ag(AcOEt-κO)]2[SbF6]2 (). Ultimately, a compound devoid of any additional ligands at the Ag(i) centers, [(μ(P,N)-)Ag]2[B(C6H3(CF3)2-3,5)4]2 (), was obtained from the reaction of with silver(i) tetrakis[3,5-bis(trifluoromethyl)phenyl]borate. The reaction of Ag[BF4] with two equivalents of produced unique coordination polymer [Ag(-κP)(μ(P,N)-)]n[BF4]n (), the structure of which contained one of the phosphinoferrocene ligands coordinated as a P,N-chelate and the other forming a bridge to an adjacent Ag(i) center. All of these compounds were structurally characterized by single-crystal X-ray crystallography, revealing that the lengths of the bonds between silver and its anionic ligand(s) typically exceed the sum of the respective

  3. Structural influence in the interaction of cysteine with five coordinated copper complexes: Theoretical and experimental studies

    Science.gov (United States)

    Huerta-Aguilar, Carlos Alberto; Thangarasu, Pandiyan; Mora, Jesús Gracia

    2018-04-01

    Copper complexes of N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,2-diaminoethane (L1) and N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,3-diaminopropane (L2) prepared were characterized completely by different analytical methods. The X-structure of the complexes shows that Cu(II) presents in trigonal bi-pyramidal (TBP) geometry, consisting with the electronic spectra where two visible bands corresponding to five coordinated structure were observed. Thus TD-DFT was used to analyze the orbital contribution to the electronic transitions for the visible bands. Furthermore, the interaction of cysteine with the complexes was spectrally studied, and the results were explained through DFT analysis, observing that the geometrical parameters and oxidation state of metal ions play a vital role in the binding of cysteine with copper ion. It appears that the TBP structure is being changed into octahedral geometry during the addition of cysteine to the complexes as two bands (from complex) is turned to a broad band in visible region, signifying the occupation of cysteine molecule at sixth position of octahedral geometry. In the molecular orbital analysis, the existence of a strong overlapping of HOMOs (from cysteine) with LUMOs of Cu ion was observed. The total energy of the systems calculated by DFT shows that cysteine binds favorably with copper (I) than that with Cu(II).

  4. Neutral, seven-coordinate dioxime complexes of technetium(III): Synthesis and characterization

    International Nuclear Information System (INIS)

    Linder, K.E.; Malley, M.F.; Gougoutas, J.Z.; Unger, S.E.; Nunn, A.D.

    1990-01-01

    The tin-capped complexes 99 Tc(oxime) 3 (μ-OH)SnCl 3 [oxime = dimethylglyoxime (DMG) or cyclohexanedione dioxime (CDO)] can be prepared by the reduction of NH 4 TcO 4 with 2 equiv of SnCl 2 in the presence of dioxime and HCl. These tin-capped complexes can be readily converted into a new class of uncapped Tc-dioxime compounds, TcCl(oxime) 3 , by treatment with HCl. This reaction is reversible. Both the tin-capped and uncapped tris(dioxime) complexes can be converted to the previously reported boron-capped Tc-dioxime complexes TcCl(oxime) 3 BR (R = alkyl, OH) by reaction with boronic acids or with boric acid at low pH. All of these complexes [Tc(oxime) 3 (μ-OH)SnCl 3 , TcCl(oxime) 3 , and TcCl(oxime) 3 BR] appear to be neutral, seven-coordinate compounds of technetium(III). They have been characterized by elemental analysis, 1 H NMR and UV/visible spectroscopy, conductivity, and fast atom bombardment mass spectrometry. The synthesis, characterization, and reactivity of these compounds is discussed. The x-ray crystal structure analysis of TcCl(DMG) 3 and an abbreviated structure report on TcCl(DMG) 3 MeB are described. Crystal data for TcCl(DMG) 3 are reported. 23 refs., 6 figs., 5 tabs

  5. Computation of resonances by two methods involving the use of complex coordinates

    International Nuclear Information System (INIS)

    Bylicki, M.; Nicolaides, C.A.

    1993-01-01

    We have studied two different systems producing resonances, a highly excited multielectron Coulombic negative ion (the He - 2s2p 2 4 P state) and a hydrogen atom in a magnetic field, via the complex-coordinate rotation (CCR) and the state-specific complex-eigenvalue Schroedinger equation (CESE) approaches. For the He - 2s2p 2 4 P resonance, a series of large CCR calculations, up to 353 basis functions with explicit r ij dependence, were carried out to serve as benchmarks. For the magnetic-field problem, the CCR results were taken from the literature. Comparison shows that the state-specific CESE theory allows the physics of the problem to be incorporated systematically while keeping the overall size of the computation tractable regardless of the number of electrons

  6. The Mediator complex: a master coordinator of transcription and cell lineage development.

    Science.gov (United States)

    Yin, Jing-wen; Wang, Gang

    2014-03-01

    Mediator is a multiprotein complex that is required for gene transcription by RNA polymerase II. Multiple subunits of the complex show specificity in relaying information from signals and transcription factors to the RNA polymerase II machinery, thus enabling control of the expression of specific genes. Recent studies have also provided novel mechanistic insights into the roles of Mediator in epigenetic regulation, transcriptional elongation, termination, mRNA processing, noncoding RNA activation and super enhancer formation. Based on these specific roles in gene regulation, Mediator has emerged as a master coordinator of development and cell lineage determination. Here, we describe the most recent advances in understanding the mechanisms of Mediator function, with an emphasis on its role during development and disease.

  7. Coordination chemistry of oxovanadium(V) complexes with active Schiff bases: synthetic, spectral, and antimicrobial approach

    International Nuclear Information System (INIS)

    Garg, R; Fahmi, N.; Singh, R.V.

    2007-01-01

    The Schiff bases, 3-(indolin-2-one)hydrazinecarbothioamide, 3-(indolin-2-one)hydrazinecarboxamide, 5,6-dimethyl-3-(indolin-2-one)hydrazinecarbothioamide, and 5,6-dimethyl-3-(indolin-2-one)hydrazinecarboxamide, have been synthesized by the condensation of 1H-indol-2,3-dione and 5,6-dimethyl-1H-indol-2,3-dione with the corresponding hydrazinecarbothioamide and hydrazinecarboxamide, respectively. The complexes of oxovanadium and ligands have been characterized by elemental analyses, melting points, conductance measurements, molecular weight determinations, and IR, 1 H NMR and UV spectral studies. These studies showed that the ligands coordinated to the oxovanadium in a monobasic bidentate fashion through oxygen or sulfur and the nitrogen donor system. Thus, penta- and hexa coordinated environment around the vanadium atom has been proposed. All the complexes and their parent organic moieties have been screened for their biological activity on several pathogenic fungi and bacteria and were found to possess appreciable fungicidal and bactericidal properties [ru

  8. Complex Information Coordination Performance: Differential Changes in Working Memory Contributions Following Training. Cognitive Components of Information Coordination

    Science.gov (United States)

    1993-06-30

    UNIVERSITY DEPARTMENT OF PSYCHOLOGY EDUCATION BUILDING TALLAHASSEE FL 32306 W LAFAYETTE IN 47907 DR NEIL DORANS DR RODNEY COCKING EDUCATIONAL TESTING SERVICE...DR LORRAINE D EYDE PSYCHOLOGY DEPARTMENT US OFFICE OF PERSONNEL MGMT IOWA STATE UNIVERSITY OFFICE OF PERSONNEL RESEARCH AMES IA 50010 AND DEVELOP...judgments were performed under the added cognitive load of the coordination task. Method Subjects A total of eighty subjects were tested , with one

  9. Integrated complex care coordination for children with medical complexity: A mixed-methods evaluation of tertiary care-community collaboration

    Directory of Open Access Journals (Sweden)

    Cohen Eyal

    2012-10-01

    Full Text Available Abstract Background Primary care medical homes may improve health outcomes for children with special healthcare needs (CSHCN, by improving care coordination. However, community-based primary care practices may be challenged to deliver comprehensive care coordination to complex subsets of CSHCN such as children with medical complexity (CMC. Linking a tertiary care center with the community may achieve cost effective and high quality care for CMC. The objective of this study was to evaluate the outcomes of community-based complex care clinics integrated with a tertiary care center. Methods A before- and after-intervention study design with mixed (quantitative/qualitative methods was utilized. Clinics at two community hospitals distant from tertiary care were staffed by local community pediatricians with the tertiary care center nurse practitioner and linked with primary care providers. Eighty-one children with underlying chronic conditions, fragility, requirement for high intensity care and/or technology assistance, and involvement of multiple providers participated. Main outcome measures included health care utilization and expenditures, parent reports of parent- and child-quality of life [QOL (SF-36®, CPCHILD©, PedsQL™], and family-centered care (MPOC-20®. Comparisons were made in equal (up to 1 year pre- and post-periods supplemented by qualitative perspectives of families and pediatricians. Results Total health care system costs decreased from median (IQR $244 (981 per patient per month (PPPM pre-enrolment to $131 (355 PPPM post-enrolment (p=.007, driven primarily by fewer inpatient days in the tertiary care center (p=.006. Parents reported decreased out of pocket expenses (p© domains [Health Standardization Section (p=.04; Comfort and Emotions (p=.03], while total CPCHILD© score decreased between baseline and 1 year (p=.003. Parents and providers reported the ability to receive care close to home as a key benefit. Conclusions Complex

  10. Combination of optically measured coordinates and displacements for quantitative investigation of complex objects

    Science.gov (United States)

    Andrae, Peter; Beeck, Manfred-Andreas; Jueptner, Werner P. O.; Nadeborn, Werner; Osten, Wolfgang

    1996-09-01

    Holographic interferometry makes it possible to measure high precision displacement data in the range of the wavelength of the used laser light. However, the determination of 3D- displacement vectors of objects with complex surfaces requires the measurement of 3D-object coordinates not only to consider local sensitivities but to distinguish between in-plane deformation, i.e. strains, and out-of-plane components, i.e. shears, too. To this purpose both the surface displacement and coordinates have to be combined and it is advantageous to make the data available for CAE- systems. The object surface has to be approximated analytically from the measured point cloud to generate a surface mesh. The displacement vectors can be assigned to the nodes of this surface mesh for visualization of the deformation of the object under test. They also can be compared to the results of FEM-calculations or can be used as boundary conditions for further numerical investigations. Here the 3D-object coordinates are measured in a separate topometric set-up using a modified fringe projection technique to acquire absolute phase values and a sophisticated geometrical model to map these phase data onto coordinates precisely. The determination of 3D-displacement vectors requires the measurement of several interference phase distributions for at least three independent sensitivity directions depending on the observation and illumination directions as well as the 3D-position of each measuring point. These geometric quantities have to be transformed into a reference coordinate system of the interferometric set-up in order to calculate the geometric matrix. The necessary transformation can be realized by means of a detection of object features in both data sets and a subsequent determination of the external camera orientation. This paper presents a consistent solution for the measurement and combination of shape and displacement data including their transformation into simulation systems. The

  11. Enhancing the magnetic anisotropy of maghemite nanoparticles via the surface coordination of molecular complexes

    Science.gov (United States)

    Prado, Yoann; Daffé, Niéli; Michel, Aude; Georgelin, Thomas; Yaacoub, Nader; Grenèche, Jean-Marc; Choueikani, Fadi; Otero, Edwige; Ohresser, Philippe; Arrio, Marie-Anne; Cartier-dit-Moulin, Christophe; Sainctavit, Philippe; Fleury, Benoit; Dupuis, Vincent; Lisnard, Laurent; Fresnais, Jérôme

    2015-01-01

    Superparamagnetic nanoparticles are promising objects for data storage or medical applications. In the smallest—and more attractive—systems, the properties are governed by the magnetic anisotropy. Here we report a molecule-based synthetic strategy to enhance this anisotropy in sub-10-nm nanoparticles. It consists of the fabrication of composite materials where anisotropic molecular complexes are coordinated to the surface of the nanoparticles. Reacting 5 nm γ-Fe2O3 nanoparticles with the [CoII(TPMA)Cl2] complex (TPMA: tris(2-pyridylmethyl)amine) leads to the desired composite materials and the characterization of the functionalized nanoparticles evidences the successful coordination—without nanoparticle aggregation and without complex dissociation—of the molecular complexes to the nanoparticles surface. Magnetic measurements indicate the significant enhancement of the anisotropy in the final objects. Indeed, the functionalized nanoparticles show a threefold increase of the blocking temperature and a coercive field increased by one order of magnitude. PMID:26634987

  12. A monofunctional platinum complex coordinated to a rhodium metalloinsertor selectively binds mismatched DNA in the minor groove.

    Science.gov (United States)

    Weidmann, Alyson G; Barton, Jacqueline K

    2015-10-05

    We report the synthesis and characterization of a bimetallic complex derived from a new family of potent and selective metalloinsertors containing an unusual Rh-O axial coordination. This complex incorporates a monofunctional platinum center containing only one labile site for coordination to DNA, rather than two, and coordinates DNA nonclassically through adduct formation in the minor groove. This conjugate displays bifunctional, interdependent binding of mismatched DNA via metalloinsertion at a mismatch as well as covalent platinum binding. DNA sequencing experiments revealed that the preferred site of platinum coordination is not the traditional N7-guanine site in the major groove, but rather N3-adenine in the minor groove. The complex also displays enhanced cytotoxicity in mismatch repair-deficient and mismatch repair-proficient human colorectal carcinoma cell lines compared to the chemotherapeutic cisplatin, and it triggers cell death via an apoptotic pathway, rather than the necrotic pathway induced by rhodium metalloinsertors.

  13. Catalytic effect in opening the coordination sphere of an organo-f-complex

    International Nuclear Information System (INIS)

    Andrea, T.; Wang, J.; Gourevich, I.; Eisen, M.S.

    2002-01-01

    Organo-f-complexes have been studied in the last decade showing unique stoichiometric and catalytic properties, which are deeply influenced by the nature of the x ancillary ligands. Opening of the metal center coordination sphere is obtained by replacing the pentamethylcyclopentadienyl ligation in Cp* 2 MR 2 (Cp* = C 5 Me 5 , M = f-element metal, R = a-bonded ligand) by the bridged ancillary ligation Anna-Me 2 SiCp 2MR 2 (Cp* = C 5 Me 4 ). For organolanthanides, this change allows an increase (10-100 fold) in rates for the olefin insertion into the M-R bond [1] and in organoactinides; this modification has been shown to cause an increase (103 fold) in their catalytic activity for the hydrogenation of 1-hexene [2]. Recently, we have shown that organoactinides of the type Cp* 2 MR 2 (Cp* = C 5 Me 5 ; M = Th, U; R = CH 3 ) are active catalysts for both the oligomerization and hydrosilylation of terminal alkynes [3J. Thus, a conceptual question arises regarding the use of an open organoactinide such as Me 2 SiCp* 2 U n Bu 2 as compared to Cp* 2 UR 2 . This opening in the coordination sphere at the metal center should be unique in such a way that it is reasonable expected the increase of the reactivity towards product formation in the hydrosilylation and metathesis catalytic processes of terminal alkynes. In this poster we report, and quantitatively compare, the effects of the ansa-organouranium complex (Me 2 SiCp'' 2 U n Bu) 2 O The synthesis of the complex was achieved as described in equations 1 and 2

  14. η2-SO2 Linkage Photoisomer of an Osmium Coordination Complex.

    Science.gov (United States)

    Cole, Jacqueline M; Velazquez-Garcia, Jose de J; Gosztola, David J; Wang, SuYin Grass; Chen, Yu-Sheng

    2018-03-05

    We report the discovery of an η 2 -SO 2 linkage photoisomer in the osmium pentaammine coordination complex, [Os(NH 3 ) 5 (SO 2 )][Os(NH 3 ) 5 (HSO 3 )]Cl 4 (1). Its dark- and light-induced crystal structures are determined via synchrotron X-ray crystallography, at 100 K, where the photoinduced state is metastable in a single crystal that has been stimulated by 505 nm light for 2.5 h. The SO 2 photoisomer in the [Os(NH 3 ) 5 (SO 2 )] 2+ cation contrasts starkly with the photoinactivity of the HSO 3 ligand in its companion [Os(NH 3 ) 5 (HSO 3 )] + cation within the crystallographic asymmetric unit of this single crystal. Panchromatic optical absorption characteristics of this single crystal are revealed in both dark- and light-induced states, using concerted absorption spectroscopy and optical microscopy. Its absorption halves across most of its visible spectrum, upon exposure to 505 nm light. The SO 2 ligand seems to be responsible for this photoinduced bleaching effect, judging from a comparison of the dark- and light-induced crystal structures of 1. The SO 2 photoisomerism is found to be thermally reversible, and so 1 presents a rare example of an osmium-based solid-state optical switch. Such switching in an osmium complex is significant because bottom-row transition metals stand to offer linkage photoisomerism with the greatest photoconversion levels and thermal stability. The demonstration of η 2 -SO 2 bonding in this complex also represents a fundamental contribution to osmium coordination chemistry.

  15. Zinc(II) complexes with intramolecular amide oxygen coordination as models of metalloamidases.

    Science.gov (United States)

    Rivas, Juan C Mareque; Salvagni, Emiliano; Prabaharan, Ravi; de Rosales, Rafael Torres Martin; Parsons, Simon

    2004-01-07

    Polydentate ligands (6-R1-2-pyridylmethyl)-R2(R1= NHCOtBu, R2= bis(2-pyridylmethyl)amine L1, bis(2-(methylthio)ethyl)amine L2 and N(CH2CH2)2S L3) form mononuclear zinc(II) complexes with intramolecular amide oxygen coordination and a range of coordination environments. Thus, the reaction of Zn(ClO4)2.6H2O with L1-3 in acetonitrile affords [(L)Zn](ClO4)2(L=L1, 1; L2, 2) and [(L3)Zn(H2O)(NCCH3)](ClO4)2 3. The simultaneous amide/water binding in resembles the motif that has been proposed to be involved in the double substrate/nucleophile Lewis acidic activation and positioning mechanism of amide bond hydrolysis in metallopeptidases. X-ray diffraction, 1H and 13C NMR and IR data suggests that the strength of amide oxygen coordination follows the trend 1>2 >3. L1-3 and undergo cleavage of the tert-butylamide upon addition of Me4NOH.5H2O (1 equiv.) in methanol at 50(1)degrees C. The rate of amide cleavage follows the order 1> 2> 3, L1-3. The extent by which the amide cleavage reaction is accelerated in 1-3 relative to the free ligands, L1-3, is correlated with the strength of amide oxygen binding and Lewis acidity of the zinc(II) centre in deduced from the X-ray, NMR and IR studies.

  16. Low-Complexity Interference-Free Downlink Channel Assignment with Improved Performance in Coordinated Small Cells

    KAUST Repository

    Radaydeh, Redha M.

    2015-05-01

    This paper proposes a low-complexity interference-free channel assignment scheme with improved desired downlink performance in coordinated multi-antenna small-coverage access points (APs) that employ the open-access control strategy. The adopted system treats the case when each user can be granted an access to one of the available channels at a time. Moreover, each receive terminal can suppress a limited number of resolvable interfering sources via its highly-correlated receive array. On the other hand, the operation of the deployed APs can be coordinated to serve active users, and the availability of multiple physical channels and the use of uncorrelated transmit antennas at each AP are exploited to improve the performance of supported users. The analysis provides new approaches to use the transmit antenna array at each AP, the multiple physical channels, the receive antenna array at each user in order to identify interference-free channels per each user, and then to select a downlink channel that provides the best possible improved performance. The event of concurrent interference-free channel identification by different users is also treated to further improve the desired link associated with the scheduled user. The analysis considers the practical scenario of imperfect identification of interference-free channel by an active user and/or the imperfectness in scheduling concurrent users requests on the same channel. The developed formulations can be used to study any performance metric and they are applicable for any statistical and geometric channel models. © 2015 IEEE.

  17. [Complexity of social and healthcare coordination in addictions and the role of the nurse].

    Science.gov (United States)

    Molina Fernández, Antonio Jesús; González Riera, Javier; Montero Bancalero, Francisco José; Gómez-Salgado, Juan

    2016-01-01

    The present article discusses the psychosocial impact of basic and advanced concepts, such as social support and prevention, as well as to establish a link between theoretical models related to the social sphere on one side, and the health aspects on the other. This work is based on the context of the influence on health shared by community psychology and social psychology. Starting from the historical background of current approaches, a review is presented of those first actions focused on the care plan and they are framed in a reaction model to the drug problem, which progressed to the current healthcare network model, through the creation of Spanish National Action Plan on Drugs. The complexity of the problem is then broken down into the following key elements: Multifactorial Model of Drugs and Addictions, importance of prevention, and social support. Subsequently, a description is presented on the different levels of the healthcare network, with their different resources. This is also illustrated using a coordination protocol. Finally, it features the nursing approach to drugs, with its contributions, particularly as regards the coordination of resources, and aspects that must be developed for improvement in this area. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  18. Low-Complexity Scheduling and Power Adaptation for Coordinated Cloud-Radio Access Networks

    KAUST Repository

    Douik, Ahmed

    2017-07-17

    In practical wireless systems, the successful implementation of resource allocation techniques strongly depends on the algorithmic complexity. Consider a cloud-radio access network (CRAN), where the central cloud is responsible for scheduling devices to the frames’ radio resources blocks (RRBs) of the single-antenna base-stations (BSs), adjusting the transmit power levels, and for synchronizing the transmit frames across the connected BSs. Previous studies show that the jointly coordinated scheduling and power control problem in the considered CRAN can be solved using an approach that scales exponentially with the number of BSs, devices, and RRBs, which makes the practical implementation infeasible for reasonably sized networks. This paper instead proposes a low-complexity solution to the problem, under the constraints that each device cannot be served by more than one BS but can be served by multiple RRBs within each BS frame, and under the practical assumption that the channel is constant during the duration of each frame. The paper utilizes graph-theoretical based techniques and shows that constructing a single power control graph is sufficient to obtain the optimal solution with a complexity that is independent of the number of RRBs. Simulation results reveal the optimality of the proposed solution for slow-varying channels, and show that the solution performs near-optimal for highly correlated channels.

  19. Synthesis, structure, and magnetic properties of two 1-D helical coordination polymeric Cu(II) complexes

    Science.gov (United States)

    Bian, He-Dong; Yang, Xiao-E.; Yu, Qing; Chen, Zi-Lu; Liang, Hong; Yan, Shi-Ping; Liao, Dai-Zheng

    2008-01-01

    Two helical coordination polymeric copper(II) complexes bearing amino acid Schiff bases HL or HL', which are condensed from 2-hydroxy-1-naphthaldehyde with 2-aminobenzoic acid or L-valine, respectively, have been prepared and characterised by X-ray crystallography. In [CuL] n ( 1) the copper(II) atoms are bridged by syn- anti carboxylate groups giving infinite 1-D right-handed helical chains which are further connected by weak C-H⋯Cu interactions to build a 2-D network. While in [CuL'] n ( 2) the carboxylate group acts as a rare monatomic bridge to connect the adjacent copper(II) atoms leading to the formation of a left-handed helical chain. Magnetic susceptibility measurements indicate that 1 exhibits weak ferromagnetic interactions whereas an antiferromagnetic coupling is established for 2. The magnetic behavior can be satisfactorily explained on the basis of the structural data.

  20. Controlling Second Coordination Sphere Effects in Luminescent Ruthenium Complexes by Means of External Pressure.

    Science.gov (United States)

    Pannwitz, Andrea; Poirier, Stéphanie; Bélanger-Desmarais, Nicolas; Prescimone, Alessandro; Wenger, Oliver S; Reber, Christian

    2018-06-04

    Two luminescent heteroleptic Ru II complexes with a 2,2'-biimidazole (biimH 2 ) ligand form doubly hydrogen-bonded salt bridges to 4-sulfobenzoate anions in single crystals. The structure of one of these cation-anion adducts shows that the biimH 2 ligand is deprotonated. Its 3 MLCT luminescence band does not shift significantly under the influence of an external hydrostatic pressure, a behavior typical for these electronic transitions. In contrast, hydrostatic pressure on the other crystalline cation-anion adduct induces a shift of proton density from the peripheral N-H groups of biimH 2 towards benzoate, leading to a pronounced redshift of the 3 MLCT luminescence band. Such a significant and pressure-tunable influence from an interaction in the second coordination sphere is unprecedented in artificial small-molecule-based systems. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Polymer complexes.. XXXX. Supramolecular assembly on coordination models of mixed-valence-ligand poly[1-acrylamido-2-(2-pyridyl)ethane] complexes

    Science.gov (United States)

    El-Sonbati, A. Z.; El-Bindary, A. A.; Diab, M. A.

    2003-02-01

    The build-up of polymer metallic supramolecules based on homopolymer (1-acrylamido-2-(2-pyridyl)ethane (AEPH)) and ruthenium, rhodium, palladium as well as platinum complexes has been pursued with great interest. The homopolymer shows three types of coordination behaviour. In the mixed valence paramagnetic trinuclear polymer complexes [( 11)+( 12)] in the paper and in mononuclear polymer complexes ( 1)-( 5) it acts as a neutral bidentate ligand coordinating through the N-pyridine and NH-imino atoms, while in the mixed ligand diamagnetic poly-chelates, which are obtained from the reaction of AEPH with PdX 2 and KPtCl 4 in the presence of N-heterocyclic base consisting of polymer complexes ( 9)+( 10), and in monouclear compounds ( 6)-( 8), it behaves as a monobasic bidentate ligand coordinating through the same donor atoms. In mononuclear compounds ( 13)+( 14) it acts as a monobasic and neutral bidentate ligand coordinating only through the same donor atoms. Monomeric distorted octahedral or trimeric chlorine-bridged, approximately octahedral structures are proposed for these polymer complexes. The poly-chelates are of 1:1, 1:2 and 3:2 (metal-homopolymer) stoichiometry and exhibit six coordination. The values of ligand field parameters were calculated. The homopolymer and their polymer complexes have been characterized physicochemically.

  2. Rheb may complex with RASSF1A to coordinate Hippo and TOR signaling.

    Science.gov (United States)

    Nelson, Nicholas; Clark, Geoffrey J

    2016-06-07

    The TOR pathway is a vital component of cellular homeostasis that controls the synthesis of proteins, nucleic acids and lipids. Its core is the TOR kinase. Activation of the TOR pathway suppresses autophagy, which plays a vital but complex role in tumorigenesis. The TOR pathway is regulated by activation of the Ras-related protein Rheb, which can bind mTOR. The Hippo pathway is a major growth control module that regulates cell growth, differentiation and apoptosis. Its core consists of an MST/LATS kinase cascade that can be activated by the RASSF1A tumor suppressor. The TOR and Hippo pathways may be coordinately regulated to promote cellular homeostasis. However, the links between the pathways remain only partially understood. We now demonstrate that in addition to mTOR regulation, Rheb also impacts the Hippo pathway by forming a complex with RASSF1A. Using stable clones of two human lung tumor cell lines (NCI-H1792 and NCI-H1299) with shRNA-mediated silencing or ectopic overexpression of RASSF1A, we show that activated Rheb stimulates the Hippo pathway, but is suppressed in its ability to stimulate the TOR pathway. Moreover, by selectively labeling autophagic vacuoles we show that RASSF1A inhibits the ability of Rheb to suppress autophagy and enhance cell growth. Thus, we identify a new connection that impacts coordination of Hippo and TOR signaling. As RASSF1A expression is frequently lost in human tumors, the RASSF1A status of a tumor may impact not just its Hippo pathway status, but also its TOR pathway status.

  3. Care coordination, medical complexity, and unmet need for prescription medications among children with special health care needs.

    Science.gov (United States)

    Aboneh, Ephrem A; Chui, Michelle A

    Children with special health care needs (CSHCN) have multiple unmet health care needs including that of prescription medications. The objectives of this study were twofold: 1) to quantify and compare unmet needs for prescription medications for subgroups of CSHCN without and with medical complexity (CMC)-those who have multiple, chronic, and complex medical conditions associated with severe functional limitations and high utilization of health care resources, and 2) to describe its association with receipt of effective care coordination services and level of medical complexity. A secondary data analysis of the 2009/2010 National Survey of CSHCN, a nationally representative telephone survey of parents of CSHCN, was conducted. Logistic regression models were constructed to determine associations between unmet need for prescription medications and medical complexity and care coordination for families of CSHCN, while controlling for demographic variables such as race, insurance, education level, and household income. Analyses accounted for the complex survey design and sampling weights. CMC represented about 3% of CSHCN. CMC parents reported significantly more unmet need for prescription medications and care coordination (4%, 68%), compared to Non-CMC parents (2%, 40%). Greater unmet need for prescription medications was associated with unmet care coordination (adjusted OR 3.81; 95% CI: 2.70-5.40) and greater medical complexity (adjusted OR 2.01; 95% CI: 1.00-4.03). Traditional care coordination is primarily facilitated by nurses and nurse practitioners with little formal training in medication management. However, pharmacists are rarely part of the CSHCN care coordination model. As care delivery models for these children evolve, and given the complexity of and numerous transitions of care for these patients, pharmacists can play an integral role to improve unmet needs for prescription medications. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Inferior Olive HCN1 Channels Coordinate Synaptic Integration and Complex Spike Timing

    Directory of Open Access Journals (Sweden)

    Derek L.F. Garden

    2018-02-01

    Full Text Available Cerebellar climbing-fiber-mediated complex spikes originate from neurons in the inferior olive (IO, are critical for motor coordination, and are central to theories of cerebellar learning. Hyperpolarization-activated cyclic-nucleotide-gated (HCN channels expressed by IO neurons have been considered as pacemaker currents important for oscillatory and resonant dynamics. Here, we demonstrate that in vitro, network actions of HCN1 channels enable bidirectional glutamatergic synaptic responses, while local actions of HCN1 channels determine the timing and waveform of synaptically driven action potentials. These roles are distinct from, and may complement, proposed pacemaker functions of HCN channels. We find that in behaving animals HCN1 channels reduce variability in the timing of cerebellar complex spikes, which serve as a readout of IO spiking. Our results suggest that spatially distributed actions of HCN1 channels enable the IO to implement network-wide rules for synaptic integration that modulate the timing of cerebellar climbing fiber signals.

  5. Synthesis and structural evaluation of five coordination complexes of benzenepentacarboxylic acid with aza-donor ligands

    Science.gov (United States)

    Shimpi, Manishkumar R.; Biswas, Sharmita Nandy; Sarkar, Sohini; Pedireddi, V. R.

    2016-06-01

    Synthesis and structural features of five new coordination assemblies, [Co(bpyH)(H2O)5](BPCH)·(bpyH2)0.5·(H2O) (1a), [{Cu(H2O)3}·{Cu0.5(bpy)0.5(H2O)0.5}2(μ-BPCH)] (1b), [{Cd0.5(BPCH)}2·{Cd0.5(bpy)(H2O)2}2]·6(H2O) (1c), [Cu(BPCH2)(bpyeaH)]·2(H2O) (1d) and [Cd2 (bpyea)0.5(oxalate)0.5(μ-BPC) (H2O)]·(bpyeaH2)·2(H2O) (1e), have been reported. All the assemblies were prepared by co-crystallization of benzenepentacarboxylic acid (BPCH5) either with 4,4‧-bipyridine (bpy) or 1,2-bis(4-pyridyl)ethane (bpyea) in the presence of a transition metal ion (either Co(II), Cu(II) or Cd(II)) as the case may be. All the five compounds were synthesized by hydrothermal method and structures were determined by single crystal X-ray diffraction. All the obtained compounds, 1a-1e, exhibit distinct 3-D polymeric architectures either in the form of stacked layers or host-guest networks in which water molecules play a pivotal role providing additional stabilization by coordinate bonds as well as hydrogen bonds. Other non-covalent interactions such as C-H … π and π … π stacking also participate in the formation of exotic 3-D structures of these complexes.

  6. Carbene complexes of zirconium. Synthesis, structure, and reactivity with carbon monoxide to affort coordinated ketene

    International Nuclear Information System (INIS)

    Barger, P.T.; Santarsiero, B.D.; Armantrout, J.; Bercaw, J.E.

    1984-01-01

    Treatment of Cp 2 Zr(L)(CO) (Cp = C 5 H 5 ; L = PMe 3 , CO) with Cp* 2 ZrH 2 (Cp* = C 5 Me 5 ) affords zirconium oxycarbene complexes, Cp 2 (L)Zr double bond CHO single bond Zr(X)Cp* 2 (L = PMe 3 , X = H, I; L = CO, X = H), that represent some of the first examples of group 4 metal-to-carbon multiple bonding. The first X-ray diffraction structure determination of a zirconium carbene complex, that of Cp(PMe 3 )Zr double bond CHO single bond Zr(H)Cp* 2 .C 6 H 6 , is reported (C2/c, a = 27.318 (4) A, b = 19.895 (3) A, c = 19.932 (5) A β = 132.188 (10) 0 , Z = 8) and shows a very short Zr-C bond length of 2.117 (7) A. Treatment of Cp 2 (CO)Zr double bond CHO single bond Zr(H)Cp* 2 with CH 3 I or Cp 2 (PMe 3 )Zr double bond CHO single bond Zr(I)Cp* 2 with CO affords the zirconium substituted enediolate zirconacycle, Cp* 2 ZrOCH double bond C(Zr(I)Cp 2 )O, which has been characterized by an X-ray diffraction study (P2 1 /c, a = 15.866 (4) A, b = 10.673 (3) A, c = 20.561 (4) A, β = 105.5 (2) 0 , Z = 4). This complex most likely forms by coupling of the zirconoxycarbene and a carbonyl to give a metal-coordinated ketene intermediate that subsequently rearranges to the isolated product. An isotopic crossover experiment has demonstrated that the new carbon-carbon bond is formed in an intramolecular coupling step. The ketene intermediate can be trapped by dissolving Cp 2 (CO)Zr double bond CHO single bond Zr(H)Cp* 2 in pyridine, giving Cp 2 (py)Zr(O double bond C double bond CHOZr(I)Cp* 2 ). Treatment of the isolated ketene complex with CH 3 I in benzene gives the enediolate zirconocycle; in pyridine Cp 2 (py)Zr(O double bond C double bond CHOZr(I)Cp* 2 ) can be observed spectroscopically. 38 references, 4 figures, 5 tables

  7. High Harmonic Generation XUV Spectroscopy for Studying Ultrafast Photophysics of Coordination Complexes

    Science.gov (United States)

    Ryland, Elizabeth S.; Lin, Ming-Fu; Benke, Kristin; Verkamp, Max A.; Zhang, Kaili; Vura-Weis, Josh

    2017-06-01

    Extreme ultraviolet (XUV) spectroscopy is an inner shell technique that probes the M_{2,3}-edge excitation of atoms. Absorption of the XUV photon causes a 3p→3d transition, the energy and shape of which is directly related to the element and ligand environment. This technique is thus element-, oxidation state-, spin state-, and ligand field specific. A process called high-harmonic generation (HHG) enables the production of ultrashort (˜20fs) pulses of collimated XUV photons in a tabletop instrument. This allows transient XUV spectroscopy to be conducted as an in-lab experiment, where it was previously only possible at accelerator-based light sources. Additionally, ultrashort pulses provide the capability for unprecedented time resolution (˜50fs IRF). This technique has the capacity to serve a pivotal role in the study of electron and energy transfer processes in materials and chemical biology. I will present the XUV transient absorption instrument we have built, along with ultrafast transient M_{2,3}-edge absorption data of a series of small inorganic molecules in order to demonstrate the high specificity and time resolution of this tabletop technique as well as how our group is applying it to the study of ultrafast electronic dynamics of coordination complexes.

  8. Complex coordinate rotation and relativistic Hylleraas-CI: helium isoelectronic series

    International Nuclear Information System (INIS)

    Pestka, G; Bylicki, M; Karwowski, J

    2007-01-01

    A combination of the Hylleraas-CI (Hy-CI) and complex coordinate rotation (CCR) methods has been applied to study the nuclear charge dependence of the eigenvalues of the Dirac-Coulomb (DC) Hamiltonian corresponding to the ground states of helium isoelectronic series atoms. It has been shown that the CCR, due to the separation of the localized states from the unphysical Brown-Ravenhall continuum, removes the instabilities of the bound-state eigenvalues observed in large-basis set Hy-CI results. The Hy-CI-CCR results are in very good agreement with the most accurate ones available in the literature. Surprisingly, the difference between the DC Hy-CI-CCR eigenvalues and the eigenvalues of the positive-energy projected no-pair Hamiltonian is equal, up to the numerical accuracy of the results, to (Zα) 3 /6π, i.e. to (Zα) 3 relativistic many-body perturbation theory contribution for electron-electron Coulomb interaction operator. An excellent agreement between the Hy-CI-CCR eigenvalues shifted by (Zα) 3 /6π and the no-pair ones confirms the very high accuracy achieved in both approaches. The numerical accuracy of the Hy-CI-CCR DC eigenvalues is estimated to eight significant figures

  9. Stability and Reactivity of Cyclometallated Naphthylamine Complexes in Pd-C Bond Insertion Reactions with Coordinated Alkynylphosphanes

    KAUST Repository

    Chen, Shuli; Chiew, Jun Xuan; Pullarkat, Sumod A.; Li, Yongxin; Leung, Pak Hing

    2013-01-01

    , whereas the P→Pd bond is labile. Upon heating of these phosphane complexes at 70 °C, one of the C≡C bonds in the coordinated PhP(C≡CPh)2 was activated towards an intermolecular Pd-C bond insertion reaction with an external ortho-palladated naphthylamine

  10. Stability and Reactivity of Cyclometallated Naphthylamine Complexes in Pd-C Bond Insertion Reactions with Coordinated Alkynylphosphanes

    KAUST Repository

    Chen, Shuli

    2013-09-17

    Phenylbis(phenylethynyl)phosphane PhP(C≡CPh)2 coordinates regiospecifically to the α-methyl-chiral ortho-platinated and -palladated naphthylamine units at the positions trans to the nitrogen donors. The P→Pt coordination bond is kinetically inert, whereas the P→Pd bond is labile. Upon heating of these phosphane complexes at 70 °C, one of the C≡C bonds in the coordinated PhP(C≡CPh)2 was activated towards an intermolecular Pd-C bond insertion reaction with an external ortho-palladated naphthylamine ring. No intramolecular insertion reaction occurred. In contrast to its palladium analogue, the ortho-platinated ring is not reactive towards coordinated PhP(C≡CPh)2, although it can promote the Pd-C bond insertion reaction. However, despite the high kinetic stability of the P→Pt coordination, the organoplatinum unit is a noticeably weaker activator than its organopalladium counterpart. The chirality of the reacting ortho-metallated naphthylamine ligand exhibited high stereochemical influence on the formation of the new stereogenic phosphorus center during the course of these C-C bond-formation reactions. The coordination chemistry and the absolute stereochemistry of the dimetallic products were determined by single-crystal X-ray crystallographic analysis. The asymmetric monoinsertion of PhP(C≡CPh)2 coordinated to a cyclometallated N,N-dimethyl naphthyl/benzylamine template into the Pd-C bonds of N,N-dimethylnaphthylamine palladacycles has been demonstrated for the synthesis of a variety of new P-stereogenic homo- or heterodimetallic complexes. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Diverse CdII coordination complexes derived from bromide isophthalic acid binding with auxiliary N-donor ligands

    International Nuclear Information System (INIS)

    Tang, Meng; Dong, Bao-Xia; Wu, Yi-Chen; Yang, Fang; Liu, Wen-Long; Teng, Yun-Lei

    2016-01-01

    The coordination characteristics of 4-bromoisophthalic acid (4-Br-H 2 ip) have been investigated in a series of Cd II -based frameworks. Hydrothermal reactions of Cd II salts and 4-Br-H 2 ip together with flexible or semiflexible N-donor auxiliary ligands resulted in the formation of four three-dimensional coordination complexes with diverse structures: (Cd(bix) 0.5 (bix) 0.5 (4-Br-ip)]·H 2 O) n (1), [Cd(bbi) 0.5 (bbi) 0.5 (4-Br-ip)] n (2), ([Cd(btx) 0.5 (4-Br-ip)(H 2 O)]·0.5CH 3 OH·H 2 O) n (3) and ([Cd(bbt) 0.5 (4-Br-ip)(H 2 O)]·3·5H 2 O) n (4). These compounds were characterized by elemental analyses, IR spectra, single-crystal and powder X-ray diffraction. They displayed diverse structures depending on the configuration of the 4-connected metal node, the coordination mode of the 4-Br-H 2 ip, the coordination ability and conformationally flexibility of the N-donor auxiliary. Compound 1 exhibits 3-fold interpenetrated 6 6 topology and compound 2 has a 4 12 topology. Compounds 3–4 have similar 3D pillar-layered structures based on 3,4-connected binodal net with the Schläfli symbol of (4·3 8 ). The thermal stabilities and photoluminescence properties of them were discussed in detail. - Graphical abstract: Four 3D Cd II coordination complexes on the basis of 4-bromoisophthalic acid (4-Br-H 2 ip) and two types of flexible (bbi, bbt) and semiflexible (bix, btx) N-donor ligands are prepared. They displayed diverse topology structures of 6 6 (1), 4 12 (2) and 4·3 8 (3−4), depending on the configuration of the 4-connected metal node, the coordination mode of the 4-Br-H 2 ip, the coordination ability and conformationally flexibility of the N-donor auxiliary ligand. - Highlights: • Four 3D Cd II coordination complexes based on 4-Br-H 2 ip and flexible/semiflexible N-donor ligands have been synthesized. • They displayed diverse topology structures of 6 6 for 1, 4 12 for 2 and 4·3 8 for 3–4. • The structural diversity depends on the configuration of 4-Br

  12. [Economic evaluation of a program of coordination between levels for complex chronic patients' management].

    Science.gov (United States)

    Allepuz Palau, Alejandro; Piñeiro Méndez, Pilar; Molina Hinojosa, José Carlos; Jou Ferre, Victoria; Gabarró Julià, Lourdes

    2015-03-01

    The complex chronic patient program (CCP) of the Alt Penedès aims to improve the coordination of care. The objective was to evaluate the relationship between the costs associated with the program, and its results in the form of avoided admissions. Dost-effectiveness analysis from the perspective of the health System based on a before-after study. Alt Penedès. Health services utilisation (hospital [admissions, emergency visits, day-care hospital] and primary care visits). CCP Program results were compared with those prior to its implementation. The cost assigned to each resource corresponded to the hospital CatSalut's concert and ICS fees for primary care. A sensitivity analysis using boot strapping was performed. The intervention was considered cost-effective if the incremental cost-effectiveness ratio (ICER) did not exceed the cost of admission (€ 1,742.01). 149 patients were included. Admissions dropped from 212 to 145. The ICER was €1,416.3 (94,892.9€/67). Sensitivity analysis showed that in 95% of cases the cost might vary between €70,847.3 and €121,882.5 and avoided admissions between 30 and 102. In 72.4% of the simulations the program was cost-effective. Sensitivity analysis showed that in most situations the PCC Program would be cost-effective, although in a percentage of cases the program could raise overall cost of care, despite always reducing the number of admissions. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  13. Inner-Sphere versus Outer-Sphere Coordination of BF4– in a NHC-Gold(I) Complex

    KAUST Repository

    Veenboer, Richard M. P.

    2017-07-20

    The role of counterions in chemistry mediated by gold complexes stretches much further than merely providing charge balance to cationic gold species. Interplay between their basicities and coordination strengths influences interactions with both the gold center and substrates in catalysis. Actual monogold(I) active species are generally believed to be monocoordinated species, formed from the abstraction or the decoordination of a second ligand from precursor complexes, but only a small amount of experimental evidence exists to underpin the existence of these transient species. The formation of a bench-stable neutral IPrCl-gold(I) tetrafluoroborate complex is reported herein. Experimental studies by X-ray diffraction analysis and NMR spectroscopy and theoretical studies by DFT calculations were conducted to determine the composition, structure, and behavior of this complex. The absence of an auxiliary ligand resulted in inner-sphere coordination of the counterion in the solid state. In solution, an equilibrium between two conformations was found with the counterion occupying inner-sphere and outer-sphere positions, respectively. Stoichiometric and catalytic reactivity studies with the tetrafluoroborate complex have been conducted. These confirmed the lability of the inner-sphere coordinating counterion that gives the IPrCl-gold(I) fragment behavior similar to that of related systems.

  14. Inner-Sphere versus Outer-Sphere Coordination of BF4– in a NHC-Gold(I) Complex

    KAUST Repository

    Veenboer, Richard M. P.; Collado, Alba; Dupuy, Sté phanie; Lebl, Tomas; Falivene, Laura; Cavallo, Luigi; Cordes, David B.; Slawin, Alexandra M. Z.; Cazin, Catherine S. J.; Nolan, Steven P.

    2017-01-01

    The role of counterions in chemistry mediated by gold complexes stretches much further than merely providing charge balance to cationic gold species. Interplay between their basicities and coordination strengths influences interactions with both the gold center and substrates in catalysis. Actual monogold(I) active species are generally believed to be monocoordinated species, formed from the abstraction or the decoordination of a second ligand from precursor complexes, but only a small amount of experimental evidence exists to underpin the existence of these transient species. The formation of a bench-stable neutral IPrCl-gold(I) tetrafluoroborate complex is reported herein. Experimental studies by X-ray diffraction analysis and NMR spectroscopy and theoretical studies by DFT calculations were conducted to determine the composition, structure, and behavior of this complex. The absence of an auxiliary ligand resulted in inner-sphere coordination of the counterion in the solid state. In solution, an equilibrium between two conformations was found with the counterion occupying inner-sphere and outer-sphere positions, respectively. Stoichiometric and catalytic reactivity studies with the tetrafluoroborate complex have been conducted. These confirmed the lability of the inner-sphere coordinating counterion that gives the IPrCl-gold(I) fragment behavior similar to that of related systems.

  15. Carbynes and carbenes in coordination chemistry: A new class of pentaammine and tetraammine complexes of osmium(II)

    Energy Technology Data Exchange (ETDEWEB)

    Hodges, L.M.; Sabat, M.; Harman, W.D. (Univ. of Virginia, Charlottesville (United States))

    1993-02-17

    Since their discovery by Fischer and co-workers in 1973, the study of transition-metal carbyne complexes and their role in alkyne metathesis has rapidly developed into a mature field. Although carbyne complexes are known for a diverse set of early- and mid-transition metals, the vast majority of these complexes contain carbon or phosphine [pi]-acids, or bulky alkoxide ligands, which limit the coordination number. We wish to report the first example of a carbyne species, as well as several heteroatom-carbene derivatives, in which the metal fragment, Os[sup II](NH[sub 3])[sub 5], provides a classical octahedral coordination environment. The carbyne [Os(NH[sub 3])[sub 5]([equivalent to]CPh)](OTf)[sub 3] (2) is synthesized in two steps from Os(NH[sub 3])[sub 5](OTf)[sub 3] and benzaledhyde dimethyl acetal.

  16. Coordination kinetics of different metal ions with the amidoximated polyacrylonitrile nanofibrous membranes and catalytic behaviors of their complexes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fu; Dong, Yong Chun; Kang, Wei Min; Cheng, Bowen; Qu, Xiang; Cui, Guixin [School of Textiles, Tianjin Polytechnic University, Tianjin (China)

    2016-12-15

    Two transition metal ions (Fe{sup 3+} and Cu{sup 2+}) and a rare earth metal ion (Ce{sup 3+}) were selected to coordinate with amidoximated polyacrylonitrile (PAN) nanofibrous membrane for preparing three metal modified PAN nanofibrous membrane complexes (M-AO-n-PANs, M = Fe, Cu, or Ce) as the heterogeneous Fenton catalysts for the dye degradation in water under visible irradiation. The coordination kinetics of three metal ions with modified PAN nanofibrous membranes was studied and the catalytic properties of the resulting complexes were also compared. The results indicated that increasing metal ion concentrations in solution or higher coordination temperature led to a significant increase in metal content, particularly in Fe and Cu contents of the complexes. Their coordination process could be described using Langmuir isotherm and pseudo-second-order kinetic equations. Moreover, Fe-AO-n-PAN had the best photocatalytic efficiency for the dye degradation in acidic medium, but a lower photocatalytic activity than Cu-AO-n-PAN in alkali medium.

  17. Tetra-, Penta- and Hexa-Coordinated Transition Metal Complexes Constructed from Coumarin-Containing N2O2 Ligand

    Directory of Open Access Journals (Sweden)

    Lei Gao

    2018-02-01

    Full Text Available Three newly designed complexes, [Cu(L]·CHCl3 (1, [Co(L(MeOH]·CHCl3 (2 and [{Ni(L(MeOH(PhCOO}2Ni] (3 a coumarin-containing Salamo-type chelating ligand (H2L have been synthesized and characterized by elemental analyses, IR and UV-VIS spectra, and X-ray crystallography. Complex 1 includes one Cu(II atom, one completely deprotonated (L2− unit and one crystalling chloroform molecule, the Cu(II atom shows a square-planar geometry. Complex 2 includes one Co(II atom, one completely deprotonated (L2− unit, one coordinated methanol molecule and one crystalling chloroform molecule. The Co(II atom is a distorted trigonal-bipyramidal geometry. While complex 3 includes three Ni(II atoms, two completely deprotonated (L2− units, two benzoates and two coordinated methanol molecules. The complexes 1 and 2 are both possess three-dimensional supra-molecular structures by abundant noncovalent interactions. But, complex 3 formed a two-dimensional supra-molecular structure by intra-molecular hydrogen bonds. In addition, the antimicrobial and fluorescence properties of H2L and its complexes 1, 2 and 3 were also investigated.

  18. Application of an electronic bulletin board, as a mechanism of coordination of actions in complex systems - reference model

    Directory of Open Access Journals (Sweden)

    Katarzyna Grzybowska

    2015-06-01

    Full Text Available Background: In her previous research, the author of this publication indicates that coordination is a dependent variable which has a great driving force and is a very unstable factor. This results in the fact that all of the actions connected with coordination have an impact on other factors of cooperation as well as the integration of the enterprises in the structures of a supply chain type structure. Material and methods:  The article has been divided into two basic parts. The first part regards the reference models in complex systems (supply chain systems. They can constitute a starting point for the modelling of target processes in the built supply chain structure. The second part presents template process models (Reference Models for selected action coordination mechanisms during enterprise cooperation. The aim of the article is the presentation the model an Electronic Bulletin Board (EBB, as a mechanism of coordination of actions in complex systems. Results: The article was prepared on the basis of literature from the researched area. The material was also prepared on the basis of interviews with practitioners. They have allowed for the preparation of template process models (Reference Models for selected action coordination methods in the supply chain. Conclusions: The result of the work is a prepared model as well as its description in the use of IDEF0. The presented model is a demonstrative model. The proposed reference model makes it possible to define the parameters of a selected mechanism of coordination of actions, and forms a basis for affecting the progression of the process through an analysis of values of identified parameters. The parameterization of elements constitutes the foundation for the monitoring of the process via 1 unambiguous identification of the object of monitoring and 2 analysis of different variants of the progression of the process.

  19. Hydrothermal synthesis, crystal structure, luminescent and magnetic properties of a new mononuclear GdIII coordination complex

    Science.gov (United States)

    Coban, Mustafa Burak

    2018-06-01

    A new GdIII coordination complex, {[Gd(2-stp)2(H2O)6].2(4,4'-bipy).4(H2O)}, complex 1, (2-stp = 2-sulfoterephthalate anion and 4,4'-bipy = 4,4'-bipyridine), has been synthesized by hydrothermal method and characterized by elemental analysis, solid state UV-Vis and FT-IR spectroscopy, single-crystal X-ray diffraction, solid state photoluminescence and variable-temperature magnetic measurements. The crystal structure determination shows that GdIII ions are eight coordinated and adopt a distorted square-antiprismatic geometry. Molecules interacting through intra- and intermolecular (O-H⋯O, O-H⋯N) hydrogen bonds in complex 1, give rise to 3D hydrogen bonded structure and the discrete lattice 4,4'-bipy molecules occupy the channel of the 3D structure. π-π stacking interactions also exist 4,4'-bipy-4,4'-bipy and 4,4'-bipy-2-stp molecule rings in 3D structures. Additionally, solid state photoluminescence properties of complex 1 at room temperature have been investigated. Under the excitation of UV light (at 349 nm), the complex 1 exhibited green emissions (at 505 nm) of GdIII ion in the visible region. Furthermore, Variable-temperature magnetic susceptibility and isothermal magnetization as function of external magnetic field studies reveal that complex 1 displays possible antiferromagnetic interaction.

  20. Coordination Behavior of Ni2+, Cu2+, and Zn2+ in Tetrahedral 1-Methylimidazole Complexes: A DFT/CSD Study

    OpenAIRE

    Tetteh, Samuel

    2018-01-01

    The interaction between nickel (Ni2+), copper (Cu2+), and zinc (Zn2+) ions and 1-methylimidazole has been studied by exploring the geometries of eleven crystal structures in the Cambridge Structural Database (CSD). The coordination behavior of the respective ions was further investigated by means of density functional theory (DFT) methods. The gas-phase complexes were fully optimized using B3LYP/GENECP functionals with 6-31G∗ and LANL2DZ basis sets. The Ni2+ and Cu2+ complexes show distorted ...

  1. Coordination of manganous ion at the active site of pyruvate, phosphate dikinase: the complex of oxalate with the phosphorylated enzyme

    International Nuclear Information System (INIS)

    Kofron, J.L.; Ash, D.E.; Reed, G.H.

    1988-01-01

    Electron paramagnetic resonance spectroscopy has been used to investigate the structure of the complex of manganous ion with the phosphorylated form of pyruvate, phosphate dikinase (E/sub p/) and the inhibitor oxalate. Oxalate, an analogue of the enolate of pyruvate, is competitive with respect to pyruvate in binding to the phosphorylated form of the enzyme. Superhyperfine coupling between the unpaired electrons of Mn(I) and ligands specifically labeled with 17 O has been used to identify oxygen ligands to Mn(II) in the complex with oxalate and the phosphorylated form of the enzyme. Oxalate binds at the active site as a bidentate chelate with Mn(II). An oxygen from the 3'-N-phosphohistidyl residue of the protein is in the coordination sphere of Mn(II), and at least two water molecules are also bound to Mn(II) in the complex. Oxalate also binds directly to Mn(II) in a complex with nonphosphorylated enzyme. The structure for the E/sub p/-Mn(II)-oxalate complex implies that simultaneous coordination of a phospho group and of the attacking nucleophile to the divalent cation is likely an important factor in catalysis of this phospho-transfer reaction

  2. Concurrent coordination of ligand in metal chloride complexes with 1-vinyl-2-(2-pyridyl)benzimidazole

    International Nuclear Information System (INIS)

    Bajkalov, L.V.; Domnina, E.S.

    1996-01-01

    The properties and structure of bivalent cadmium and 1-vinyl-2-(2-pyridyl)benzimidazole chloride complexes, which have been prepared for the first time, have been studied by the methods of potentiometric titration and PMR, 35 Cl NQR, UV and IR spectroscopy. For the complexes above di- and polymeric structures in crystal phase are suggested, where ligand plays the role of a bridge. N,N-bidentate ligand. In solution the complexes dissociate with formation of monomeric coordination compounds, their metal being bound by different ways, stemming from participation of N benzimidazole or pyridine fragment of the ligand. Adducts of ionic type with second sphere 1-vinyl-2-(2-pyridyl)benzimidazole cation have been obtained in the course of hydrochlorination of the complexes prepared

  3. Synthesis, structural, thermal and optical studies of rare earth coordinated complex: Tb(Sal){sub 3}Phen

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Gagandeep; Dwivedi, Y. [Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Rai, S.B., E-mail: sbrai49@yahoo.co.in [Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005 (India)

    2011-11-01

    Highlights: {yields} RE coordinated complex of Tb(Sal){sub 3}Phen in crystalline phases were synthesized. {yields} Enhancement in luminescence of Tb{sup 3+} was observed in complex on 355 nm excitation. {yields} Fluorescence enhancement is due to the efficient energy transfer from Sal to Tb{sup 3+}. {yields} An observed increase in lifetime of Tb{sup 3+} is due to encapsulation in Sal/Phen network. {yields} The present system is a deserving candidate for LSC when coupled with solar cells. - Abstract: Complexes of salicylic acid (Sal) and 1,10-phenanthroline (Phen) were synthesized coordinated with terbium ion (Tb{sup 3+}) in crystalline phases. The structural characterizations of the lanthanide complex were made using FT-IR, NMR ({sup 1}H and {sup 13}C) and XRD techniques. These measurements confirm the formation of Tb(Sal){sub 3}Phen complex structure. The thermal aspects of the complex were examined using DTA and TGA techniques. An enhancement in luminescence intensity of Tb{sup 3+} ion bands were observed in Tb(Sal){sub 3}Phen complex as compared to TbCl{sub 3} crystals on 355 nm laser excitation. Enhancement is reported due to the efficient energy transfer process from Sal to Tb{sup 3+} ions. This is also confirmed by the time resolved photoluminescence spectroscopy with increase in lifetime of Tb{sup 3+} ions due to encapsulation in Sal/Phen network. Our system in itself can be a deserving candidate for luminescent solar collector material when coupled with solar cells.

  4. Titanium coordination compounds: from discrete metal complexes to metal–organic frameworks

    KAUST Repository

    Assi, Hala

    2017-05-24

    Owing to their promise in photocatalysis and optoelectronics, titanium based metal–organic frameworks (MOFs) are one of the most appealing classes of MOFs reported to date. Nevertheless, Ti-MOFs are still very scarce because of their challenging synthesis associated with a poor degree of control of their chemistry and crystallization. This review aims at giving an overview of the recent progress in this field focusing on the most relevant existing titanium coordination compounds as well as their promising photoredox properties. Not only Ti-MOFs but also Ti-oxo-clusters will be discussed and particular interest will be dedicated to highlight the different successful synthetic strategies allowing to overcome the still “unpredictable” reactivity of titanium ions, particularly to afford crystalline porous coordination polymers.

  5. Dance choreography is coordinated with song repertoire in a complex avian display.

    Science.gov (United States)

    Dalziell, Anastasia H; Peters, Richard A; Cockburn, Andrew; Dorland, Alexandra D; Maisey, Alex C; Magrath, Robert D

    2013-06-17

    All human cultures have music and dance, and the two activities are so closely integrated that many languages use just one word to describe both. Recent research points to a deep cognitive connection between music and dance-like movements in humans, fueling speculation that music and dance have coevolved and prompting the need for studies of audiovisual displays in other animals. However, little is known about how nonhuman animals integrate acoustic and movement display components. One striking property of human displays is that performers coordinate dance with music by matching types of dance movements with types of music, as when dancers waltz to waltz music. Here, we show that a bird also temporally coordinates a repertoire of song types with a repertoire of dance-like movements. During displays, male superb lyrebirds (Menura novaehollandiae) sing four different song types, matching each with a unique set of movements and delivering song and dance types in a predictable sequence. Crucially, display movements are both unnecessary for the production of sound and voluntary, because males sometimes sing without dancing. Thus, the coordination of independently produced repertoires of acoustic and movement signals is not a uniquely human trait. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Influence of a Heterocyclic Nitrogen-Donor Group on the Coordination of Trivalent Actinides and Lanthanides by Aminopolycarboxylate Complexants.

    Science.gov (United States)

    Grimes, Travis S; Heathman, Colt R; Jansone-Popova, Santa; Ivanov, Alexander S; Roy, Santanu; Bryantsev, Vyacheslav S; Zalupski, Peter R

    2018-02-05

    The novel metal chelator N-2-(pyridylmethyl)diethylenetriamine-N,N',N″,N″-tetraacetic acid (DTTA-PyM) was designed to replace a single oxygen-donor acetate group of the well-known aminopolycarboxylate complexant diethylenetriamine-N,N,N',N″,N″-pentaacetic acid (DTPA) with a nitrogen-donor 2-pyridylmethyl. Potentiometric, spectroscopic, computational, and radioisotope distribution methods show distinct differences for the 4f and 5f coordination environments and enhanced actinide binding due to the nitrogen-bearing heterocyclic moiety. The Am 3+ , Cm 3+ , and Ln 3+ complexation studies for DTTA-PyM reveal an enhanced preference, relative to DTPA, for trivalent actinide binding. Fluorescence studies indicate no changes to the octadentate coordination of trivalent curium, while evidence of heptadentate complexation of trivalent europium is found in mixtures containing EuHL (aq) complexes at the same aqueous acidity. The denticity change observed for Eu 3+ suggests that complex protonation occurs on the pyridyl nitrogen. Formation of the CmHL (aq) complex is likely due to the protonation of an available carboxylate group because the carbonyl oxygen can maintain octadentate coordination through a rotation. The observed suppressed protonation of the pyridyl nitrogen in the curium complexes may be attributed to stronger trivalent actinide binding by DTTA-PyM. Density functional theory calculations indicate that added stabilization of the actinide complexes with DTTA-PyM may originate from π-back-bonding interactions between singly occupied 5f orbitals of Am 3+ and the pyridyl nitrogen. The differences between the stabilities of trivalent actinide chelates (Am 3+ , Cm 3+ ) and trivalent lanthanide chelates (La 3+ -Lu 3+ ) are observed in liquid-liquid extraction systems, yielding unprecedented 4f/5f differentiation when using DTTA-PyM as an aqueous holdback reagent. In addition, the enhanced nitrogen-donor softness of the new DTTA-PyM chelator was perturbed by

  7. Influence of a Heterocyclic Nitrogen-Donor Group on the Coordination of Trivalent Actinides and Lanthanides by Aminopolycarboxylate Complexants

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Heathman, Colt R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jansone-Popova, Santa [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ivanov, Alexander S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roy, Santanu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bryantsev, Vyacheslav S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zalupski, Peter R. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2018-01-05

    Here, the novel metal chelator N-2-(pyridylmethyl)diethylenetriamine-N,N',N",N"-tetraacetic acid (DTTA-PyM) was designed to replace a single oxygen-donor acetate group of the well-known aminopolycarboxylate complexant diethylenetriamine-N,N,N',N",N"-pentaacetic acid (DTPA) with a nitrogen-donor 2-pyridylmethyl. Potentiometric, spectroscopic, computational, and radioisotope distribution methods show distinct differences for the 4f and 5f coordination environments and enhanced actinide binding due to the nitrogen-bearing heterocyclic moiety. The Am3+, Cm3+, and Ln3+ complexation studies for DTTA-PyM reveal an enhanced preference, relative to DTPA, for trivalent actinide binding. Fluorescence studies indicate no changes to the octadentate coordination of trivalent curium, while evidence of heptadentate complexation of trivalent europium is found in mixtures containing EuHL(aq) complexes at the same aqueous acidity. The denticity change observed for Eu3+ suggests that complex protonation occurs on the pyridyl nitrogen. Formation of the CmHL(aq) complex is likely due to the protonation of an available carboxylate group because the carbonyl oxygen can maintain octadentate coordination through a rotation. The observed suppressed protonation of the pyridyl nitrogen in the curium complexes may be attributed to stronger trivalent actinide binding by DTTA-PyM. Density functional theory calculations indicate that added stabilization of the actinide complexes with DTTA-PyM may originate from π-back-bonding interactions between singly occupied 5f orbitals of Am3+ and the pyridyl nitrogen. The differences between the stabilities of trivalent actinide chelates (Am3+, Cm3+) and trivalent lanthanide chelates (La3+–Lu3+) are observed in liquid–liquid extraction systems, yielding unprecedented 4f/5f differentiation when using DTTA

  8. Making oxidation potentials predictable: Coordination of additives applied to the electronic fine tuning of an iron(II) complex

    KAUST Repository

    Haslinger, Stefan

    2014-11-03

    This work examines the impact of axially coordinating additives on the electronic structure of a bioinspired octahedral low-spin iron(II) N-heterocyclic carbene (Fe-NHC) complex. Bearing two labile trans-acetonitrile ligands, the Fe-NHC complex, which is also an excellent oxidation catalyst, is prone to axial ligand exchange. Phosphine- and pyridine-based additives are used for substitution of the acetonitrile ligands. On the basis of the resulting defined complexes, predictability of the oxidation potentials is demonstrated, based on a correlation between cyclic voltammetry experiments and density functional theory calculated molecular orbital energies. Fundamental insights into changes of the electronic properties upon axial ligand exchange and the impact on related attributes will finally lead to target-oriented manipulation of the electronic properties and consequently to the effective tuning of the reactivity of bioinspired systems.

  9. Making oxidation potentials predictable: Coordination of additives applied to the electronic fine tuning of an iron(II) complex

    KAUST Repository

    Haslinger, Stefan; Kü ck, Jens W.; Hahn, Eva M.; Cokoja, Mirza; Pö thig, Alexander; Basset, Jean-Marie; Kü hn, Fritz

    2014-01-01

    This work examines the impact of axially coordinating additives on the electronic structure of a bioinspired octahedral low-spin iron(II) N-heterocyclic carbene (Fe-NHC) complex. Bearing two labile trans-acetonitrile ligands, the Fe-NHC complex, which is also an excellent oxidation catalyst, is prone to axial ligand exchange. Phosphine- and pyridine-based additives are used for substitution of the acetonitrile ligands. On the basis of the resulting defined complexes, predictability of the oxidation potentials is demonstrated, based on a correlation between cyclic voltammetry experiments and density functional theory calculated molecular orbital energies. Fundamental insights into changes of the electronic properties upon axial ligand exchange and the impact on related attributes will finally lead to target-oriented manipulation of the electronic properties and consequently to the effective tuning of the reactivity of bioinspired systems.

  10. Jahn-Teller distortion in the phosphorescent excited state of three-coordinate Au(I) phosphine complexes.

    Science.gov (United States)

    Barakat, Khaldoon A; Cundari, Thomas R; Omary, Mohammad A

    2003-11-26

    DFT calculations were used to optimize the phosphorescent excited state of three-coordinate [Au(PR3)3]+ complexes. The results indicate that the complexes rearrange from their singlet ground-state trigonal planar geometry to a T-shape in the lowest triplet luminescent excited state. The optimized structure of the exciton contradicts the structure predicted based on the AuP bonding properties of the ground-state HOMO and LUMO. The rearrangement to T-shape is a Jahn-Teller distortion because an electron is taken from the degenerate e' (5dxy, 5dx2-y2) orbital upon photoexcitation of the ground-state D3h complex. The calculated UV absorption and visible emission energies are consistent with the experimental data and explain the large Stokes' shifts while such correlations are not possible in optimized models that constrained the exciton to the ground-state trigonal geometry.

  11. Exploring the practicing-connections hypothesis: using gesture to support coordination of ideas in understanding a complex statistical concept.

    Science.gov (United States)

    Son, Ji Y; Ramos, Priscilla; DeWolf, Melissa; Loftus, William; Stigler, James W

    2018-01-01

    In this article, we begin to lay out a framework and approach for studying how students come to understand complex concepts in rich domains. Grounded in theories of embodied cognition, we advance the view that understanding of complex concepts requires students to practice, over time, the coordination of multiple concepts, and the connection of this system of concepts to situations in the world. Specifically, we explore the role that a teacher's gesture might play in supporting students' coordination of two concepts central to understanding in the domain of statistics: mean and standard deviation. In Study 1 we show that university students who have just taken a statistics course nevertheless have difficulty taking both mean and standard deviation into account when thinking about a statistical scenario. In Study 2 we show that presenting the same scenario with an accompanying gesture to represent variation significantly impacts students' interpretation of the scenario. Finally, in Study 3 we present evidence that instructional videos on the internet fail to leverage gesture as a means of facilitating understanding of complex concepts. Taken together, these studies illustrate an approach to translating current theories of cognition into principles that can guide instructional design.

  12. Coordination chemistry of sugar-phosphate complexes with palladium(II), rhenium(V) and zinc(II)

    Energy Technology Data Exchange (ETDEWEB)

    Steinborn, Christian Martin

    2013-05-21

    As described before, some studies dealing with coordination chemistry of sugar phosphates are available but no analogous complexes of Zn{sup II} have been investigated yet. The primary goal of this work is, therefore, to fill this gap. In order to stay close to the active sites of enzymes such as class-II-aldolase, the simple metal fragment Zn{sup II}(dien) is used. NMR spectroscopy is used primarily as analytical method since it enables the investigation of both complex equilibria in solution and pH dependence of metal-binding sites. Since this approach is challenging due to the fast metal-ligand exchange and the absence of CIS values, it is necessary to improve the significance of NMR data collected from sugar-phosphate complexes with Zn{sup II}. Hence, further experiments are performed with molecules similar to sugar phosphates such as reducing and methylated sugars or polyols. Beside NMR spectroscopy, crystal-structure analysis will be used to get more detailed information about the binding pattern of the complexes. Additionally, sugar-phosphate complexes of Pd{sup II} are investigated. Further experiments are conducted, on the one hand, to synthesise more sugarphosphate complexes with ReVON2 fragments, and, on the other hand, to grow crystals confirming the theory about mixed sugar-core-phosphate chelation.

  13. Enhanced π-Back-Donation as a Way to Higher Coordination Numbers in d10 [M(NHC)n] Complexes: A DFT Study

    NARCIS (Netherlands)

    Nitsch, J.; Wolters, L.P.; Fonseca Guerra, C.; Bickelhaupt, F.M.; Steffen, A.

    2016-01-01

    We aim to understand the electronic factors determining the stability and coordination number of d10 transition-metal complexes bearing N-heterocyclic carbene (NHC) ligands, with a particular emphasis on higher coordinated species. In this DFT study on the formation and bonding of Group 9–12 d10

  14. Enhanced pi-Back-Donation as a Way to Higher Coordination Numbers in d10 [M(NHC)n] Complexes: A DFT Study

    NARCIS (Netherlands)

    Nitsch, J.S.; Wolters, L.P.; Fonseca Guerra, C.; Bickelhaupt, F.M.; Steffen, A.

    2017-01-01

    We aim to understand the electronic factors determining the stability and coordination number of d10 transition-metal complexes bearing N-heterocyclic carbene (NHC) ligands, with a particular emphasis on higher coordinated species. In this DFT study on the formation and bonding of Group 9–12 d10

  15. Ten-decimal tables of the logarithms of complex numbers and for the transformation from Cartesian to polar coordinates

    CERN Document Server

    Lyusternik, L A

    1965-01-01

    Ten-Decimal Tables of the Logarithms of Complex Numbers and for the Transformation from Cartesian to Polar Coordinates contains Tables of mathematical functions up to ten-decimal value. These tables are compiled in the Department for Approximate Computations of the Institute of Exact Mechanics and Computational Methods of the U.S.S.R. Academy of Sciences. The computations are carried out by this department in conjunction with the Computational-Experimental Laboratory of the Institute.This book will be of value to mathematicians and researchers.

  16. Manipulating charge transfer excited state relaxation and spin crossover in iron coordination complexes with ligand substitution

    DEFF Research Database (Denmark)

    Zhang, Wenkai; Kjær, Kasper Skov; Alonso-Mori, Roberto

    2017-01-01

    iron complexes with four cyanide (CN-;) ligands and one 2,2′-bipyridine (bpy) ligand. This enables MLCT excited state and metal-centered excited state energies to be manipulated with partial independence and provides a path to suppressing spin crossover. We have combined X-ray Free-Electron Laser (XFEL...... state lifetime of iron based complexes due to spin crossover-the extremely fast intersystem crossing and internal conversion to high spin metal-centered excited states. We revitalize a 30 year old synthetic strategy for extending the MLCT excited state lifetimes of iron complexes by making mixed ligand...

  17. Bowl adamanzanes-bicyclic tetraamines: syntheses and crystal structures of complexes with cobalt(III) and chelating coordinated oxo-anions

    DEFF Research Database (Denmark)

    Broge, Louise; Søtofte, Inger; Jensen, Kristian

    2007-01-01

    complex is provided. Four of the seven complexes contain a chelate coordinating oxo-anion ( sulfate, formiate, nitrate, carbonate). Equilibration of these species with the corresponding diaqua complex is generally slow. The rates of equilibration in 5 mol dm(-3) perchloric acid at 25 degrees C have been...

  18. Low-Complexity Scheduling and Power Adaptation for Coordinated Cloud-Radio Access Networks

    KAUST Repository

    Douik, Ahmed; Dahrouj, Hayssam; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2017-01-01

    In practical wireless systems, the successful implementation of resource allocation techniques strongly depends on the algorithmic complexity. Consider a cloud-radio access network (CRAN), where the central cloud is responsible for scheduling

  19. Exploring Trianglamine Derivatives and Trianglamine Coordination Complexes as Porous Organic Materials

    KAUST Repository

    Eziashi, Magdalene

    2018-01-01

    , they are still a poorly researched class of macrocycles today. Trianglamines have yet a role to play as porous organic molecules for separation processes, as macrocyclic precursors to build increasingly complex supramolecular assemblies and as building blocks

  20. A New Polynuclear Coordination Type for (Salicylaldoxime)copper(II) Complexes: Structure and Magnetic Properties of an (Oxime)Cu6 Cluster

    DEFF Research Database (Denmark)

    Wenzel, Marco; Forgan, Ross S.; Faure, Anaëlle

    2009-01-01

    A previously unseen coordination mode is reported for (salicylaldoxime)copper complexes utilising a linked zwitterionic NO22- donor set. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)...

  1. Preparations and crystal structures of 8 coordinate uranyl(VI) complexes having macrocyclic ligands derived from pyrroledicarboxialdehydes and diamines

    International Nuclear Information System (INIS)

    Komagine, J.; Takeda, M.; Takahashi, M.

    2006-01-01

    Six 8-coordinate uranyl(VI) complexes with macrocyclic Schiff base ligands derived from 2,6-pyrroledicarboxialdehyde and diamines are prepared and the crystal structures for two of them are determined focusing on the relation between the size of the ligands and U-N bond distances. No difference in average uranyl bond distances and bond angles are observed between [UO 2 (bipytn)](a) and [UO 2 (bipydmtn)](b). U-N bonds of these complexes are, however, not equal; the U-N(pyrrole) bonds [2.45(a), 2.44(b) A] are much shorter than the U-N(imine) bonds [2.67(a), 2.67(b) A]. (author)

  2. Synthesis, structures and properties of a series of manganese coordination complexes constructed from dicarboxylic fluorene derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Li Xing, E-mail: lixing@nbu.edu.cn [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211 (China); Zhao Xiuhua; Bing Yue; Zha Meiqin; Xie Hongzhen; Guo Zhiyong [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211 (China)

    2013-01-15

    Assembly reactions of 9,9-diethylfluorene-2,7-dicarboxylic acid (H{sub 2}DFDC) and Mn(CH{sub 3}COO){sub 2}{center_dot}4H{sub 2}O or MnCl{sub 2}{center_dot}4H{sub 2}O by tuning of various secondary ligands such as 2,2 Prime -bipyridine (2,2 Prime -bpy), 4,4 Prime -bipyridine (4,4 Prime -bpy) or 1,3-bis(4-pyridyl)propane) (bpp), gave rise to four complexes {l_brace} [Mn{sub 2}(DFDC){sub 2}(DMF){sub 2}]{center_dot}H{sub 2}O{r_brace} {sub n} (1), [Mn(DFDC)(2,2 Prime -bpy)]{sub n} (2), {l_brace} [Mn{sub 2}(DFDC){sub 2}(4,4 Prime -bpy){sub 2}]{center_dot}2CH{sub 3}OH{r_brace} {sub n} (3), and {l_brace} [Mn{sub 4}(DFDC){sub 4}(bpp){sub 2}(CH{sub 3}OH){sub 3} (H{sub 2}O){sub 3}]{center_dot}3(CH{sub 3}OH){center_dot}3(H{sub 2}O){r_brace} {sub n} (4). Single crystal X-ray diffraction analysis reveal that complex 1 is three dimensional structure with rhombic channels filled by guest water molecules; 2 presents a close-packed structure with high thermal stability; 3 exhibits a three dimensional framework with micro-porous channels filled by guest methanol molecules and 4 is a two-dimensional structure. The photoluminescent properties of 1-4 have been studied, respectively, showing that the Mn(II) ions, accessorial organic ligands or crystal structures exert important influences on the photoluminescence emissions of H{sub 2}DFDC ligands. Thermogravimetric analysis show that the complexes have remarkably high thermal stability. Magnetic susceptibility measurements have been finished and discussed for the complexes. - Graphical abstract: Assembly of 9,9-diethylfluorene-2,7-dicarboxylic acid and Mn(II) salts by tuning of various accessorial ligands resulted in four manganese complexes with different topological frameworks. Highlights: Black-Right-Pointing-Pointer Four manganese complexes based on 9,9-diethylfluorene-2,7-dicarboxylic acid were obtained. Black-Right-Pointing-Pointer The complexes were structurally characterized by single-crystal X-ray diffraction. Black

  3. Multidisciplinary management of pregnancy in complex congenital heart disease: a model for coordination of care.

    Science.gov (United States)

    Harris, Rachel C; Fries, Melissa H; Boyle, Annelee; Adeniji-Adele, Hassan; Cherian, Zacharia; Klein, Nancy; John, Anitha S

    2014-01-01

    With advancements in medical care, many women with complex congenital heart disease (CHD) are now living into adulthood and childbearing years. The strains of pregnancy and parturition can be dangerous in such patients, and careful interdisciplinary plans must be made to optimize maternal and fetal health through this process. Several large studies have been published regarding risk prediction and medical management of pregnancy in complex CHD, though few case studies detailing clinical care plans have been published. The objective of this report is to describe the process of developing a detailed pregnancy and delivery care plan for three women with complex CHD, including perspectives from the multidisciplinary specialists involved in the process. This article demonstrates that collaboration between specialists in the fields of cardiology, anesthesiology, high-risk obstetrics, maternal fetal medicine, and neonatology results in clinically successful individualized treatment plans for the management of pregnancy in complex CHD. Multidisciplinary collaboration is a crucial element in the management of pregnancy in complex CHD. We provide a template used in three cases which can serve as a model for the design of future care plans. © 2014 Wiley Periodicals, Inc.

  4. Tracking excited-state charge and spin dynamics in iron coordination complexes

    DEFF Research Database (Denmark)

    Zhang, Wenkai; Alonso-Mori, Roberto; Bergmann, Uwe

    2014-01-01

    to spin state, can elucidate the spin crossover dynamics of [Fe(2,2'-bipyridine)(3)](2+) on photoinduced metal-to-ligand charge transfer excitation. We are able to track the charge and spin dynamics, and establish the critical role of intermediate spin states in the crossover mechanism. We anticipate......Crucial to many light-driven processes in transition metal complexes is the absorption and dissipation of energy by 3d electrons(1-4). But a detailed understanding of such non-equilibrium excited-state dynamics and their interplay with structural changes is challenging: a multitude of excited...... states and possible transitions result in phenomena too complex to unravel when faced with the indirect sensitivity of optical spectroscopy to spin dynamics(5) and the flux limitations of ultrafast X-ray sources(6,7). Such a situation exists for archetypal poly-pyridyl iron complexes, such as [Fe(2...

  5. Synthesis, characterization and antifungal efficacy of C-coordinated O-carboxymethyl chitosan Cu(II) complexes.

    Science.gov (United States)

    Liu, Weixiang; Qin, Yukun; Liu, Song; Xing, Ronge; Yu, Huahua; Chen, Xiaolin; Li, Kecheng; Li, Pengcheng

    2017-03-15

    A novel type of O-carboxymethyl chitosan Schiff bases (O-CSPX) was synthesized via a condensation reaction. After the coordination reaction of cupric ions, Cu(II) complexes (O-CSPX-Cu) were achieved. The theoretical structure of O-CSPX-Cu calculated by Gaussian 09 reveals that the copper ions underwent dsp 2 hybridization, coordinated by the carbon atom in the p-π conjugate group and the oxygen atoms in the acetate ion. Then, the structures were confirmed by FT-IR, 1 H NMR, CP-MAS 13 C NMR, elemental analysis, DSC and XRD. The antifungal properties of O-CSPX-Cu against Phytophthora capsici (P. capsici), Gibberella zeae (G. zeae) and Glomerella cingulata (G. cingulata) were evaluated at concentrations ranging from 0.05mg/mL to 0.20mg/mL. The experiments indicated that the derivatives have significantly enhanced antifungal activity after copper ion complexation compared with the original chitosan. Moreover, it was shown that 0.20mg/mL of O-CSP3-Cu and O-CSP4-Cu can 100% inhibit the growth of P. capsici. The experimental results reveal that the antifungal efficiency is related to the space steric hindrance on the benzene ring, which may provide a novel direction for the development of copper fungicides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. A Coordination Chemistry Approach to Fine-Tune the Physicochemical Parameters of Lanthanide Complexes Relevant to Medical Applications.

    Science.gov (United States)

    Le Fur, Mariane; Molnár, Enikő; Beyler, Maryline; Kálmán, Ferenc K; Fougère, Olivier; Esteban-Gómez, David; Rousseaux, Olivier; Tripier, Raphaël; Tircsó, Gyula; Platas-Iglesias, Carlos

    2018-03-02

    The geometric features of two pyclen-based ligands possessing identical donor atoms but different site organization have a profound impact in their complexation properties toward lanthanide ions. The ligand containing two acetate groups and a picolinate arm arranged in a symmetrical fashion (L1) forms a Gd 3+ complex being two orders of magnitude less stable than its dissymmetric analogue GdL2. Besides, GdL1 experiences a much faster dissociation following the acid-catalyzed mechanism than GdL2. On the contrary, GdL1 exhibits a lower exchange rate of the coordinated water molecule compared to GdL2. These very different properties are related to different strengths of the Gd-ligand bonds associated to steric effects, which hinder the coordination of a water molecule in GdL2 and the binding of acetate groups in GdL1. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Condition-based maintenance for complex systems : Coordinating maintenance and logistics planning for the process industries

    NARCIS (Netherlands)

    Olde Keizer, Minou Catharina Anselma

    2016-01-01

    Maintenance planning in the process industries is extremely complex for various reasons. Plants often run nonstop, allowing little time for performing preventive maintenance. Failures should be prevented, however, as they can lead to system downtime and high losses of revenue. Corrective maintenance

  8. Antiferromagnetic coupling in a six-coordinate high spin cobalt(II)-semiquinonato complex.

    Science.gov (United States)

    Caneschi, Andrea; Dei, Andrea; Gatteschi, Dante; Tangoulis, Vassilis

    2002-07-01

    The 3,5-di-tert-butyl-catecholato and 9,10-phenanthrenecatecholato adducts of the cobalt-tetraazamacrocycle complex Co(Me(4)cyclam)(2+) (Me(4)cyclam = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) were synthesized and oxidized. The oxidation reaction products were isolated in the solid state as hexafluorophosphate derivatives. Both these complexes can be formulated as 1:1 cobalt(II)-semiquinonato complexes, that is, Co(Me(4)cyclam)(DBSQ)PF(6) (1) and Co(Me(4)cyclam)(PhSQ)PF(6) (2), in the temperature range 4-300 K, in striking contrast with the charge distribution found in similar adducts formed by related tetraazamacrocycles. The synthesis strategy and the structural, spectroscopic, and magnetic properties are reported and discussed. The crystallographic data for 2 are as follows: monoclinic, space group P2(1)/a, nomicron. 14, a = 14.087(4) A, b = 15.873(4) A, c = 14.263 (7) A, alpha = 89.91(3) degrees, beta = 107.34(2) degrees, gamma = 90.08(2) degrees, Z = 4. Both these complexes are characterized by triplet electronic ground states arising from the antiferromagnetic coupling between the high-spin d(7) metal ion and the radical ligand.

  9. An Iminosemiquinone-Coordinated Oxidovanadium(V) Complex: A Combined Experimental and Computational Study

    Czech Academy of Sciences Publication Activity Database

    Sarkar, P.; Mondal, M. K.; Sarmah, Amrit; Maity, S.; Mukherjee, C.

    2017-01-01

    Roč. 56, č. 14 (2017), s. 8068-8077 ISSN 0020-1669 Institutional support: RVO:61388963 Keywords : transition metal complexes * induced electron transfer * non-innocent ligands Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 4.857, year: 2016

  10. The coordination chemistry of dipyridylbenzene: N-deficient terpyridine or panacea for brightly luminescent metal complexes?

    Science.gov (United States)

    Williams, J A Gareth

    2009-06-01

    1,3-Di(2-pyridyl)benzene (dpybH) structurally resembles the widely-used ligand terpyridine (tpy), with which it is isoelectronic. In this critical review, following a brief overview of synthetic strategies for dpybH and derivatives, we survey the different types of complex that are possible with these ligands. Whilst metals such as ruthenium(ii), osmium(ii) and platinum(ii) give a terdentate N--C--N binding mode in which cyclometallation occurs at C(2), the ions iridium(iii), rhodium(iii) and palladium(ii) favour C(4) metallation. The latter process can be blocked by appropriate ligand modification, to allow the N--C--N mode to be accessed with these metal ions too. The luminescence properties of the complexes are discussed. A huge range of emission efficiencies are encountered amongst Ir(iii) complexes containing dpyb derivatives, according to the other ligands present. Trends can be rationalised with the aid of simple frontier-orbital considerations. The Pt(ii) complexes of dipyridylbenzenes are also intensely luminescent. Their application to contemporary organic light-emitting device (OLED) technology is discussed, including white light emitters exploiting excimer emission. Their potential as cell imaging agents amenable to time-resolved detection procedures on the microsecond timescale has also been demonstrated (118 references).

  11. Crystal structures of bis- and hexakis[(6,6′-dihydroxybipyridinecopper(II] nitrate coordination complexes

    Directory of Open Access Journals (Sweden)

    Deidra L. Gerlach

    2015-12-01

    Full Text Available Two multinuclear complexes synthesized from Cu(NO32 and 6,6′-dihydroxybipyridine (dhbp exhibit bridging nitrate and hydroxide ligands. The dinuclear complex (6,6′-dihydroxybipyridine-2κ2N,N′[μ-6-(6-hydroxypyridin-2-ylpyridin-2-olato-1:2κ3N,N′:O2](μ-hydroxido-1:2κ2O:O′(μ-nitrato-1:2κ2O:O′(nitrato-1κOdicopper(II, [Cu2(C10H7N2O2(OH(NO32(C10H8N2O2] or [Cu(6-OH-6′-O-bpy(NO3(μ-OH(μ-NO3Cu(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 hexanuclear complex bis(μ3-bipyridine-2,2′-diolato-κ3O:N,N′:O′tetrakis(6,6′-dihydroxybipyridine-κ2N,N′tetrakis(μ-hydroxido-κ2O:O′bis(methanol-κOtetrakis(μ-nitrato-κ2O:O′hexacopper(II, [Cu6(C10H6N2O22(CH4O2(OH4(NO34(C10H8N2O24] or [Cu(6,6′-dhbp(μ-NO32(μ-OHCu(6,6′-O-bpy(μ-OHCu(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 intramolecular O—H...O hydrogen bonding. Intermolecular O—H...O hydrogen bonding links symmetry-related molecules forming chains along [100] for complex (I with π-stacking along [010] and [001]. Complex (II forms intermolecular O—H...O hydrogen-bonded chains along [010] with π-stacking along [100] and [001].

  12. Cycloheptatrienyl zirconium sandwich complexes with lewis basic phospholyl ligands (phosphatrozircenes): synthesis, structure, bonding and coordination chemistry.

    Science.gov (United States)

    Glöckner, Andreas; Bannenberg, Thomas; Büschel, Susanne; Daniliuc, Constantin G; Jones, Peter G; Tamm, Matthias

    2011-05-23

    The transmetalation reaction between [(η(7) -C(7) H(7) )ZrCl(tmeda)] (1; tmeda=N,N,N',N'-tetramethylethylenediamine) and various phospholide anions leads to a new class of mixed sandwich complexes: [(η(7)-C(7)H(7))Zr(η(5)-C(4)PMe(4))] (2), [(η(7)-C(7)H(7))Zr(η(5)-C(4)PH(2)Me(2))] (3) and [(η(7)-C(7)H(7))Zr(η(5)-C(4)PPhHMe(2))] (4). The presence of Lewis basic phosphorus atoms and Lewis acidic zirconium atoms allows ambiphilic behaviour to be observed, and X-ray diffraction analysis reveals dimeric arrangements for 2 and 3 with long intermolecular Zr-P bonds, whereas 4 remains monomeric in the solid state. DFT calculations indicate that the metal-phosphorus interaction is weak, and accordingly, complexes 2-4 act as monodentate ligands upon reaction with [W(CO)(5)(thf)]. The resulting complexes [W(CO)(5)(L)] 5-7 (L=2-4) were studied by IR spectroscopy and compared with the [W(CO)(5) ] complex 9, containing the phosphane-functionalised trozircene [(η(7)-C(7)H(7))Zr(η(5)-C(5)H(4)PPh(2))] (8). They all show a close resemblance to simple phosphanes, such as PMe(3) , although molecular orbital analysis of 2 reveals that the free electron pair in the phosphatrozircenes is not the HOMO. Four equivalents of 2 can replace 1,4-cyclooctadiene (COD) in [Ni(cod)(2)] to form the homoleptic, distorted tetrahedral complex [Ni{2}(4)] (10). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Luminescent, magnetic and ferroelectric properties of noncentrosymmetric chain-like complexes composed of nine-coordinate lanthanide ions.

    Science.gov (United States)

    Li, Xi-Li; Chen, Chun-Lai; Xiao, Hong-Ping; Wang, Ai-Ling; Liu, Cai-Ming; Zheng, Xianjun; Gao, Li-Jun; Yang, Xiao-Gang; Fang, Shao-Ming

    2013-11-21

    Reaction of the chiral ligand (-)-4,5-pinenepyridyl-2-pyrazine (L) with Ln(hfac)3·2H2O precursors [hfac(-) = 1,1,1,5,5,5-hexafluoroacetylacetonate, Ln = Sm(3+) (1), Eu(3+) (2), Tb(3+) (3) and Dy(3+) (4)] in methanol solution led to the formation of four noncentrosymmetric lanthanide complexes with the general formula [Ln(hfac)3L]n·H2O. The single-crystal X-ray diffraction analyses revealed that they are isostructural and take a one-dimensional (1D) chain structure based on the Ln(hfac)3L repeating units, in which the nine-coordinate Ln(3+) ions reside in a tricapped trigonal prism (TTP) environment never reported in previous 1D chain lanthanide complexes. The investigations of their photophysical properties showed that complexes 1, and 3 exhibit characteristic emissions of Sm(3+), Eu(3+) and Tb(3+) ions with respective luminescent lifetime values of 0.065, 1.066 and 0.129 ms, while complex 4 does not display any emission. The different luminescent intensities and lifetimes among them were further discussed in detail. Moreover, the magnetic properties of complexes 1-4 were assessed with a special emphasis on the Dy(3+) complex 4. Alternating-current (ac) magnetic susceptibility measurements indicated that field-induced two-step slow magnetic relaxation processes were observed in 4, indicating the single-molecule magnet (SMM) behavior of 4. In addition, the noncentrosymmetric complexes 1-4 crystallizing in the same polar point group (Cs) exhibit both ferroelectric and nonlinear optical properties at room temperature. All these features make them multifunctional crystalline molecule materials.

  14. Evolving dynamics of trading behavior based on coordination game in complex networks

    Science.gov (United States)

    Bian, Yue-tang; Xu, Lu; Li, Jin-sheng

    2016-05-01

    This work concerns the modeling of evolvement of trading behavior in stock markets. Based on the assumption of the investors' limited rationality, the evolution mechanism of trading behavior is modeled according to the investment strategy of coordination game in network, that investors are prone to imitate their neighbors' activity through comprehensive analysis on the risk dominance degree of certain investment behavior, the network topology of their relationship and its heterogeneity. We investigate by mean-field analysis and extensive simulations the evolution of investors' trading behavior in various typical networks under different risk dominance degree of investment behavior. Our results indicate that the evolution of investors' behavior is affected by the network structure of stock market and the effect of risk dominance degree of investment behavior; the stability of equilibrium states of investors' behavior dynamics is directly related with the risk dominance degree of some behavior; connectivity and heterogeneity of the network plays an important role in the evolution of the investment behavior in stock market.

  15. Synthesis and coordination behavior of a bipyridine platinum(II) complex with thioglucose.

    Science.gov (United States)

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

    2013-05-06

    A mononuclear platinum(II) complex with two monodentate-S H4tg(-) ligands, [Pt(H4tg-κS)2(bpy)] (1), was newly synthesized by the reaction of [PtCl2(bpy)] (bpy = 2,2'-bipyridyl) with NaH4tg (NaH4tg =1-thio-β-d-glucose sodium salt) in water. Complex 1 reacted with additional [PtCl2(bpy)] in water to give an S-bridged dinuclear complex, [Pt2(μ2-H4tg-κ(1)S:κ(1)S)2(bpy)2](2+) ([2](2+)), in which a square-planar [Pt(H4tg)2(bpy)] unit binds to a [Pt(bpy)](2+) moiety through two thiolato groups. Treatments of 1 with Cu(2+) and Ni(2+) in water in the presence of bpy produced S-bridged dinuclear complexes [PtCu(μ2-H4tg-κ(1)S:κ(2)O,S)2(bpy)2](2+) ([3](2+)) and [PtNi(μ2-H4tg-κ(1)S:κ(2)O,S)2(bpy)2](2+) ([4](2+)), respectively, in which a square-planar [Pt(H4tg)2(bpy)] unit binds to a [M(bpy)](2+) (M = Cu(II), Ni(II)) moiety through two thiolato and two hydroxyl groups to form a chiral [M(N)2(O)2(S)2] octahedron with the Δ configuration. On the other hand, similar treatment with Cd(2+) in the presence of bpy resulted in the formation of an S-bridged trinuclear complex, [Cd{Pt(μ2-H4tg-κ(1)S:κ(2)O,S)(μ2-H4tg-κ(1)S:κ(1)S)(bpy)}2](2+) ([5](2+)), in which each of two square-planar [Pt(H4tg)2(bpy)] units binds to a Cd(II) ion through two thiolato groups and one hydroxyl group to form a chiral [Cd(O)2(S)4] octahedron with the Λ configuration. Of two geometrical configurations, syn and anti, which arise from the relative arrangement of two β-D-pyranose moieties, [2](2+) adopts the syn configuration with symmetric bridging sulfur atoms, while [3](2+), [4](2+), and [5](2+) all have the anti configuration with R configurational bridging sulfur atoms. All of the complexes were fully characterized by electronic absorption, CD, and NMR spectroscopies, along with single-crystal X-ray crystallography.

  16. Broad-Complex acts downstream of Met in juvenile hormone signaling to coordinate primitive holometabolan metamorphosis

    Czech Academy of Sciences Publication Activity Database

    Konopová, Barbora; Jindra, Marek

    2008-01-01

    Roč. 135, č. 3 (2008), s. 559-568 ISSN 0950-1991 R&D Projects: GA ČR(CZ) GA204/07/1032; GA AV ČR IAA5007305; GA MŠk LC07032 Institutional research plan: CEZ:AV0Z50070508 Keywords : metamorphosis * juvenile hormone * broad-complex Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.812, year: 2008

  17. Exploring Trianglamine Derivatives and Trianglamine Coordination Complexes as Porous Organic Materials

    KAUST Repository

    Eziashi, Magdalene

    2018-05-01

    Trianglamines are triangular chiral macrocycles that were first synthesized by Gawronski’s group in Poland in the year 2000.1 Despite their unique properties; triangular pore shape, chirality, symmetric structure and tunable pore size, they are still a poorly researched class of macrocycles today. Trianglamines have yet a role to play as porous organic molecules for separation processes, as macrocyclic precursors to build increasingly complex supramolecular assemblies and as building blocks for caged porous organic structures. The aim of the Thesis work is to explore trianglamine, its derivatives, and assemblies as viable porous organic molecules for potential gas capture and separation.

  18. System Coordination of Survivability and Safety of Complex Engineering Objects Operation

    Directory of Open Access Journals (Sweden)

    Nataliya Pankratova

    2014-11-01

    Full Text Available A system strategy to estimation the guaranteed survivability and safety of complex engineering objects (CEO operation is proposed. The principles that underlie the strategy of the guaranteed safety of CEO operation provide a flexible approach to timely detection, recognition, forecast, and system diagnostics of risk factors and situations, to formulation and implementation of a rational decision in a practicable time within an unremovable time constraint. Implementation of the proposed strategy is shown on example of diagnostics of electromobile-refrigerator functioning in real mode.

  19. A new hybrid optimization algorithm CRO-DE for optimal coordination of overcurrent relays in complex power systems

    Directory of Open Access Journals (Sweden)

    Mohamed Zellagui

    2017-09-01

    Full Text Available The paper presents a new hybrid global optimization algorithm based on Chemical Reaction based Optimization (CRO and Di¤erential evolution (DE algorithm for nonlinear constrained optimization problems. This approach proposed for the optimal coordination and setting relays of directional overcurrent relays in complex power systems. In protection coordination problem, the objective function to be minimized is the sum of the operating time of all main relays. The optimization problem is subject to a number of constraints which are mainly focused on the operation of the backup relay, which should operate if a primary relay fails to respond to the fault near to it, Time Dial Setting (TDS, Plug Setting (PS and the minimum operating time of a relay. The hybrid global proposed optimization algorithm aims to minimize the total operating time of each protection relay. Two systems are used as case study to check the effeciency of the optimization algorithm which are IEEE 4-bus and IEEE 6-bus models. Results are obtained and presented for CRO and DE and hybrid CRO-DE algorithms. The obtained results for the studied cases are compared with those results obtained when using other optimization algorithms which are Teaching Learning-Based Optimization (TLBO, Chaotic Differential Evolution Algorithm (CDEA and Modiffied Differential Evolution Algorithm (MDEA, and Hybrid optimization algorithms (PSO-DE, IA-PSO, and BFOA-PSO. From analysing the obtained results, it has been concluded that hybrid CRO-DO algorithm provides the most optimum solution with the best convergence rate.

  20. Restoring Lands - Coordinating Science, Politics and Action Complexities of Climate and Governance

    CERN Document Server

    Scarlett, Lynn; Vargas-Moreno, Juan; Flaxman, Michael

    2012-01-01

    Environmental issues, vast and varied in their details, unfold at the confluence of people and place. They present complexities in their biophysical details, their scope and scale, and the dynamic character of human action and natural systems. Addressing environmental issues often invokes tensions among battling interests and competing priorities. Air and water pollution, the effects of climate change, ecosystem transformations—these and other environmental issues involve scientific, social, economic, and institutional challenges. This book analyzes why tackling many of these problems is so difficult and why sustainability involves more than adoption of greener, cleaner technologies. Sustainability, as discussed in this book, involves knowledge flows and collaborative decision processes that integrate scientific and technological methods and tools, political and governance structures and regimes, and social and community values. The authors synthesize a holistic and adaptive approach to rethinking the frame...

  1. Atom transfer as a preparative tool in coordination chemistry. Synthesis and characterization of Cr(V) nitrido complexes of bidentate ligands

    DEFF Research Database (Denmark)

    Birk, Torben; Bendix, Jesper

    2003-01-01

     = 11.8267(12) Å, ß = 106.528(7)°, V = 1441.7(2) Å3, Z = 4. Complexes 2 and 3 represent new coordination environments for first row transition metal nitrido complexes. The d-orbital energy splitting in these systems with relatively weak equatorial donors differs significantly from the pattern in vanadyl...

  2. Care Coordination for Children with Complex Special Health Care Needs: The Value of the Advanced Practice Nurse’s Enhanced Scope of Knowledge and Practice

    Science.gov (United States)

    Looman, Wendy S.; Presler, Elizabeth; Erickson, Mary M.; Garwick, Ann E.; Cady, Rhonda G.; Kelly, Anne M.; Finkelstein, Stanley M.

    2012-01-01

    Efficiency and effectiveness of care coordination depends on a match between the needs of the population and the skills, scope of practice, and intensity of services provided by the care coordinator. There is limited existing literature that addresses the relevance of the APN role as a fit for coordination of care for children with SHCN. The objective of this paper is to describe the value of the advanced practice nurse’s (APN’s) enhanced scope of knowledge and practice for relationship-based care coordination in healthcare homes that serve children with complex special health care needs (SHCN). The TeleFamilies project is provided as an example of the integration of an APN care coordinator in a healthcare home for children with SHCN. PMID:22560803

  3. Two mechanisms coordinate replication termination by the Escherichia coli Tus-Ter complex.

    Science.gov (United States)

    Pandey, Manjula; Elshenawy, Mohamed M; Jergic, Slobodan; Takahashi, Masateru; Dixon, Nicholas E; Hamdan, Samir M; Patel, Smita S

    2015-07-13

    The Escherichia coli replication terminator protein (Tus) binds to Ter sequences to block replication forks approaching from one direction. Here, we used single molecule and transient state kinetics to study responses of the heterologous phage T7 replisome to the Tus-Ter complex. The T7 replisome was arrested at the non-permissive end of Tus-Ter in a manner that is explained by a composite mousetrap and dynamic clamp model. An unpaired C(6) that forms a lock by binding into the cytosine binding pocket of Tus was most effective in arresting the replisome and mutation of C(6) removed the barrier. Isolated helicase was also blocked at the non-permissive end, but unexpectedly the isolated polymerase was not, unless C(6) was unpaired. Instead, the polymerase was blocked at the permissive end. This indicates that the Tus-Ter mechanism is sensitive to the translocation polarity of the DNA motor. The polymerase tracking along the template strand traps the C(6) to prevent lock formation; the helicase tracking along the other strand traps the complementary G(6) to aid lock formation. Our results are consistent with the model where strand separation by the helicase unpairs the GC(6) base pair and triggers lock formation immediately before the polymerase can sequester the C(6) base. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Two mechanisms coordinate replication termination by the Escherichia coli Tus–Ter complex

    KAUST Repository

    Pandey, Manjula

    2015-07-13

    The Escherichia coli replication terminator protein (Tus) binds to Ter sequences to block replication forks approaching from one direction. Here, we used single molecule and transient state kinetics to study responses of the heterologous phage T7 replisome to the Tus–Ter complex. The T7 replisome was arrested at the non-permissive end of Tus–Ter in a manner that is explained by a composite mousetrap and dynamic clamp model. An unpaired C(6) that forms a lock by binding into the cytosine binding pocket of Tus was most effective in arresting the replisome and mutation of C(6) removed the barrier. Isolated helicase was also blocked at the non-permissive end, but unexpectedly the isolated polymerase was not, unless C(6) was unpaired. Instead, the polymerase was blocked at the permissive end. This indicates that the Tus–Ter mechanism is sensitive to the translocation polarity of the DNA motor. The polymerase tracking along the template strand traps the C(6) to prevent lock formation; the helicase tracking along the other strand traps the complementary G(6) to aid lock formation. Our results are consistent with the model where strand separation by the helicase unpairs the GC(6) base pair and triggers lock formation immediately before the polymerase can sequester the C(6) base.

  5. Gas-phase fragmentation of coordination compounds: loss of CO(2) from inorganic carbonato complexes to give metal oxide ions

    Science.gov (United States)

    Dalgaard; McKenzie

    1999-10-01

    Using electrospray ionization mass spectrometry, novel transition metal oxide coordination complex ions are proposed as the products of the collision-induced dissociation (CID) of some carbonato complex ions through the loss of a mass equivalent to CO(2). CID spectra of [(tpa)CoCO(3)](+) (tpa = tris(2-pyridylmethyl)methylamine), [(bispicMe(2)en)Fe(&mgr;-O)(&mgr;-CO(3))Fe(bispicMe(2)en)]2+ (bispicMe(2)en = N,N'-dimethyl-N,N'-bis(2-pyridylmethy)eth- ane-1, 2-diamine) and [(bpbp)Cu(2)CO(3)](+) (bpbp(-) = bis[(bis-(2-pyridylmethyl)amino)methyl]-4-tertbutylpheno-lato(1-)), show peaks assigned to the mono- and dinuclear oxide cations, [(tpa)CoO](+), [(bispicMe(2)en)(2)Fe(2)(O)(2)]2+ and [(bpbp)Cu(2)O](+), as the dominant species. These results can be likened to the reverse of typical synthetic reactions in which metal hydroxide compounds react with CO(2) to give metal carbonato compounds. Because of the lack of available protons in the gas phase, novel oxide species rather than the more common hydroxide ions are generated. These oxide ions are relevant to the highly oxidizing species proposed in oxygenation reactions catalysed by metal oxides and metalloenzymes. Copyright 1999 John Wiley & Sons, Ltd.

  6. Photoluminescence and Coordination Behaviour of Lanthanide Complexes of Tris (Aminomethyl)Ethane-5-Oxine in Aqueous Solution.

    Science.gov (United States)

    Akbar, Rifat; Baral, Minati; Kanungo, B K

    2017-01-01

    Photophysical properties of a multidentate tripodal ligand, 5,5'-(2-(((8-hydroxyquinolin-5-yl) methylamino)methyl)-2-methylpropane-1,3-diyl) bis (azanediyl)bis (methylene)diquinolin-8-ol, (TAME5OX), with La 3+ and Er 3+ ions have been examined for photonics applications. The change in behavior in electronic spectra of these complexes reveals the use of TAME5OX as a sensitive optical pH based sensor to detect Ln 3+ ions whereas indication of strong green fluorescence allows simultaneous sensing within the visible region in competitive medium. The intense fluorescence intermittently gets quenched under acidic and basic conditions due to photoinduced intramolecular electron transfer from the excited 8-hydroxyquinoline (8-HQ) moiety to the metal ion. This renders these compounds the OFF-ON-OFF type of pH-dependent fluorescent sensor. The thermodynamic stability and coordination behaviour of the chelator with the said lanthanide ions have also been probed by potentiometric, UV - visible and fluorescence spectrophotometric method. TAME5OX forms protonated complex [Ln (H 4 L)] 4+ below pH ~4.0 which sequentially deprotonates through one proton process with increase of pH. The stability constants of neutral complexes have been determined to be in the range log β 110  = 32-34 and pLn in the range of 14-20, indicating TAME5OX is a good synthetic lanthanide chelator. Theoretical spectra were also calculated by ZINDO/s methodology at single excitations (CIS) level on PM7 as sparkle energy-minimized geometries.

  7. The intra-annular acylamide chelate-coordinated compound: The keto-tautomer of metal (II) milrinone complex

    Science.gov (United States)

    Gong, Yun; Liu, Jinzhi; Tang, Wang; Hu, Changwen

    2008-03-01

    In the presence of N, N'-dimethyllformamide (DMF), two isostructural metal (II)-milrinone complexes formulated as M(C 12H 8N 3O) 2 (M = Co 1 and Ni 2) have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The two compounds crystallize in the tetragonal system, chiral space group P4 32 12. They exhibit similar two dimensional (2D) square grid-like framework, in which milrinone acts as a ditopic ligand with its terminal pyridine and intra-annular acylamide groups covalently bridging different metal centers. The intra-annular acylamide ligand shows a chelate-coordinated mode. Compounds 1 and 2 are stable under 200 °C. Compound 3 formulated as (C 12H 9N 3O) 4·H 2O was obtained in the presence of water, the water molecule in the structure leads to the racemization of compound 3 and it crystallizes in the monoclinic system, non-chiral space group P2 1/ c. Milrinone exhibits a keto-form in the three compounds and compounds 1- 3 exhibit different photoluminescence properties.

  8. The Impact of Telehealth and Care Coordination on the Number and Type of Clinical Visits for Children With Medical Complexity.

    Science.gov (United States)

    McKissick, Holly D; Cady, Rhonda G; Looman, Wendy S; Finkelstein, Stanley M

    The purpose of this analysis was to evaluate the effects of an advanced practice nurse-delivered telehealth intervention on health care use by children with medical complexity (CMC). Because CMC account for a large share of health care use costs, finding effective ways to care for them is an important challenge requiring exploration. This was a secondary analysis of data from a randomized clinical trial with a control group and two intervention groups. The focus of the analysis was planned and unplanned clinical and therapy visits by CMC over a 30-month data collection period. Nonparametric tests were used to compare visit counts among and within the three groups. The number of unplanned visits decreased over time across all groups, with the greatest decrease in the video telehealth intervention group. Planned visits were higher in the video telehealth group across all time periods. Advanced practice registered nurse-delivered telehealth care coordination may support a shift from unplanned to planned health care service use among CMC. Copyright © 2016 National Association of Pediatric Nurse Practitioners. Published by Elsevier Inc. All rights reserved.

  9. Synthesis, crystal structures, and urease inhibition of an acetohydroxamate-coordinated oxovanadium(V) complex derived from N'-(3-bromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide.

    Science.gov (United States)

    Qu, Dan; Niu, Fang; Zhao, Xinlu; Yan, Ke-Xiang; Ye, Yu-Ting; Wang, Jia; Zhang, Mei; You, Zhonglu

    2015-05-01

    A new benzohydrazone compound N'-(3-bromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide (H₂L) was prepared. Reaction of H₂L and acetohydroxamic acid (HAHA) with VO(acac)₂ in methanol gave the complex [VOL(AHA)]. Both H₂L and the oxovanadium complex were characterized by elemental analysis, IR, UV-vis and (1)H NMR spectra, and single crystal X-ray diffraction. H₂L was also characterized by high-resolution mass spectrum. Thermal analysis of the oxovanadium complex was carried out. The benzohydrazone ligand, in its dianionic form, coordinates to V atom through the phenolate oxygen, imino nitrogen and enolate oxygen. The acetohydroxamic acid coordinates to V atom through the carbonyl oxygen and deprotonated hydroxyl oxygen. The V atom is in octahedral coordination. H₂L, HAHA and the oxovanadium complex were tested for their urease inhibitory activities. The percent inhibition at concentration of 100 μmol·L(-1) on Helicobacter pylori urease is 78% for the oxovanadium complex. The IC₅₀ value for the complex is 36.5 μmol·L(-1). Molecular docking study was performed to study the inhibition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Carbonate formation within a nickel dimer: synthesis of a coordinatively unsaturated bis(mu-hydroxo) dinickel complex and its reactivity toward carbon dioxide.

    Science.gov (United States)

    Wikstrom, Jeffrey P; Filatov, Alexander S; Mikhalyova, Elena A; Shatruk, Michael; Foxman, Bruce M; Rybak-Akimova, Elena V

    2010-03-14

    The tridentate aminopyridine ligand bearing a bulky tert-butyl substituent at the amine nitrogen, tert-butyl-dipicolylamine (tBuDPA), occupies three coordination sites in six-coordinate complexes of nickel(ii), leaving the remaining three sites available for additional ligand binding and activation. New crystallographically characterized complexes include two mononuclear species with 1:1 metal:ligand complexation: a trihydrate solvate (1.3H(2)O) and a monohydrate biacetonitrile solvate (1.H(2)O.2CH(3)CN). Complexation in the presence of sodium hydroxide results in a bis(mu-hydroxo) complex (2), the bridging hydroxide anions of which are labile and become displaced by methoxide anions in methanol solvent, affording bis-methoxo-bridged (4). Nickel(II) centers in 2 are five-coordinate and antiferromagnetically coupled (with J = -31.4(5) cm(-1), H = -2JS(1)S(2), in agreement with Ni-O-Ni angle of 103.7 degrees). Bridging hydroxide or alkoxide anions in coordinatively unsaturated dinuclear nickel(II) complexes with tBuDPA react as active nucleophiles. 2 readily performs carbon dioxide fixation, resulting in the formation of a bis(mu-carbonato) tetrameric complex (3), which features a novel binding geometry in the form of an inverted butterfly-type nickel-carbonate core. Temperature-dependent magnetic measurements of tetranuclear carbonato-bridged revealed relatively weak antiferromagnetic coupling (J(1) = -3.1(2) cm(-1)) between the two nickel centers in the core of the cluster, as well as weak antiferromagnetic pairwise interactions (J(2) = J(3) = -4.54(5) cm(-1)) between central and terminal nickel ions.

  11. A complex regulatory network coordinating cell cycles during C. elegans development is revealed by a genome-wide RNAi screen.

    Science.gov (United States)

    Roy, Sarah H; Tobin, David V; Memar, Nadin; Beltz, Eleanor; Holmen, Jenna; Clayton, Joseph E; Chiu, Daniel J; Young, Laura D; Green, Travis H; Lubin, Isabella; Liu, Yuying; Conradt, Barbara; Saito, R Mako

    2014-02-28

    The development and homeostasis of multicellular animals requires precise coordination of cell division and differentiation. We performed a genome-wide RNA interference screen in Caenorhabditis elegans to reveal the components of a regulatory network that promotes developmentally programmed cell-cycle quiescence. The 107 identified genes are predicted to constitute regulatory networks that are conserved among higher animals because almost half of the genes are represented by clear human orthologs. Using a series of mutant backgrounds to assess their genetic activities, the RNA interference clones displaying similar properties were clustered to establish potential regulatory relationships within the network. This approach uncovered four distinct genetic pathways controlling cell-cycle entry during intestinal organogenesis. The enhanced phenotypes observed for animals carrying compound mutations attest to the collaboration between distinct mechanisms to ensure strict developmental regulation of cell cycles. Moreover, we characterized ubc-25, a gene encoding an E2 ubiquitin-conjugating enzyme whose human ortholog, UBE2Q2, is deregulated in several cancers. Our genetic analyses suggested that ubc-25 acts in a linear pathway with cul-1/Cul1, in parallel to pathways employing cki-1/p27 and lin-35/pRb to promote cell-cycle quiescence. Further investigation of the potential regulatory mechanism demonstrated that ubc-25 activity negatively regulates CYE-1/cyclin E protein abundance in vivo. Together, our results show that the ubc-25-mediated pathway acts within a complex network that integrates the actions of multiple molecular mechanisms to control cell cycles during development. Copyright © 2014 Roy et al.

  12. Towards the Rational Design of MRI Contrast Agents: Electron Spin Relaxation Is Largely Unaffected by the Coordination Geometry of Gadolinium(III)–DOTA-Type Complexes

    Science.gov (United States)

    Bean, Jonathan F.; Clarkson, Robert B.; Helm, Lothar; Moriggi, Loïck; Sherry, A. Dean

    2009-01-01

    Electron-spin relaxation is one of the determining factors in the efficacy of MRI contrast agents. Of all the parameters involved in determining relaxivity it remains the least well understood, particularly as it relates to the structure of the complex. One of the reasons for the poor understanding of electron-spin relaxation is that it is closely related to the ligand-field parameters of the Gd3+ ion that forms the basis of MRI contrast agents and these complexes generally exhibit a structural isomerism that inherently complicates the study of electron spin relaxation. We have recently shown that two DOTA-type ligands could be synthesised that, when coordinated to Gd3+, would adopt well defined coordination geometries and are not subject to the problems of intramolecular motion of other complexes. The EPR properties of these two chelates were studied and the results examined with theory to probe their electron-spin relaxation properties. PMID:18283704

  13. Synthesis and characterization of bright green terbium coordination complex derived from 1,4-bis(carbonylmethyl)terephthalate: Structure and luminescence properties

    Science.gov (United States)

    Ma, Mengjiao; Li, Congcong; Shu, Dengkun; Wang, Chaohua; Xi, Peng

    2018-02-01

    A photoluminescent terbium (Tb) complex involving a novel benzoic-acid compound with a unique coordinated structure, namely 1,4-bis(carbonylmethyl)terephthalate (BCMT), has been designed and synthesized. The new coordinate structure and energy-transfer mechanism between the ligand and Tb(III) ions were investigated in detail. The results demonstrated that the BCMT-Tb(III) complex shows strong fluorescence intensity (4 × 106 a.u.) and long fluorescence lifetime (1.302 ms), owing to the favorable degree of energy matching between the triplet excited level of the ligand and the resonant level of Tb(III) ions. Based on the analysis of three-dimensional luminescence spectra, the as-prepared Tb(III) complex can be effectively excited in the range of 250-310 nm, and it shows high color purity, with a bright green appearance.

  14. Thioether-ligated iron(ii) and iron(iii)-hydroperoxo/alkylperoxo complexes with an H-bond donor in the second coordination sphere†

    OpenAIRE

    Widger, Leland R.; Jiang, Yunbo; McQuilken, Alison C.; Yang, Tzuhsiung; Siegler, Maxime A.; Matsumura, Hirotoshi; Moënne-Loccoz, Pierre; Kumar, Devesh; de Visser, Sam P.; Goldberg, David P.

    2014-01-01

    The non-heme iron complexes, [FeII(N3PySR)(CH3CN)](BF4)2 (1) and [FeII(N3PyamideSR)](BF4)2 (2), afford rare examples of metastable Fe(iii)-OOH and Fe(iii)-OOtBu complexes containing equatorial thioether ligands and a single H-bond donor in the second coordination sphere. These peroxo complexes were characterized by a range of spectroscopic methods and density functional theory studies. The influence of a thioether ligand and of one H-bond donor on the stability and spectroscopic properties of...

  15. Structure and Heme-Independent Peroxidase Activity of a Fully-Coordinated Mononuclear Mn(II) Complex with a Schiff-Base Tripodal Ligand Containing Three Imidazole Groups

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Shuranjan; Lee, Hong In [Kyungpook National University, Daegu (Korea, Republic of); Moon, Do Hyun [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Lah, Myoung Soo [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2010-11-15

    New complex [Mn(II)H{sub 1.5}L]{sub 2}[Mn(II)H{sub 3}L]{sub 2}(ClO{sub 4}){sub 5}·3H{sub 2}O, where H{sub 3}L is tris{2-(4-imidazolyl)methyliminoethyl} amine (imtren), has been prepared by reacting manganese(II) perchlorate hexahydrate with the imtren ligand in methanol. X-ray crystallographic study revealed that the imtren ligand hexadentately binds to Mn(II) ion through the three Schiff-base imine N atoms and three imidazole N atoms with a distorted octahedral geometry, and the apical tertiary amine N atom of the ligand pseudo-coordinates to Mn(II), forming overall a pseudo-seven coordination environment. The hydrogen-bonds between imidazole and imidazolate of [Mn(II)H{sub 1.5}L]{sup 0.5+} complex ions are extended to build a 2D puckered network with trigonal voids. [Mn(II)H{sub 3}L]{sup 2+} complex ions constitutes another extended 2D puckered layer without hydrogen bonds. Two layers are wedged each other to constitute overall stack of the crystal. Peroxidase activity of complex 1 was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)- 6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of complex 1. Generation of ABTS{sup +·} was observed by UV-vis and EPR spectroscopies, indicating that the complex 1, a fully-coordinated mononuclear Mn(II) complex with nitrogen-only ligand, has a heme-independent peroxidase activity.

  16. Bowl adamanzanes--bicyclic tetraamines: syntheses and crystal structures of complexes with cobalt(III) and chelating coordinated oxo-anions.

    Science.gov (United States)

    Broge, Louise; Søtofte, Inger; Jensen, Kristian; Jensen, Nicolai; Pretzmann, Ulla; Springborg, Johan

    2007-09-14

    Seven cobalt(III) complexes of the macrobicyclic tetraamine ligand [2(4).3(1)]adamanzane ([2(4).3(1)]adz) are reported along with the crystal structure of six of these complexes. The solid state and solution structures are discussed, and a detailed assignment of the NMR spectra of the sulfato complex is provided. Four of the seven complexes contain a chelate coordinating oxo-anion (sulfate, formiate, nitrate, carbonate). Equilibration of these species with the corresponding diaqua complex is generally slow. The rates of equilibration in 5 mol dm(-3) perchloric acid at 25 degrees C have been measured, yielding half lives of 20 min, 10 min and 3 h for the sulfato, formiato and carbonato species respectively. The corresponding reaction for the nitrato complex occurs with a half life of less than 3 min. The concentration acid dissociation constant for the Co([2(4).3(1)]adz)(HCO(3))(2+) ion has been measured to K(a) = 0.33 mol dm(-3) [25 degrees C, I = 2 mol dm(-3)] and K(a) = 0.15 mol dm(-3) [25 degrees C, I = 5 mol dm(-3)]. The propensity for coordination of sulfate was found to be large enough for a quantitative conversion of the carbonato complex to the sulfato complex to occur in 3 mol dm(-3) triflic acid containing a small sulfate contamination. On this basis the decarboxylation in 5 mol dm(-3) triflic acid of the corresponding cobalt(III) carbonato complex of the larger macrobicyclic tetraamine ligand [3(5)]adz was reinvestigated and found to lead to the sulfato complex as well. The difference in exchange rate of the oxo-anion ligands for the cobalt(III) complexes of the two adamanzane ligands is discussed and attributed to fundamental differences in the molecular structure where an inverted configuration of the secondary non-bridged amine groups is seen for the complexes of the larger [3(5)]adz ligand. The high affinity for chelating coordination of oxo-anions for these two cobalt(iii)-adamanzane-moieties is rationalised on basis of the N-Co-N angles. N

  17. Coordinated leading and lagging strand DNA synthesis by using the herpes simplex virus 1 replication complex and minicircle DNA templates.

    Science.gov (United States)

    Stengel, Gudrun; Kuchta, Robert D

    2011-01-01

    The origin-specific replication of the herpes simplex virus 1 genome requires seven proteins: the helicase-primase (UL5-UL8-UL52), the DNA polymerase (UL30-UL42), the single-strand DNA binding protein (ICP8), and the origin-binding protein (UL9). We reconstituted these proteins, excluding UL9, on synthetic minicircular DNA templates and monitored leading and lagging strand DNA synthesis using the strand-specific incorporation of dTMP and dAMP. Critical features of the assays that led to efficient leading and lagging stand synthesis included high helicase-primase concentrations and a lagging strand template whose sequence resembled that of the viral DNA. Depending on the nature of the minicircle template, the replication complex synthesized leading and lagging strand products at molar ratios varying between 1:1 and 3:1. Lagging strand products (∼0.2 to 0.6 kb) were significantly shorter than leading strand products (∼2 to 10 kb), and conditions that stimulated primer synthesis led to shorter lagging strand products. ICP8 was not essential; however, its presence stimulated DNA synthesis and increased the length of both leading and lagging strand products. Curiously, human DNA polymerase α (p70-p180 or p49-p58-p70-p180), which improves the utilization of RNA primers synthesized by herpesvirus primase on linear DNA templates, had no effect on the replication of the minicircles. The lack of stimulation by polymerase α suggests the existence of a macromolecular assembly that enhances the utilization of RNA primers and may functionally couple leading and lagging strand synthesis. Evidence for functional coupling is further provided by our observations that (i) leading and lagging strand synthesis produce equal amounts of DNA, (ii) leading strand synthesis proceeds faster under conditions that disable primer synthesis on the lagging strand, and (iii) conditions that accelerate helicase-catalyzed DNA unwinding stimulate decoupled leading strand synthesis but not

  18. Coordination and structure of Ca(II)-acetate complexes in aqueous solution studied by a combination of Raman and XAFS spectroscopies

    Science.gov (United States)

    Muñoz Noval, Álvaro; Nishio, Daisuke; Kuruma, Takuya; Hayakawa, Shinjiro

    2018-06-01

    The determination of the structure of Ca(II)-acetate in aqueous solution has been addressed by combining Raman and X-ray absorption fine structure spectroscopies. The pH-dependent speciation of the acetate/Ca(II) system has been studied observing modifications in specific Raman bands of the carboxyl group. The current results evidence the Ca(II)-acetate above acetate pKa forms a bidentate complex and presents a coordination 6, in which the Ca-O shell radius decrease of about 0.1 Å with respect the hydrated Ca2+ with coordination 8. The experimental results show the OCO angle of the carboxyl in the complex is close to 124°, being the OCaO angle about 60°.

  19. Synthesis and Crystal Structure of a Five-Coordinate Complex of Copper(II) with 4-Nitrobenzenesulfonate and 2, 2'-Bipyridine.

    Science.gov (United States)

    Sharif, Mahboubeh A; Tabatabaee, Masoumeh; Beik, Vahideh; Khavasi, Hamid Reza

    2012-06-01

    [Cu(bipy)2Cl](nbs) (1) (bipy = 2,2'-bipyridine, nbs = 4-nitrobenzenesulfonate) was obtained from the reaction of 4-nitrobenzenesulfonyl chloride and 2-amine-4-methylopyridine with CuCl2 in the presence of 2,2'-bipyridine and characterized by elemental analysis, IR spectra and X-ray single-crystal diffraction. The asymmetric unit of (1) contains the cationic complex [Cu(bipy)2Cl]+ and, in the outer coordination sphere, an (nbs)- counter ion.

  20. Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: Synthesis, X-ray crystallography and biological activity

    Science.gov (United States)

    Mokhtaruddin, Nur Shuhada Mohd; Yusof, Enis Nadia Md; Ravoof, Thahira B. S. A.; Tiekink, Edward R. T.; Veerakumarasivam, Abhi; Tahir, Mohamed Ibrahim Mohamed

    2017-07-01

    Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines.

  1. Studies on coordination chemistry and bioactivity of metal complexes of some nitrogen-sulfur donor ligands: Section A: hydraziniumdithiocarbazate and its complexes. Section B: complexes of Ni2+ and Cu2+ ions with s-picolyldithiocarbazate

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Liza bt Abdullah; Crouse, Karen A.; Ali, A.M.

    2003-08-01

    Two new nitrogen - sulphur donor ligands, hydraziniumdithiocarbazate(HzDTC) and S-picolyldithiocarbazate(SPDTC), along with three novel Schiff bases were prepared. Complexes of some of HzDTC with nickel(II), zinc(II), and those of SPDTC with nickel(II) and copper(II) were prepared and characterized by a variety of physico- chemical techniques. The ligand, HzDTC, was a potential bidentate and uninegatively charged providing terminal amino and thiolate bindings with the metal ions, while SPDTC coordinates via the pyridine nitrogen and the thiolate anion. All of the compounds were tested against four pathogenic bacteria and fungi. HzDTC was found to be very effective antimicrobial than its complexes. The complexes of SPDTC and the Schiff bases of HzDTC were more antifungal. None of the compounds were effective anti- cancer agents except for [Ni(HzDTCA)Cl.H 2 O], which was moderately active against CEM- SS (Human cell T- lymphoblastic) leukemic cells. (author)

  2. Synthesis of 2D polymeric dicyanamide bridged hexa-coordinated Cu(II) complex: Structural characterization, spectral studies and TDDFT calculation

    Science.gov (United States)

    Konar, Saugata; Saha, Urmila; Dolai, Malay; Chatterjee, Sudipta

    2014-10-01

    A rare 2D polymeric dicyanamide bridged hexa-coordinated copper(II) complex [Cu(L1‧)(μ1,5-dca)2]n (1) (L1‧ = 2-carboxypyrazine) has been synthesized from the reaction of Cu(NO3)2ṡ6H2O, 2-pyrazinecarbonitrile (L1) and sodium dicyanamide (Nadca) in methanolic medium. Single crystal X-ray analysis reveals that the complex has a 2D infinite zigzag chain structure in which copper(II) ions are bridged by single dicyanamide ligand in an end-to-end fashion. Such 2-carboxypyrazine can be obtained on the way of metal-assisted nitrile hydrolysis which well connected with Cu(NO3)2ṡ6H2O and dicyanamide (dca) to give rare 2D Cu(II) polymeric complex due to the flexibility in the coordination ability of the copper(II) ions within the polymeric chain. The geometry of the asymmetric unit of the complex was optimized in singlet state by DFT method with multilayer ONIOM model at doublet spin state accordance with repeating asymmetric unit only. The electronic spectrum of the complex is explained using TDDFT calculation.

  3. VARIABILITY OF COORDINATION COMPLEXES OF COPPER ACCUMULATED WITHIN FUNGAL COLONY IN THE PRESENCE OF COPPER-CONTAINING MINERALS

    Directory of Open Access Journals (Sweden)

    M. O. Fomina

    2014-04-01

    Full Text Available The aim of work was to elucidate the mechanisms of bioaccumulation of copper leached from minerals by fungus Aspergillus niger with great bioremedial potential due to its ability to produce chelating metabolites and transform toxic metals and minerals. The special attention was paid to the chemical speciation of copper bioaccumulated within fungal colony in the process of fungal transformation of copper-containing minerals. Chemical speciation of copper within different parts of the fungal colony was studied using solid-state chemistry methods such as synchrotron-based X-ray absorption spectroscopy providing information about the oxidation state of the target element, and its coordination environment. The analysis of the obtained X-ray absorption spectroscopy spectra was carried out using Fourier transforms of Extended X-ray Absorption Fine Structure regions, which correspond to the oscillating part of the spectrum to the right of the absorption edge. Results of this study showed that fungus A. niger was involved in the process of solubilization of copper-containing minerals resulted in leaching of mobile copper and its further immobilization by fungal biomass with variable coordination of accumulated copper within fungal colony which depended on the age and physiological/reproductive state of fungal mycelium. X-ray absorption spectroscopy data demonstrated that copper accumulated within outer zone of fungal colony with immature vegetative mycelium was coordinated with sulphur–containing ligands, in contrast to copper coordination with phosphate ligands within mature mycelium with profuse conidia in the central zone of the colony. The findings of this study not only broaden our understanding of the biogeochemical role of fungi but can also be used in the development of various fungal-based biometallurgy technologies such as bioremediation, bioaccumulation and bioleaching and in the assessment of their reliability. The main conclusion is that

  4. Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

    KAUST Repository

    Vidal, Fernando

    2016-07-07

    The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

  5. Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

    KAUST Repository

    Vidal, Fernando; Falivene, Laura; Caporaso, Lucia; Cavallo, Luigi; Chen, Eugene Y.-X.

    2016-01-01

    The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

  6. Synthesis and investigation of new heteronuclear [Zn-La] coordination compounds based on unsaturated lanthanum complex with N,N'-tetraethyl-N''-trichloacetylphosphortriamide

    International Nuclear Information System (INIS)

    Amyirkhanov, O.V.; Sliva, T.Yu.; Moroz, O.V.; Trush, Je.A.; Frits'kij, Yi.O.

    2011-01-01

    New heteronuclear [Zn-La] coordination compounds, perspective luminescent materials, with general formulas [Zn(Ve)La(X) 2 (Ac)] ({Zn-La;Ve;X}) and [Zn(Vp)La(X) 2 (Ac)] ({Zn-La;Vp;X}) have been synthesized HX=CCl 3 C(O)NHP(O)[N(C 2 H 5 ) 2 ] 2 - N,N'-tetraethyl-N''-trichloracetylphosphortriamide, H 2 Ve and H 2 Vp are products of the condensation of 1,2-diaminoethane and 1,3-diaminopropane with o-vanillin, respectively). The composition of [Zn-La] complexes has been determined, and the coordination mode of a phosphorylated ligand has been suggested by element analysis, IR- and 1 H, 31 P NMR-spectroscopy.

  7. Coordinating controls

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-07-15

    While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics.

  8. Coordinating controls

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    While physics Laboratories are having to absorb cuts in resources, the machines they rely on are becoming more and more complex, requiring increasingly sophisticated systems. Rather than being a resourceful engineer or physicist able to timber together solutions in his 'backyard', the modern controls specialist has become a professional in his own right. Because of possible conflicts between increasing sophistication on one hand and scarcer resources on the other, there was felt a need for more contacts among controls specialists to exchange experiences, coordinate development and discuss 'family problems', away from meetings where the main interest is on experimental physics

  9. 3-Methylindole-Based Tripodal Tetraphosphine Ruthenium Complexes in N2 Coordination and Reduction and Formic Acid Dehydrogenation

    Directory of Open Access Journals (Sweden)

    Fenna F. van de Watering

    2017-10-01

    Full Text Available The ruthenium(II complexes RuCl2L1H, RuCl2L1CF3, RuCl2L1OMe and RuCl2L2H were synthesized from [Ru(η6-benzeneCl(μ-Cl]2 and the corresponding tripodal tris-3-methylindolephosphine-based ligands L1H, L1CF3, L1OMe, and L2H. Stoichiometric reduction of these complexes with KC8 yielded the corresponding ruthenium(0 dinitrogen complexes. The latter complexes were studied in the N2 reduction with chlorosilanes and KC8, yielding stoichiometric amounts of the silylamines. The synthesized ruthenium(II complexes are also active catalysts for the formic acid dehydrogenation reaction.

  10. Synthesis, characterisation and catalytic activity of 4, 5-imidazoledicarboxylate ligated Co(II) and Cd(II) metal-organic coordination complexes

    Science.gov (United States)

    Gangu, Kranthi Kumar; Maddila, Suresh; Mukkamala, Saratchandra Babu; Jonnalagadda, Sreekantha B.

    2017-09-01

    Two mono nuclear coordination complexes, namely, [Co(4,5-Imdc)2 (H2O)2] (1) and [Cd(4,5-Imdc)2(H2O)3]·H2O (2) were constructed using Co(II) and Cd(II) metal salts with 4,5-Imidazoledicarboxylic acid (4,5-Imdc) as organic ligand. Both 1, 2 were structurally characterized by single crystal XRD and the results reveal that 1 belongs to P21/n space group with unit cell parameters [a = 5.0514(3) Å, b = 22.5786(9) Å, c = 6.5377(3) Å, β = 111.5°] whereas, 2 belongs to P21/c space group with unit cell parameters [a = 6.9116(1) Å, b = 17.4579(2) Å, c = 13.8941(2) Å, β = 97.7°]. While Co(II) in 1 exhibited a six coordination geometry with 4,5-Imdc and water molecules, Cd(II) ion in 2 showed a seven coordination with the same ligand and solvent. In both 1 and 2, the hydrogen bond interactions with mononuclear unit generated 3D-supramolecular structures. Both complexes exhibit solid state fluorescent emission at room temperature. The efficacy of both the complexes as heterogeneous catalysts was examined in the green synthesis of six pyrano[2,3,c]pyrazole derivatives with ethanol as solvent via one-pot reaction between four components, a mixture of aromatic aldehyde, malononitrile, hydrazine hydrate and dimethyl acetylenedicarboxylate. Both 1 and 2 have produced pyrano [2,3,c]pyrazoles in impressive yields (92-98%) at room temperature in short interval of times (<20 min), with no need for any chromatographic separations. With good stability, ease of preparation and recovery plus reusability up to six cycles, both 1 and 2 prove to be excellent environmental friendly catalysts for the value-added organic transformations using green principles.

  11. Crystal structures of a manganese(I and a rhenium(I complex of a bipyridine ligand with a non-coordinating benzoic acid moiety

    Directory of Open Access Journals (Sweden)

    Sheri Lense

    2018-05-01

    Full Text Available The structures of two facially coordinated Group VII metal complexes are reported, namely: fac-bromido[2-(2,2′-bipyridin-6-ylbenzoic acid-κ2N,N′]tricarbonylmanganese(I tetrahydrofuran monosolvate, [MnBr(C17H12N2O2(CO3]·C4H8O, I, and fac-[2-(2,2′-bipyridin-6-ylbenzoic acid-κ2N,N′]tricarbonylchloridorhenium(I tetrahydrofuran monosolvate, [ReCl(C17H12N2O2(CO3]·C4H8O, II. In both complexes, the metal ion is coordinated by three carbonyl ligands, a halide ion, and a 2-(2,2′-bipyridin-6-ylbenzoic acid ligand, in a distorted octahedral geometry. In manganese complex I, the tetrahydrofuran (THF solvent molecule could not be refined due to disorder. The benzoic acid fragment is also disordered over two positions, such that the carboxylic acid group is either positioned near to the bromide ligand or to the axial carbonyl ligand. In the crystal of I, the complex molecules are linked by a pair of C—H...Br hydrogen bonds, forming inversion dimers that stack up the a-axis direction. In the rhenium complex II, there is hydrogen bonding between the benzoic acid moiety and a disordered co-crystallized THF molecule. In the crystal, the molecules are linked by C—H...Cl hydrogen bonds, forming layers parallel to (100 separated by layers of THF solvent molecules.

  12. 4th July 2011 - Russian Deputy Director-General Director of Directorate for Scientific and Technical Complex ROSATOM V. Pershukov in the ATLAS underground experimental area with Adviser T. Kurtyka, ATLAS Technical Coordinator M. Nessi and ATLAS Russian users.

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    4th July 2011 - Russian Deputy Director-General Director of Directorate for Scientific and Technical Complex ROSATOM V. Pershukov in the ATLAS underground experimental area with Adviser T. Kurtyka, ATLAS Technical Coordinator M. Nessi and ATLAS Russian users.

  13. Studies on coordination chemistry and bioactivity of complexes of a tridentate ONS Schiff base with some heavier transition metal ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Tan Mei Lin; Ali, A.M.

    2003-09-01

    A tridentate Schiff base, S-benzyl-β-N-(2-hydroxyphenyl)methylenedithiocarbazate, (HONSH), with a donor sequence of ONS, was synthesized from the condensation of S-benzyldithiocarbazate (SBDTC) with an equimolar amount of 2-hydroxybenzaldehyde in absolute ethanol. The reactions of HONSH with metal ions [La(III), Ce(IV) and Th(IV)] yielded complexes of compositions, [La(ONS)NO 3 .2H 2 O], [Ce(ONS)(NO 3 ) 2 ] and [Th(ONS) 2 ]. The ligands and the complexes were characterized from elemental analyses and spectroscopic measurements. The metal complexes were found to be active against colon cancer cell lines with the CD 50 values of 27.5, 28.4 and 19.3 μg/ml for the La(III), Ce(FV) and Th(IV) complexes, respectively. The La(IH) complex was found to be very active against leukemic cell lines with the CD 50 value of 6.8 μg/ml. (author)

  14. Novel bipyridinyl oxadiazole-based metal coordination complexes: High efficient and green synthesis of 3,4-dihydropyrimidin-2(1H)-ones through the Biginelli reactions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin-Hua; Zhang, E. [Department of Chemical Engineering, Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Tang, Gui-Mei, E-mail: meiguit@163.com [Department of Chemical Engineering, Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Wang, Yong-Tao, E-mail: ceswyt@qlu.edu.cn [Department of Chemical Engineering, Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Cui, Yue-Zhi [Department of Chemical Engineering, Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Ng, Seik Weng [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2016-09-15

    Three new metal coordination complexes, namely, [Co(BPO){sub 2}(H{sub 2}O){sub 4}](BS){sub 2}(H{sub 2}O){sub 2} (1), [Co(BPO){sub 2}(H{sub 2}O){sub 4}](ABS){sub 2}(H{sub 2}O){sub 2} (2), [Co(BPO){sub 2}(H{sub 2}O){sub 4}](MBS){sub 2}(H{sub 2}O){sub 2} (3) [BPO=2,5-di(pyridin-4-yl)-1,3,4-oxadiazole, BS=benzenesulphonate, ABS=4-aminobenzenesulphonate, MBS=4-methylbenzenesulphonate] were obtained under hydrothermal conditions. Complexes 1–3 were structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR and thermogravimetric analyses (TGA). All of them display a zero-dimensional motif, in which strong intermolecular hydrogen bonding interactions (O–H···O/N) and packing interactions (C–H···π and π···π) make them achieve a three-dimensional supramolecular architecture. The primary catalytic results of these three complexes show that high efficiency for the green synthesis of a variety of 3,4-dihydropyrimidin-2(1H)-ones was observed under solvent free conditions through Biginelli reactions. The present catalytic protocols exhibit advantages such as excellent yield, easy isolation, eco-friendly conditions, and short reaction time. - Graphical abstract: Three new metal coordination complexes with bipyridinyl-oxadiazole were obtained under hydrothermal conditions, which display a zero-dimensional motif, and show high efficiency for the green synthesis of a variety of 3,4-dihydropyrimidin-2(1H)-ones under solvent free conditions through Biginelli reactions. The present catalytic protocols exhibit advantages such as excellent yield, easy isolation, eco-friendly conditions, and short reaction time. Display Omitted.

  15. Direct Observation of Very Large Zero-Field Splitting in a Tetrahedral Ni(II)Se4 Coordination Complex.

    Science.gov (United States)

    Jiang, Shang-Da; Maganas, Dimitrios; Levesanos, Nikolaos; Ferentinos, Eleftherios; Haas, Sabrina; Thirunavukkuarasu, Komalavalli; Krzystek, J; Dressel, Martin; Bogani, Lapo; Neese, Frank; Kyritsis, Panayotis

    2015-10-14

    The high-spin (S = 1) tetrahedral Ni(II) complex [Ni{(i)Pr2P(Se)NP(Se)(i)Pr2}2] was investigated by magnetometry, spectroscopic, and quantum chemical methods. Angle-resolved magnetometry studies revealed the orientation of the magnetization principal axes. The very large zero-field splitting (zfs), D = 45.40(2) cm(-1), E = 1.91(2) cm(-1), of the complex was accurately determined by far-infrared magnetic spectroscopy, directly observing transitions between the spin sublevels of the triplet ground state. These are the largest zfs values ever determined--directly--for a high-spin Ni(II) complex. Ab initio calculations further probed the electronic structure of the system, elucidating the factors controlling the sign and magnitude of D. The latter is dominated by spin-orbit coupling contributions of the Ni ions, whereas the corresponding effects of the Se atoms are remarkably smaller.

  16. Carbonyltrichlorotris(dimethylphenylphosphine)technetium-ethanol (1/1), the first seven-coordinate complex of technetium; position of this molecule in the Csub(3v) family

    Energy Technology Data Exchange (ETDEWEB)

    Bandoli, G; Clemente, D A; Mazzi, U [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

    1978-01-01

    The preparation and the crystal and molecular structure of the title complex are reported. The coordination polyhedron is that of a distorted capped octahedron Csub(3v) symmetry). The technetium atom is seven-coordnate and bonded to three phosphine ligands (capped face), three chlorine ligands (uncapped face), and to the carbonyl group, which occupies the unique capping position. Crystals are monoclinic, space group P2/sub 1//c, with cell dimensions a = 11.732(9), b = 11.807(9), c = 23.588(12) A, and ..beta..103.42(8)/sup 0/. The structure has been refined by least squares to a conventional R of 0.093 for 1 794 observed reflections. Metal-ligand bond lengths are: Tc-CO 1.86(2), Tc-C1 2.48(1). and Tc-p 2.44(1) A. Seven coordinate complexes are briefly reviewed: in particular, a description of Csub(3v) symmetry and its distortions has been developed in terms of repulsion theory and the angular-overlap model.

  17. Extending the NIF DISCO framework to automate complex workflow: coordinating the harvest and integration of data from diverse neuroscience information resources.

    Science.gov (United States)

    Marenco, Luis N; Wang, Rixin; Bandrowski, Anita E; Grethe, Jeffrey S; Shepherd, Gordon M; Miller, Perry L

    2014-01-01

    This paper describes how DISCO, the data aggregator that supports the Neuroscience Information Framework (NIF), has been extended to play a central role in automating the complex workflow required to support and coordinate the NIF's data integration capabilities. The NIF is an NIH Neuroscience Blueprint initiative designed to help researchers access the wealth of data related to the neurosciences available via the Internet. A central component is the NIF Federation, a searchable database that currently contains data from 231 data and information resources regularly harvested, updated, and warehoused in the DISCO system. In the past several years, DISCO has greatly extended its functionality and has evolved to play a central role in automating the complex, ongoing process of harvesting, validating, integrating, and displaying neuroscience data from a growing set of participating resources. This paper provides an overview of DISCO's current capabilities and discusses a number of the challenges and future directions related to the process of coordinating the integration of neuroscience data within the NIF Federation.

  18. Tris-amidoximate uranyl complexes via η2 binding mode coordinated in aqueous solution shown by X-ray absorption spectroscopy and density functional theory methods.

    Science.gov (United States)

    Zhang, Linjuan; Qie, Meiying; Su, Jing; Zhang, Shuo; Zhou, Jing; Li, Jiong; Wang, Yu; Yang, Shitong; Wang, Shuao; Li, Jingye; Wu, Guozhong; Wang, Jian Qiang

    2018-03-01

    The present study sheds some light on the long-standing debate concerning the coordination properties between uranyl ions and the amidoxime ligand, which is a key ingredient for achieving efficient extraction of uranium. Using X-ray absorption fine structure combined with theoretical simulation methods, the binding mode and bonding nature of a uranyl-amidoxime complex in aqueous solution were determined for the first time. The results show that in a highly concentrated amidoxime solution the preferred binding mode between UO 2 2+ and the amidoxime ligand is η 2 coordination with tris-amidoximate species. In such a uranyl-amidoximate complex with η 2 binding motif, strong covalent interaction and orbital hybridization between U 5f/6d and (N, O) 2p should be responsible for the excellent binding ability of the amidoximate ligand to uranyl. The study was performed directly in aqueous solution to avoid the possible binding mode differences caused by crystallization of a single-crystal sample. This work also is an example of the simultaneous study of local structure and electronic structure in solution systems using combined diagnostic tools.

  19. Differences and Comparisons of the Properties and Reactivities of Iron(III)–hydroperoxo Complexes with Saturated Coordination Sphere

    Science.gov (United States)

    Faponle, Abayomi S; Quesne, Matthew G; Sastri, Chivukula V; Banse, Frédéric; de Visser, Sam P

    2015-01-01

    Heme and nonheme monoxygenases and dioxygenases catalyze important oxygen atom transfer reactions to substrates in the body. It is now well established that the cytochrome P450 enzymes react through the formation of a high-valent iron(IV)–oxo heme cation radical. Its precursor in the catalytic cycle, the iron(III)–hydroperoxo complex, was tested for catalytic activity and found to be a sluggish oxidant of hydroxylation, epoxidation and sulfoxidation reactions. In a recent twist of events, evidence has emerged of several nonheme iron(III)–hydroperoxo complexes that appear to react with substrates via oxygen atom transfer processes. Although it was not clear from these studies whether the iron(III)–hydroperoxo reacted directly with substrates or that an initial O–O bond cleavage preceded the reaction. Clearly, the catalytic activity of heme and nonheme iron(III)–hydroperoxo complexes is substantially different, but the origins of this are still poorly understood and warrant a detailed analysis. In this work, an extensive computational analysis of aromatic hydroxylation by biomimetic nonheme and heme iron systems is presented, starting from an iron(III)–hydroperoxo complex with pentadentate ligand system (L52). Direct C–O bond formation by an iron(III)–hydroperoxo complex is investigated, as well as the initial heterolytic and homolytic bond cleavage of the hydroperoxo group. The calculations show that [(L52)FeIII(OOH)]2+ should be able to initiate an aromatic hydroxylation process, although a low-energy homolytic cleavage pathway is only slightly higher in energy. A detailed valence bond and thermochemical analysis rationalizes the differences in chemical reactivity of heme and nonheme iron(III)–hydroperoxo and show that the main reason for this particular nonheme complex to be reactive comes from the fact that they homolytically split the O–O bond, whereas a heterolytic O–O bond breaking in heme iron(III)–hydroperoxo is found. PMID:25399782

  20. Structural Reassessment of [W(CO)(5)(TCNE)]: N (sigma) Coordination Instead of an Olefin (pi) Complex

    Czech Academy of Sciences Publication Activity Database

    Bubrin, M.; Krafft, M. J.; Steudle, L.; Hübner, R.; Field, J. S.; Záliš, Stanislav; Kaim, W.

    2012-01-01

    Roč. 31, č. 17 (2012), s. 6305-6311 ISSN 0276-7333 R&D Projects: GA MŠk LD11086 Institutional support: RVO:61388955 Keywords : TRANSFER-CATALYZED SUBSTITUTION * CARBONYL-COMPLEXES * CHARGE-TRANSFER Subject RIV: CG - Electrochemistry Impact factor: 4.145, year: 2012

  1. Coordination chemistry of actinide elements: preparation of new uranium complexes with schiff bases and their characterization (Preprint No. CT-31)

    International Nuclear Information System (INIS)

    Hingorani, S.; Reddy, P.S.N.; Agarwala, B.V.

    1988-02-01

    The Schiff bases, o-vanillin semicarbazone (oVSC) and 2-pyridine carboxaldehyde isonicotinoyl hydrazone (PCINH) have been prepared and their novel complexes with dioxouranium(VI) have been synthesized and characterized by IR spectra, elemental analysis and other physico-chemical techniques. (author)

  2. New in situ generated acylhydrazidate-coordinated complexes and acylhydrazide molecules: Synthesis, structural characterization and photoluminescence property

    Science.gov (United States)

    Wang, Yan-Ning; Huo, Qi-Sheng; Zhang, Ping; Yu, Jie-Hui; Xu, Ji-Qing

    2016-10-01

    By utilizing the hydrothermal in situ acylation of organic acids with N2H4, three acylhydrazidate-coordinated compounds [Mn(L1)2(H2O)2] (L1 = 2,3-quinolinedicarboxylhydrazidate; HL1 = 2,3-dihydropyridazino[4,5-b] quinoline-1,4-dione) 1, [Mn2(ox)(L2)2(H2O)6]·2H2O (L2 = benzimidazolate-5,6-dicarboxylhydrazide; HL2 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; ox = oxalate) 2, and [Cd(HL3)(bpy)] (L3 = 4,5-di(3‧-carboxylphenyl)phthalhydrazidate; H3L3 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; bpy = 2,2‧-bipyridine) 3, as well as two acylhydrazide molecules L4 (L4 = oxepino[2,3,4-de:7,6,5-d‧e‧]diphthalazine-4,10(5H,9H)-dione) 4 and L5 (L5 = 4,5-dibromophthalhydrazide; L5 = 6,7-dibromo-2,3-dihydrophthalazine-1,4-dione) 5 were obtained. X-ray single-crystal diffraction analysis reveals that (i) 1 only possesses a mononuclear structure, but it self-assembles into a 2-D supramolecular network via the Nhydrazinesbnd H ⋯ Nhydrazine and Owsbnd H ⋯ Ohydroxylimino interactions; (ii) 2 exhibits a dinuclear structure. Ox acts as the linker, while L2 just serves as a terminal ligand; (iii) In 3, L3 acts as a 3-connected node to propagate the 7-coordinated Cd2 + centers into a 1-D double-chain structure; (iv) 4 is a special acylhydrazide molecule. Two sbnd OH groups for the intermediates 3,3‧-biphthalhydrazide further lose one water molecule to form 4; (v) 5 is a common monoacylhydrazide molecule. Via the Nhydrazinesbnd H ⋯ Ohydrazine, Ohydroxyliminosbnd H ⋯ Oacylamino and the π ⋯ π interactions, it self-assembles into a 2-D supramolecular network. The photoluminescence analysis reveals that 4 emits light with the maxima at 510 nm.

  3. Deprotonation/protonation of coordinated secondary thioamide units of pincer ruthenium complexes: modulation of voltammetric and spectroscopic characterization of the pincer complexes.

    Science.gov (United States)

    Teratani, Takuya; Koizumi, Take-aki; Yamamoto, Takakazu; Tanaka, Koji; Kanbara, Takaki

    2011-09-21

    New pincer ruthenium complexes, [Ru(SCS)(tpy)]PF(6) (1) (SCS = 2,6-bis(benzylaminothiocarbonyl)phenyl), tpy = 2,2':6',2''-terpyridyl) and [Ru(SNS)(tpy)]PF(6) (2) (SNS = 2,5-bis(benzylaminothiocarbonyl)pyrrolyl), having κ(3)SCS and κ(3)SNS pincer ligands with two secondary thioamide units were synthesized by the reactions of [RuCl(3)(tpy)] with N,N'-dibenzyl-1,3-benzenedicarbothioamide (L1) and N,N'-dibenzyl-2,5-1H-pyrroledicarbothioamide (L2), respectively, and their chemical and electrochemical properties were elucidated. The structure of 1 was determined by X-ray crystallography. The complexes 1 and 2 showed a two-step deprotonation reaction by treatment with 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU), and the addition of DBU led to a shift of the metal-centered redox couples to a lower potential by 720 and 550 mV, respectively. The di-deprotonated complexes were also studied by (1)H-NMR and UV-vis spectroscopy. The addition of methanesulfonic acid (MSA) to the di-deprotonated complexes enabled the recovery of 1 and 2, indicating that the thioamide moiety underwent a reversible deprotonation-protonation process, which resulted in regulating the redox potentials of the metal center. The Pourbaix diagram of 1 revealed that 1 underwent a one-proton/one-electron transfer process in the pH range of 5.83-10.35, and a two-proton/one-electron process at a pH of over 10.35, indicating that the deprotonation/protonation process of the complexes is related to proton-coupled electron transfer (PCET). This journal is © The Royal Society of Chemistry 2011

  4. Characterization of the TolB-Pal trans-envelope complex from Xylella fastidiosa reveals a dynamic and coordinated protein expression profile during the biofilm development process.

    Science.gov (United States)

    Santos, Clelton A; Janissen, Richard; Toledo, Marcelo A S; Beloti, Lilian L; Azzoni, Adriano R; Cotta, Monica A; Souza, Anete P

    2015-10-01

    The intriguing roles of the bacterial Tol-Pal trans-envelope protein complex range from maintenance of cell envelope integrity to potential participation in the process of cell division. In this study, we report the characterization of the XfTolB and XfPal proteins of the Tol-Pal complex of Xylella fastidiosa. X. fastidiosa is a major plant pathogen that forms biofilms inside xylem vessels, triggering the development of diseases in important cultivable plants around the word. Based on functional complementation experiments in Escherichia coli tolB and pal mutant strains, we confirmed the role of xftolB and xfpal in outer membrane integrity. In addition, we observed a dynamic and coordinated protein expression profile during the X. fastidiosa biofilm development process. Using small-angle X-ray scattering (SAXS), the low-resolution structure of the isolated XfTolB-XfPal complex in solution was solved for the first time. Finally, the localization of the XfTolB and XfPal polar ends was visualized via immunofluorescence labeling in vivo during bacterial cell growth. Our results highlight the major role of the components of the cell envelope, particularly the TolB-Pal complex, during the different phases of bacterial biofilm development. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. A quantum dynamical study of the rotation of the dihydrogen ligand in the Fe(H)2(H2)(PEtPh2)3 coordination complex

    Science.gov (United States)

    Gonzalez, Megan E.; Eckert, Juergen; Aquino, Adelia J. A.; Poirier, Bill

    2018-04-01

    Progress in the hydrogen fuel field requires a clear understanding and characterization of how materials of interest interact with hydrogen. Due to the inherently quantum mechanical nature of hydrogen nuclei, any theoretical studies of these systems must be treated quantum dynamically. One class of material that has been examined in this context are dihydrogen complexes. Since their discovery by Kubas in 1984, many such complexes have been studied both experimentally and theoretically. This particular study examines the rotational dynamics of the dihydrogen ligand in the Fe(H)2(H2)(PEtPh2)3 complex, allowing for full motion in both the rotational degrees of freedom and treating the quantum dynamics (QD) explicitly. A "gas-phase" global potential energy surface is first constructed using density functional theory with the Becke, 3-parameter, Lee-Yang-Parr functional; this is followed by an exact QD calculation of the corresponding rotation/libration states. The results provide insight into the dynamical correlation of the two rotation angles as well as a comprehensive analysis of both ground- and excited-state librational tunneling splittings. The latter was computed to be 6.914 cm-1—in excellent agreement with the experimental value of 6.4 cm-1. This work represents the first full-dimensional ab initio exact QD calculation ever performed for dihydrogen ligand rotation in a coordination complex.

  6. Synthesis and characterisation of luminescent rhenium tricarbonyl complexes with axially coordinated 1,2,3-triazole ligands.

    Science.gov (United States)

    Uppal, Baljinder S; Booth, Rebecca K; Ali, Noreen; Lockwood, Cindy; Rice, Craig R; Elliott, Paul I P

    2011-08-07

    A series of 1-alkyl-4-aryl-1,2,3-triazoles (1-methyl-4-phenyl-1,2,3-triazole (1a); 1-propyl-4-phenyl-1,2,3-triazole (1b); 1-benzyl-4-phenyl-1,2,3-triazole (1c); 1-propyl-4-p-tolyl-1,2,3-triazole (1d)) have been prepared through a one-pot procedure involving in situ generation of the alkyl azide from a halide precursor followed by copper catalysed alkyne/azide cycloaddition (CuAAC) with the appropriate aryl alkyne. Cationic Re(I) complexes [Re(bpy)(CO)(3)(1a-d)]PF(6) (2a-d) were then prepared by stirring [Re(bpy)(CO)(3)Cl] with AgPF(6) in dichloromethane in the presence of ligands 1a-d. X-ray crystal structures were obtained for 2a and 2b. In the solid state, 2a adopts a highly distorted geometry, which is not seen for 2b, in which the plane of the triazole ligand tilts by 13° with respect to the Re-N bond as a result of a π-stacking interaction between the Ph substituent and one of the rings of the bpy ligand. This π-stacking interaction also results in severe twisting of the bpy ligand. Infrared spectra of 2a-d exhibit ν(CO) bands at ∼2035 and ∼1926 cm(-1) suggesting that these ligands are marginally better donors than pyridine (ν(CO) = 2037, 1932 cm(-1)). The complexes are luminescent in aerated dichloromethane at room temperature with emission maxima at 542 to 552 nm comparable to that of the pyridine analogue (549 nm) and blue shifted relative to the parent chloride complex. Long luminescent lifetimes are observed for the triazole complexes (475 to 513 ns) in aerated dichloromethane solutions at room temperature.

  7. Spectroscopic and electrochemical investigation with coordination stabilities: Mononuclear manganese(II) complexes derived from different constituents macrocyclic ligands

    Science.gov (United States)

    Kumar, Rajiv; Chnadra, S.; Mishra, Parashuram

    2007-12-01

    Since the manganese(II) complexes are known as having a high degree of stability, some of them may be able to play a very important role in biosystems. We prepared manganese(II) complexes with different chromospheres containing macrocyclic ligands bearing N, S and O like functional donor atoms in order to obtain different models of compounds. So these new manganese(II) complexes were derived from macrocyclic ligands by chelating them with metal ions. Thus, two macrocyclic ligands, L 1: 2,4-diphenyl-1,5-diaza-8,12-dioxo-6,7:13,14-dibenzocyclo tetradeca-1,4-diene[N 2O 2]ane; L 2: 2,4,9,11-tetraphenyl-6,13-dimethyl-1,5,8,12-traazacyclotertr-adeca-1,4,8,11-tetraene[N 4]ane; and two more different form first one viz.—L 3: 1,7-diaza-4-monothia-10,14-dioxo-8,9:15,16-cyclohexadecane[N 2O 2S]ane and L 4: 4,13-diaoxa-1,7,10,16-hexazacyclooctadecane[N 4O 2]ane were prepared and their capacity to retain the manganese(II) ion in solid as well as aqueous solution was determined from various physiochemical techniques viz: characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, mass, IR, electronic, ESR spectral studies and cyclic voltammetric measurements.

  8. CASPT2 study of inverse sandwich-type dinuclear Cr(I) and Fe(I) complexes of the dinitrogen molecule: significant differences in spin multiplicity and coordination structure between these two complexes.

    Science.gov (United States)

    Nakagaki, Masayuki; Sakaki, Shigeyoshi

    2014-02-20

    Inverse sandwich-type complexes (ISTCs), (μ-N2)[M(AIP)]2 (AIPH = (Z)-1-amino-3-imino-prop-1-ene; M = Cr and Fe), were investigated with the CASPT2 method. In the ISTC of Cr, the ground state takes a singlet spin multiplicity. However, the singlet to nonet spin states are close in energy to each other. The thermal average of effective magnetic moments (μeff) of these spin multiplicities is close to the experimental value. The η(2)-side-on coordination structure of N2 is calculated to be more stable than the η(1)-end-on coordination one. This is because the d-orbital of Cr forms a strong dπ-π* bonding interaction with the π* orbital of N2 in molecular plane. In the ISTC of Fe, on the other hand, the ground state takes a septet spin multiplicity, which agrees well with the experimentally reported μeff value. The η(1)-end-on structure of N2 is more stable than the η(2)-side-on structure. In the η(1)-end-on structure, two doubly occupied d-orbitals of Fe can form two dπ-π* bonding interactions. The negative spin density is found on the bridging N2 ligand in the Fe complex but is not in the Cr complex. All these interesting differences between ISTCs of Cr and Fe are discussed on the basis of the electronic structure and bonding nature.

  9. Hydration energies and specific influence of oxo complexes and high coordination numbers on the predicted chemistry of superheavy elements

    International Nuclear Information System (INIS)

    Jorgensen, C.K.; Penneman, R.A.

    1975-01-01

    On the basis of an analysis of the known ionization energies of gaseous ions and aqua ions of the 3d, 4f, and 6d transition groups and the radius effects, the chemistry of the superheavy elements is predicted. The formation of aqua ion and oxo complexes in the elements with Z below 121 is considered. It is probable that the series from 123 to 140 constitute a close analogy to the lanthanides with Th-like chemistry. Above Z = 140 the elements will probably displace a transition group behavior. A brief comment is made on the analytical aspects to be expected. (U.S.)

  10. Six-coordinate oxo-vanadium(V) dimer complex with methoxy bridging: synthesis, crystal structure, biological activity and molecular docking

    Czech Academy of Sciences Publication Activity Database

    Heidari, F.; Fatemi, S.J.A.; Yousef Ebrahimipour, S.; Ebrahimnejad, H.; Castro, J.; Dušek, Michal; Eigner, Václav

    2017-01-01

    Roč. 76, Feb (2017), s. 1-4 ISSN 1387-7003 R&D Projects: GA MŠk(CZ) LO1603; GA ČR(CZ) GA14-03276S EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : oxo-vanadium(V) * Schiff base complex * antimicrobial activity * X-ray crystal structure Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 1.640, year: 2016

  11. Coordinating Work with Groupware

    DEFF Research Database (Denmark)

    Pors, Jens Kaaber; Simonsen, Jesper

    2003-01-01

    One important goal of employing groupware is to make possible complex collaboration between geographically distributed groups. This requires a dual transformation of both technology and work practice. The challenge is to re­duce the complexity of the coordination work by successfully inte....... Using the CSCW frame­work of coordination mechanisms, we have elicited six general factors influencing the integration of the groupware application in two situations....

  12. Sonochemical synthesis and characterization of nano-sized zinc(II coordination complex as a precursor for the preparation of pure-phase zinc(II oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Maryam Ranjbar

    2017-01-01

    Full Text Available In current study, nanoparticles and single crystals of a Zn(II coordination complex, [Zn(dmphI2](1, {dmph=2,9-dimethyl-1,10-phenanthroline(neocuproine}, have been synthesized by the reaction of zinc(II acetate, KI and neocuproine as ligand in methanol using sonochemical and heat gradient methods, respectively. The nanostructure of 1 was characterized by scanning electron microscopy (SEM, X-ray powder diffraction (XRD, FT-IR spectroscopy and elemental analyses, and the structure of compound 1 was determined by single-crystal X-ray diffraction. The thermal stability of nano-sized 1 has been studied by thermogravimetric (TG and differential thermal analyses (DTA. Structural determination of compound 1 reveals the Zn(II ion is four-coordinated in a distorted tetrahedral configuration by two N atoms from a 2,9-dimethyl-1,10-Phenanthroline ligand and two terminal I atoms. The effect of supercritical condition on stability, size and morphology of nano-structured compound 1 has also been studied. The XRD pattern of the residue obtained from thermal decomposition of nano-sized compound 1 at 600 °C under air atmosphere provided pure phase of ZnO with the average particles size of about 31 nm.

  13. m-AAA and i-AAA complexes coordinate to regulate OMA1, the stress-activated supervisor of mitochondrial dynamics.

    Science.gov (United States)

    Consolato, Francesco; Maltecca, Francesca; Tulli, Susanna; Sambri, Irene; Casari, Giorgio

    2018-04-09

    The proteolytic processing of dynamin-like GTPase OPA1, mediated by the activity of both YME1L1 [intermembrane (i)-AAA protease complex] and OMA1, is a crucial step in the regulation of mitochondrial dynamics. OMA1 is a zinc metallopeptidase of the inner mitochondrial membrane that undergoes pre-activating proteolytic and auto-proteolytic cleavage after mitochondrial import. Here, we identify AFG3L2 [matrix (m) - AAA complex] as the major protease mediating this event, which acts by maturing the 60 kDa pre-pro-OMA1 to the 40 kDa pro-OMA1 form by severing the N-terminal portion without recognizing a specific consensus sequence. Therefore, m - AAA and i - AAA complexes coordinately regulate OMA1 processing and turnover, and consequently control which OPA1 isoforms are present, thus adding new information on the molecular mechanisms of mitochondrial dynamics and neurodegenerative diseases affected by these phenomena.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

  14. XRCC1 coordinates disparate responses and multiprotein repair complexes depending on the nature and context of the DNA damage

    DEFF Research Database (Denmark)

    Hanssen-Bauer, Audun; Solvang-Garten, Karin; Sundheim, Ottar

    2011-01-01

    . We demonstrate that the laser dose used for introducing DNA damage determines the repertoire of DNA repair proteins recruited. Furthermore, we demonstrate that recruitment of POLß and PNK to regions irradiated with low laser dose requires XRCC1 and that inhibition of PARylation by PARP......-inhibitors only slightly reduces the recruitment of XRCC1, PNK, or POLß to sites of DNA damage. Recruitment of PCNA and FEN-1 requires higher doses of irradiation and is enhanced by XRCC1, as well as by accumulation of PARP-1 at the site of DNA damage. These data improve our understanding of recruitment of BER......XRCC1 is a scaffold protein capable of interacting with several DNA repair proteins. Here we provide evidence for the presence of XRCC1 in different complexes of sizes from 200 to 1500 kDa, and we show that immunoprecipitates using XRCC1 as bait are capable of complete repair of AP sites via both...

  15. Influence of the π-coordinated arene on the anticancer activity of ruthenium(II carbohydrate organometallic complexes

    Directory of Open Access Journals (Sweden)

    Muhammad eHanif

    2013-10-01

    Full Text Available The synthesis and in vitro cytotoxicity of a series of RuII(arene complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well with cellular accumulation. The most lipophilic compound bearing a biphenyl moiety and a cyclohexylidene-protected carbohydrate is the most cytotoxic with unprecedented IC50 values for the compound class in three human cancer cell lines. This compound shows reactivity to the DNA model nucleobase 9-ethylguanine, but does not alter the secondary structure of plasmid DNA indicating that other biological targets are responsible for its cytotoxic effect.

  16. Managing interteam coordination within and between organizations

    NARCIS (Netherlands)

    de Vries, Thomas Arend

    2015-01-01

    To accomplish complex tasks and effectively respond to environmental contingencies, teams must coordinate task-related issues with other teams (i.e., interteam coordination). Regrettably, interteam coordination is often complicated by misunderstandings that can arise from differences in teams’

  17. The First Homoleptic Complex of Seven-Coordinated Osmium: Synthesis and Crystallographical Evidence of Pentagonal Bipyramidal Polyhedron of Heptacyanoosmate(IV

    Directory of Open Access Journals (Sweden)

    Eugenia V. Peresypkina

    2016-08-01

    Full Text Available The ligand exchange in (n-Bu4N2OsIVCl6 (n-Bu4N = tetra-n-butylammonium leads to the formation of the osmium(IV heptacyanide, the first fully inorganic homoleptic complex of heptacoordinated osmium. The single-crystal X-ray diffraction (SC-XRD study reveals the pentagonal bipyramidal molecular structure of the [Os(CN7]3− anion. The latter being a diamagnetic analogue of the highly anisotropic paramagnetic synthon, [ReIV(CN7]3− can be used for the synthesis of the model heterometallic coordination compounds for the detailed study and simulation of the magnetic properties of the low-dimensional molecular nanomagnets involving 5d metal heptacyanides.

  18. Binuclear Pt-Tl bonded complex with square pyramidal coordination around Pt: a combined multinuclear NMR, EXAFS, UV-Vis, and DFT/TDDFT study in dimethylsulfoxide solution.

    Science.gov (United States)

    Purgel, Mihály; Maliarik, Mikhail; Glaser, Julius; Platas-Iglesias, Carlos; Persson, Ingmar; Tóth, Imre

    2011-07-04

    The structure and bonding of a new Pt-Tl bonded complex formed in dimethylsulfoxide (dmso), (CN)(4)Pt-Tl(dmso)(5)(+), have been studied by multinuclear NMR and UV-vis spectroscopies, and EXAFS measurements in combination with density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations. This complex is formed following the equilibrium reaction Pt(CN)(4)(2-) + Tl(dmso)(6)(3+) ⇆ (CN)(4)Pt-Tl(dmso)(5)(+) + dmso. The stability constant of the Pt-Tl bonded species, as determined using (13)C NMR spectroscopy, amounts to log K = 2.9 ± 0.2. The (NC)(4)Pt-Tl(dmso)(5)(+) species constitutes the first example of a Pt-Tl bonded cyanide complex in which the sixth coordination position around Pt (in trans with respect to the Tl atom) is not occupied. The spectral parameters confirm the formation of the metal-metal bond, but differ substantially from those measured earlier in aqueous solution for complexes (CN)(5)Pt-Tl(CN)(n)(H(2)O)(x)(n-) (n = 0-3). The (205) Tl NMR chemical shift, δ = 75 ppm, is at extraordinary high field, while spin-spin coupling constant, (1)J(Pt-Tl) = 93 kHz, is the largest measured to date for a Pt-Tl bond in the absence of supporting bridging ligands. The absorption spectrum is dominated by two strong absorption bands in the UV region that are assigned to MMCT (Pt → Tl) and LMCT (dmso → Tl) bands, respectively, on the basis of MO and TDDFT calculations. The solution of the complex has a bright yellow color as a result of a shoulder present on the low energy side of the band at 355 nm. The geometry of the (CN)(4)Pt-Tl core can be elucidated from NMR data, but the particular stoichiometry and structure involving the dmso ligands are established by using Tl and Pt L(III)-edge EXAFS measurements. The Pt-Tl bond distance is 2.67(1) Å, the Tl-O bond distance is 2.282(6) Å, and the Pt-C-N entity is linear with Pt-C and Pt···N distances amounting to 1.969(6) and 3.096(6) Å, respectively. Geometry optimizations on

  19. 1H and 13C NMR coordination-induced shifts in a series of tris(α-diimine)ruthenium(II) complexes containing pyridine, pyrazine, and thiazole moieties

    International Nuclear Information System (INIS)

    Orellana, G.; Ibarra, C.A.; Santoro, J.

    1988-01-01

    1 H and 13 C NMR chemical shifts of a series of ruthenium(II) tris chelates containing the heterocyclic ligands 2,2'-bipyridine, 2-(2-pyridyl)thiazole, 2-(2-pyrazyl)thiazole, and 2,2'-bithiazole are reported and compared to those of the corresponding free ligands. Calculated coordination-induced shifts (CIS, δ complexed - δ free ) range from +0.41 to -1.00 ppM for 1 H and from +5.8 to -3.7 ppM for 13 C nuclei. These values are discussed on the basis of the various effects (charge perturbation and field interactions) that arise upon chelation: electronic σ-donation to the metallic center via the nitrogen lone pair, d-π* back-donation to the ligand, van der Waals interactions, and magnetic anisotropy of the spectator ligands. Semiquantitative values of each effect at the different positions have been proposed, taking theoretical calculations of steric and anisotropic contributions as the starting point. Shielding van der Waals interaction between proximate atoms influences only the H(3') CIS of six-membered moieties, but to a very low extent (<0.15 ppM). Magnetic anisotropy of proximate ring currents practically determines the CIS of the α positions for all the complexed ligands examined (upfield shifts from -0.8 to -1.0 ppm), has a lower influence on external β positions (< 0.2 ppM), and is negligible for γ-protons. σ-donation deshields all the positions, its contribution increasing as protons separate from the coordinated nitrogen atom (up to 0.4 ppM). Π-back-bonding is a weaker effect (< 0.2 ppM upfield contribution) that operates mainly on the γ position of the pyridine and α and β positions of the pyrazine rings. 36 refs., 3 figs., 4 tabs

  20. Integrating complex functions: coordination of nuclear pore complex assembly and membrane expansion of the nuclear envelope requires a family of integral membrane proteins.

    Science.gov (United States)

    Schneiter, Roger; Cole, Charles N

    2010-01-01

    The nuclear envelope harbors numerous large proteinaceous channels, the nuclear pore complexes (NPCs), through which macromolecular exchange between the cytosol and the nucleoplasm occurs. This double-membrane nuclear envelope is continuous with the endoplasmic reticulum and thus functionally connected to such diverse processes as vesicular transport, protein maturation and lipid synthesis. Recent results obtained from studies in Saccharomyces cerevisiae indicate that assembly of the nuclear pore complex is functionally dependent upon maintenance of lipid homeostasis of the ER membrane. Previous work from one of our laboratories has revealed that an integral membrane protein Apq12 is important for the assembly of functional nuclear pores. Cells lacking APQ12 are viable but cannot grow at low temperatures, have aberrant NPCs and a defect in mRNA export. Remarkably, these defects in NPC assembly can be overcome by supplementing cells with a membrane fluidizing agent, benzyl alcohol, suggesting that Apq12 impacts the flexibility of the nuclear membrane, possibly by adjusting its lipid composition when cells are shifted to a reduced temperature. Our new study now expands these findings and reveals that an essential membrane protein, Brr6, shares at least partially overlapping functions with Apq12 and is also required for assembly of functional NPCs. A third nuclear envelope membrane protein, Brl1, is related to Brr6, and is also required for NPC assembly. Because maintenance of membrane homeostasis is essential for cellular survival, the fact that these three proteins are conserved in fungi that undergo closed mitoses, but are not found in metazoans or plants, may indicate that their functions are performed by proteins unrelated at the primary sequence level to Brr6, Brl1 and Apq12 in cells that disassemble their nuclear envelopes during mitosis.

  1. Studies on the distribution of platinum in tumour-bearing rats after the administration of platinum co-ordination complexes used in cancer chemotherapy

    International Nuclear Information System (INIS)

    Zeisler, R.; Lux, F.; Beck, W.

    1979-01-01

    Platinum co-ordination complexes like dichlorodiamineplatinum(II) (DDP) feature broad spectrum antitumour activity which, however, is marred by a certain toxicity related especially to renal tubular damage. The activity of such drugs depends on the chemical structure of the complexes, with changes in the ligands resulting in changes in their antitumour activity and toxicity. Assessments of the biological and toxicological effects of recently synthesized complexes must include distribution studies of platinum in the body. It is demonstrated that instrumental neutron activation analysis can be used for these studies because of its accuracy, precision and the low detection limit for platinum (approximately equal to 2 ng), when a standardized method is used. The time-dependent retention of platinum was determined in blood, liver, kidneys and cells of ascitic Walker 256 carcinosarcoma in tumour-bearing rats and controls after the administration of the cis-Pt(Gly-Gly-0Et) 2 Cl 2 complex. Two series of experiments, one with the therapeutic amount of the drug (80 mg/kg body weight) and one low-dose experiment with 1/100 of this amount, were carried out. The results of both experiments are discussed with regard to changes in the platinum concentration with time (0-48 h) in the different samples. From the data a selective uptake of the drug by the tumour cells, causing their destruction, is deduced. Because this drug has shown excellent antitumour activity, this observed selectivity suggests promise for its application in cancer chemotherapy, although platinum retention is still found in the kidneys, which might cause renal tubular damage. This latter aspect requires further clinical research to evaluate fully its effects. (author)

  2. Enantioseparation of dansyl amino acids and dipeptides by chiral ligand exchange capillary electrophoresis based on Zn(II)-L-hydroxyproline complexes coordinating with γ-cyclodextrins.

    Science.gov (United States)

    Mu, Xiaoyu; Qi, Li; Qiao, Juan; Yang, Xinzheng; Ma, Huimin

    2014-10-10

    A chiral ligand exchange capillary electrophoresis (CLE-CE) method using Zn(II) as the central ion and L-4-hydroxyproline as the chiral ligand coordinating with γ-cyclodextrin (γ-CD) was developed for the enantioseparation of amino acids (AAs) and dipeptides. The effects of various separation parameters, including the pH of the running buffer, the ratio of Zn(II) to L-4-hydroxyproline, the concentration of complexes and cyclodextrins (CDs) were systematically investigated. After optimization, it has been found that eight pairs of labeled AAs and six pairs of labeled dipeptides could be baseline-separated with a running electrolyte of 100.0mM boric acid, 5.0mM ammonium acetate, 3.0mM Zn(II), 6.0mM L-hydroxyproline and 4.0mM γ-CD at pH 8.2. The quantitation of AAs and dipeptides was conducted and good linearity (r(2)≥0.997) and favorable repeatability (RSD≤3.6%) were obtained. Furthermore, the proposed method was applied in determining the enantiomeric purity of AAs and dipeptides. Meanwhile, the possible enantiorecognition mechanism based on the synergistic effect of chiral metal complexes and γ-CD was explored and discussed briefly. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The physical chemistry of coordinated aqua-, ammine-, and mixed-ligand Co2+ complexes: DFT studies on the structure, energetics, and topological properties of the electron density.

    Science.gov (United States)

    Varadwaj, Pradeep R; Marques, Helder M

    2010-03-07

    Spin-unrestricted DFT-X3LYP/6-311++G(d,p) calculations have been performed on a series of complexes of the form [Co(H(2)O)(6-n)(NH(3))(n)](2+) (n = 0-6) to examine their equilibrium gas-phase structures, energetics, and electronic properties in their quartet electronic ground states. In all cases Co(2+) in the energy-minimised structures is in a pseudo-octahedral environment. The calculations overestimate the Co-O and Co-N bond lengths by 0.04 and 0.08 A, respectively, compared to the crystallographically observed mean values. There is a very small Jahn-Teller distortion in the structure of [Co(H(2)O)(6)](2+) which is in contrast to the very marked distortions observed in most (but not all) structures of this cation that have been observed experimentally. The successive replacement of ligated H(2)O by NH(3) leads to an increase in complex stability by 6 +/- 1 kcal mol(-1) per additional NH(3) ligand. Calculations using UB3LYP give stabilisation energies of the complexes about 5 kcal mol(-1) smaller and metal-ligand bond lengths about 0.005 A longer than the X3LYP values since the X3LYP level accounts for the London dispersion energy contribution to the overall stabilisation energy whilst it is largely missing at the B3LYP level. From a natural population analysis (NPA) it is shown that the formation of these complexes is accompanied by ligand-to-metal charge transfer the extent of which increases with the number of NH(3) ligands in the coordination sphere of Co(2+). From an examination of the topological properties of the electron charge density using Bader's quantum theory of atoms in molecules it is shown that the electron density rho(c) at the Co-O bond critical points is generally smaller than that at the Co-N bond critical points. Hence Co-O bonds are weaker than Co-N bonds in these complexes and the stability increases as NH(3) replaces H(2)O in the metal's coordination sphere. Several indicators, including the sign and magnitude of the Laplacian of the

  4. Two pathways for electrocatalytic oxidation of hydrogen by a nickel bis(diphosphine) complex with pendant amines in the second coordination sphere.

    Science.gov (United States)

    Yang, Jenny Y; Smith, Stuart E; Liu, Tianbiao; Dougherty, William G; Hoffert, Wesley A; Kassel, W Scott; Rakowski DuBois, M; DuBois, Daniel L; Bullock, R Morris

    2013-07-03

    A nickel bis(diphosphine) complex containing pendant amines in the second coordination sphere, [Ni(P(Cy)2N(t-Bu)2)2](BF4)2 (P(Cy)2N(t-Bu)2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. The addition of hydrogen to the Ni(II) complex gives three isomers of the doubly protonated Ni(0) complex [Ni(P(Cy)2N(t-Bu)2H)2](BF4)2. Using the pKa values and Ni(II/I) and Ni(I/0) redox potentials in a thermochemical cycle, the free energy of hydrogen addition to [Ni(P(Cy)2N(t-Bu)2)2](2+) was determined to be -7.9 kcal mol(-1). The catalytic rate observed in dry acetonitrile for the oxidation of H2 depends on base size, with larger bases (NEt3, t-BuNH2) resulting in much slower catalysis than n-BuNH2. The addition of water accelerates the rate of catalysis by facilitating deprotonation of the hydrogen addition product before oxidation, especially for the larger bases NEt3 and t-BuNH2. This catalytic pathway, where deprotonation occurs prior to oxidation, leads to an overpotential that is 0.38 V lower compared to the pathway where oxidation precedes proton movement. Under the optimal conditions of 1.0 atm H2 using n-BuNH2 as a base and with added water, a turnover frequency of 58 s(-1) is observed at 23 °C.

  5. Complex chemistry

    International Nuclear Information System (INIS)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-01

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  6. DDX3 directly regulates TRAF3 ubiquitination and acts as a scaffold to co-ordinate assembly of signalling complexes downstream from MAVS.

    Science.gov (United States)

    Gu, Lili; Fullam, Anthony; McCormack, Niamh; Höhn, Yvette; Schröder, Martina

    2017-02-15

    The human DEAD-box helicase 3 (DDX3) has been shown to contribute to type I interferon (IFN) induction downstream from antiviral pattern recognition receptors. It binds to TANK-binding kinase 1 and IκB-kinase-ε (IKKε), the two key kinases mediating activation of IFN regulatory factor (IRF) 3 and IRF7. We previously demonstrated that DDX3 facilitates IKKε activation downstream from RIG-I and then links the activated kinase to IRF3. In the present study, we probed the interactions between DDX3 and other key signalling molecules in the RIG-I pathway and identified a novel direct interaction between DDX3 and TNF receptor-associated factor 3 (TRAF3) mediated by a TRAF-interaction motif in the N-terminus of DDX3, which was required for TRAF3 ubiquitination. Interestingly, we observed two waves of K63-linked TRAF3 ubiquitination following RIG-I activation by Sendai virus (SeV) infection, both of which were suppressed by DDX3 knockdown. We also investigated the spatiotemporal formation of endogenous downstream signalling complexes containing the mitochondrial antiviral signalling (MAVS) adaptor, DDX3, IκB-kinase-ε (IKKε), TRAF3 and IRF3. DDX3 was recruited to MAVS early after SeV infection, suggesting that it might mediate subsequent recruitment of other molecules. Indeed, knockdown of DDX3 prevented the formation of TRAF3-MAVS and TRAF3-IKKε complexes. Based on our data, we propose that early TRAF3 ubiquitination is required for the formation of a stable MAVS-TRAF3 complex, while the second wave of TRAF3 ubiquitination mediates IRF3 recruitment and activation. Our study characterises DDX3 as a multifunctional adaptor molecule that co-ordinates assembly of different TRAF3, IKKε and IRF3-containing signalling complexes downstream from MAVS. Additionally, it provides novel insights into the role of TRAF3 in RIG-I signalling. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  7. Co-ordinate expression of the pre-T-cell receptor complex and a novel immature thymocyte-specific antigen, IMT-1, during thymocyte development.

    Science.gov (United States)

    Tong, J J; Kishi, H; Nagata, T; Muraguchi, A

    1999-01-01

    Previously we described a monoclonal antibody (mAb) that reacted with a cell-surface antigen, immature thymocyte antigen-1 (IMT-1), which is expressed on thymocytes of late CD4- CD8- (double negative) to early CD4+ CD8+ (double positive) differentiation stages. In this study, we investigated the expression of IMT-1 on various cell lineages in thymus as well as in peripheral lymphoid organs. We found that IMT-1 is expressed on T-cell receptor (TCR)-betalo and TCR-deltalo thymocytes, but not on TCR-betahi, TCR-deltahi or natural killer (NK)1.1+ thymocytes, or on peripheral alpha beta or gamma delta T cells. We also investigated the kinetics of expression of IMT-1 during fetal thymocyte development and compared it with the expression of the pre-TCR complex, comprising CD3, pre-TCR-alpha (pTalpha) and TCR-beta. We found that expression of both was similar, starting at day 14.5 of gestation, peaking on day 16.5 and gradually decreasing thereafter. Furthermore, the expression of both IMT-1 and pTalpha was drastically reduced when DN thymocytes in recombination activating gene (RAG)-2-/- mice were challenged in vivo with anti-CD3 mAb. These results indicate that IMT-1 is expressed on not only immature thymocytes of alpha beta T-cell lineage but also on those of gamma delta T-cell lineage, and that the expression of IMT-1 and the pre-TCR complex is co-ordinately regulated during the alpha beta lineage thymocyte development.

  8. Spectroscopic Studies of a Three-dimensional, Five-coordinated Copper(Ⅱ) Complex via Hydrogen Bonds: [Cu(PDA)(H2O)2](H2PDA=Pyridine-2,6-dicarboxylic Acid)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new copper(Ⅱ) complex [Cu(PDA)(H2O)2] was synthesized and its structure was determined. Cu(Ⅱ) is five-coordinated in a tetragonal pyramid geometry. The two coordinating water molecules are different and the two Cu-O bond lengths differ by nearly 0.02 nm. The whole crystal is linked to form a three-dimensional network by means of hydrogen bonds. The X-band ESR spectrum shows three different g tensors with a well-resolved hyperfine structure in the gz signal, giving the ESR parameters gx=2.05, gy=2.065 and gz=2.29. The covalency of the coordinate bonds and the deviation from tetragonal pyramid geometry for the complex are discussed based on the ESR spectra.

  9. Copper(II) and zinc(II) as metal-carboxylate coordination complexes based on (1-methyl-1H-benzo[d]imidazol-2-yl) methanol derivative: Synthesis, crystal structure, spectroscopy, DFT calculations and antioxidant activity

    Science.gov (United States)

    Benhassine, Anfel; Boulebd, Houssem; Anak, Barkahem; Bouraiou, Abdelmalek; Bouacida, Sofiane; Bencharif, Mustapha; Belfaitah, Ali

    2018-05-01

    This work presents a combined experimental and theoretical study of two new metal-carboxylate coordination compounds. These complexes were prepared from (1-methyl-1H-benzimidazol-2-yl)methanol under mild conditions. The structures of the prepared compounds were characterized by single-crystal X-ray analysis, FTIR and UV-Vis spectroscopy. In the Cupper complex, the Cu(II) ion is coordinated by two ligands, which act as bidentate chelator through the non-substituted N and O atoms, and two carboxylicg oxygen atoms, displaying a hexa-coordinated compound in a distorted octahedral geometry, while in the Zinc complex the ligand is ligated to the Zn(II) ion in monodentate fashion through the N atom, and the metal ion is also bonded to carboxylic oxygen atoms. The tetra-coordinated compound displays a distorted tetrahedral shape. The density functional theory calculations are carried out for the determination of the optimized structures. The electronic transitions and fundamental vibrational wave numbers are calculated and are in good agreement with experimental. In addition, the ligand and its Cu(II) and Zn(II) complexes were screened and evaluated for their potential as DPPH radical scavenger.

  10. Luminescent lanthanide coordination polymers

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L.; Evans, O.R.; Foxman, B.M.; Lin, W.

    1999-12-13

    One-dimensional lanthanide coordination polymers with the formula Ln(isonicotinate){sub 3}(H{sub 2}O){sub 2} (Ln = Ce, Pr, Nd, Sm, Eu, Tb; 1a-f) were synthesized by treating nitrate or perchlorate salts of Ln(III) with 4-pyridinecarboxaldehyde under hydro(solvo)thermal conditions. Single-crystal and powder X-ray diffraction studies indicate that these lanthanide coordination polymers adopt two different structures. While Ce(III), Pr(III), and Nd(III) complexes adopt a chain structure with alternating Ln-(carboxylate){sub 2}-Ln and Ln-(carboxylate){sub 4}-Ln linkages, Sm(III), Eu(III), and Tb(III) complexes have a doubly carboxylate-bridged infinite-chain structure with one chelating carboxylate group on each metal center. In both structures, the lanthanide centers also bind to two water molecules to yield an eight-coordinate, square antiprismatic geometry. The pyridine nitrogen atoms of the isonicotinate groups do not coordinate to the metal centers in these lanthanide(III) complexes; instead, they direct the formation of Ln(III) coordination polymers via hydrogen bonding with coordinated water molecules. Photoluminescence measurements show that Tb(isonicotinate){sub 3}(H{sub 2}O){sub 2} is highly emissive at room temperature with a quantum yield of {approximately}90%. These results indicate that highly luminescent lanthanide coordination polymers can be assembled using a combination of coordination and hydrogen bonds. Crystal data for 1a: monoclinic space group P2{sub 1}/c, a = 9.712(2) {angstrom}, b = 19.833(4) {angstrom}, c = 11.616(2) {angstrom}, {beta} = 111.89(3){degree}, Z = 4. Crystal data for 1f: monoclinic space group C2/c, a = 20.253(4) {angstrom}, b = 11.584(2) {angstrom}, c = 9.839(2) {angstrom}, {beta} = 115.64(3){degree}, Z = 8.

  11. Poisson Coordinates.

    Science.gov (United States)

    Li, Xian-Ying; Hu, Shi-Min

    2013-02-01

    Harmonic functions are the critical points of a Dirichlet energy functional, the linear projections of conformal maps. They play an important role in computer graphics, particularly for gradient-domain image processing and shape-preserving geometric computation. We propose Poisson coordinates, a novel transfinite interpolation scheme based on the Poisson integral formula, as a rapid way to estimate a harmonic function on a certain domain with desired boundary values. Poisson coordinates are an extension of the Mean Value coordinates (MVCs) which inherit their linear precision, smoothness, and kernel positivity. We give explicit formulas for Poisson coordinates in both continuous and 2D discrete forms. Superior to MVCs, Poisson coordinates are proved to be pseudoharmonic (i.e., they reproduce harmonic functions on n-dimensional balls). Our experimental results show that Poisson coordinates have lower Dirichlet energies than MVCs on a number of typical 2D domains (particularly convex domains). As well as presenting a formula, our approach provides useful insights for further studies on coordinates-based interpolation and fast estimation of harmonic functions.

  12. Gas-phase behaviour of Ru(II) cyclopentadienyl-derived complexes with N-coordinated ligands by electrospray ionization mass spectrometry: fragmentation pathways and energetics.

    Science.gov (United States)

    Madeira, Paulo J Amorim; Morais, Tânia S; Silva, Tiago J L; Florindo, Pedro; Garcia, M Helena

    2012-08-15

    The gas-phase behaviour of six Ru(II) cyclopentadienyl-derived complexes with N-coordinated ligands, compounds with antitumor activities against several cancer lines, was studied. This was performed with the intent of establishing fragmentation pathways and to determine the Ru-L(N) and Ru-L(P) ligand bond dissociation energies. Such knowledge can be an important tool for the postulation of the mechanisms of action of these anticancer drugs. Two types of instruments equipped with electrospray ionisation were used (ion trap and a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer). The dissociation energies were determined using energy-variable collision-induced dissociation measurements in the ion trap. The FTICR instrument was used to perform MS(n) experiments on one of the compounds and to obtain accurate mass measurements. Theoretical calculations were performed at the density functional theory (DFT) level using two different functionals (B3LYP and M06L) to estimate the dissociation energies of the complexes under study. The influence of the L(N) on the bond dissociation energy (D) of RuCp compounds with different nitrogen ligands was studied. The lability order of L(N) was: imidazole<1-butylimidazole<5-phenyl-1H-tetrazole<1-benzylimidazole. Both the functionals used gave the following ligand lability order: imidazole<1-benzylimidazole<5-phenyl-1H-tetrazole<1-butylimidazole. It is clear that there is an inversion between 1-benzylimidazole and 1-butylimidazole for the experimental and theoretical lability orders. The M06L functional afforded values of D closer to the experimental values. The type of phosphane (L(P) ) influenced the dissociation energies, with values of D being higher for Ru-L(N) with 1-butylimidazole when the phosphane was 1,2-bis(diphenylphosphino)ethane. The Ru-L(P) bond dissociation energy for triphenylphosphane was independent of the type of complex. The D values of Ru-L(N) and Ru-L(P) were determined for all six compounds and

  13. Binuclear complexes of technetium. Evidence for bis(terdentate)bidentate coordination by the bridging ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine to technetium(V)

    International Nuclear Information System (INIS)

    Du Preez, J.G.H.; Gerber, T.I.A.; Gibson, M.L.; Geyser, R.

    1990-01-01

    The authors have used the potentially bis(terdentate) nitrogen aromatic heterocyclic ligand 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz) to prepare mono- and bimetallic technetium(V) complexes bound to tppz. The stimulus for the development of the coordination chemistry of the man-made element technetium is provided by the use of complexes of this element as anatomical imaging agents in nuclear medicine. Although the chemistry of technetium(V) with nitrogen donor ligands is well understood, no complexes have been prepared using potentially terdentate neutral nitrogen donor ligands of this metal in the +5 oxidation state

  14. Synthesis, electrochemistry, and spectroscopic properties of six-coordinate monooxomolybdenum(VI) complexes containing tridentate Schiff base and bidentate catecholate ligands. Crystal and molecular structure of (N-salicylidene-2-aminophenolato)(naphthalene-2,3-diolato)oxomolybdenum(VI)

    International Nuclear Information System (INIS)

    Mondal, J.U.; Schultz, F.A.; Brennan, T.D.; Scheidt, W.R.

    1988-01-01

    Six-coordinate monooxomolybdenum(VI) complexes, MoO(cat)(Sap), where Sap 2- = the Schiff base dianion N-salicylidene-2-aminophenolate and cat 2- = catecholate Cat 2- , naphthalene-2,3-diolate (Naphcat 2- ), or 3,5-di-tert-butylcatecholate (DTBcat 2- ), are prepared by reacting the Mo(VI) dimer. [MoO 2 (Sap)] 2 , with the appropriate catechol. The products are characterized by cyclic voltammetry, mass spectrometry, and uv/vis, ir, and 95 Mo NMR spectroscopy. The MoO(cat)(Sap) complexes represent the first examples of a mononuclear MoO 4+ center with a coordination number of six. The crystal structure of the MoO-(Naphcat)(Sap) derivative is reported, confirming the six-coordinate, distorted octahedrla environment about Mo(VI). Bond angles in the coordination group deviate from the ideal value of 90/degrees/ as a consequence of the ligand bite constraints and because all four O-Mo-O angles involving the terminal oxo ligand are larger than the ideal 90/degrees/ value. MoO(cat)(Sap) complexes undergo reversible one-electronic reduction at -0.5 to -0.7 V versus Fc /sup +/0/ followed by irreversible one-electron reduction at -1.6 to -1.9 V. Reversible MoO 4+ /MoO 3+ electrochemistry is attributed to the fact that the Mo d/sub xy/orbital of MoO(cat)(Sap) can be singly occupied upon reduction to Mo(V) without unfavorable interaction with the four bonds in its equatorial plane. This contrasts with the irreversible electrochemical behavior of seven-coordinate MoO 4+ complexes, which contain five such bonds. The 95 Mo NMR chemical shift of MoO(Naphcat)(Sap) is +385 ppM versus external molybdate; this value is highly deshielded with respect to seven-coordinate MoO 4+ and six-coordinate MoO 2 2+ complexes with O and N donors. 35 references, 4 figures, 5 tables

  15. Heteronuclear 2D (1H-13C) MAS NMR Resolves the Electronic Structure of Coordinated Histidines in Light-Harvesting Complex II: Assessment of Charge Transfer and Electronic Delocalization Effect

    International Nuclear Information System (INIS)

    Matysik, Joerg; Boer, Ido de; Gast, Peter; Gorkom, Hans J. van; Groot, Huub J.M. de

    2004-01-01

    In a recent MAS NMR study, two types of histidine residues in the light-harvesting complex II (LH2) of Rhodopseudomonas acidophila were resolved: Type 1 (neutral) and Type 2 (positively charged) (Alia et al. J. Am. Chem. Soc.). The isotropic 13 C shifts of histidines coordinating to B850 BChl a are similar to fully positively charged histidine, while the 15 N shift anisotropy shows a predominantly neutral character. In addition the possibility that the ring currents are quenched by overlap in the superstructure of the complete ring of 18 B850 molecules in the LH2 complex could not be excluded. In the present work, by using two-dimensional heteronuclear ( 1 H- 13 C) dipolar correlation spectroscopy with phase-modulated Lee-Goldburg homonuclear 1 H decoupling applied during the t 1 period, a clear and unambiguous assignment of the protons of histidine interacting with the magnesium of a BChl a molecule is obtained and a significant ring current effect from B850 on the coordinating histidine is resolved. Using the ring current shift on 1 H, we refine the 13 C chemical shift assignment of the coordinating histidine and clearly distinguish the electronic structure of coordinating histidines from that of fully positively charged histidine. The DFT calculations corroborate that the coordinating histidines carry ∼0.2 electronic equivalent of positive charge in LH2. In addition, the data indicate that the ground state electronic structures of individual BChl a/His complexes is largely independent of supermolecular π interactions in the assembly of 18 B850 ring in LH2

  16. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    -, č. 274 (2005), s. 1-26 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * crises * cycles and fluctuations Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp274.pdf

  17. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    2008-01-01

    Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

  18. Possibility of extending space-time coordinates

    International Nuclear Information System (INIS)

    Wang Yongcheng.

    1993-11-01

    It has been shown that one coordinate system can describe a whole space-time region except some supersurfaces on which there are coordinate singularities. The conditions of extending a coordinate from real field to complex field are studied. It has been shown that many-valued coordinate transformations may help us to extend space-time regions and many-valued metric functions may make one coordinate region to describe more than one space-time regions. (author). 11 refs

  19. Electronic transitions and bonding properties in a series of five-coordinate "16-electron" complexes [Mn(CO)3(L2)]- (L2 = chelating redox-active .pi.-donor ligand)

    Czech Academy of Sciences Publication Activity Database

    Hartl, F.; Rosa, P.; Ricard, L.; Le Floch, P.; Záliš, Stanislav

    2007-01-01

    Roč. 251, 3-4 (2007), s. 557-576 ISSN 0010-8545 R&D Projects: GA MŠk 1P05OC068; GA AV ČR 1ET400400413 Institutional research plan: CEZ:AV0Z40400503 Keywords : manganese carbonyl * .pi.-donor ligand * electronic delocalization * Five-coordinate complex Subject RIV: CG - Electrochemistry Impact factor: 8.568, year: 2007

  20. Studies on coordination chemistry and bioactivity of metal complexes of a bidentate NN schiff base, (2-pyridyl-methylene)(phenyl) hydrazine, produced from the condensation of pyridine-2-carboxaldehyde with phenylhydrazine

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Zakaria, C.M.; Idrus, Razmi Mohd; Crouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

    2003-07-01

    A bidentate Schiff base, (2-pyridyl-methylene)(phenyl) hydrazine, with NN donor sequence, was isolated from the condensation of pyridine-2-carboxaldehyde with phenylhydrazine in ethanol. Metal complexes of this ligand with Ni(II), Zn(It), and Cu(n) ions were synthesized and characterized by a variety of physico-chemical techniques. The structure of the Schiff base was solved by X-ray diffraction studies, which indicated that it was monoclinic with a space group of C2/c. The complexes were all four coordinated. The compounds were tested against four pathogenic bacteria and fungi. The nickel complex, [Ni(NN) 2 Cl 2 ], in particular, was found to be active against all the fungi tested. The complexes were however inactive against leukemic cell lines (CEM-SS). (author)

  1. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    Overview From a technical perspective, CMS has been in “beam operation” state since 6th November. The detector is fully closed with all components operational and the magnetic field is normally at the nominal 3.8T. The UXC cavern is normally closed with the radiation veto set. Access to UXC is now only possible during downtimes of LHC. Such accesses must be carefully planned, documented and carried out in agreement with CMS Technical Coordination, Experimental Area Management, LHC programme coordination and the CCC. Material flow in and out of UXC is now strictly controlled. Access to USC remains possible at any time, although, for safety reasons, it is necessary to register with the shift crew in the control room before going down.It is obligatory for all material leaving UXC to pass through the underground buffer zone for RP scanning, database entry and appropriate labeling for traceability. Technical coordination (notably Stephane Bally and Christoph Schaefer), the shift crew and run ...

  2. Synthesis, chemistry and catalytic activity of complexes of lanthanide and actinide metals in unusual oxidation states and coordination environments. Progress report, February 1, 1978--January 31, 1979

    International Nuclear Information System (INIS)

    Evans, W.J.

    1978-11-01

    Previous syntheses of Ln(olefin) complexes and their catalytic effect on the hydrogenation of the olefin are discussed. The tert-butyl complexes of Sn, Er, and Yb were synthesized and their decomposition studied

  3. Coordinated unbundling

    DEFF Research Database (Denmark)

    Timmermans, Bram; Zabala-Iturriagagoitia, Jon Mikel

    2013-01-01

    Public procurement for innovation is a matter of using public demand to trigger innovation. Empirical studies have demonstrated that demand-based policy instruments can be considered to be a powerful tool in stimulating innovative processes among existing firms; however, the existing literature has...... not focused on the role this policy instrument can play in the promotion of (knowledge-intensive) entrepreneurship. This paper investigates this link in more detail and introduces the concept of coordinated unbundling as a strategy that can facilitate this purpose. We also present a framework on how...

  4. Study on Stereochemical Activity of Lone Pair Electrons in Sulfur and Halogen Coordinated Antimony(III) Complexes by 121Sb Moessbauer Spectroscopy

    International Nuclear Information System (INIS)

    Ohyama, Ryuhichi; Takahashi, Masashi; Takeda, Masuo

    2005-01-01

    We have measured 121 Sb Moessbauer spectra at 20 K for 52 compounds of antimony(III). An Sb(III) atom with the electron configuration [Kr] 4d 10 5s 2 has a lone pair electrons. The stereochemical property of the lone pair has been found to depend very much on the kinds of atoms surrounding the antimony atom and the configurations of the coordinating atoms.

  5. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    2010-01-01

    Operational Experience At the end of the first full-year running period of LHC, CMS is established as a reliable, robust and mature experiment. In particular common systems and infrastructure faults accounted for <0.6 % CMS downtime during LHC pp physics. Technical operation throughout the entire year was rather smooth, the main faults requiring UXC access being sub-detector power systems and rack-cooling turbines. All such problems were corrected during scheduled technical stops, in the shadow of tunnel access needed by the LHC, or in negotiated accesses or access extensions. Nevertheless, the number of necessary accesses to the UXC averaged more than one per week and the technical stops were inevitably packed with work packages, typically 30 being executed within a few days, placing a high load on the coordination and area management teams. It is an appropriate moment for CMS Technical Coordination to thank all those in many CERN departments and in the Collaboration, who were involved in CMS techni...

  6. A novel tridentate coordination mode for the carbonatonickel system exhibited in an unusual hexanuclear nickel(II) mu3-carbonato-bridged complex.

    Science.gov (United States)

    Anderson, James C; Blake, Alexander J; Moreno, Rafael Bou; Raynel, Guillaume; van Slageren, Joris

    2009-11-14

    The fixation of CO(2) at ambient temperature has been achieved by the reaction of Ni(cod)(2) and TMEDA in CO(2) saturated THF that yields a novel hexanuclear nickel(II) mu(3)-carbonato bridged complex [Ni(6)(mu(3)-CO(3))(4)(TMEDA)(6)(H(2)O)(12)](OH)(4) in 59% yield. The complex was characterised by MS analysis and the structure corroborated by single-crystal X-ray crystallography. The complex exhibits a rare carbonato binding mode for Ni(II) complexes and moderately strong antiferromagnetic interactions.

  7. Low-coordinate rare-earth complexes of the asymmetric 2,4-di-tert-butylphenolate ligand prepared by redox transmetallation/protolysis reactions, and their reactivity towards ring-opening polymerisation.

    Science.gov (United States)

    Clark, Lawrence; Deacon, Glen B; Forsyth, Craig M; Junk, Peter C; Mountford, Philip; Townley, Josh P

    2010-08-07

    New trivalent lanthanoid aryloxide complexes have been prepared by redox transmetallation/protolysis (rtp) reactions using 2,4-di-tert-butylphenol (dbpH). Mononuclear octahedral complexes from tetrahydrofuran (thf) were of the type [Ln(dbp)(3)(thf)(3)] (Ln = La (1), Pr (2), Nd (3), Gd (4), Er (5)). The lanthanoid contraction results in the rather subtle change in stereochemistry from meridional (La, Pr, Nd, Gd) to facial (Er). An analogous reaction with neodymium in dimethoxyethane (dme), resulted in the isolation of the seven coordinate [Nd(dbp)(3)(dme)(2)] (6), and this is comparable with the thf complexes in terms of steric crowding. Dinuclear complexes of the type [Ln(2)(dbp)(6)(thf)(2)], (Ln = Nd (7), Er (8)) were obtained when 1 and 5 were recrystallised from toluene. These dimeric complexes contain two bridging and four terminal phenolates, as well as a single coordinated molecule of thf at each metal. A similar structural motif was observed for the products when the reaction was performed in diethyl ether, and in the absence of a solvent, yielding [Nd(2)(dbp)(6)(Et(2)O)(2)] (9) and [Nd(2)(dbp)(6)(dbpH)(2)] (10) respectively. Complexes 3 and 4 alone were efficient but poorly-controlled initiators for the ROP of rac-lactide, but with an excess of BnOH as a co-initiator they showed features consistent with immortal polymerisation. Use of BnNH(2) led to well-controlled, amine-initiated immortal ROP of rac-lactide, only the second report of this type of process for a group 3 or lanthanoid system.

  8. Formation of a Six-Coordinate fac-[Re(Co)3]+ Complex by the N-C bond cleavage of a potentially tetradentate ligand

    International Nuclear Information System (INIS)

    Booysen, I.; Gerber, T. I. A.; Hosten, E.; Mayer, P.

    2008-01-01

    The rhenium(I) compound fac-[Re(CO) 3 (daa)]. Hpab.H 2 O (Hpab N,N'-(l,2-phenylene)bis(2'-aminobenzamide); Hdaa 2-amino-N-(2-aminophenyl)benzamide) was synthesized from the reaction of [Re(CO) 5 ,Br] with two equivalent of Hpab in toluene. The monoanionic tridentate ligand daa was formed by the rhenium-mediated cleavage of an amido N-C bond of the potentially tetradentate ligand Hpab. The compound was characterized by IR spectroscopy and X-ray crystallography, and daa is coordinated as a diamino amide via three nitrogen-donor atoms

  9. Magnetic adsorbent constructed from the loading of amino functionalized Fe{sub 3}O{sub 4} on coordination complex modified polyoxometalates nanoparticle and its tetracycline adsorption removal property study

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Jinzhao; Mei, Mingliang; Xu, Xinxin, E-mail: xuxx@mail.neu.edu.cn

    2016-06-15

    A magnetic polyoxometalates based adsorbent has been synthesized successfully through the loading of amino functionalized Fe{sub 3}O{sub 4} (NH{sub 2}-Fe{sub 3}O{sub 4}) on nanoparticle of a coordination complex modified polyoxometalates (CC/POMNP). FTIR illustrate there exist intense hydrogen bonds between NH{sub 2}-Fe{sub 3}O{sub 4} and CC/POMNP, which keep the stability of this adsorbent. At room temperature, this adsorbent exhibits ferromagnetic character with saturation magnetization of 8.19 emu g{sup −1}, which provides prerequisite for fast magnetic separation. Water treatment experiment illustrates this POM based magnetic adsorbent exhibits high adsorption capacity on tetracycline. The adsorption process can be described well with Temkin model, which illustrates the interaction between adsorbent and tetracycline plays the dominated role in tetracycline removal. The rapid, high efficient tetracycline adsorption ability suggests this POM based magnetic adsorbent exhibits promising prospect in medical and agriculture waste water purification. A magnetic polyoxometalates based adsorbent, which exhibits excellent tetracycline adsorption removal property has been synthesized through the loading of NH{sub 2}-Fe{sub 3}O{sub 4} on coordination complex modified polyoxometalates - Graphical abstract: A magnetic polyoxometalates based adsorbent, which exhibits excellent tetracycline adsorption removal property has been synthesized through the loading of NH{sub 2}-Fe{sub 3}O{sub 4} on coordination complex modified polyoxometalate. Display Omitted - Highlights: • A POM based magnetic adsorbent was fabricated through the loading of NH{sub 2}-Fe{sub 3}O{sub 4} on POM nanoparticle. • This adsorbent possesses excellent tetracycline adsorption property. • Saturation magnetization value of this adsorbent is 8.19 emug−1, which is enough for magnetic separation.

  10. [Civilian-military coordination].

    Science.gov (United States)

    de Montravel, G

    2002-01-01

    Current humanitarian emergencies create complex, mutidimensional situations that stimulate simultaneous responses from a wide variety of sources including governments, non-governmental organizations (NGO), United Nations agencies, and private individuals. As a result, it has become essential to establish a coherent framework in which each actor can contribute promptly and effectively to the overall effort. This is the role of the United Nations Office for the Coordination of Humanitarian Affairs. Regardless of the circumstances and level of coordination, cooperation and collaboration between humanitarian and military personnel, it is necessary to bear in mind their objectives. The purpose of humanitarian action is to reduce human suffering. The purpose of military intervention is to stop warfare. The author of this article will discuss the three major obstacles to civilian-military coordination (strategic, tactical, and operational). Operations cannot be conducted smoothly and differences cannot be ironed out without mutual respect between the two parties, an explicit definition of their respective duties and responsibilities, a clear understanding of their cultural differences, and the presence of an organization and facilities for coordination and arbitrage by a neutral referee.

  11. 基于区间不确定性水资源复杂系统的协调演化研究%Study on coordination evolvement of complex water resources system with interval uncertainty

    Institute of Scientific and Technical Information of China (English)

    韩雁; 黄跃飞; 王光谦; 王丽珍

    2011-01-01

    水资源系统是具有不确定性的复杂系统。本文通过分析水资源系统的复杂性与不确定性,构建了基于区间不确定条件下的水资源复杂系统协调演化分析方法。在利用主成分分析法得到子系统综合发展水平的基础上,采用系统的协调性指数模型来揭示系统间的相互关系,然后根据系统的信息熵得到其协调有序度,以此来反映水资源复杂系统的演化规律。以大连市为例的应用研究表明,观真实地揭示水资源复杂系统的演化区间及其发展趋势,指导意义。基于区间不确定性的水资源复杂系统协调演化,能够客对于实现区域水资源和社会经济的可持续发展具有重要指导意义。%Water resources system is a kind of complex system with great uncertainties. In this paper, a methodology for analyzing coordination degree of complex and uncertainty characteristics of water resources system is proposed. Based on interval uncertainty, a comprehensive development level of each subsystem in a water resources system with interval parameters could be obtained by using the Principal Component Analysis method. Then the mutual relationships between subsystems are obtained by using coordination exponent method. Finally, the order degree is determined by using information entropy to reveal the coordinated evolvement of complex water resources system. Such method has been applied to Dalian City and the resuits indicate that the coordinated evolvement of water resources system under uncertainty could objectively and factually reflect the evolutional interval and trend of a complex water resources system, which is important to decision-making for sustainable development of water resources and socio-economy.

  12. New insights into the coordination chemistry of Schiff bases derived from amino acids: Planar [Ni4] complexes with tyrosine side-chains

    Science.gov (United States)

    Muche, Simon; Hołyńska, Małgorzata

    2017-08-01

    Structure and properties of a rare metal complex of the chiral Schiff base ligand derived from ortho-vanillin and L-tyrosine are presented. This study is a continuation of research on ligands containing biologically compatible moieties. The ligand is also fully characterized in form of a sodium salt, in particular in solution, for the first time. The metal complex contains a unique bowl-shaped [Ni4] core. Its structure is investigated both in solution (ESI-MS, NMR) and in solid state (X-ray diffraction studies). Under certain conditions the complex can be isolated as crystalline DMF solvate which is studied in solid state.

  13. Effect of applied hydrostatic pressure on the quenching kinetics, and electronic and molecular structure of eight and nine-coordinate lanthanide complexes in solution

    International Nuclear Information System (INIS)

    Maupin, C.L.; Riehl, J.P.

    1998-01-01

    Full text: Applied hydrostatic pressure may be used as a probe of the reaction mechanism for various solution reactions involving lanthanide ions. In this work we report on the use of high pressure to probe the mechanism of enantioselective quenching between racemic luminescent lanthanide complexes containing Dy(III) Tb(III) and Eu(III), and optically active transition metal complexes as quenchers. Diastereomeric rate constants are obtained from a biexponential fit of the luminescence decay. Particular attention will be given to solvation effects on the measured diastereomeric rate constants. The source of chirality is ascribed to a enantioselective rearrangement step within a bimolecular 'encounter' complex yielding a intermolecular geometry in which the energy transfer is efficient. The effect of high pressure on the molecular and electronic structure of these complexes will also be discussed

  14. Nonlinear optical and G-Quadruplex DNA stabilization properties of novel mixed ligand copper(II) complexes and coordination polymers: Synthesis, structural characterization and computational studies

    Science.gov (United States)

    Rajasekhar, Bathula; Bodavarapu, Navya; Sridevi, M.; Thamizhselvi, G.; RizhaNazar, K.; Padmanaban, R.; Swu, Toka

    2018-03-01

    The present study reports the synthesis and evaluation of nonlinear optical property and G-Quadruplex DNA Stabilization of five novel copper(II) mixed ligand complexes. They were synthesized from copper(II) salt, 2,5- and 2,3- pyridinedicarboxylic acid, diethylenetriamine and amide based ligand (AL). The crystal structure of these complexes were determined through X-ray diffraction and supported by ESI-MAS, NMR, UV-Vis and FT-IR spectroscopic methods. Their nonlinear optical property was studied using Gaussian09 computer program. For structural optimization and nonlinear optical property, density functional theory (DFT) based B3LYP method was used with LANL2DZ basis set for metal ion and 6-31G∗ for C,H,N,O and Cl atoms. The present work reveals that pre-polarized Complex-2 showed higher β value (29.59 × 10-30e.s.u) as compared to that of neutral complex-1 (β = 0.276 × 10-30e.s.u.) which may be due to greater advantage of polarizability. Complex-2 is expected to be a potential material for optoelectronic and photonic technologies. Docking studies using AutodockVina revealed that complex-2 has higher binding energy for both G-Quadruplex DNA (-8.7 kcal/mol) and duplex DNA (-10.1 kcal/mol). It was also observed that structure plays an important role in binding efficiency.

  15. RUN COORDINATION

    CERN Multimedia

    Christophe Delaere

    2013-01-01

    The focus of Run Coordination during LS1 is to monitor closely the advance of maintenance and upgrade activities, to smooth interactions between subsystems and to ensure that all are ready in time to resume operations in 2015 with a fully calibrated and understood detector. After electricity and cooling were restored to all equipment, at about the time of the last CMS week, recommissioning activities were resumed for all subsystems. On 7 October, DCS shifts began 24/7 to allow subsystems to remain on to facilitate operations. That culminated with the Global Run in November (GriN), which   took place as scheduled during the week of 4 November. The GriN has been the first centrally managed operation since the beginning of LS1, and involved all subdetectors but the Pixel Tracker presently in a lab upstairs. All nights were therefore dedicated to long stable runs with as many subdetectors as possible. Among the many achievements in that week, three items may be highlighted. First, the Strip...

  16. RUN COORDINATION

    CERN Multimedia

    C. Delaere

    2013-01-01

    Since the LHC ceased operations in February, a lot has been going on at Point 5, and Run Coordination continues to monitor closely the advance of maintenance and upgrade activities. In the last months, the Pixel detector was extracted and is now stored in the pixel lab in SX5; the beam pipe has been removed and ME1/1 removal has started. We regained access to the vactank and some work on the RBX of HB has started. Since mid-June, electricity and cooling are back in S1 and S2, allowing us to turn equipment back on, at least during the day. 24/7 shifts are not foreseen in the next weeks, and safety tours are mandatory to keep equipment on overnight, but re-commissioning activities are slowly being resumed. Given the (slight) delays accumulated in LS1, it was decided to merge the two global runs initially foreseen into a single exercise during the week of 4 November 2013. The aim of the global run is to check that we can run (parts of) CMS after several months switched off, with the new VME PCs installed, th...

  17. Coordination-organometallic hybrid materials based on the trinuclear M(II)-Ru(II) (M=Ni and Zn) complexes: Synthesis, structural characterization, luminescence and electrochemical properties

    Science.gov (United States)

    Pawal, S. B.; Lolage, S. R.; Chavan, S. S.

    2018-02-01

    A new series of trinuclear complexes of the type Ni[R-C6H4Ndbnd CH(O)C6H3Ctbnd CRu(dppe)2Cl]2 (1a-c) and Zn[Rsbnd C6H4Ndbnd CH(O)C6H3Ctbnd CRu(dppe)2Cl]2 (2a-c) have been prepared from the reaction of trans-[RuCl(dppe)2Ctbnd Csbnd C6H3(OH)(CHO)] (1) with aniline, 4-nitroaniline and 4-methoxyaniline (R1-3) in presence of nickel acetate and zinc acetate in CH2Cl2/MeOH (1:1) mixture. The structural properties of the complexes have been characterized by elemental analyses and spectroscopic techniques viz. FTIR, UV-Visible, 1H NMR and 31P NMR spectral studies. The crystal structure and morphology of the hybrid complexes was investigated with the help of X-ray powder diffraction (XRPD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The thermal properties of 1a-c and 2a-c were studied by thermogravimetric (TG) analysis. The electrochemical behaviour of the complexes reveals that all complexes displayed a quasireversible redox behaviour corresponding to Ru(II)/Ru(III) and Ni(II)/Ni(III) couples for 1a-c and only Ru(II)/Ru(III) couple for 2a-c. All complexes are emissive in solution at room temperature revealing the influence of substituents and solvent polarity on emission properties of the complexes.

  18. Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II, Co(II, Ni(II, Cu(II, and Zn(II] metals

    Directory of Open Access Journals (Sweden)

    Nahid Nishat

    2016-09-01

    Full Text Available A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II. All the polymeric compounds were characterized by (FT-IR spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA and antibacterial activities. Polymer complexes of Mn(II, Co(II and Ni(II show octahedral geometry, while polymer complexes of Cu(II and Zn(II show square planar and tetrahedral geometry, respectively. The TGA revealed that all the polymer metal complexes are more thermally stable than their parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM-D-5338-93 standards of biodegradable polymers by CO2 evolution method which says that coordination decreases biodegradability. The antibacterial activity was screened with the agar well diffusion method against some selected microorganisms. Among all the complexes, the antibacterial activity of the Cu(II polymer–metal complex showed the highest zone of inhibition because of its higher stability constant.

  19. Coordination chemistry and bioactivity of Ni2+, Cu2+, and Zn2+ complexes containing a bidentate NS ligand, β-N-phenyldithiocarbazic acid, and the crystal structure of β-hydroxy-β-phenylmethylene α-phenylimine

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Ahmed Faizal Shamsuddin; Grouse, Karen A.; Yamin, B.M.; Ali, A.M.; Fun, H.-K.

    2003-07-01

    A bidentate ligand (PhDTCH) with NS donor sequence was prepared from the reaction between carbon disulfide and phenylhydrazine in ethanol. Complexes of this ligand with Ni(II), Cu(II) and Zn(II) were synthesized and characterized by elemental analyses, and various physicochemical techniques. The metal complexes were all four coordinated. In an attempt to resolve the crystal structure of PhDTCH, an ethanolic solution, after leaving for a few days gave bright crystals of PhD6, β-hydroxy-β-phenylmethylene α-phenylimine, the crystal structure of which has been resolved. The crystal packing indicated that it is monoclinic with a space group of P21/n. All of the compounds were tested against different bacteria and fungi, and also against leukemic cell lines. All of the compounds showed weak biological properties compared to standard drugs. (author)

  20. A new Kaempferol-based Ru(II) coordination complex, Ru(kaem)Cl(DMSO){sub 3}: Structure and absorption-emission spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Ming Wei; Gang, Jong Back; Kim, Sang Ho; Yoon, Min Young [Gachon University, Sungnam (Korea, Republic of)

    2016-10-15

    Recent interest in developing a new anticancer drug with low side effects has led to the study of the combination of two new anticancer drugs. Although both kaempferol (kaem) and Ru-based metal complexes have not been proven as effective drugs, their unique anticancer activities with reduced side effects have drawn our attention to the need for further studies on their potential in anticancer application. Herein, we report the synthesis, characterization, structure, and spectroscopic properties of a kaem-based Ru (II) complex, RuCl(kaem)(DMSO){sub 3} (1). Because of the presence of a catechol-like functional group in its dihydropyran ring, kaem can strongly bind to the Ru(II) metal center in a basic medium. The molecular structure of the complex was characterized by spectroscopic studies and X-ray crystal structure analysis. In addition, the complex forms a molecular dimer as a result of the cooperative effect of H-bonding and π–π stacking interactions. Moreover, the molecular dimer forms a ladder-like one-dimensional network structure by water mediated H-bonding that further extended into a three-dimensional packing structure. UV–Vis spectroscopy studies of the complex demonstrated the appearance of a strong metal to ligand charge transfer (MLCT) band in the visible region with strong fluorescence emission derived from the MLCT. Further studies are now in progress to demonstrate synergetic anticancer activity.

  1. A new Kaempferol-based Ru(II) coordination complex, Ru(kaem)Cl(DMSO)3: Structure and absorption-emission spectroscopy study

    International Nuclear Information System (INIS)

    Shao, Ming Wei; Gang, Jong Back; Kim, Sang Ho; Yoon, Min Young

    2016-01-01

    Recent interest in developing a new anticancer drug with low side effects has led to the study of the combination of two new anticancer drugs. Although both kaempferol (kaem) and Ru-based metal complexes have not been proven as effective drugs, their unique anticancer activities with reduced side effects have drawn our attention to the need for further studies on their potential in anticancer application. Herein, we report the synthesis, characterization, structure, and spectroscopic properties of a kaem-based Ru (II) complex, RuCl(kaem)(DMSO) 3 (1). Because of the presence of a catechol-like functional group in its dihydropyran ring, kaem can strongly bind to the Ru(II) metal center in a basic medium. The molecular structure of the complex was characterized by spectroscopic studies and X-ray crystal structure analysis. In addition, the complex forms a molecular dimer as a result of the cooperative effect of H-bonding and π–π stacking interactions. Moreover, the molecular dimer forms a ladder-like one-dimensional network structure by water mediated H-bonding that further extended into a three-dimensional packing structure. UV–Vis spectroscopy studies of the complex demonstrated the appearance of a strong metal to ligand charge transfer (MLCT) band in the visible region with strong fluorescence emission derived from the MLCT. Further studies are now in progress to demonstrate synergetic anticancer activity

  2. Coordination chemistry of two heavy metals: I, Ligand preferences in lead(II) complexation, toward the development of therapeutic agents for lead poisoning: II, Plutonium solubility and speciation relevant to the environment

    Energy Technology Data Exchange (ETDEWEB)

    Neu, Mary Patricia [Univ. of California, Berkeley, CA (United States)

    1993-11-01

    The coordination chemistry and solution behavior of the toxic ions lead(II) and plutonium(IV, V, VI) have been investigated. The ligand pKas and ligand-lead(II) stability constants of one hydroxamic acid and four thiohydroaxamic acids were determined. Solution thermodynamic results indicate that thiohydroxamic acids are more acidic and slightly better lead chelators than hydroxamates, e.g., N-methylthioaceto-hydroxamic acid, pKa = 5.94, logβ120 = 10.92; acetohydroxamic acid, pKa = 9.34, logβ120 = 9.52. The syntheses of lead complexes of two bulky hydroxamate ligands are presented. The X-ray crystal structures show the lead hydroxamates are di-bridged dimers with irregular five-coordinate geometry about the metal atom and a stereochemically active lone pair of electrons. Molecular orbital calculations of a lead hydroxamate and a highly symmetric pseudo octahedral lead complex were performed. The thermodynamic stability of plutonium(IV) complexes of the siderophore, desferrioxamine B (DFO), and two octadentate derivatives of DFO were investigated using competition spectrophotometric titrations. The stability constant measured for the plutonium(IV) complex of DFO-methylterephthalamide is logβ120 = 41.7. The solubility limited speciation of 242Pu as a function of time in near neutral carbonate solution was measured. Individual solutions of plutonium in a single oxidation state were added to individual solutions at pH = 6.0, T = 30.0, 1.93 mM dissolved carbonate, and sampled over intervals up to 150 days. Plutonium solubility was measured, and speciation was investigated using laser photoacoustic spectroscopy and chemical methods.

  3. Coordination chemistry of two heavy metals: I, Ligand preferences in lead(II) complexation, toward the development of therapeutic agents for lead poisoning: II, Plutonium solubility and speciation relevant to the environment

    International Nuclear Information System (INIS)

    Neu, M.P.

    1993-11-01

    The coordination chemistry and solution behavior of the toxic ions lead(II) and plutonium(IV, V, VI) have been investigated. The ligand pK a s and ligand-lead(II) stability constants of one hydroxamic acid and four thiohydroaxamic acids were determined. Solution thermodynamic results indicate that thiohydroxamic acids are more acidic and slightly better lead chelators than hydroxamates, e.g., N-methylthioaceto-hydroxamic acid, pK a = 5.94, logβ 120 = 10.92; acetohydroxamic acid, pK a = 9.34, logβ l20 = 9.52. The syntheses of lead complexes of two bulky hydroxamate ligands are presented. The X-ray crystal structures show the lead hydroxamates are di-bridged dimers with irregular five-coordinate geometry about the metal atom and a stereochemically active lone pair of electrons. Molecular orbital calculations of a lead hydroxamate and a highly symmetric pseudo octahedral lead complex were performed. The thermodynamic stability of plutonium(IV) complexes of the siderophore, desferrioxamine B (DFO), and two octadentate derivatives of DFO were investigated using competition spectrophotometric titrations. The stability constant measured for the plutonium(IV) complex of DFO-methylterephthalamide is logβ 110 = 41.7. The solubility limited speciation of 242 Pu as a function of time in near neutral carbonate solution was measured. Individual solutions of plutonium in a single oxidation state were added to individual solutions at pH = 6.0, T = 30.0, 1.93 mM dissolved carbonate, and sampled over intervals up to 150 days. Plutonium solubility was measured, and speciation was investigated using laser photoacoustic spectroscopy and chemical methods

  4. Prophage induction and mutagenicity of a series of anti-tumour platinum(II) and platinum(IV) co-ordination complexes

    NARCIS (Netherlands)

    Mattern, I.E.; Cocchiarella, L.; Kralingen, C.G. van; Lohman, P.H.M.

    1982-01-01

    Eleven platinum compounds with nitrogen donor ligands, previously tested for anti-tumour activity were studied for induction of prophage lambda and for mutagenicity in the Ames assay, with various strains of Salmonella. The compounds included cis and trans isomers of Pt(II) and Pt(IV) complexes and

  5. Synthesis, chemistry and catalytic activity of complexes of lanthanide and actinide metals in unusual oxidation states and coordination environments. Progress report, February 1, 1979-January 31, 1980

    International Nuclear Information System (INIS)

    Evans, W.J.

    1979-10-01

    The new synthetic and catalytic reactions involving lanthanide metals which were discovered in the first years of this project have been examined in more detail in the past year. Synthetic and catalytic model systems have been theoretically developed and experimental testing of these hypotheses is in progress. New techniques are being applied to the lanthanide metals to further elucidate the chemistry of these complexes

  6. Combination of Scanning Probe Microscopy and Coordination Chemistry: Structural and Electronic Study of Bis(methylbenzimidazolyl)ketone and Its Iron Complex

    NARCIS (Netherlands)

    Folkertsma, Emma; Van Der Lit, Joost; Di Cicco, Francesca; Lutz, Martin; Klein Gebbink, Robertus J. M.; Swart, Ingmar; Moret, Marc-etienne

    2017-01-01

    Here, we report the bulk synthesis of [FeII(BMBIK)Cl2] bearing the redox noninnocent bis(methylbenzimidazolyl)ketone (BMBIK) ligand and the synthesis of the similar complex [FeI(BMBIK)]+ on a Au(111) surface using lateral manipulation at the atomic level. Cyclic voltammetry and scanning tunneling

  7. Synthesis and spectroscopy of clay intercalated Cu(II) bio-monomer complexes: coordination of Cu(II) with purines and nucleotides

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Leeman, H.; Schoonheydt, R.A.

    1999-01-01

    The spectroscopic properties of Cu(bio-monomer)nm+ complexes [BM=bio-monomer (purine, adenine, guanine, hypoxanthine, 5-ADP and 5-GMP)] in saponite clays have been investigated by diffuse reflectance spectroscopy (DRS) in the UV-Vis-NIR region and electron paramagnetic resonance (EPR) at X-band.

  8. Probing the lowest coordination number of dianionic platinum-cyanide complexes in the gas phase: Dynamics of the charge dissociation process

    DEFF Research Database (Denmark)

    Bojesen, G; Hvelplund, P; Jørgensen, Thomas J. D.

    2000-01-01

    Low-energy and high-energy collision induced dissociation techniques are used to study the dissociation behavior of the gaseous Pt(CN)(6)(2-) and Pt(CN)(4)(2-) dianion complexes in order to probe the smallest stable dianion complex. Loss of neutral molecules from Pt(CN)(6)(2-) occurs resulting...... in Pt(CN)(5)(2-) and Pt(CN)(4)(2-), but no indication of the existence of Pt(CN)(3)(2-) was found. This indicates that the lifetime of Pt(CN)(3)(2-) is less than 4 mus (the flight time from the collision region to the detector). In contrast, all monoanion platinum-cyanide complexes were observed, i.......e., Pt(CN)(n)(-) (n=1-6). The kinetic energy released in processes where monoanions are formed is much lower than the barrier height for the reverse reaction (>1.5 eV), which indicates that electron detachment is involved, e.g., Pt(CN)(3)(-) and CN- are not formed in the same dynamical process from Pt(CN...

  9. Binding of hydrocarbons and other extremely weak ligands to transition metal complexes that coordinate hydrogen: Investigation of cis-interactions and delocalized bonding involving sigma bonds

    International Nuclear Information System (INIS)

    Kubas, G.J.; Eckert, J.; Luo, X.L.

    1997-01-01

    This is the final report of a three-year Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). At the forefront of chemistry are efforts to catalytically transform the inert C-H bonds in alkanes to more useful products using metal compounds. The goal is to observe binding and cleavage of alkane C-H bonds on metals or to use related silane Si-H bonding as models, analogous to the discovery of hydrogen (H 2 ) binding to metals. Studies of these unique sigma complexes (M hor-ellipsis H-Y; Y double-bond H, Si, C) will aid in developing new catalysts or technologies relevant to DOE interest, e.g., new methods for tritium isotope separation. Several transition metals (Mo, W, Mn, and Pt) were found to reversibly bind and cleave H 2 , silanes, and halocarbons. The first metal-SiH 4 complexes, thus serving as a model for methane reactions. A second goal is to study the dynamics and energetics of H-Y bonds on metals by neutron scattering, and evidence for interactions between bound H-Y and nearby H atoms on metal complexes has been found

  10. Complex Interplay between FleQ, Cyclic Diguanylate and Multiple σ Factors Coordinately Regulates Flagellar Motility and Biofilm Development in Pseudomonas putida.

    Directory of Open Access Journals (Sweden)

    Alicia Jiménez-Fernández

    Full Text Available Most bacteria alternate between a free living planktonic lifestyle and the formation of structured surface-associated communities named biofilms. The transition between these two lifestyles requires a precise and timely regulation of the factors involved in each of the stages that has been likened to a developmental process. Here we characterize the involvement of the transcriptional regulator FleQ and the second messenger cyclic diguanylate in the coordinate regulation of multiple functions related to motility and surface colonization in Pseudomonas putida. Disruption of fleQ caused strong defects in flagellar motility, biofilm formation and surface attachment, and the ability of this mutation to suppress multiple biofilm-related phenotypes associated to cyclic diguanylate overproduction suggests that FleQ mediates cyclic diguanylate signaling critical to biofilm growth. We have constructed a library containing 94 promoters potentially involved in motility and biofilm development fused to gfp and lacZ, screened this library for FleQ and cyclic diguanylate regulation, and assessed the involvement of alternative σ factors σN and FliA in the transcription of FleQ-regulated promoters. Our results suggest a dual mode of action for FleQ. Low cyclic diguanylate levels favor FleQ interaction with σN-dependent promoters to activate the flagellar cascade, encompassing the flagellar cluster and additional genes involved in cyclic diguanylate metabolism, signal transduction and gene regulation. On the other hand, characterization of the FleQ-regulated σN- and FliA-independent PlapA and PbcsD promoters revealed two disparate regulatory mechanisms leading to a similar outcome: the synthesis of biofilm matrix components in response to increased cyclic diguanylate levels.

  11. (15)N NMR spectroscopy unambiguously establishes the coordination mode of the diimine linker 2-(2'-pyridyl)pyrimidine-4-carboxylic acid (cppH) in Ru(ii) complexes.

    Science.gov (United States)

    Battistin, Federica; Balducci, Gabriele; Demitri, Nicola; Iengo, Elisabetta; Milani, Barbara; Alessio, Enzo

    2015-09-21

    We investigated the reactivity of three Ru(ii) precursors -trans,cis,cis-[RuCl2(CO)2(dmso-O)2], cis,fac-[RuCl2(dmso-O)(dmso-S)3], and trans-[RuCl2(dmso-S)4] - towards the diimine linker 2-(2'-pyridyl)pyrimidine-4-carboxylic acid (cppH) or its parent compound 4-methyl-2-(2'-pyridyl)pyrimidine ligand (mpp), in which a methyl group replaces the carboxylic group on the pyrimidine ring. In principle, both cppH and mpp can originate linkage isomers, depending on how the pyrimidine ring binds to ruthenium through the nitrogen atom ortho (N(o)) or para (N(p)) to the group in position 4. The principal aim of this work was to establish a spectroscopic fingerprint for distinguishing the coordination mode of cppH/mpp also in the absence of an X-ray structural characterization. By virtue of the new complexes described here, together with the others previously reported by us, we successfully recorded {(1)H,(15)N}-HMBC NMR spectra at natural abundance of the (15)N isotope on a consistent number of fully characterized Ru(ii)-cppH/mpp compounds, most of them being stereoisomers and/or linkage isomers. Thus, we found that (15)N NMR chemical shifts unambiguously establish the binding mode of cppH and mpp - either through N(o) or N(p)- and can be conveniently applied also in the absence of the X-ray structure. In fact, coordination of cppH to Ru(ii) induces a marked upfield shift for the resonance of the N atoms directly bound to the metal, with coordination induced shifts (CIS) ranging from ca.-45 to -75 ppm, depending on the complex, whereas the unbound N atom resonates at a frequency similar to that of the free ligand. Similar results were found for the complexes of mpp. This work confirmed our previous finding that cppH has no binding preference, whereas mpp binds exclusively through N(p). Interestingly, the two cppH linkage isomers trans,cis-[RuCl2(CO)2(cppH-κN(p))] (5) and trans,cis-[RuCl2(CO)2(cppH-κN(o))] (6) were easily obtained in pure form by exploiting their different

  12. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    Shutdown critical path: progress and prospects The 2008-09 CMS shutdown is proceeding as intended.  The first two phases, in which the dominant activity (besides heavy logistics) was maintenance and repair of the barrel muon and alignment systems on all wheels and disks (but particularly YB0), have been finished successfully and on time. The yoke wheels at both ends are once again closed over the vactank. Phase 3 is in full swing and has reached maximum complexity, with work-intensity and associated risks similar those encountered in summer 2008. The status going into this CMS week is that the forward pixel tracker at the +z end (FPIX+) has been extracted and transported for maintenance, while the installation of preshower ES+, taking place in parallel, has reached the stage where the active “dee” elements are installed and the drum structures have just been moved back along the beampipe and re-mated to the electromagnetic endcaps. The phase 3 activity requires the large &l...

  13. Coordination studies of 1,2-bis(diphenylphosphinoethane with di-μ-hydroxo dinuclear complexes of tungsten(IV and molybdenum(IV

    Directory of Open Access Journals (Sweden)

    Minato Makoto

    2016-01-01

    Full Text Available The new trifluoroethoxo phosphine complexes [Cp2M(η1-dppe(CF3CH2O]+ and [Cp2(CF3CH2OM(μ-dppeMCp2(CF3CH2O]2+ (M = Mo or W, Cp = η-C5H5 and dppe = Ph2PCH2CH2PPh2 have been prepared by reaction of cationic di-μ-hydroxo dinuclear complex of molybdenocene or tungstenocene [Cp2M(μ-OH2MCp2]2+ with dppe. From the 1H and 31P NMR data, the configurations of the products could be assigned. Furtheremore, X-ray crystallography was used to definitively identify one of the product [Cp2(CF3CH2OMo(μ-dppeMoCp2(CF3CH2O]2+, which crystallizes in space group P21/c(#14 with a = 12.230(5 Å, b = 11.149(5 Å, c = 28.966(7 Å, β = 101.07(3°, V = 3876(2 Å3, and Z = 2. It was ascertained that the amount of dppe added to the reaction mixture could influence the product distribution. A mechanism involving initial replacement of the hydroxo ligand by the alkoxo group followed by nucleophilic attack of the phosphine is proposed on the basis of the reaction profile.

  14. Shared and differentiated motor skill impairments in children with dyslexia and/or attention deficit disorder: From simple to complex sequential coordination.

    Directory of Open Access Journals (Sweden)

    Marie-Ève Marchand-Krynski

    Full Text Available Dyslexia and Attention deficit disorder (AD are prevalent neurodevelopmental conditions in children and adolescents. They have high comorbidity rates and have both been associated with motor difficulties. Little is known, however, about what is shared or differentiated in dyslexia and AD in terms of motor abilities. Even when motor skill problems are identified, few studies have used the same measurement tools, resulting in inconstant findings. The present study assessed increasingly complex gross motor skills in children and adolescents with dyslexia, AD, and with both Dyslexia and AD. Our results suggest normal performance on simple motor-speed tests, whereas all three groups share a common impairment on unimanual and bimanual sequential motor tasks. Children in these groups generally improve with practice to the same level as normal subjects, though they make more errors. In addition, children with AD are the most impaired on complex bimanual out-of-phase movements and with manual dexterity. These latter findings are examined in light of the Multiple Deficit Model.

  15. Bipolar Mass Spectrometry of Labile Coordination Complexes, Redox Active Inorganic Compounds, and Proteins Using a Glass Nebulizer for Sonic-Spray Ionization

    Science.gov (United States)

    Antonakis, Manolis M.; Tsirigotaki, Alexandra; Kanaki, Katerina; Milios, Constantinos J.; Pergantis, Spiros A.

    2013-08-01

    In this study, we report on the development of a novel nebulizer configuration for sonic-spray ionization (SSI) mass spectrometry (MS), more specifically for a version of SSI that is referred to as Venturi easy ambient sonic-spray ionization (V-EASI) MS. The developed nebulizer configuration is based on a commercially available pneumatic glass nebulizer that has been used extensively for aerosol formation in atomic spectrometry. In the present study, the nebulizer was modified in order to achieve efficient V-EASI-MS operation. Upon evaluating this system, it has been demonstrated that V-EASI-MS offers some distinct advantages for the analysis of coordination compounds and redox active inorganic compounds over the predominantly used electrospray ionization (ESI) technique. Such advantages, for this type of compounds, are demonstrated here for the first time. More specifically, a series of labile heptanuclear heterometallic [CuII 6LnIII] clusters held together with artificial amino acid ligands, in addition to easily oxidized inorganic oxyanions of selenium and arsenic, were analyzed. The observed advantages pertain to V-EASI appearing to be a "milder" ionization source than ESI, not requiring electrical potentials for gas phase ion formation, thus eliminating the possibility of unwanted redox transformations, allowing for the "simultaneous" detection of negative and positive ions (bipolar analysis) without the need to change source ionization conditions, and also not requiring the use of syringes and delivery pumps. Because of such features, especially because of the absence of ionization potentials, EASI can be operated with minimal requirements for source parameter optimization. We observed that source temperature and accelerating voltage do not seem to affect labile compounds to the extent they do in ESI-MS. In addition, bipolar analysis of proteins was demonstrated here by acquiring both positive and negative ion mass spectra from the same protein solutions

  16. Syntheses, crystal structures and Hirshfeld surface analysis of a coordination polymer of Cu(II) chlorido and a tris-octahedral complex of Ni(II) containing isonicotinoylhydrazone blockers

    Science.gov (United States)

    Mahmoudi, Ghodrat; Chowdhury, Habibar; Ghosh, Barindra K.; Lofland, Samuel E.; Maniukiewicz, Waldemar

    2018-05-01

    One-pot reactions of pre-assigned molar ratios of appropriate metal (II) salts and HL1 (2-acetylpyridine nicotinoylhydrazone) or HL2 (2-acetylpyridine isonicotinoylhydrazone) in MeOH solutions at room temperature afford 1D coordination polymeric chain [Cu(μ-L1) (Cl)]n (1) and a mononuclear complex [Ni(L2)2] (2). The compounds (1) and (2) were characterized using elemental analyses, spectral and other physicochemical methods. Single crystal X-ray diffraction measurements for (1) and (2) have been made to define the molecular aggregates and crystalline architectures. In (1), each copper (II) center adopts a distorted square pyramidal geometry with a CuN3OCl chromophore linked through μ-L1 to form the 1D polymeric chain. While in (2) each Ni(II) cation is six-coordinate with octahedral structure having NiN4O2 chromophore containing two L2 units each functioning as a classical tridentate (N,N,O) chelator. Different weak non-covalent interactions promote dimensionalities in the compounds. A Hirshfeld surface analysis was employed to gain additional insight into interactions responsible for packing of (1) and (2). Magnetic susceptibility measurement of (1) in the 4-300 K range reveals simple paramagnetism.

  17. 25-hydroxycholesterol promotes RANKL-induced osteoclastogenesis through coordinating NFATc1 and Sp1 complex in the transcription of miR-139-5p

    International Nuclear Information System (INIS)

    Zhang, Lishan; Lv, Yinping; Xian, Guozhe; Lin, Yanliang

    2017-01-01

    25-hydroxycholesterol (25-HC) is implicated in many processes, including lipid metabolism and the immune response. However, the role of 25-HC in RANKL-induced osteoclastogenesis remains largely unknown. Our results showed that 25-HC inhibited miR-139-5p expression in mouse bone marrow macrophages (BMMs) cultured in receptor activator of NF-κB ligand (RANKL) and monocyte macrophage colony-stimulating factor (M-CSF). Further investigation suggested that 25-HC promoted the expression of nuclear factor of activated T cell cytoplasmic 1 (NFATc1) and Sp1, especially in the presence of RANKL and M-CSF. Meanwhile, 25-HC induced nuclear translocation of NFATc1, resulting in the interaction between NFATc1 and Sp1 that was confirmed by co-immunoprecipitation. Chromatin immunoprecipitation assay indicated that Sp1 could bind to miR-139-5p promoter, but NFATc1 had no binding capacity. Although forming NFATc1/Sp1 complex increased its binding to miR-139-5p promoter, the complex inhibited the transcriptional activity of Sp1. Inhibition of NFATc1 increase the expression of miR-139-5p, which might be due to the release of free Sp1 that could bind to the promoter of miR-139-5p. Enforced expression of miR-139-5p impaired osteoclastogenesis induced by co-treatment with 25-HC and RANKL. These results suggested that 25-HC induced the interaction between NFATc1 and Sp1, reducing the level of free Sp1 to inhibit miR-139-5p expression and promote osteoclastogenesis. - Highlights: • 25-hydroxycholesterol inhibited miR-139-5p expression in bone marrow macrophages. • 25-hydroxycholesterol promoted the expression of NFATc1 and Sp1. • 25-hydroxycholesterol induced the interaction between NFATc1 and Sp1. • NFATc1/Sp1 complex inhibited the transcription of miR-139-5p. • MiR-139-5p impaired osteoclastogenesis induced by 25-hydroxycholesterol and RANKL.

  18. Theory and X-ray Absorption Spectroscopy for Aluminum Coordination Complexes – Al K-Edge Studies of Charge and Bonding in (BDI)Al, (BDI)AlR2, and (BDI)AlX2 Complexes.

    Science.gov (United States)

    Altman, Alison B; Pemmaraju, C D; Camp, Clément; Arnold, John; Minasian, Stefan G; Prendergast, David; Shuh, David K; Tyliszczak, Tolek

    2015-08-19

    Polarized aluminum K-edge X-ray absorption near edge structure (XANES) spectroscopy and first-principles calculations were used to probe electronic structure in a series of (BDI)Al, (BDI)AlX2, and (BDI)AlR2 coordination compounds (X = F, Cl, I; R = H, Me; BDI = 2,6-diisopropylphenyl-β-diketiminate). Spectral interpretations were guided by examination of the calculated transition energies and polarization-dependent oscillator strengths, which agreed well with the XANES spectroscopy measurements. Pre-edge features were assigned to transitions associated with the Al 3p orbitals involved in metal-ligand bonding. Qualitative trends in Al 1s core energy and valence orbital occupation were established through a systematic comparison of excited states derived from Al 3p orbitals with similar symmetries in a molecular orbital framework. These trends suggested that the higher transition energies observed for (BDI)AlX2 systems with more electronegative X(1-) ligands could be ascribed to a decrease in electron density around the aluminum atom, which causes an increase in the attractive potential of the Al nucleus and concomitant increase in the binding energy of the Al 1s core orbitals. For (BDI)Al and (BDI)AlH2 the experimental Al K-edge XANES spectra and spectra calculated using the eXcited electron and Core-Hole (XCH) approach had nearly identical energies for transitions to final state orbitals of similar composition and symmetry. These results implied that the charge distributions about the aluminum atoms in (BDI)Al and (BDI)AlH2 are similar relative to the (BDI)AlX2 and (BDI)AlMe2 compounds, despite having different formal oxidation states of +1 and +3, respectively. However, (BDI)Al was unique in that it exhibited a low-energy feature that was attributed to transitions into a low-lying p-orbital of b1 symmetry that is localized on Al and orthogonal to the (BDI)Al plane. The presence of this low-energy unoccupied molecular orbital on electron-rich (BDI)Al distinguishes

  19. Coordinate Activation of Redox-Dependent ASK1/TGF-β Signaling by a Multiprotein Complex (MPK38, ASK1, SMADs, ZPR9, and TRX) Improves Glucose and Lipid Metabolism in Mice.

    Science.gov (United States)

    Seong, Hyun-A; Manoharan, Ravi; Ha, Hyunjung

    2016-03-10

    To explore the molecular connections between redox-dependent apoptosis signal-regulating kinase 1 (ASK1) and transforming growth factor-β (TGF-β) signaling pathways and to examine the physiological processes in which coordinated regulation of these two signaling pathways plays a critical role. We provide evidence that the ASK1 and TGF-β signaling pathways are interconnected by a multiprotein complex harboring murine protein serine-threonine kinase 38 (MPK38), ASK1, Sma- and Mad-related proteins (SMADs), zinc-finger-like protein 9 (ZPR9), and thioredoxin (TRX) and demonstrate that the activation of either ASK1 or TGF-β activity is sufficient to activate both the redox-dependent ASK1 and TGF-β signaling pathways. Physiologically, the restoration of the downregulated activation levels of ASK1 and TGF-β signaling in genetically and diet-induced obese mice by adenoviral delivery of SMAD3 or ZPR9 results in the amelioration of adiposity, hyperglycemia, hyperlipidemia, and impaired ketogenesis. Our data suggest that the multiprotein complex linking ASK1 and TGF-β signaling pathways may be a potential target for redox-mediated metabolic complications.

  20. Controlled synthesis, formation mechanism, and carbon oxidation properties of Ho{sub 2}Cu{sub 2}O{sub 5} nanoplates prepared with a coordination-complex method

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Rui [School of Resources and Materials, Northeastern University at Qinhuangdao 066004 (China); School of Metallurgy, Northeastern University, Shenyang 110004 (China); You, Junhua [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 (China); Han, Fei; Li, Chaoyang; Zheng, Guiyuan; Xiao, Weicheng [School of Resources and Materials, Northeastern University at Qinhuangdao 066004 (China); Liu, Xuanwen, E-mail: lxw@mail.neuq.edu.cn [School of Resources and Materials, Northeastern University at Qinhuangdao 066004 (China); School of Metallurgy, Northeastern University, Shenyang 110004 (China)

    2017-02-28

    Highlights: • The crystallization mechanism relies on Ho{sup 3+} and Cu{sup 2+} diffusion. • The Ho{sub 2}Cu{sub 2}O{sub 5} particles are refined by the coordination complex method under N{sub 2} environment. • The catalytic oxidation activity of Ho{sub 2}Cu{sub 2}O{sub 5} samples for carbon is enhanced. - Abstract: Ho{sub 2}Cu{sub 2}O{sub 5} nanoplates with perovskite structures were synthesized via a simple solution method (SSM) and a coordination-complex method (CCM) using [HoCu(3,4-pdc){sub 2}(OAc)(H{sub 2}O){sub 3}]·8H{sub 2}O (L = 3,4-pyridinedicarboxylic acid) as a precursor. The CCM was also performed in an N{sub 2} environment (CCMN) under various calcination conditions. The crystallization processes were characterized using X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. Ho{sub 2}Cu{sub 2}O{sub 5} formed through the diffusion of CuO into Ho{sub 2}O{sub 3} particles. Cu{sup 2+} diffused faster than Ho{sup 3+} during this process. The initial products of CCMN (along with the thermal decomposition products) were initially laminarized in the N{sub 2} atmosphere, which prevented the growth of CuO particles and decreased the size of the Ho{sub 2}Cu{sub 2}O{sub 5} particles. The final Ho{sub 2}Cu{sub 2}O{sub 5} particles from CCMN had a nanoplate morphology with an average thickness of 75 nm. The decomposition of organic molecules and protection from N{sub 2} played important roles in determining the morphology of the resulting Ho{sub 2}Cu{sub 2}O{sub 5}. The catalytic oxidation activity of Ho{sub 2}Cu{sub 2}O{sub 5} samples for carbon was characterized using a specific surface area measurement and thermogravimetric analysis, which revealed that the samples produced by CCMN had the highest catalytic activity.

  1. Low temperature X-ray structure analyses combined with NBO studies of a new heteroleptic octa-coordinated Holmium(III) complex with N,N,N-tridentate hydrazono-phthalazine-type ligand

    Science.gov (United States)

    Soliman, Saied M.; El-Faham, Ayman

    2018-04-01

    The new heteroleptic [HoL(H2O)5]Br3 complex, L is hydrazono-phthalazine ligand, is synthesized and its molecular structure aspects were analyzed using single crystal X-ray structure (SCXRD), Hirshfeld (HF) analysis, quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) method. The SCXRD showed that the Ho is octa-coordinated with one N,N,N-tridentate ligand L and five water molecules. The HF analysis is used to analyze the molecular packing in the [HoL(H2O)5]Br3crystal structure. The complex cations are connected via strong Osbnd H⋯Br and Nsbnd H⋯Br H-bonding interactions which have greater importance than the Csbnd H⋯Br contacts. Also, all the Hosbnd N and Hosbnd O bonds have the characteristics of closed shell interactions using QTAIM. The natural orbitals included in these interactions were analyzed using NBO method. The alpha LP*(8)Ho and beta LP*(4)Ho which have mainly s-orbital characters are the most important anti-bonding natural orbitals included in all Ho-N and Hosbnd O bonds. The rest of the Ho anti-bonding orbitals which have either p or d-orbital characters shared partially in the Ho-ligands interactions. Natural charges analysis revealed the presence of significant amount of electron density (0.9225-0.9300 e) transferred from the ligands to Ho (2.0700-2.0775 e). Spherical spin density with ∼4.0 e is predicted over the Ho atom.

  2. A Novel Pentadentate Coordination Mode for the Carbonato Bridge: Synthesis, Crystal Structure, and Magnetic Behavior of (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)], a New Trinuclear Nickel(II) Carbonato-Bridged Complex with Strong Antiferromagnetic Coupling.

    Science.gov (United States)

    Escuer, Albert; Vicente, Ramon; Kumar, Sujit B.; Solans, Xavier; Font-Bardía, Mercé; Caneschi, Andrea

    1996-05-22

    The trinuclear complex (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] was obtained by reaction of basic solutions of nickel(II), Medpt (bis(3aminopropyl)methylamine) and thiocyanate ligand with atmospheric CO(2) or by simple reaction with carbonate anion. (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] crystallizes in the triclinic system, space group P&onemacr;, with a = 12.107(5) Å, b = 12.535(7) Å, c = 16.169(9) Å, alpha = 102.69(5) degrees, beta = 92.91(5) degrees, gamma = 118.01(4) degrees, Z = 2, and R = 0.043. The three nickel atoms are asymmetrically bridged by one pentadentate carbonato ligand, which shows a novel coordination mode. The (&mgr;(3)-CO(3))[Ni(3)(Medpt)(3)(NCS)(4)] compound shows a very strong antiferromagnetic coupling. Fit as irregular triangular arrangement gave J(1) = -88.4, J(2) = -57.7, and J(3) = -9.6 cm(-)(1), which is the strongest AF coupling observed to date for Ni(3) compounds. The magnetic behavior of the carbonato bridge is discussed.

  3. Explicitly computing geodetic coordinates from Cartesian coordinates

    Science.gov (United States)

    Zeng, Huaien

    2013-04-01

    This paper presents a new form of quartic equation based on Lagrange's extremum law and a Groebner basis under the constraint that the geodetic height is the shortest distance between a given point and the reference ellipsoid. A very explicit and concise formulae of the quartic equation by Ferrari's line is found, which avoids the need of a good starting guess for iterative methods. A new explicit algorithm is then proposed to compute geodetic coordinates from Cartesian coordinates. The convergence region of the algorithm is investigated and the corresponding correct solution is given. Lastly, the algorithm is validated with numerical experiments.

  4. Traceability and uncertainty estimation in coordinate metrology

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Savio, Enrico; De Chiffre, Leonardo

    2001-01-01

    National and international standards have defined performance verification procedures for coordinate measuring machines (CMMs) that typically involve their ability to measure calibrated lengths and to a certain extent form. It is recognised that, without further analysis or testing, these results...... are required. Depending on the requirements for uncertainty level, different approaches may be adopted to achieve traceability. Especially in the case of complex measurement situations and workpieces the procedures are not trivial. This paper discusses the establishment of traceability in coordinate metrology...

  5. The curvature coordinate system

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2007-01-01

    The paper describes a concept for a curvature coordinate system on regular curved surfaces from which faceted surfaces with plane quadrangular facets can be designed. The lines of curvature are used as parametric lines for the curvature coordinate system on the surface. A new conjugate set of lin...

  6. Coordinate measuring machines

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceabilit...... and uncertainty during coordinate measurements, 3) Digitalisation and Reverse Engineering. This document contains a short description of each step in the exercise and schemes with room for taking notes of the results.......This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceability...

  7. Regional transit coordination guidebook.

    Science.gov (United States)

    2009-01-01

    Constant growth in rural areas and extensive suburban development have contributed to increasingly more people needing seamless and adequate public transportation into and from nearby cities. Coordinating existing services or determining the need for...

  8. Supercritical Airfoil Coordinates

    Data.gov (United States)

    National Aeronautics and Space Administration — Rectangular Supercritical Wing (Ricketts) - design and measured locations are provided in an Excel file RSW_airfoil_coordinates_ricketts.xls . One sheet is with Non...

  9. Developmental coordination disorder

    Science.gov (United States)

    Developmental coordination disorder can lead to: Learning problems Low self-esteem resulting from poor ability at sports and teasing by other children Repeated injuries Weight gain as a result of not wanting to participate ...

  10. Environmental Compliance Issue Coordination

    Science.gov (United States)

    An order to establish the Department of Energy (DOE) requirements for coordination of significant environmental compliance issues to ensure timely development and consistent application of Departmental environmental policy and guidance

  11. Data Management Coordinators (DMC)

    Science.gov (United States)

    The Regional Data Management Coordinators (DMCs) were identified to serve as the primary contact for each region for all Water Quality Framework activities. They will facilitate and communicate information to the necessary individuals at the region and tra

  12. Coordinate-invariant regularization

    International Nuclear Information System (INIS)

    Halpern, M.B.

    1987-01-01

    A general phase-space framework for coordinate-invariant regularization is given. The development is geometric, with all regularization contained in regularized DeWitt Superstructures on field deformations. Parallel development of invariant coordinate-space regularization is obtained by regularized functional integration of the momenta. As representative examples of the general formulation, the regularized general non-linear sigma model and regularized quantum gravity are discussed. copyright 1987 Academic Press, Inc

  13. Hypersensitive transition spectrum of f-element and coordination structure

    International Nuclear Information System (INIS)

    Cao Xuan; Song Chongli; Zhu Youngjun

    1992-10-01

    Some f-f transitions of Ln(An) metallic ions have particular super-sensitivity to the change of coordination environments. This is called super-sensitive transitions. Based on the irreducible tensor operator method, a computation model and corresponding computer program for calculating the hypersensitive transition spectrum of f-element were developed. By comparing the theoretical spectra of all possible coordination structures with experimental one, the possible coordination structures of complex can be determined. The coordination structures of Nd 3+ , Er 3 + hydrate and their extraction complex with H(DEHP) were successfully determined by this method, and the experimental spectra were also assigned

  14. Magnetic Coordinate Systems

    Science.gov (United States)

    Laundal, K. M.; Richmond, A. D.

    2017-03-01

    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.

  15. Construction of a monoanionic S,N,S-pincer ligand with a pyrrole core by sequential [1,2] phospho-Fries rearrangement. Characterization of palladium and silver coordination complexes

    NARCIS (Netherlands)

    Fraix, A.; Lutz, M.; Spek, A.L.; Klein Gebbink, R.J.M.; van Koten, G.; Salaun, J. -Y; Jaffrès, P. -A

    2010-01-01

    The synthesis of an S,NH,S-pincer ligand possessing a pyrrole core and two O,O-diethylthiophosphonyl groups to design PS lateral coordination sites is reported. The synthetic procedure to produce this ligand makes use of the nitrogen atom of the pyrrole heterocycle to successively functionalize the

  16. The thermodynamic of complex formation in system of the Fe(III)-Fe(II)-benzimidazole-water in the inflation of ion strength in the formation of co-ordination compounds in the 288 K

    International Nuclear Information System (INIS)

    Nazarova, Kh.D.; Rajabov, U.R.; Yusupov, Z.N.

    2005-01-01

    With the Method of Oxredmatrion with application of the Oxidation Function in the Temperature 288 K and ion strength 0.1; 0.25; 0.50 and 1.00 in the Water solution of Benzimidazole been obtained the Formation Constants of the Coordination and their dependence with ion strength

  17. Silver(I) complexes of the weakly coordinating solvents SO(2) and CH(2)Cl(2): crystal structures, bonding, and energetics of [Ag(OSO)][Al{OC(CF(3))(3)}(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(CH(2)Cl(2))(2)][SbF(6)].

    Science.gov (United States)

    Decken, Andreas; Knapp, Carsten; Nikiforov, Grigori B; Passmore, Jack; Rautiainen, J Mikko; Wang, Xinping; Zeng, Xiaoqing

    2009-06-22

    Pushing the limits of coordination chemistry: The most weakly coordinated silver complexes of the very weakly coordinating solvents dichloromethane and liquid sulfur dioxide were prepared. Special techniques at low temperatures and the use of weakly coordinating anions allowed structural characterization of [Ag(OSO)][Al{OC(CF(3))(3)}(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(Cl(2)CH(2))(2)][SbF(6)] (see figure). An investigation of the bonding shows that these complexes are mainly stabilized by electrostatic monopole-dipole interactions.The synthetically useful solvent-free silver(I) salt Ag[Al(pftb)(4)] (pftb=--OC(CF(3))(3)) was prepared by metathesis reaction of Li[Al(pftb)(4)] with Ag[SbF(6)] in liquid SO(2). The solvated complexes [Ag(OSO)][Al(pftb)(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(CH(2)Cl(2))(2)][SbF(6)] were prepared and isolated by special techniques at low temperatures and structurally characterized by single-crystal X-ray diffraction. The SO(2) complexes provide the first examples of coordination of the very weak Lewis base SO(2) to silver(I). The SO(2) molecule in [Ag(OSO)][Al(pftb)(4)] is eta(1)-O coordinated to Ag(+), while the SO(2) ligands in [Ag(OSO)(2/2)][SbF(6)] bridge two Ag(+) ions in an eta(2)-O,O' (trans,trans) manner. [Ag(CH(2)Cl(2))(2)][SbF(6)] contains [Ag(CH(2)Cl(2))(2)](+) ions linked through [SbF(6)](-) ions to give a polymeric structure. The solid-state silver(I) ion affinities (SIA) of SO(2) and CH(2)Cl(2), based on bond lengths and corresponding valence units in the corresponding complexes and tensimetric titrations of Ag[Al(pftb)(4)] and Ag[SbF(6)] with SO(2) vapor, show that SO(2) is a weaker ligand to Ag(+) than the commonly used weakly coordinating solvent CH(2)Cl(2) and indicated that binding strength of SO(2) to silver(I) in the silver(I) salts increases with increasing size of the corresponding counteranion ([Al(pftb)(4)](-)>[SbF(6)](-)). The experimental findings are in good agreement with theoretical gas-phase ligand

  18. Variationally optimal selection of slow coordinates and reaction coordinates in macromolecular systems

    Science.gov (United States)

    Noe, Frank

    To efficiently simulate and generate understanding from simulations of complex macromolecular systems, the concept of slow collective coordinates or reaction coordinates is of fundamental importance. Here we will introduce variational approaches to approximate the slow coordinates and the reaction coordinates between selected end-states given MD simulations of the macromolecular system and a (possibly large) basis set of candidate coordinates. We will then discuss how to select physically intuitive order paremeters that are good surrogates of this variationally optimal result. These result can be used in order to construct Markov state models or other models of the stationary and kinetics properties, in order to parametrize low-dimensional / coarse-grained model of the dynamics. Deutsche Forschungsgemeinschaft, European Research Council.

  19. Spectroscopic, thermal and biological studies of coordination

    Indian Academy of Sciences (India)

    Spectroscopic, thermal and biological studies of coordination compounds of sulfasalazine drug: Mn(II), Hg(II), Cr(III), ZrO(II), VO(II) and Y(III) transition metal ... The thermal decomposition of the complexes as well as thermodynamic parameters ( *}, *, * and *) were estimated using Coats–Redfern and ...

  20. [Binocular coordination during reading].

    Science.gov (United States)

    Bassou, L; Granié, M; Pugh, A K; Morucci, J P

    1992-01-01

    Is there an effect on binocular coordination during reading of oculomotor imbalance (heterophoria, strabismus and inadequate convergence) and of functional lateral characteristics (eye preference and perceptually privileged visual laterality)? Recordings of the binocular eye-movements of ten-year-old children show that oculomotor imbalances occur most often among children whose left visual perceptual channel is privileged, and that these subjects can present optomotor dissociation and manifest lack of motor coordination. Close binocular motor coordination is far from being the norm in reading. The faster reader displays saccades of differing spatial amplitude and the slower reader an oculomotor hyperactivity, especially during fixations. The recording of binocular movements in reading appears to be an excellent means of diagnosing difficulties related to visual laterality and to problems associated with oculomotor imbalance.

  1. Quantifying linguistic coordination

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    task (Bahrami et al 2010, Fusaroli et al. 2012) we extend to linguistic coordination dynamical measures of recurrence employed in the analysis of sensorimotor coordination (such as heart-rate (Konvalinka et al 2011), postural sway (Shockley 2005) and eye-movements (Dale, Richardson and Kirkham 2012......). We employ nominal recurrence analysis (Orsucci et al 2005, Dale et al 2011) on the decision-making conversations between the participants. We report strong correlations between various indexes of recurrence and collective performance. We argue this method allows us to quantify the qualities...

  2. Postural Coordination during Socio-motor Improvisation.

    Science.gov (United States)

    Gueugnon, Mathieu; Salesse, Robin N; Coste, Alexandre; Zhao, Zhong; Bardy, Benoît G; Marin, Ludovic

    2016-01-01

    Human interaction often relies on socio-motor improvisation. Creating unprepared movements during social interaction is not a random process but relies on rules of synchronization. These situations do not only involve people to be coordinated, but also require the adjustment of their posture in order to maintain balance and support movements. The present study investigated posture in such a context. More precisely, we first evaluated the impact of amplitude and complexity of arm movements on posture in solo situation. Then, we assessed the impact of interpersonal coordination on posture using the mirror game in which dyads performed improvised and synchronized movements (i.e., duo situation). Posture was measured through ankle-hip coordination in medio-lateral and antero-posterior directions (ML and AP respectively). Our results revealed the spontaneous emergence of in-phase pattern in ML direction and antiphase pattern in AP direction for solo and duo situations. These two patterns respectively refer to the simultaneous flexion/extension of the ankles and the hips in the same or opposite direction. It suggests different functional roles of postural coordination patterns in each direction, with in-phase supporting task performance in ML (dynamical stability) and antiphase supporting postural control in AP (mechanical stability). Although amplitude of movement did not influence posture, movement complexity disturbed postural stability in both directions. Conversely, interpersonal coordination promoted postural stability in ML but not in AP direction. These results are discussed in terms of the difference in coupling strength between ankle-hip coordination and interpersonal coordination.

  3. Postural coordination during socio-motor improvisation

    Directory of Open Access Journals (Sweden)

    Mathieu Gueugnon

    2016-08-01

    Full Text Available Human interaction often relies on socio-motor improvisation. Creating unprepared movements during social interaction is not a random process but relies on rules of synchronization. These situations do not only involve people to be coordinated, but also require the adjustment of their posture in order to maintain balance and support movements. The present study investigated posture in such a context. More precisely, we first evaluated the impact of amplitude and complexity of arm movements on posture in solo situation. Then, we assessed the impact of interpersonal coordination on posture using the mirror game in which dyads performed improvised and synchronized movements (i.e., duo situation. Posture was measured through ankle-hip coordination in medio-lateral and antero-posterior directions (ML and AP respectively. Our results revealed the spontaneous emergence of in-phase pattern in ML direction and anti-phase pattern in AP direction for solo and duo situations. These two patterns respectively refer to the simultaneous flexion/extension of the ankles and the hips in the same or opposite direction. It suggests different functional roles of postural coordination patterns in each direction, with in-phase supporting task performance in ML (dynamical stability and antiphase supporting postural control in AP (mechanical stability. Although amplitude of movement did not influence posture, movement complexity disturbed postural stability in both directions. Conversely, interpersonal coordination promoted postural stability in ML but not in AP direction. These results are discussed in terms of the difference in coupling strength between ankle-hip coordination and interpersonal coordination.

  4. Coordination behavior of tetraaza [N4] ligand towards Co(II), Ni(II), Cu(II), Cu(I) and Pd(II) complexes: Synthesis, spectroscopic characterization and anticancer activity

    Science.gov (United States)

    El-Boraey, Hanaa A.

    2012-11-01

    Novel eight Co(II), Ni(II), Cu(II), Cu(I) and Pd(II) complexes with [N4] ligand (L) i.e. 2-amino-N-{2-[(2-aminobenzoyl)amino]ethyl}benzamide have been synthesized and structurally characterized by elemental analysis, spectral, thermal (TG/DTG), magnetic, and molar conductivity measurements. On the basis of IR, mass, electronic and EPR spectral studies an octahedral geometry has been proposed for Co(II), Ni(II) complexes and Cu(II) chloride complex, square-pyramidal for Cu(I) bromide complex. For Cu(II) nitrate complex (6), Pd(II) complex (8) square planar geometry was proposed. The EPR data of Cu(II) complexes in powdered form indicate dx2-y2 ground state of Cu(II) ion. The antitumor activity of the synthesized ligand and some selected metal complexes has been studied. The palladium(II) complex (8) was found to display cytotoxicity (IC50 = 25.6 and 41 μM) against human breast cancer cell line MCF-7 and human hepatocarcinoma HEPG2 cell line.

  5. Dimensions of Organizational Coordination

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Aldewereld, Huib; Dignum, Virginia

    2013-01-01

    be supported to include organizational objectives and constraints into their reasoning processes by considering two alternatives: agent reasoning and middleware regulation. We show how agents can use an organizational specification to achieve organizational objectives by delegating and coordinating...... their activities with other agents in the society, using the GOAL agent programming language and the OperA organizational model....

  6. Reusability of coordination programs

    NARCIS (Netherlands)

    F. Arbab (Farhad); C.L. Blom (Kees); F.J. Burger (Freek); C.T.H. Everaars (Kees)

    1996-01-01

    textabstractIsolating computation and communication concerns into separate pure computation and pure coordination modules enhances modularity, understandability, and reusability of parallel and/or distributed software. This can be achieved by moving communication primitives (such as SendMessage and

  7. Coordination of hand shape.

    Science.gov (United States)

    Pesyna, Colin; Pundi, Krishna; Flanders, Martha

    2011-03-09

    The neural control of hand movement involves coordination of the sensory, motor, and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In the first experiment, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, and pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support, or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus, somatosensory and motor information appear to be coordinated in an object-based, spatial-coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness.

  8. Block coordination copolymers

    Science.gov (United States)

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2012-11-13

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  9. Breakdowns in Coordination Between Air Traffic Controllers

    Science.gov (United States)

    Bearman, Chris; Orasanu, Judith; Miller, Ronald C.

    2011-01-01

    This talk outlines the complexity of coordination in air traffic control, introduces the NextGen technologies, identifies common causes for coordination breakdowns in air traffic control and examines whether these causes are likely to be reduced with the introduction of NextGen technologies. While some of the common causes of breakdowns will be reduced in a NextGen environment this conclusion should be drawn carefully given the current stage of development of the technologies and the observation that new technologies often shift problems rather than reduce them.

  10. Coordination failure caused by sunspots

    DEFF Research Database (Denmark)

    Beugnot, Julie; Gürgüç, Zeynep; Øvlisen, Frederik Roose

    2012-01-01

    on the efficient equilibrium, we consider sunspots as a potential reason for coordination failure. We conduct an experiment with a three player 2x2x2 game in which coordination on the efficient equilibrium is easy and should normally occur. In the control session, we find almost perfect coordination on the payoff......-dominant equilibrium, but in the sunspot treatment, dis-coordination is frequent. Sunspots lead to significant inefficiency, and we conclude that sunspots can indeed cause coordination failure....

  11. Oxidative degradation of the organometallic iron(II) complex [Fe{bis[3-(pyridin-2-yl)-1H-imidazol-1-yl]methane}(MeCN)(PMe3)](PF6)2: structure of the ligand decomposition product trapped via coordination to iron(II).

    Science.gov (United States)

    Haslinger, Stefan; Pöthig, Alexander; Cokoja, Mirza; Kühn, Fritz E

    2015-12-01

    Iron is of interest as a catalyst because of its established use in the Haber-Bosch process and because of its high abundance and low toxicity. Nitrogen-heterocyclic carbenes (NHC) are important ligands in homogeneous catalysis and iron-NHC complexes have attracted increasing attention in recent years but still face problems in terms of stability under oxidative conditions. The structure of the iron(II) complex [1,1'-bis(pyridin-2-yl)-2,2-bi(1H-imidazole)-κN(3)][3,3'-bis(pyridin-2-yl-κN)-1,1'-methanediylbi(1H-imidazol-2-yl-κC(2))](trimethylphosphane-κP)iron(II) bis(hexafluoridophosphate), [Fe(C17H14N6)(C16H12N6)(C3H9P)](PF6)2, features coordination by an organic decomposition product of a tetradentate NHC ligand in an axial position. The decomposition product, a C-C-coupled biimidazole, is trapped by coordination to still-intact iron(II) complexes. Insights into the structural features of the organic decomposition products might help to improve the stability of oxidation catalysts under harsh conditions.

  12. Arene ruthenium(II) azido complexes incorporating N intersection O chelate ligands: Synthesis, spectral studies and 1,3-dipolar-cycloaddition to a coordinated azide in ruthenium(II) compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, K.S.; Kaminsky, W.

    showed a slightly different spectra pattern for p- cymene ligand as compared to the rest of the complexes. For instant, the complex 1 exhibits two doublets for diastereotopic methyl protons of the isopropyl group at around δ 1.12-0.99 (Fig. 1). Likewise... formed are exclusively N(2) bound isomer which is supported by their NMR spectral data. For instant, the proton NMR spectrum of 8 displayed a, singlet at δ 3.75 assignable to the protons of a methoxy carbonyl group while for complex 9 a quartet...

  13. Synthesis of a ruthenium(II) bipyridyl complex coordinated by a functionalized Schiff base ligand: characterization, spectroscopic and isothermal titration calorimetry measurements of M2+ binding and sensing (M2+=Ca2+, Mg2+).

    Science.gov (United States)

    Dixit, Namrata; Mishra, Lallan; Mustafi, Sourajit M; Chary, Kandala V R; Houjou, Hirohiko

    2009-07-01

    Bis-[methylsalicylidine-4'benzoic acid]-ethylene (LH2) complexed with cis-Ru(bpy)2Cl(2).2H2O provides a complex of composition [Ru(bpy)2L].2NH4PF6 (1), which has been characterized spectroscopically. Its binding behaviour towards Mg2+ and Ca2+ ions is monitored using 1H NMR titration, isothermal titration calorimetry (ITC) and luminescence microscopy. The luminescent ruthenium complex binds Ca2+ in a more selective manner as compared to Mg2+.

  14. Nonparametric variational optimization of reaction coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Banushkina, Polina V.; Krivov, Sergei V., E-mail: s.krivov@leeds.ac.uk [Astbury Center for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2015-11-14

    State of the art realistic simulations of complex atomic processes commonly produce trajectories of large size, making the development of automated analysis tools very important. A popular approach aimed at extracting dynamical information consists of projecting these trajectories into optimally selected reaction coordinates or collective variables. For equilibrium dynamics between any two boundary states, the committor function also known as the folding probability in protein folding studies is often considered as the optimal coordinate. To determine it, one selects a functional form with many parameters and trains it on the trajectories using various criteria. A major problem with such an approach is that a poor initial choice of the functional form may lead to sub-optimal results. Here, we describe an approach which allows one to optimize the reaction coordinate without selecting its functional form and thus avoiding this source of error.

  15. Coordination: Neural, Behavioral and Social Dynamics

    CERN Document Server

    Fuchs, Armin

    2008-01-01

    One of the most striking features of Coordination Dynamics is its interdisciplinary character. The problems we are trying to solve in this field range from behavioral phenomena of interlimb coordination and coordination between stimuli and movements (perception-action tasks) through neural activation patterns that can be observed during these tasks to clinical applications and social behavior. It is not surprising that close collaboration among scientists from different fields as psychology, kinesiology, neurology and even physics are imperative to deal with the enormous difficulties we are facing when we try to understand a system as complex as the human brain. The chapters in this volume are not simply write-ups of the lectures given by the experts at the meeting but are written in a way that they give sufficient introductory information to be comprehensible and useful for all interested scientists and students.

  16. A Process Algebra for Supervisory Coordination

    Directory of Open Access Journals (Sweden)

    Jos Baeten

    2011-08-01

    Full Text Available A supervisory controller controls and coordinates the behavior of different components of a complex machine by observing their discrete behaviour. Supervisory control theory studies automated synthesis of controller models, known as supervisors, based on formal models of the machine components and a formalization of the requirements. Subsequently, code generation can be used to implement this supervisor in software, on a PLC, or embedded microprocessor. In this article, we take a closer look at the control loop that couples the supervisory controller and the machine. We model both event-based and state-based observations using process algebra and bisimulation-based semantics. The main application area of supervisory control that we consider is coordination, referred to as supervisory coordination, and we give an academic and an industrial example, discussing the process-theoretic concepts employed.

  17. Improving Project Manufacturing Coordination

    Directory of Open Access Journals (Sweden)

    Korpivaara Ville

    2014-09-01

    Full Text Available The objective of this research is to develop firms’ project manufacturing coordination. The development will be made by centralizing the manufacturing information flows in one system. To be able to centralize information, a deep user need assessment is required. After user needs have been identified, the existing system will be developed to match these needs. The theoretical background is achieved through exploring the literature of project manufacturing, development project success factors and different frameworks and tools for development project execution. The focus of this research is rather in customer need assessment than in system’s technical expertise. To ensure the deep understanding of customer needs this study is executed by action research method. As a result of this research the information system for project manufacturing coordination was developed to respond revealed needs of the stakeholders. The new system improves the quality of the manufacturing information, eliminates waste in manufacturing coordination processes and offers a better visibility to the project manufacturing. Hence it provides a solid base for the further development of project manufacturing.

  18. Universal mechatronics coordinator

    Science.gov (United States)

    Muir, Patrick F.

    1999-11-01

    Mechatronic systems incorporate multiple actuators and sensor which must be properly coordinated to achieve the desired system functionality. Many mechatronic systems are designed as one-of-a-kind custom projects without consideration for facilitating future system or alterations and extensions to the current syste. Thus, subsequent changes to the system are slow, different, and costly. It has become apparent that manufacturing processes, and thus the mechatronics which embody them, need to be agile in order to more quickly and easily respond to changing customer demands or market pressures. To achieve agility, both the hardware and software of the system need to be designed such that the creation of new system and the alteration and extension of current system is fast and easy. This paper describes the design of a Universal Mechatronics Coordinator (UMC) which facilitates agile setup and changeover of coordination software for mechatronic systems. The UMC is capable of sequencing continuous and discrete actions that are programmed as stimulus-response pairs, as state machines, or a combination of the two. It facilitates the modular, reusable programing of continuous actions such as servo control algorithms, data collection code, and safety checking routines; and discrete actions such as reporting achieved states, and turning on/off binary devices. The UMC has been applied to the control of a z- theta assembly robot for the Minifactory project and is applicable to a spectrum of widely differing mechatronic systems.

  19. Communicating Processes with Data for Supervisory Coordination

    Directory of Open Access Journals (Sweden)

    Jasen Markovski

    2012-08-01

    Full Text Available We employ supervisory controllers to safely coordinate high-level discrete(-event behavior of distributed components of complex systems. Supervisory controllers observe discrete-event system behavior, make a decision on allowed activities, and communicate the control signals to the involved parties. Models of the supervisory controllers can be automatically synthesized based on formal models of the system components and a formalization of the safe coordination (control requirements. Based on the obtained models, code generation can be used to implement the supervisory controllers in software, on a PLC, or an embedded (microprocessor. In this article, we develop a process theory with data that supports a model-based systems engineering framework for supervisory coordination. We employ communication to distinguish between the different flows of information, i.e., observation and supervision, whereas we employ data to specify the coordination requirements more compactly, and to increase the expressivity of the framework. To illustrate the framework, we remodel an industrial case study involving coordination of maintenance procedures of a printing process of a high-tech Oce printer.

  20. Coordinator, Translation Services | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The Coordinator, Translation Services coordinates the overall operations of the ... services in IDRC by acting as the main resource person for internal clients ... all operational issues in order to ensure good quality products delivered on time.

  1. Method of complex scaling

    International Nuclear Information System (INIS)

    Braendas, E.

    1986-01-01

    The method of complex scaling is taken to include bound states, resonances, remaining scattering background and interference. Particular points of the general complex coordinate formulation are presented. It is shown that care must be exercised to avoid paradoxical situations resulting from inadequate definitions of operator domains. A new resonance localization theorem is presented

  2. Facilitating Group Decision-Making: Facilitator's Subjective Theories on Group Coordination

    Directory of Open Access Journals (Sweden)

    Michaela Kolbe

    2008-10-01

    Full Text Available A key feature of group facilitation is motivating and coordinating people to perform their joint work. This paper focuses on group coordination which is a prerequisite to group effectiveness, especially in complex tasks. Decision-making in groups is a complex task that consequently needs to be coordinated by explicit rather than implicit coordination mechanisms. Based on the embedded definition that explicit coordination does not just happen but is purposely executed by individuals, we argue that individual coordination intentions and mechanisms should be taken into account. Thus far, the subjective perspective of coordination has been neglected in coordination theory, which is understandable given the difficulties in defining and measuring subjective aspects of group facilitation. We therefore conducted focused interviews with eight experts who either worked as senior managers or as experienced group facilitators and analysed their approaches to group coordination using methods of content analysis. Results show that these experts possess sophisticated mental representations of their coordination behaviour. These subjective coordination theories can be organised in terms of coordination schemes in which coordination-releasing situations are facilitated by special coordination mechanisms that, in turn, lead to the perception of specific consequences. We discuss the importance of these subjective coordination theories for effectively facilitating group decision-making and minimising process losses. URN: urn:nbn:de:0114-fqs0901287

  3. Recursive Advice for Coordination

    DEFF Research Database (Denmark)

    Terepeta, Michal Tomasz; Nielson, Hanne Riis; Nielson, Flemming

    2012-01-01

    Aspect-oriented programming is a programming paradigm that is often praised for the ability to create modular software and separate cross-cutting concerns. Recently aspects have been also considered in the context of coordination languages, offering similar advantages. However, introducing aspects...... challenging. This is important since ensuring that a system does not contain errors is often equivalent to proving that some states are not reachable. In this paper we show how to solve these challenges by applying a successful technique from the area of software model checking, namely communicating pushdown...

  4. Enzymatic conformational fluctuations along the reaction coordinate of cytidine deaminase

    OpenAIRE

    Noonan, Ryan C.; Carter, Charles W.; Bagdassarian, Carey K.

    2002-01-01

    Analysis of the crystal structures for cytidine deaminase complexed with substrate analog 3-deazacytidine, transition-state analog zebularine 3,4-hydrate, and product uridine establishes significant changes in the magnitude of atomic-scale fluctuations along the (approximate) reaction coordinate of this enzyme. Differences in fluctuations between the substrate analog complex, transition-state analog complex, and product complex are monitored via changes in corresponding crystallographic tempe...

  5. Reaction of cyanide with cytochrome ba3 from Thermus thermophilus: spectroscopic characterization of the Fe(II)a3-CN.Cu(II)B-CN complex suggests four 14N atoms are coordinated to CuB.

    Science.gov (United States)

    Surerus, K K; Oertling, W A; Fan, C; Gurbiel, R J; Einarsdóttir, O; Antholine, W E; Dyer, R B; Hoffman, B M; Woodruff, W H; Fee, J A

    1992-01-01

    Cytochrome ba3 from Thermus thermophilus reacts slowly with excess HCN at pH 7.4 to create a form of the enzyme in which CuA, cytochrome b, and CuB remain oxidized, while cytochrome a3 is reduced by one electron, presumably with the formation of cyanogen. We have examined this form of the enzyme by UV-visible, resonance Raman, EPR, and electron nuclear double resonance spectroscopies in conjunction with permutations of 13C- and 15N-labeled cyanide. The results support a model in which one CN- binds through the carbon atom to ferrous a3, supporting a low-spin (S = 0) configuration on the Fe; bridging by this cyanide to the CuB is weak or absent. Four 14N atoms, presumably donated by histidine residues of the protein, provide a strong equatorial ligand field about CuB; a second CN- is coordinated through the carbon atom to CuB in an axial position. PMID:1314380

  6. Synthesis, chemistry and catalytic activity of complexes of lanthanide and actinide metals in unusual oxidation states and coordination environments. Progress report for period February 1, 1980-January 31, 1981

    International Nuclear Information System (INIS)

    Evans, W.J.

    1980-10-01

    Investigations are being conducted on two classes of lanthanide compounds: metal vapor co-condensation reactions with unsaturated hydrocarbons and homoleptic and heteroleptic alkyl lanthanide complexes. Three models have been considered for the interaction of erbium atoms with 3-hexyne. The structure of the heteroleptic alkynide [(C 5 H 5 ) 2 ErC triple bond CCMe 3 ] 2 was studied. Some new organolanthanides have been prepared

  7. The coordination dynamics of social neuromarkers

    Science.gov (United States)

    Tognoli, Emmanuelle; Kelso, J. A. Scott

    2015-01-01

    Social behavior is a complex integrative function that entails many aspects of the brain’s sensory, cognitive, emotional and movement capacities. Its neural processes are seldom simultaneous but occur according to precise spatiotemporal choreographies, manifested by the coordination of their oscillations within and between brains. Methods with good temporal resolution can help to identify so-called “neuromarkers” of social function and aid in disentangling the dynamical architecture of social brains. In our ongoing research, we have used dual-electroencephalography (EEG) to study neuromarker dynamics during synchronic interactions in which pairs of subjects coordinate behavior spontaneously and intentionally (social coordination) and during diachronic transactions that require subjects to perceive or behave in turn (action observation, delayed imitation). In this paper, after outlining our dynamical approach to the neurophysiological basis of social behavior, we examine commonalities and differences in the neuromarkers that are recruited for both kinds of tasks. We find the neuromarker landscape to be task-specific: synchronic paradigms of social coordination reveal medial mu, alpha and the phi complex as contributing neuromarkers. Diachronic tasks recruit alpha as well, in addition to lateral mu rhythms and the newly discovered nu and kappa rhythms whose functional significance is still unclear. Social coordination, observation, and delayed imitation share commonality of context: in each of our experiments, subjects exchanged information through visual perception and moved in similar ways. Nonetheless, there was little overlap between their neuromarkers, a result that hints strongly of task-specific neural mechanisms for social behavior. The only neuromarker that transcended both synchronic and diachronic social behaviors was the ubiquitous alpha rhythm, which appears to be a key signature of visually-mediated social behaviors. The present paper is both an

  8. The coordination dynamics of social neuromarkers

    Directory of Open Access Journals (Sweden)

    Emmanuelle eTognoli

    2015-10-01

    Full Text Available Social behavior is a complex integrative function that entails many aspects of the brain's sensory, cognitive, emotional and motor capacities. Its neural processes are seldom simultaneous but occur according to precise spatiotemporal choreographies, manifested by the coordination of their oscillations within and between brains. Methods with good temporal resolution can help to identify so-called neuromarkers of social function and aid in disentangling the dynamical architecture of social brains. In our ongoing research, we have used dual-EEG to study neuromarker dynamics during synchronic interactions in which pairs of subjects coordinate behavior spontaneously and intentionally (social coordination and during diachronic transactions that require subjects to perceive or behave in turn (action observation, delayed imitation. In this paper, after outlining our dynamical approach to the neurophysiological basis of social behavior, we examine commonalities and differences in the neuromarkers that are recruited for both kinds of tasks. We find the neuromarker landscape to be task-specific: synchronic paradigms of social coordination reveal medial mu, alpha and the phi complex as contributing neuromarkers. Diachronic tasks recruit alpha as well, in addition to lateral mu rhythms and the newly discovered nu and kappa rhythms whose functional significance is still unclear. Social coordination, observation, and delayed imitation share commonality of context: in each of our experiments, subjects exchanged information through visual perception and moved in similar ways. Nonetheless, there was little overlap between their neuromarkers, a result that hints strongly of task-specific neural mechanisms for social behavior. The only neuromarker that transcended both synchronic and diachronic social behaviors was the ubiquitous alpha rhythm, which appears to be a key signature of visually-mediated social behaviors. The present paper is both an entry point and a

  9. The coordination dynamics of social neuromarkers.

    Science.gov (United States)

    Tognoli, Emmanuelle; Kelso, J A Scott

    2015-01-01

    Social behavior is a complex integrative function that entails many aspects of the brain's sensory, cognitive, emotional and movement capacities. Its neural processes are seldom simultaneous but occur according to precise spatiotemporal choreographies, manifested by the coordination of their oscillations within and between brains. Methods with good temporal resolution can help to identify so-called "neuromarkers" of social function and aid in disentangling the dynamical architecture of social brains. In our ongoing research, we have used dual-electroencephalography (EEG) to study neuromarker dynamics during synchronic interactions in which pairs of subjects coordinate behavior spontaneously and intentionally (social coordination) and during diachronic transactions that require subjects to perceive or behave in turn (action observation, delayed imitation). In this paper, after outlining our dynamical approach to the neurophysiological basis of social behavior, we examine commonalities and differences in the neuromarkers that are recruited for both kinds of tasks. We find the neuromarker landscape to be task-specific: synchronic paradigms of social coordination reveal medial mu, alpha and the phi complex as contributing neuromarkers. Diachronic tasks recruit alpha as well, in addition to lateral mu rhythms and the newly discovered nu and kappa rhythms whose functional significance is still unclear. Social coordination, observation, and delayed imitation share commonality of context: in each of our experiments, subjects exchanged information through visual perception and moved in similar ways. Nonetheless, there was little overlap between their neuromarkers, a result that hints strongly of task-specific neural mechanisms for social behavior. The only neuromarker that transcended both synchronic and diachronic social behaviors was the ubiquitous alpha rhythm, which appears to be a key signature of visually-mediated social behaviors. The present paper is both an entry

  10. A 3d-4f complex constructed by the assembly of a cationic template, [Cu(en){sub 2}]{sup 2+}, and a 3D anionic coordination polymer, [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-}

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Szu-Yu; Yeh, Chang-Tsung; Wang, Chih-Chieh [Department of Chemistry, Soochow University, Taipei, Taiwan (China); Lee, Gene-Hsiang [Instrumentation Center, National Taiwan University, Taipei, Taiwan (China); Sheu, Hwo-Shuenn [National Synchrotron Radiation Research Center, Hsinchu, Taiwan (China)

    2017-05-18

    A three-dimensional (3D) 3d-4f complex, [Cu(en){sub 2}][Sm{sub 2}(C{sub 5}O{sub 5})(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 2}].8H{sub 2}O (1) (en = ethylenediamine, C{sub 5}O{sub 5}{sup 2-} = dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione), were prepared via the in-situ ring-opening oxidation reaction of croconate in the presence of the template-directed complex, [Cu(en){sub 2}]{sup 2+} cation. The structural characterization determined by X-ray diffraction determination reveals that the 3D anionic coordination polymer of [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-} in 1 can be describe in terms of in-plane 2D honeycomb-like [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}] layered frameworks bridged by oxalate with bis-chelating mode, being mutually interlinked via the bridge of μ{sub 1,2,3,4}-croconate ligands with bis-chelating coordination mode to complete the 3D open framework, which gives rise to 1D channels with pore size of 14.023 x 11.893 Aa (longest atom-atom contact distances) along the b axis. The structure-directing complex, [Cu(en){sub 2}]{sup 2+}, and solvated water molecules are resided into these honeycomb-type hexagonal channels. The thermal stability of 1 was further studied by TGA and in-situ powder X-ray diffraction measurement. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. The Design Co-ordination Framework: key elements for effective product development

    DEFF Research Database (Denmark)

    Andreasen, Mogens Myrup; Bowen, J.; Storm, T.

    1997-01-01

    This paper proposes a Design Co-ordination Framework (DCF) i.e. a concept for an ideal DC system with the abilities to support co-ordination of various complex aspects of product development. A set of frames, modelling key elements of co-ordination, which reflect the states of design, plans, orga...

  12. Redox reactivity and coordination chemistry of uranium

    International Nuclear Information System (INIS)

    Nocton, G.

    2009-09-01

    The study and the understanding of actinides chemistry have important implications in the nuclear field both for the development of new actinides materials and the retreatment of the nuclear wastes. One of the major issues in that chemistry is that the actinides elements are known to undergo redox reaction and to form assemblies of different size and different topologies. In that context uranium can be a good model of the heavier radioelement because it is much less radioactive. So, this work concerns the synthesis and the study of the spectroscopy and the magnetic properties of several uranium based polymetallic assemblies synthesized by taking advantage of the redox properties and the coordination chemistry of uranium. The hydrolysis reactivity of trivalent uranium has been studied in absence of sterically hindered ligands and led to the synthesis of oxo/hydroxo uranium assemblies with different sizes by changing the starting complex or the reaction conditions. By following the same strategy, the controlled oxidation of trivalent uranium complexes led to an original azido/nitrido uranium complex. The coordination chemistry of the pentavalent uranyl polymer {[UO 2 py 5 ][KI 2 py 3 ]} n has also been studied with different ligand and in different conditions and led to several cation-cation complexes for which the stability is sufficient for studying there dismutation by proton NMR. By changing the ancillary ligands stable monomeric complexes of pentavalent uranyl complexes were also obtained. The magnetic properties of all the complexes, monomers and polymetallic complexes were studied and an antiferromagnetic coupling was observed for the cation-cation pentavalent uranyl dimer [UO 2 (dbm) 2 (K 18 C 6 )] 2 . (author)

  13. Network Coordinator Report

    Science.gov (United States)

    Himwich, Ed; Strand, Richard

    2013-01-01

    This report includes an assessment of the network performance in terms of lost observing time for the 2012 calendar year. Overall, the observing time loss was about 12.3%, which is in-line with previous years. A table of relative incidence of problems with various subsystems is presented. The most significant identified causes of loss were electronics rack problems (accounting for about 21.8% of losses), antenna reliability (18.1%), RFI (11.8%), and receiver problems (11.7%). About 14.2% of the losses occurred for unknown reasons. New antennas are under development in the USA, Germany, and Spain. There are plans for new telescopes in Norway and Sweden. Other activities of the Network Coordinator are summarized.

  14. Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II), Co(II), Ni(II), Cu(II), and Zn(II)] metals

    OpenAIRE

    Nahid Nishat; Ashraf Malik

    2016-01-01

    A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). All the polymeric compounds were characterized by (FT-IR) spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA) and antibacterial activities. Polymer complexes of Mn(II), Co(II) and Ni(II) show octahedral geometry, wh...

  15. Coordinating Group report

    International Nuclear Information System (INIS)

    1994-01-01

    In December 1992, western governors and four federal agencies established a Federal Advisory Committee to Develop On-site Innovative Technologies for Environmental Restoration and Waste Management (the DOIT Committee). The purpose of the Committee is to advise the federal government on ways to improve waste cleanup technology development and the cleanup of federal sites in the West. The Committee directed in January 1993 that information be collected from a wide range of potential stakeholders and that innovative technology candidate projects be identified, organized, set in motion, and evaluated to test new partnerships, regulatory approaches, and technologies which will lead to improve site cleanup. Five working groups were organized, one to develop broad project selection and evaluation criteria and four to focus on specific contaminant problems. A Coordinating Group comprised of working group spokesmen and federal and state representatives, was set up to plan and organize the routine functioning of these working groups. The working groups were charged with defining particular contaminant problems; identifying shortcomings in technology development, stakeholder involvement, regulatory review, and commercialization which impede the resolution of these problems; and identifying candidate sites or technologies which could serve as regional innovative demonstration projects to test new approaches to overcome the shortcomings. This report from the Coordinating Group to the DOIT Committee highlights the key findings and opportunities uncovered by these fact-finding working groups. It provides a basis from which recommendations from the DOIT Committee to the federal government can be made. It also includes observations from two public roundtables, one on commercialization and another on regulatory and institutional barriers impeding technology development and cleanup

  16. Coordination of cassava starch to metal ions and thermolysis of ...

    African Journals Online (AJOL)

    Cassava starch formed Werner-type complexes with ions of metals from the transition groups. This was proven by conductivity and electron paramagnetic resonance measurements. The coordination of starch to central metal ions influenced the thermal decomposition of starch. As a rule complexes started to decompose at ...

  17. State-of-the-art coordination chemistry of radioactive elements

    International Nuclear Information System (INIS)

    Kharisov, B I; Mendez-Rojas, Miguel A

    2001-01-01

    Modern procedures for the synthesis of coordination and organometallic compounds of actinides and technetium and the properties of these compounds are surveyed. Experimental techniques, including methods for the synthesis of actinide and technetium complexes from elemental metals (oxidative dissolution and direct electrosynthesis), salts and halide, carbonyl and other complexes are generalised. The bibliography includes 283 references.

  18. The students’ coordinating conjunction acquisition order

    Directory of Open Access Journals (Sweden)

    Deby Irawan

    2018-03-01

    Full Text Available This study is aimed at uncovering the students’ acquisition order of coordinating conjunction for then to seek the possible causes of such phenomenon. Quantitative approach with implicational scaling and qualitative approach with case study were employed with test, focused-group interview, and document analysis of some related textbooks as the instruments. A test consist of 70 questions about the usage of seven coordinating conjunctions in which each word is represented by 10 questions was given to the 13 students of eleventh grade of senior high school for the data collection related to the students’ acquisition order. The documents were then analyzed through several steps as suggested by the expert. The results show that the students acquire “and”, “so”, “for”, “but”, “or”, “yet”, and “nor” as in order. The external factors which influence the order are the formal complexity of each conjunction and the lack of exposure of coordinating conjunction both in the teaching activity and textbooks. Thus, teachers are suggested to provide more explicit teaching on coordinating conjunction and necessary knowledge about the usage of each word. Also, book writers should provide ample exposure to give students more knowledge about the usage of those conjunctions in a meaningful context.

  19. Redox-active porous coordination polymers prepared by trinuclear heterometallic pivalate linking with the redox-active nickel(II) complex: synthesis, structure, magnetic and redox properties, and electrocatalytic activity in organic compound dehalogenation in heterogeneous medium.

    Science.gov (United States)

    Lytvynenko, A S; Kolotilov, S V; Kiskin, M A; Cador, O; Golhen, S; Aleksandrov, G G; Mishura, A M; Titov, V E; Ouahab, L; Eremenko, I L; Novotortsev, V M

    2014-05-19

    Linking of the trinuclear pivalate fragment Fe2CoO(Piv)6 by the redox-active bridge Ni(L)2 (compound 1; LH is Schiff base from hydrazide of 4-pyridinecarboxylic acid and 2-pyridinecarbaldehyde, Piv(-) = pivalate) led to formation of a new porous coordination polymer (PCP) {Fe2CoO(Piv)6}{Ni(L)2}1.5 (2). X-ray structures of 1 and 2 were determined. A crystal lattice of compound 2 is built from stacked 2D layers; the Ni(L)2 units can be considered as bridges, which bind two Fe2CoO(Piv)6 units. In desolvated form, 2 possesses a porous crystal lattice (SBET = 50 m(2) g(-1), VDR = 0.017 cm(3) g(-1) estimated from N2 sorption at 78 K). At 298 K, 2 absorbed a significant quantity of methanol (up to 0.3 cm(3) g(-1)) and chloroform. Temperature dependence of molar magnetic susceptibility of 2 could be fitted as superposition of χMT of Fe2CoO(Piv)6 and Ni(L)2 units, possible interactions between them were taken into account using molecular field model. In turn, magnetic properties of the Fe2CoO(Piv)6 unit were fitted using two models, one of which directly took into account a spin-orbit coupling of Co(II), and in the second model the spin-orbit coupling of Co(II) was approximated as zero-field splitting. Electrochemical and electrocatalytic properties of 2 were studied by cyclic voltammetry in suspension and compared with electrochemical and electrocatalytic properties of a soluble analogue 1. A catalytic effect was determined by analysis of the catalytic current dependency on concentrations of the substrate. Compound 1 possessed electrocatalytic activity in organic halide dehalogenation, and such activity was preserved for the Ni(L)2 units, incorporated into the framework of 2. In addition, a new property occurred in the case of 2: the catalytic activity of PCP depended on its sorption capacity with respect to the substrate. In contrast to homogeneous catalysts, usage of solid PCPs may allow selectivity due to porous structure and simplify separation of product.

  20. Hydrothermal synthesis and study of an inorganic-organic hybrid vanadate of a nickel(II) coordination complex with pyrazine, Ni{sub 3}(C{sub 4}H{sub 4}N{sub 2}){sub 3}(V{sub 8}O{sub 23})

    Energy Technology Data Exchange (ETDEWEB)

    Larrea, Edurne S. [Dpto. de Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, UPV/EHU, Apdo. 644, E-48080 Bilbao (Spain); Mesa, Jose L., E-mail: joseluis.mesa@ehu.es [Dpto. de Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, UPV/EHU, Apdo. 644, E-48080 Bilbao (Spain); Arriortua, Maria I. [Dpto. de Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, UPV/EHU, Apdo. 644, E-48080 Bilbao (Spain)

    2011-06-15

    Highlights: {yields} A novel inorganic-organic hybrid vanadate of nickel(II) coordination complex with pyrazine has been synthesized hydrothermally. {yields} The thermal and spectroscopic behavior has been studied. {yields} The compound shows AFM interactions which has been fitted to a magnetic model of lineal chains. -- Abstract: The three-dimensional hybrid compound Ni{sub 3}(C{sub 4}H{sub 4}N{sub 2}){sub 3}(V{sub 8}O{sub 23}) has been synthesized by mild hydrothermal methods under autogenous pressure at 170 {sup o}C. The structure of the phase is stable until 380 {sup o}C. The removal of the pyrazine molecules from the structure induces its collapse. The IR spectrum shows the vibration modes of the pyrazine molecule and those of the [VO{sub 4}]{sup 3-} groups. A UV-visible spectrum shows the characteristic bands of the Ni(II) d{sup 8}-high-spin cation in a slightly distorted octahedral coordination. Magnetic measurements indicate the existence of antiferromagnetic interactions that can be fitted with a chain model to give g = 2.31, J/k = -5.3, and zJ'/k = -5.5.

  1. Studies on coordination chemistry and bioactivity of complexes of a bidentate oxygen-oxygen donor ligand, 1,2-dibenzoylhydrazine, with Cr3+, Co2+, Ni2+, Cu2+ and Zn2+ Ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Lai Wee Wong; Crouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

    2003-08-01

    A new bidentate ligand, 1,2-dibenzoylhydrazine (DBHz), with OO donor sequences, was prepared. Several complexes of DBHz containing Cr(JJI), Fe(UI), Co(U), Ni(JJ), Cu(II) and Zn(TJ) ions have been synthesized and characterized by CHN analyses, IR, molar conductivity and UV/Visible spectroscopic studies. All of the compounds were tested for their antibacterial, antifungal and anticancer properties. DBHz was very effective against Pseudomonas aeruginosa, Bacillus subtilis mutant and Bacillus subtilis wild type bacteria. It was also effective against Saccaromyces cereiviceae, Candida albicans, Candida albicans lypolytica and Aspergillus ochraceous fungi. The free ligand, DBHz, in particular, was strongly active against colon cancer cell lines (HT-29), with a CD 50 value of 2.5 /μg/ml. (author)

  2. Coordinates in relativistic Hamiltonian mechanics

    International Nuclear Information System (INIS)

    Sokolov, S.N.

    1984-01-01

    The physical (covariant and measurable) coordinates of free particles and covariant coordinates of the center of inertia are found for three main forms of relativistic dynamics. In the point form of dynamics, the covariant coordinates of two directly interacting particles are found, and the equations of motion are brought to the explicitly covariant form. These equations are generalized to the case of interaction with an external electromagnetic field

  3. Capital projects coordination

    Directory of Open Access Journals (Sweden)

    Zubović Jovan

    2004-01-01

    Full Text Available This paper looks at the difficulties of managing modem capital projects and endeavors to reduce the complexities to simpler and more understandable terms. It examines the project environment, defines project management and discusses points of difference from traditional management. In the second part of the paper are presented fundamentals for project success for different types of projects.

  4. Unusual metal coordination chemistry from an amino-amide derivative of 4-nitrophenol, a surprising ligand

    DEFF Research Database (Denmark)

    McGinley, John; McKee, Vickie; Toftlund, Hans

    2009-01-01

    The simple ligand N-(2-aminoethyl)-2-hydroxy-5-nitrobenzamide () exhibits several coordination modes depending on the reaction conditions, acting as a zwitterion on its own or being ionic in the presence of acid and depending on the concentration of metal present in a reaction, it can coordinate...... to the metal in either a 1:1 or a 1:2 metal:ligand mode. Furthermore, the role of solvent plays an important role in these complexation reactions with both four and six coordinate copper complexes being obtained using water as solvent but only six coordinate copper complexes obtained using acetonitrile...

  5. Use of mass spectrometry for study of coordination compounds

    International Nuclear Information System (INIS)

    Gehrbehlehu, N.V.; Indrichan, K.M.

    1981-01-01

    A review on mass-spectrometry of coordination compounds including the works published up to 1979 inclusive is provided. Mainly the products of metals with bi- and tetradentate ligands are considered using the method. Mo and Be carboxylates for which molecular ions lines are found in mass-spectra are studied. The study of mass-spectra for VO chelates with thiosemicarbazone of salicyl aldehyde is carried out. Application of the mass-spectrometry method permits to establish the mass of coordination compounds, the structure of complexes, dentate structure and the way of ligand coordination, the bond strength [ru

  6. Wavefield extrapolation in caustic-free normal ray coordinates

    KAUST Repository

    Ma, Xuxin

    2012-11-04

    Normal ray coordinates are conventionally constructed from ray tracing, which inherently requires smooth velocity profiles. To use rays as coordinates, the velocities have to be smoothed further to avoid caustics, which is detrimental to the mapping process. Solving the eikonal equation numerically for a line source at the surface provides a platform to map normal rays in complex unsmoothed velocity models and avoid caustics. We implement reverse-time migration (RTM) and downward continuation in the new ray coordinate system, which allows us to obtain efficient images and avoid some of the dip limitations of downward continuation.

  7. Coordination structure of adsorbed Zn(II) at Water-TiO2 interfaces

    Energy Technology Data Exchange (ETDEWEB)

    He, G.; Pan, G.; Zhang, M.; Waychunas, G.A.

    2011-01-15

    The local structure of aqueous metal ions on solid surfaces is central to understanding many chemical and biological processes in soil and aquatic environments. Here, the local coordination structure of hydrated Zn(II) at water-TiO{sub 2} interfaces was identified by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) spectroscopy combined with density functional theory (DFT) calculations. A nonintegral coordination number of average {approx}4.5 O atoms around a central Zn atom was obtained by EXAFS analysis. DFT calculations indicated that this coordination structure was consistent with the mixture of 4-coordinated bidentate binuclear (BB) and 5-coordinated bidentate mononuclear (BM) metastable equilibrium adsorption (MEA) states. The BB complex has 4-coordinated Zn, while the monodentate mononuclear (MM) complex has 6-coordinated Zn, and a 5-coordinated adsorbed Zn was found in the BM adsorption mode. DFT calculated energies showed that the lower-coordinated BB and BM modes were thermodynamically more favorable than the higher-coordinated MM MEA state. The experimentally observed XANES fingerprinting provided additional direct spectral evidence of 4- and 5-coordinated Zn-O modes. The overall spectral and computational evidence indicated that Zn(II) can occur in 4-, 5-, and 6-oxygen coordinated sites in different MEA states due to steric hindrance effects, and the coexistence of different MEA states formed the multiple coordination environments.

  8. Development of an International School Nurse Asthma Care Coordination Model.

    Science.gov (United States)

    Garwick, Ann W; Svavarsdóttir, Erla Kolbrun; Seppelt, Ann M; Looman, Wendy S; Anderson, Lori S; Örlygsdóttir, Brynja

    2015-03-01

    To identify and compare how school nurses in Reykjavik, Iceland and St. Paul, Minnesota coordinated care for youth with asthma (ages 10-18) and to develop an asthma school nurse care coordination model. Little is known about how school nurses coordinate care for youth with asthma in different countries. A qualitative descriptive study design using focus group data. Six focus groups with 32 school nurses were conducted in Reykjavik (n = 17) and St. Paul (n = 15) using the same protocol between September 2008 and January 2009. Descriptive content analytic and constant comparison strategies were used to categorize and compare how school nurses coordinated care, which resulted in the development of an International School Nurse Asthma Care Coordination Model. Participants in both countries spontaneously described a similar asthma care coordination process that involved information gathering, assessing risk for asthma episodes, prioritizing healthcare needs and anticipating and planning for student needs at the individual and school levels. This process informed how they individualized symptom management, case management and/or asthma education. School nurses played a pivotal part in collaborating with families, school and healthcare professionals to ensure quality care for youth with asthma. Results indicate a high level of complexity in school nurses' approaches to asthma care coordination that were responsive to the diverse and changing needs of students in school settings. The conceptual model derived provides a framework for investigators to use in examining the asthma care coordination process of school nurses in other geographic locations. © 2014 John Wiley & Sons Ltd.

  9. Identification of coordination factors affecting building projects performance

    Directory of Open Access Journals (Sweden)

    Wesam Salah Alaloul

    2016-09-01

    Full Text Available Construction projects performance requires improvement to fulfil the complexity of the stakeholders’ needs and expectations. Coordination process is proposed as an efficient solution for weak performance of construction projects. Therefore, coordination factors are vital in ensuring a successful implementation of all project phases. This study aimed to identify and prioritise coordination factors that influence the performance of building projects in Malaysian context. A vast body of literature on coordination process was reviewed and resulted in 53 coordination factor. Three rounds of Delphi technique were conducted. The most effective coordination factors were ranked based on the Relative Importance Index (RII such as Scheduling (RII = 0.97, Quality assurance plan (RII = 0.93, and all parties’ participation in plans (RII = 0.89. These coordination factors have fulfilled the research gap and provided better management and higher performance for project parties. The results offer insightful perspectives to define the most effective coordination factors, for addressing the dependency between project tasks and the parties to enhance project performance.

  10. Coordination of Conditional Poisson Samples

    Directory of Open Access Journals (Sweden)

    Grafström Anton

    2015-12-01

    Full Text Available Sample coordination seeks to maximize or to minimize the overlap of two or more samples. The former is known as positive coordination, and the latter as negative coordination. Positive coordination is mainly used for estimation purposes and to reduce data collection costs. Negative coordination is mainly performed to diminish the response burden of the sampled units. Poisson sampling design with permanent random numbers provides an optimum coordination degree of two or more samples. The size of a Poisson sample is, however, random. Conditional Poisson (CP sampling is a modification of the classical Poisson sampling that produces a fixed-size πps sample. We introduce two methods to coordinate Conditional Poisson samples over time or simultaneously. The first one uses permanent random numbers and the list-sequential implementation of CP sampling. The second method uses a CP sample in the first selection and provides an approximate one in the second selection because the prescribed inclusion probabilities are not respected exactly. The methods are evaluated using the size of the expected sample overlap, and are compared with their competitors using Monte Carlo simulation. The new methods provide a good coordination degree of two samples, close to the performance of Poisson sampling with permanent random numbers.

  11. Coordination in continuously repeated games

    NARCIS (Netherlands)

    Weeren, A.J.T.M.; Schumacher, J.M.; Engwerda, J.C.

    1995-01-01

    In this paper we propose a model to describe the effectiveness of coordination in a continuously repeated two-player game. We study how the choice of a decision rule by a coordinator affects the strategic behavior of the players, resulting in more or less cooperation. Our model requires the analysis

  12. Coordinated Transportation: Problems and Promise?

    Science.gov (United States)

    Fickes, Michael

    1998-01-01

    Examines the legal, administrative, and logistical barriers that have prevented the wide acceptance of coordinating community and school transportation services and why these barriers may be breaking down. Two examples of successful implementation of coordinated transportation are examined: employing a single system to serve all transportation…

  13. Bare coordination: the semantic shift

    NARCIS (Netherlands)

    de Swart, Henriette; Le Bruyn, Bert

    2014-01-01

    This paper develops an analysis of the syntax-semantics interface of two types of split coordination structures. In the first type, two bare singular count nouns appear as arguments in a coordinated structure, as in bride and groom were happy. We call this the N&N construction. In the second type,

  14. Multipole structure and coordinate systems

    International Nuclear Information System (INIS)

    Burko, Lior M

    2007-01-01

    Multipole expansions depend on the coordinate system, so that coefficients of multipole moments can be set equal to zero by an appropriate choice of coordinates. Therefore, it is meaningless to say that a physical system has a nonvanishing quadrupole moment, say, without specifying which coordinate system is used. (Except if this moment is the lowest non-vanishing one.) This result is demonstrated for the case of two equal like electric charges. Specifically, an adapted coordinate system in which the potential is given by a monopole term only is explicitly found, the coefficients of all higher multipoles vanish identically. It is suggested that this result can be generalized to other potential problems, by making equal coordinate surfaces adapt to the potential problem's equipotential surfaces

  15. Novel rare earth quinolinolate complexes

    International Nuclear Information System (INIS)

    Deacon, Glen B.; Forsyth, Craig M.; Junk, Peter C.; Kynast, Ulrich; Meyer, Gerd; Moore, Joanne; Sierau, Jennyfer; Urbatsch, Aron

    2008-01-01

    The reaction of europium 8-quinolinolate Eu(OQ) 3 with calcium 8-quinolinolate, Ca(OQ) 2 , in the flux 1,2,4,5-tetramethylbenzene (TMB) at 210 deg. C yields the bimetallic [Eu 2 Ca(OQ) 8 ], which is a linear tri-nuclear complex with two eight coordinate europium atoms flanking a six coordinate calcium atom bonded by six bridging phenolate oxygen atoms. A similar reaction between La(OQ) 3 and Co(OQ) 2 gave [LaCo 2 (OQ) 7 ], in which two six coordinate cobalt atoms flank an eight coordinate lanthanum atom with six bridging phenolate oxygen atoms and a terminal OQ group

  16. COORDINATION COMPOUNDS OF 3D-METALS ACETYLACETONATES WITH THIOSEMICARBAZIDE

    Directory of Open Access Journals (Sweden)

    T. V. Koksharova

    2015-03-01

    Full Text Available Coordination Compounds of 3d-Metals acetylacetonates with Thiosemicarbazide were synthesized. Their physical and chemical properties and structure were studied by conductometry, IR spectroscopy, electronic spectroscopy, magnetochemistry and thermo-gravimetricstudies. The complexes compositions correspond to the formulas Co(L2(Acac and M(L(Acac, where M = Cu, Ni, Zn, HL is thiosemicarbazide, HAcac is acetylacetone. All of them are nonelectrolytes. Thiosemicarbazide is deprotonated and coordinated through the nitrogen and sulphur atoms with the formation of four-membered ring in all cases. Acetylacetonate co-ordination mode does not change at acetylacetonates with Thiosemicarbazide interaction. Copper(II and nickel(II complexes have square-planar structure, and cobalt(III complex is octahedral.

  17. Synthesis and reaction of [[HC(CMeNAr)2]Mn]2 (Ar = 2,6-iPr2C6H3): the complex containing three-coordinate manganese(I) with a Mn-Mn bond exhibiting unusual magnetic properties and electronic structure.

    Science.gov (United States)

    Chai, Jianfang; Zhu, Hongping; Stückl, A Claudia; Roesky, Herbert W; Magull, Jörg; Bencini, Alessandro; Caneschi, Andrea; Gatteschi, Dante

    2005-06-29

    This paper reports on the synthesis, X-ray structure, magnetic properties, and DFT calculations of [[HC(CMeNAr)2]Mn]2 (Ar = 2,6-iPr2C6H3) (2), the first complex with three-coordinate manganese(I). Reduction of the iodide [[HC(CMeNAr)2]Mn(mu-I)]2 (1) with Na/K in toluene afforded 2 as dark-red crystals. The molecule of 2 contains a Mn2(2+) core with a Mn-Mn bond. The magnetic investigations show a rare example of a high-spin manganese(I) complex with an antiferromagnetic interaction between the two Mn(I) centers. The DFT calculations indicate a strong s-s interaction of the two Mn(I) ions with the open shell configuration (3d54s1). This suggests that the magnetic behavior of 2 could be correctly described as the coupling between two S1 = S2 = 5/2 spin centers. The Mn-Mn bond energy is estimated at 44 kcal mol(-1) by first principle calculations with the B3LYP functional. The further oxidative reaction of 2 with KMnO4 or O2 resulted in the formation of manganese(III) oxide [[HC(CMeNAr)2]Mn(mu-O)]2 (3). Compound 3 shows an antiferromagnetic coupling between the two oxo-bridged manganese(III) centers by magnetic measurements.

  18. Probing the coordination environment of Ti(3+) ions coordinated to nitrogen-containing Lewis bases.

    Science.gov (United States)

    Morra, E; Maurelli, S; Chiesa, M; Van Doorslaer, S

    2015-08-28

    Multi-frequency continuous-wave and pulsed EPR techniques are employed to investigate the coordination of nitrogen-containing ligands to Ti(3+)-chloro complexes. Frozen solutions of TiCl3 and TiCl3(Py)3 dissolved in nitrogen-containing solvents have been investigated together with the TiCl3(Py)3 solid-state complex. For these different systems, the hyperfine and nuclear quadrupole data of Ti(3+)-bound (14)N nuclei are reported and discussed in the light of DFT computations, allowing for a detailed description of the microscopic structure of these systems.

  19. Engineering the oxygen coordination in digital superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Seyoung [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA; Department of Materials Science, Northwestern University, Evanston, Illinois 60202, USA; Andersen, Tassie K. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA; Department of Materials Science, Northwestern University, Evanston, Illinois 60202, USA; Hong, Hawoong [X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA; Rosenberg, Richard A. [X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA; Marks, Laurence D. [Department of Materials Science, Northwestern University, Evanston, Illinois 60202, USA; Fong, Dillon D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA

    2017-12-01

    The oxygen sublattice in the complex oxides is typically composed of corner-shared polyhedra, with transition metals at their centers. The electronic and chemical properties of the oxide depend on the type and geometric arrangement of these polyhedra, which can be controlled through epitaxial synthesis. Here, we use oxide molecular beam epitaxy to create SrCoOx:SrTiO3 superlattices with tunable oxygen coordination environments and sublattice geometries. Using soft X-ray spectroscopy, we find that the chemical state of Co can be varied with the polyhedral arrangement, demonstrating a new strategy for achieving unique electronic properties in the transition metal oxides.

  20. Keep Meaning in Conversational Coordination

    Directory of Open Access Journals (Sweden)

    Elena Clare Cuffari

    2014-12-01

    Full Text Available Coordination is a widely employed term across recent quantitative and qualitative approaches to intersubjectivity, particularly approaches that give embodiment and enaction central explanatory roles. With a focus on linguistic and bodily coordination in conversational contexts, I review the operational meaning of coordination in recent empirical research and related theorizing of embodied intersubjectivity. This discussion articulates what must be involved in treating linguistic meaning as dynamic processes of coordination. The coordination approach presents languaging as a set of dynamic self-organizing processes and actions on multiple timescales and across multiple modalities that come about and work in certain domains (those jointly constructed in social, interactive, high-order sense-making. These processes go beyond meaning at the level that is available to first-person experience. I take one crucial consequence of this to be the ubiquitously moral nature of languaging with others. Languaging coordinates experience, among other levels of behavior and event. Ethical effort is called for by the automatic autonomy-influencing forces of languaging as coordination.

  1. Coordinating distributed work : Exploring situated coordination with gaming-simulation

    NARCIS (Netherlands)

    van Laere, J.

    2003-01-01

    Organizational work has become more and more distributed nowadays. Information and communication technologies (ICT) provide opportunities to improve coordination of distributed work, but in practice many organizations struggle with integrating new organizational structures, new work practices and

  2. Coordination of geothermal research

    Energy Technology Data Exchange (ETDEWEB)

    Jessop, A.M.; Drury, M.J.

    1983-01-01

    Visits were made in 1983 to various investigators and institutions in Canada to examine developments in geothermal research. Proposals for drilling geothermal wells to provide hot water for heating at a college in Prince Edward Island were made. In Alberta, the first phase of a program examining the feasibility of mapping sedimentary geothermal reservoirs was discussed. Some sites for possible geothermal demonstration projects were identified. In British Columbia, discussions were held between BC Hydro and Energy, Mines and Resources Canada on the drilling of a research hole into the peak of a temperature anomaly in the Meager Creek Valley. The British Columbia government has offered blocks of land in the Mount Cayley volcanic complex for lease to develop geothermal resources. A list of papers of interest to the Canadian geothermal energy program is appended.

  3. (VI) ML6 Complexes

    African Journals Online (AJOL)

    A geometric analysis revealed that beta-(C-H) and alpha-(C-C) can occupy the seventh and eighth coordination sites in the title Fischer carbene complexes as agostic interactions, which allows classifying the carbene as a η3 ligand in these cases. This theory was supported by the relative energies of the conformers and an ...

  4. Uranyl complexes of glutathione

    Energy Technology Data Exchange (ETDEWEB)

    Marzotto, A [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

    1977-01-01

    Dioxouranium(VI) complexes of the tripeptide glutathione having different molar ratios were prepared and studied by IR, PMR, electronic absorption and circular dichroism spectra. The results indicate that coordination occurs at the carboxylato groups, acting as monodentate ligands, whereas no significant interaction with the amino and sulfhydrylic groups takes place.

  5. The coordinate transforming in geography information system

    International Nuclear Information System (INIS)

    Zhao Xiang; Chen Gang

    2003-01-01

    The coordinate transforming of geography information system includes two kinds of transforming, map projection and coordinate-transforming. This paper proposed a arithmetic of coordinate-transforming, it implement the transforming between the longitude-latitude coordinate and the screen coordinate and apply it in the GIS. The preferable effect was made. (authors)

  6. Metal complexes with 5-aminotetrazole

    International Nuclear Information System (INIS)

    Lavrenova, L.G.; Larionov, S.V.; Grankina, Z.A.; Ikorskij, V.N.

    1983-01-01

    Nitrate and chloride complexes of Co(2), Ni(2), Cu(2), Cd(2), Hg(2), Pb(2) with 5 aminotetrazole (ATE) and compoUnds Zn(ATE') 2 and Cd(ATEE') 2 , where ATE' is a 5 aminotetrazole ano /nion. On the base of spectroscopic data (spectrophotometry, IR- spectra, EPR and magnetic measurements assumptions on M(2) coordination in complexes are made. Most probably ATE is a bridge ligand which is joined by two nitrogen atoms to various M(2) ions. In Co(2), Ni(2) and Cu(ATE) 3 -Cl 2 compounds the metal has a distorted actahedral coordination and forms MN 6 unit, which suggests the interaction of metal ions with ATE nitrogen atoms along the Z-axis. In the Cu(ATE) 2 (NO 3 ) 2 octahedral complex the CuN 4 O 2 coordination unit is realized at the expense of participation of nitratogroups in coordination

  7. Who matters in coordination problems?

    Czech Academy of Sciences Publication Activity Database

    Sákovics, J.; Steiner, Jakub

    2012-01-01

    Roč. 102, č. 7 (2012), s. 3439-3461 ISSN 0002-8282 Institutional support: RVO:67985998 Keywords : coordination problem s * heterogeneous agents Subject RIV: AH - Economics Impact factor: 2.792, year: 2012

  8. Coordination Processes in International Organisations

    DEFF Research Database (Denmark)

    Nedergaard, Peter

    2008-01-01

    The EU is not a member of the International Labour Organisation (ILO), but relatively elaborate EU coordination takes place anyway. This paper addresses two research questions: 1) How is it possible to evaluate the coordination of the EU in its specific observable configuration in the ILO?, and 2......-à-vis their principals, the Member States. The Commission is the leading agent in the phase leading up to the Conference; the Presidency then takes over. On the one hand, due to the Treaty obligations and their interpretations by the Court of Justice, both the Presidency and the Commission are kept within tight limits...... by the principals. On the other hand, both before and during the Conference, the Member States accept the so-called discursive coordination of the Commission, which seems to be of great (but often neglected) importance. Owing to the organisational set-up in which coordination takes place, the EU is able...

  9. Hall effect in noncommutative coordinates

    International Nuclear Information System (INIS)

    Dayi, Oemer F.; Jellal, Ahmed

    2002-01-01

    We consider electrons in uniform external magnetic and electric fields which move on a plane whose coordinates are noncommuting. Spectrum and eigenfunctions of the related Hamiltonian are obtained. We derive the electric current whose expectation value gives the Hall effect in terms of an effective magnetic field. We present a receipt to find the action which can be utilized in path integrals for noncommuting coordinates. In terms of this action we calculate the related Aharonov-Bohm phase and show that it also yields the same effective magnetic field. When magnetic field is strong enough this phase becomes independent of magnetic field. Measurement of it may give some hints on spatial noncommutativity. The noncommutativity parameter θ can be tuned such that electrons moving in noncommutative coordinates are interpreted as either leading to the fractional quantum Hall effect or composite fermions in the usual coordinates

  10. Future in actinoids coordination chemistry

    International Nuclear Information System (INIS)

    Kitazawa, Takafumi

    2006-01-01

    Actinoids coordination chemistry is concerned with spent nuclear fuel reprocessing, specifically with solid-state chemistry of nuclear fuels, separation process with radioactive substances, and geological disposal of high-level radioactive substances. In the 21st century, accumulation of minor actinides, Np, Am, Cm, and others will be realized according with the present program of nuclear energy development. The present article briefly introduces general properties of actinide elements, followed by their coordination chemistry compared with rare earths coordination chemistry. Special facility needed to treat actinoids as well as their chemistry is briefly explained, together with the specific experimental apparatus such as X-ray Absorption Fine Structure (XAFS) and time-resolved laser-induced fluorescence spectrometry (TRLFS) with synchrotron radiation facilities. The effect of coordination with actinoids in the environment chemistry is important in underground disposal of high-level radioactive wastes. For theoretical analysis of the results with actinoids chemistry, relativistic calculation is needed. (S. Ohno)

  11. Insulation coordination workstation for AC and DC substations

    International Nuclear Information System (INIS)

    Booth, R.R.; Hileman, A.R.

    1990-01-01

    The Insulation Coordination Workstation was designed to aid the substation design engineer in the insulation coordination process. The workstation utilizes state of the art computer technology to present a set of tools necessary for substation insulation coordination, and to support the decision making process for all aspects of insulation coordination. The workstation is currently being developed for personal computers supporting OS/2 Presentation Manager. Modern Computer-Aided Software Engineering (CASE) technology was utilized to create an easily expandable framework which currently consists of four modules, each accessing a central application database. The heart of the workstation is a library of user-friendly application programs for the calculation of important voltage stresses used for the evaluation of insulation coordination. The Oneline Diagram is a graphic interface for data entry into the EPRI distributed EMTP program, which allows the creation of complex systems on the CRT screen using simple mouse clicks and keyboard entries. Station shielding is graphically represented in the Geographic Viewport using a three-dimensional substation model, and the interactive plotting package allows plotting of EPRI EMTP output results on the CRT screen, printer, or pen plotter. The Insulation Coordination Workstation was designed by Advanced Systems Technology (AST), a division of ABB Power Systems, Inc., and sponsored by the Electric Power Research Institute under RP 2323-5, AC/DC Insulation Coordination Workstation

  12. Coordination theory and collaboration technology

    CERN Document Server

    Olson, Gary M; Smith, John B

    2001-01-01

    The National Science Foundation funded the first Coordination Theory and Collaboration Technology initiative to look at systems that support collaborations in business and elsewhere. This book explores the global revolution in human interconnectedness. It will discuss the various collaborative workgroups and their use in technology. The initiative focuses on processes of coordination and cooperation among autonomous units in human systems, in computer and communication systems, and in hybrid organizations of both systems. This initiative is motivated by three scientific issues which have been

  13. Path integrals in curvilinear coordinates

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1984-01-01

    Integration limits are studied for presenting the path integral curvilinear coordinates. For spherical (and topoloqically equivalent) coordinates it is shown that in formulas involving classical action in the exponent integration over all variables should be carried out within infinite limits. Another peculiarity is associated with appearance of the operator q which provides a complete definition of the wave functions out of the physical region. arguments are given upporting the validity of the cited statament in the general case

  14. A multi-functional coordination polymer coexisting spontaneous chirality resolution and weak ferromagnetism

    International Nuclear Information System (INIS)

    Li, Xiu-Hua; Zhang, Qi; Hu, Ping

    2014-01-01

    A multifunctional homochiral coordination polymer, [Co(H 2 O)(BDC)(4,4′-BPY)]∙3H 2 O (1) (H 2 BDC=1,2-benzenedicarboxylate and 4,4′-BPY=4,4′-bipyridine), has been successfully isolated from Co(II) ions and mixed ligands (1,2-benzenedicarboxylate and 4,4′-bipyridine). Complex 1, which exhibits spontaneous chirality resolution and weak ferromagnetism, is built by chiral helices interconnected via end-to-end 4,4′-BPY bridges into a two-dimensional (2D) layer structure. - Graphical abstract: A 2D cobalt coordination polymer compound showing spontaneous chirality resolution and weak ferromagnetism. - Highlights: • A new 2D cobalt mix-ligand coordination polymer complex has been synthesized. • The cobalt coordination polymer complex shows spontaneous chirality resolution in solid state. • The cobalt coordination polymer complex displays dominant and weak intrachain ferromagnetic interactions

  15. Double-double effect and coordination number

    International Nuclear Information System (INIS)

    Mioduski, T.

    1992-01-01

    The original method of interpretation together with its theoretical foundations is developed, making it possible to use location and direction of the double-double (tetrad) effect within the Ln and An series to determine the coordination number (CN) complexes of the f-block elements. The method is applied for potentiometric and radiometric equilibrium studies. It has been pointed and that the decisive factor for the direction of the double-double effect in the case of the Gibbs energy variations is a difference in the CN of the f-element ion between the reaction product complex and that for the reaction substrate the ''regular'' effect for a given tetrad is accompanied by decrease in the CN while the ''reverse'' effect by increase in the CN. (author). 122 refs, 5 tabs, 8 figs

  16. Thiosemicarbazone complexes of the platinum metals. A story of ...

    Indian Academy of Sciences (India)

    Unknown

    Thiosemicarbazone complexes; platinum metals; variable coordination; ... carbonylic carbon via one or two intervening atoms, D,N,S tricoordination usually takes .... modelling studies show that in this coordination mode, the phenyl ring of the.

  17. Three coordination compounds based on benzene tetracarboxylate ...

    Indian Academy of Sciences (India)

    YUNLONG WU

    nescence, considerable attention has been focused on the construction of coordination .... measurements were performed on ground powder samples at .... Figure 2. (a) Coordination environment of Co1 ion in compound 2. (b) Coordination.

  18. Motor coordination uses external spatial coordinates independent of developmental vision.

    Science.gov (United States)

    Heed, Tobias; Röder, Brigitte

    2014-07-01

    The constraints that guide bimanual movement coordination are informative about the processing principles underlying movement planning in humans. For example, symmetry relative to the body midline benefits finger and hand movements independent of hand posture. This symmetry constraint has been interpreted to indicate that movement coordination is guided by a perceptual code. Although it has been assumed implicitly that the perceptual system at the heart of this constraint is vision, this relationship has not been tested. Here, congenitally blind and sighted participants made symmetrical and non-symmetrical (that is, parallel) bimanual tapping and finger oscillation movements. For both groups, symmetrical movements were executed more correctly than parallel movements, independent of anatomical constraints like finger homology and hand posture. For the blind, the reliance on external spatial factors in movement coordination stands in stark contrast to their use of an anatomical reference frame in perceptual processing. Thus, the externally coded symmetry constraint evident in bimanual coordination can develop in the absence of the visual system, suggesting that the visual system is not critical for the establishment of an external-spatial reference frame in movement coordination. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Towards Coordination Patterns for Complex Experimentations in Data Mining

    NARCIS (Netherlands)

    F. Arbab (Farhad); C. Diamantini (Claudia); D. Potena (Domenico); E. Storti (Emanuele)

    2010-01-01

    htmlabstractIn order to support the management of experimental activities in a networked scientic community, the exploitation of serviceoriented paradigm and technologies is a hot research topic in E-science. In particular, scientic workows can be modeled by resorting to the notion of process.

  20. Carboxylate-bridged Cu(II) coordination polymeric complex ...

    Indian Academy of Sciences (India)

    SABITHAKALA THATITURI

    and magnetic materials.10–13 In view of the interest- ing applications, the ... using Cu-Kα λ-radiation (λ = 1.5406Е) at 40 kV and 30. mA. Magnetic moments were ..... netic nature shifts slowly to hard ferromagnetic due to an increase in hopping ...

  1. Molecular nanomagnetism in actinide-based coordination complexes

    International Nuclear Information System (INIS)

    Caciuffo, R.; Colineau; Magnani, N.; Santini, G.; Amoretti, S.; Carretta, P.; Mougel, J.; Pécaut, L.; Chatelain, S.; Gambarelli, J.; Hermle, M.; Mazzanti, V.; Degeyer, A.; Tuna, E.F.

    2014-01-01

    We present very recent results obtained for a hetero-metallic U(V)-Mn(II) one-dimensional chain assembled through cation-cation interactions , and for a triangular molecule containing three U(V)O2+ (5f1) ions . The former is the first example of an actinidecontaining single-chain magnet (SCM), with a relaxation barrier of 134 K, a blocking temperature of 6 K, and an impressive coercive field Bc = 3.4 tesla at 2 K. The latter is characterized by a non-magnetic ground doublet corresponding to two oppositely twisted chiral arrangements of the U moments, and (in presence of a magnetic field orthogonal to the triangle plane) by quantum tunnelling of the noncollinear magnetization accompanied by oscillations of the anapole (toroidal) moment

  2. INO80 Chromatin Remodeling Coordinates Metabolic Homeostasis with Cell Division

    Directory of Open Access Journals (Sweden)

    Graeme J. Gowans

    2018-01-01

    Full Text Available Adaptive survival requires the coordination of nutrient availability with expenditure of cellular resources. For example, in nutrient-limited environments, 50% of all S. cerevisiae genes synchronize and exhibit periodic bursts of expression in coordination with respiration and cell division in the yeast metabolic cycle (YMC. Despite the importance of metabolic and proliferative synchrony, the majority of YMC regulators are currently unknown. Here, we demonstrate that the INO80 chromatin-remodeling complex is required to coordinate respiration and cell division with periodic gene expression. Specifically, INO80 mutants have severe defects in oxygen consumption and promiscuous cell division that is no longer coupled with metabolic status. In mutant cells, chromatin accessibility of periodic genes, including TORC1-responsive genes, is relatively static, concomitant with severely attenuated gene expression. Collectively, these results reveal that the INO80 complex mediates metabolic signaling to chromatin to restrict proliferation to metabolically optimal states.

  3. Coordination compounds of metals with imidazoles and benzimidazoles

    International Nuclear Information System (INIS)

    Novikova, G.A.; Molodkin, A.K.; Kukalenko, S.S.

    1988-01-01

    Methods of preparation, composition and structure of UO 2 2+ , Th 4+ , Mo 3+ , Cd 2+ , Ln 3+ metal ion complexes with imidazoles and benzimidazoles are considered in reviews of native and foreign literature of up to 1985. Complexes are customarily prepared by direct interaction of ligands with inorganic salts in different organic solvents. Complex composition is defined by the nature of complexing metal and inorganic salt anion, ligand volume and basicity, as well as solvent characteristics. Effect of R substituent in imidazole and benzimidazole side chain on composition of coordination compounds is considered

  4. The multitalented Mediator complex.

    Science.gov (United States)

    Carlsten, Jonas O P; Zhu, Xuefeng; Gustafsson, Claes M

    2013-11-01

    The Mediator complex is needed for regulated transcription of RNA polymerase II (Pol II)-dependent genes. Initially, Mediator was only seen as a protein bridge that conveyed regulatory information from enhancers to the promoter. Later studies have added many other functions to the Mediator repertoire. Indeed, recent findings show that Mediator influences nearly all stages of transcription and coordinates these events with concomitant changes in chromatin organization. We review the multitude of activities associated with Mediator and discuss how this complex coordinates transcription with other cellular events. We also discuss the inherent difficulties associated with in vivo characterization of a coactivator complex that can indirectly affect diverse cellular processes via changes in gene transcription. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Coordination chemistry of the tiing tris(2-sallicilamidoetil)amina

    International Nuclear Information System (INIS)

    Fernandez Montalto, A. C.

    1997-01-01

    Synthesizes a new one tiing hexadented denominated tris (2-salicilamidoetil)amina, starting from the tris (2-aminoetil) amina and three equivalent of fenilo salicilato (salol). The aductos that are formed starting from this tiing with metallic ions of transition di- and trivalent, they are complex of the type LHM and LM respectively, showing a sphere of coordination pseudooctaedrica. The complex Lfe, Lcr and LHCu were synthesized, which were characterized by means of methods spectroscopy and magnetic [es

  6. Selenophene transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    White, Carter James [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the η5- and the η1(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The 77Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of η1(S)-bound thiophenes, η1(S)-benzothiophene and η1(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the η1(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh3)Re(2-benzothioenylcarbene)]O3SCF3 was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the η1(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.

  7. Dynamic Routing and Coordination in Multi-Agent Networks

    Science.gov (United States)

    2016-06-10

    epidemics spreading . Bibliography (J1) F. Pasqualetti, S. Zampieri, and F. Bullo. Controllability metrics, limitations and algorithms for complex networks ...controllability properties of the clusters and on their coupling strength. We validate our results with examples from power networks , social networks , and...SECURITY CLASSIFICATION OF: Supported by this project, we designed innovative routing, planning and coordination strategies for robotic networks and

  8. Multiple Sensory-Motor Pathways Lead to Coordinated Visual Attention

    Science.gov (United States)

    Yu, Chen; Smith, Linda B.

    2017-01-01

    Joint attention has been extensively studied in the developmental literature because of overwhelming evidence that the ability to socially coordinate visual attention to an object is essential to healthy developmental outcomes, including language learning. The goal of this study was to understand the complex system of sensory-motor behaviors that…

  9. Using Cultures and Values to Support Flexible Coordination

    NARCIS (Netherlands)

    Vanhée, L.C.B.C.

    2015-01-01

    This thesis proposes a method for supporting flexible coordination in multi-agent systems (MASs). In other words, we aim at influencing societies of artificial agents such that they can handle complex and evolving environments and collective goals (emergency rescue robots capable of handling various

  10. Cobalt(II) and Cobalt(III) Coordination Compounds.

    Science.gov (United States)

    Thomas, Nicholas C.; And Others

    1989-01-01

    Presents a laboratory experiment which illustrates the formation of tris(phenanthroline)cobalt complexes in the 2+ and 3+ oxidation states, the effect of coordination on reactions of the ligand, and the use of a ligand displacement reaction in recovering the transformed ligand. Uses IR, UV-VIS, conductivity, and NMR. (MVL)

  11. Coordination compounds of scandium with dimethylsulfoxide and dimethylformamide

    International Nuclear Information System (INIS)

    Cherkasova, T.G.; Tatarinova, Eh.S.; Tryasunov, B.G.

    1991-01-01

    The possibility to prepare crystal coordination compounds in the systems ScCl 3 -K 3 [Cr(SCN) 6 ]-DMSO (DMFA) was studied. The complexes isolated were investigated by physicochemical methods. Their composition, behaviour in chemically agressive media, density, electric conductivity of solutions and magnetic susceptibility at 298 K were ascertained

  12. Towards the Integration of Value and Coordination Models - Position Paper -

    NARCIS (Netherlands)

    Bodenstaff, L.; Reichert, M.U.; Wieringa, Roelf J.; Pernici, B; Gulla, J.A.

    Cross-organizational collaborations have a high complexity. Modelling these collaborations can be done from di®erent perspectives. For example, the value perspective represents expected value exchanges in a collaboration while the coordination perspective represents the order in which these

  13. Federal interagency radiation policy coordination

    International Nuclear Information System (INIS)

    Young, A.L.

    1984-01-01

    The author discusses Federal interagency radiation policy coordination. The Committee on Interagency Radiation Research and Policy Coordination (CIRRPC) is explained as being dedicated to the success and forward motion of enhanced radiation research and policy coordination. Both CIRRPC and the Science Panel are staffed with Federal employees. Their expertise includes many and various radiation disciplines including cytogenetics, dosimetry, epidemiology, genetics, health physics, nuclear medicine, radiology, radiation carcinogenesis, and risk assessment. Ten scientific and technical issues in their preliminary order are presented: radioepidemiological tables; de minimis radiation levels; radon progeny health effects; occupational exposure registry; measurement, recording, and control of radiation; food irradiation; use of radiation in science, industry, and medicine; nonionizing radiation; and remedial actions

  14. An argument for VP coordination: scene-setting coordination and ...

    African Journals Online (AJOL)

    This article demonstrates the properties of this curious construction type and proposes the first analysis to date. It is argued that this is an instance of VP coordination and that this configuration allows the possibility of high merger of direct objects in a constrained fashion. Southern African Linguistics and Applied Language ...

  15. Evaluating the Relational Coordination instrument

    DEFF Research Database (Denmark)

    Edwards, Kasper; Lundstrøm, Sanne Lykke

    2014-01-01

    consistency, interrater agreement and reliability, structural validity, content validity. However as relational coordination is being used as a diagnostics tool it is important to examine further if the instrument can measure changes. Indeed we need to know how precise and sensitive the instrument is when....... We distinguish between statistical and clinical significance. Statistical significance is calculated using T-test. Clinical significance is the minimal amount of change in relational coordination score that is not considered noise. Sensitivity of the instrument i.e. the ability of the instrument...

  16. Cation coordination in oxychloride glasses

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J A [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States); Holland, D [Physics Department, Warwick University, Coventry (United Kingdom); Bland, J [Physics Department, University of Liverpool, PO Box 147, Liverpool (United Kingdom); Johnson, C E [Physics Department, Northern Illinois University, DeKalb, IL (United States); Thomas, M F [Physics Department, University of Liverpool, PO Box 147, Liverpool (United Kingdom)

    2003-02-19

    Glasses containing mixtures of cations and anions of nominal compositions [Sb{sub 2}O{sub 3}]{sub x} - [ZnCl{sub 2}]{sub 1-x} where x = 0.25, 0.50, 0.75, and 1.00, have been studied by means of neutron diffraction and Raman and Moessbauer spectroscopy. There is preferential bonding within the system with the absence of Sb-Cl bonds. Antimony is found to be threefold coordinated to oxygen, and zinc fourfold coordinated. The main contributing species are of the form [Sb(OSb){sub 2}(OZn)] and [Zn(ClZn){sub 2}(OSb){sub 2}].

  17. Cation coordination in oxychloride glasses

    International Nuclear Information System (INIS)

    Johnson, J A; Holland, D; Bland, J; Johnson, C E; Thomas, M F

    2003-01-01

    Glasses containing mixtures of cations and anions of nominal compositions [Sb 2 O 3 ] x - [ZnCl 2 ] 1-x where x = 0.25, 0.50, 0.75, and 1.00, have been studied by means of neutron diffraction and Raman and Moessbauer spectroscopy. There is preferential bonding within the system with the absence of Sb-Cl bonds. Antimony is found to be threefold coordinated to oxygen, and zinc fourfold coordinated. The main contributing species are of the form [Sb(OSb) 2 (OZn)] and [Zn(ClZn) 2 (OSb) 2

  18. Bare coordination: the semantic shift

    OpenAIRE

    de Swart, Henriette; Le Bruyn, Bert

    2014-01-01

    This paper develops an analysis of the syntax-semantics interface of two types of split coordination structures. In the first type, two bare singular count nouns appear as arguments in a coordinated structure, as in bride and groom were happy. We call this the N&N construction. In the second type, the determiner shows agreement with the first conjunct, while the second conjunct is bare, as in the Spanish example el hornero y hornera cobraban en panes (‘thesg.m bakersg.m and bakersg.f werepl p...

  19. Coordination in fast repetitive violin-bowing patterns.

    Science.gov (United States)

    Schoonderwaldt, Erwin; Altenmüller, Eckart

    2014-01-01

    We present a study of coordination behavior in complex violin-bowing patterns involving simultaneous bow changes (reversal of bowing direction) and string crossings (changing from one string to another). Twenty-two violinists (8 advanced amateurs, 8 students with violin as major subject, and 6 elite professionals) participated in the experiment. We investigated the influence of a variety of performance conditions (specific bowing patterns, dynamic level, tempo, and transposition) and level of expertise on coordination behavior (a.o., relative phase and amplitude) and stability. It was found that the general coordination behavior was highly consistent, characterized by a systematic phase lead of bow inclination over bow velocity of about 15° (i.e., string crossings were consistently timed earlier than bow changes). Within similar conditions, a high individual consistency was found, whereas the inter-individual agreement was considerably less. Furthermore, systematic influences of performance conditions on coordination behavior and stability were found, which could be partly explained in terms of particular performance constraints. Concerning level of expertise, only subtle differences were found, the student and professional groups (higher level of expertise) showing a slightly higher stability than the amateur group (lower level of expertise). The general coordination behavior as observed in the current study showed a high agreement with perceptual preferences reported in an earlier study to similar bowing patterns, implying that complex bowing trajectories for an important part emerge from auditory-motor interaction.

  20. Coordination in fast repetitive violin-bowing patterns.

    Directory of Open Access Journals (Sweden)

    Erwin Schoonderwaldt

    Full Text Available We present a study of coordination behavior in complex violin-bowing patterns involving simultaneous bow changes (reversal of bowing direction and string crossings (changing from one string to another. Twenty-two violinists (8 advanced amateurs, 8 students with violin as major subject, and 6 elite professionals participated in the experiment. We investigated the influence of a variety of performance conditions (specific bowing patterns, dynamic level, tempo, and transposition and level of expertise on coordination behavior (a.o., relative phase and amplitude and stability. It was found that the general coordination behavior was highly consistent, characterized by a systematic phase lead of bow inclination over bow velocity of about 15° (i.e., string crossings were consistently timed earlier than bow changes. Within similar conditions, a high individual consistency was found, whereas the inter-individual agreement was considerably less. Furthermore, systematic influences of performance conditions on coordination behavior and stability were found, which could be partly explained in terms of particular performance constraints. Concerning level of expertise, only subtle differences were found, the student and professional groups (higher level of expertise showing a slightly higher stability than the amateur group (lower level of expertise. The general coordination behavior as observed in the current study showed a high agreement with perceptual preferences reported in an earlier study to similar bowing patterns, implying that complex bowing trajectories for an important part emerge from auditory-motor interaction.

  1. Coordination of plant mitochondrial biogenesis: keeping pace with cellular requirements.

    Directory of Open Access Journals (Sweden)

    Elina eWelchen

    2014-01-01

    Full Text Available Plant mitochondria are complex organelles that carry out numerous metabolic processes related with the generation of energy for cellular functions and the synthesis and degradation of several compounds. Mitochondria are semiautonomous and dynamic organelles changing in shape, number and composition depending on tissue or developmental stage. The biogenesis of functional mitochondria requires the coordination of genes present both in the nucleus and the organelle. In addition, due to their central role, all processes held inside mitochondria must be finely coordinated with those in other organelles according to cellular demands. Coordination is achieved by transcriptional control of nuclear genes encoding mitochondrial proteins by specific transcription factors that recognize conserved elements in their promoter regions. In turn, the expression of most of these transcription factors is linked to developmental and environmental cues, according to the availability of nutrients, light-dark cycles and warning signals generated in response to stress conditions. Among the signals impacting in the expression of nuclear genes, retrograde signals that originate inside mitochondria help to adjust mitochondrial biogenesis to organelle demands. Adding more complexity, several nuclear encoded proteins are dual localized to mitochondria and either chloroplasts or the nucleus. Dual targeting might establish a crosstalk between the nucleus and cell organelles to ensure a fine coordination of cellular activities. In this article, we discuss how the different levels of coordination of mitochondrial biogenesis interconnect to optimize the function of the organelle according to both internal and external demands.

  2. Coordination of plant mitochondrial biogenesis: keeping pace with cellular requirements

    Science.gov (United States)

    Welchen, Elina; García, Lucila; Mansilla, Natanael; Gonzalez, Daniel H.

    2014-01-01

    Plant mitochondria are complex organelles that carry out numerous metabolic processes related with the generation of energy for cellular functions and the synthesis and degradation of several compounds. Mitochondria are semiautonomous and dynamic organelles changing in shape, number, and composition depending on tissue or developmental stage. The biogenesis of functional mitochondria requires the coordination of genes present both in the nucleus and the organelle. In addition, due to their central role, all processes held inside mitochondria must be finely coordinated with those in other organelles according to cellular demands. Coordination is achieved by transcriptional control of nuclear genes encoding mitochondrial proteins by specific transcription factors that recognize conserved elements in their promoter regions. In turn, the expression of most of these transcription factors is linked to developmental and environmental cues, according to the availability of nutrients, light–dark cycles, and warning signals generated in response to stress conditions. Among the signals impacting in the expression of nuclear genes, retrograde signals that originate inside mitochondria help to adjust mitochondrial biogenesis to organelle demands. Adding more complexity, several nuclear encoded proteins are dual localized to mitochondria and either chloroplasts or the nucleus. Dual targeting might establish a crosstalk between the nucleus and cell organelles to ensure a fine coordination of cellular activities. In this article, we discuss how the different levels of coordination of mitochondrial biogenesis interconnect to optimize the function of the organelle according to both internal and external demands. PMID:24409193

  3. Implicit Coordination Strategies for Effective Team Communication.

    Science.gov (United States)

    Butchibabu, Abhizna; Sparano-Huiban, Christopher; Sonenberg, Liz; Shah, Julie

    2016-06-01

    We investigated implicit communication strategies for anticipatory information sharing during team performance of tasks with varying degrees of complexity. We compared the strategies used by teams with the highest level of performance to those used by the lowest-performing teams to evaluate the frequency and methods of communications used as a function of task structure. High-performing teams share information by anticipating the needs of their teammates rather than explicitly requesting the exchange of information. As the complexity of a task increases to involve more interdependence among teammates, the impact of coordination on team performance also increases. This observation motivated us to conduct a study of anticipatory information sharing as a function of task complexity. We conducted an experiment in which 13 teams of four people performed collaborative search-and-deliver tasks with varying degrees of complexity in a simulation environment. We elaborated upon prior characterizations of communication as implicit versus explicit by dividing implicit communication into two subtypes: (a) deliberative/goal information and (b) reactive status updates. We then characterized relationships between task structure, implicit communication, and team performance. We found that the five teams with the fastest task completion times and lowest idle times exhibited higher rates of deliberative communication versus reactive communication during high-complexity tasks compared with the five teams with the slowest completion times and longest idle times (p = .039). Teams in which members proactively communicated information about their next goal to teammates exhibited improved team performance. The findings from our work can inform the design of communication strategies for team training to improve performance of complex tasks. © 2016, Human Factors and Ergonomics Society.

  4. 47 CFR 95.1113 - Frequency coordinator.

    Science.gov (United States)

    2010-10-01

    ... SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1113 Frequency coordinator. (a) The Commission will designate a frequency coordinator(s) to manage the usage of the frequency bands for the operation of medical telemetry devices. (b) The frequency coordinator shall (1) Review and...

  5. 29 CFR 42.8 - Coordination plan.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Coordination plan. 42.8 Section 42.8 Labor Office of the Secretary of Labor COORDINATED ENFORCEMENT § 42.8 Coordination plan. (a) Based upon, among other things, the... coordination plan concerning farm labor-related responsibilities of the Department, including migrant housing...

  6. Service Coordination Policies and Models: National Status.

    Science.gov (United States)

    Harbin, Gloria L.; Bruder, M.; Mazzarella, C.; Gabbard, G.; Reynolds, C.

    This report discusses the findings of a study that investigated state coordination of early intervention services for infants, toddlers, and young children with disabilities. State Part C coordinators participated in a survey that sought their perceptions of values under girding service coordination, approach to service coordination, policies,…

  7. Spectral studies of coordination compounds of cobalt(II) with thiosemicarbazone of heterocyclic ketone

    Science.gov (United States)

    Chandra, Sulekh; Kumar, Umendra

    2005-12-01

    The paper presents the spectral analysis of cobalt(II) complexes with indoxyl thiosemicarbazone (ITSC) of general composition [CoL 2X 2] (where L = ITSC, X = Cl -, NO 3-, (1/2)SO 42-, NCS -). The geometry of the complexes have been characterized by elemental analysis, molar conductance, magnetic susceptibility measurements and spectral (electronic, IR, EPR, 1H NMR, mass) studies. The various physico-chemical techniques suggested a coordination number of six (octahedral) for chloro, nitrato and thiocyanato complexes. Whereas sulfato complex was found to have five coordinate trigonal-bipyramidal geometry. All the complexes are of high spin type showing magnetic moment corresponding to three unpaired electrons.

  8. Development of an International School Nurse Asthma Care Coordination Model

    Science.gov (United States)

    Garwick, Ann W.; Svavarsdóttir, Erla Kolbrun; Seppelt, Ann M.; Looman, Wendy S.; Anderson, Lori S.; Örlygsdóttir, Brynja

    2015-01-01

    Aim To identify and compare how school nurses in Reykjavik, Iceland and St. Paul, Minnesota coordinated care for youth with asthma (ages 10–18) and to develop an asthma school nurse care coordination model. Background Little is known about how school nurses coordinate care for youth with asthma in different countries. Design A qualitative descriptive study design using focus group data. Methods Six focus groups with 32 school nurses were conducted in Reykjavik (n=17) and St. Paul (n=15) using the same protocol between September 2008 – January 2009. Descriptive content analytic and constant comparison strategies were used to categorize and compare how school nurses coordinated care, which resulted in the development of an International School Nurse Asthma Care Coordination Model. Findings Participants in both countries spontaneously described a similar asthma care coordination process that involved information gathering, assessing risk for asthma episodes, prioritizing health care needs and anticipating and planning for student needs at the individual and school levels. This process informed how they individualized symptom management, case management and/or asthma education. School nurses played a pivotal part in collaborating with families, school and health care professionals to ensure quality care for youth with asthma. Conclusions Results indicate a high level of complexity in school nurses’ approaches to asthma care coordination that were responsive to the diverse and changing needs of students in school settings. The conceptual model derived provides a framework for investigators to use in examining the asthma care coordination process of school nurses in other geographic locations. PMID:25223389

  9. "Low-coordinate" 1,2-oxaphosphetanes - a new opportunity in coordination and main group chemistry.

    Science.gov (United States)

    Kyri, A W; Gleim, F; García Alcaraz, A; Schnakenburg, G; Espinosa Ferao, A; Streubel, R

    2018-05-17

    While 1,2σ5λ5-oxaphosphetanes are well known intermediates from the Wittig-reaction, no 1,2σ3λ3-oxaphosphetanes have been described, so far. Herein, we present the first synthesis of 1,2σ3λ3-oxaphosphetanes derived from their κP-Mo(CO)5 complexes and first investigations towards metal coordination and P-oxidation. Bonding, ring strain energy and potential retro-[2+2] cycloaddition reactions of the 1,2-oxaphosphetane ring were studied by DFT methods.

  10. U.S. CWMD Coordination

    Science.gov (United States)

    2012-12-11

    coordination. For example, it conducted joint vehicle inspection training for Pakistani Customs and Border Guard personnel at a US- Mexico border...biological material, including such hazards as: anthrax, botulism, cholera , Ebola virus hemorrhagic fever, E. coli, Plague, and smallpox 79

  11. Collective coordinates on symplectic manifolds

    International Nuclear Information System (INIS)

    Razumov, A.V.; Taranov, A.Yu.

    1981-01-01

    For an arbitrary Lie group of canonical transformations on a symplectic manifold collective coordinates are introduced. They describe a motion of the dynamical system as a whole under the group transformations. Some properties of Lie group of canonical transformations are considered [ru

  12. Motivic amplitudes and cluster coordinates

    International Nuclear Information System (INIS)

    Golden, J.K.; Goncharov, A.B.; Spradlin, M.; Vergu, C.; Volovich, A.

    2014-01-01

    In this paper we study motivic amplitudes — objects which contain all of the essential mathematical content of scattering amplitudes in planar SYM theory in a completely canonical way, free from the ambiguities inherent in any attempt to choose particular functional representatives. We find that the cluster structure on the kinematic configuration space Conf n (ℙ 3 ) underlies the structure of motivic amplitudes. Specifically, we compute explicitly the coproduct of the two-loop seven-particle MHV motivic amplitude A 7,2 M and find that like the previously known six-particle amplitude, it depends only on certain preferred coordinates known in the mathematics literature as cluster X-coordinates on Conf n (ℙ 3 ). We also find intriguing relations between motivic amplitudes and the geometry of generalized associahedrons, to which cluster coordinates have a natural combinatoric connection. For example, the obstruction to A 7,2 M being expressible in terms of classical polylogarithms is most naturally represented by certain quadrilateral faces of the appropriate associahedron. We also find and prove the first known functional equation for the trilogarithm in which all 40 arguments are cluster X-coordinates of a single algebra. In this respect it is similar to Abel’s 5-term dilogarithm identity

  13. Co-ordinated Classroom Lectures.

    Science.gov (United States)

    Harmon, Darell Boyd

    From a series of lectures, a selection of eight are oriented principally toward the biologically developing child, and the physiological operations in visual process. The numbered lectures are--(1) The Coordinated Classroom, its Philosophy and Principles, (2) An Outline of a Biological Point of View, (3) The Evolution of Structure--despite man's…

  14. Henry Taube and Coordination Chemistry

    Science.gov (United States)

    dropdown arrow Site Map A-Z Index Menu Synopsis Henry Taube and Coordination Chemistry Resources with Professor of Chemistry, Emeritus, at Stanford University, received the 1983 Nobel Prize in Chemistry " there from 1940-41. "I became deeply interested in chemistry soon after I came to Berkeley,"

  15. The Open Method of Coordination and the Implementation of the Bologna Process

    Science.gov (United States)

    Veiga, Amelia; Amaral, Alberto

    2006-01-01

    In this paper the authors argue that the use of the Open Method of Coordination (OMC) in the implementation of the Bologna process presents coordination problems that do not allow for the full coherence of the results. As the process is quite complex, involving three different levels (European, national and local) and as the final actors in the…

  16. Strengthening the Signature Pedagogy of Social Work: Conceptualizing Field Coordination as a Negotiated Social Work Pedagogy

    Science.gov (United States)

    Asakura, Kenta; Todd, Sarah; Eagle, Brooke; Morris, Brenda

    2018-01-01

    Although field education is considered the signature pedagogy of social work, the work of field coordinators appear to remain peripheral to other aspects of social work education, such as coursework and research. In this article, we suggest that field coordination requires a far more complex set of knowledge and skills than merely matching…

  17. Integration and Continuity of Primary Care: Polyclinics and Alternatives, a Patient-Centred Analysis of How Organisation Constrains Care Coordination

    OpenAIRE

    Sheaff, WR; Halliday, J; Øvretveit, J; Byng, R; Exworthy, M; Peckham, S; Asthana, S

    2015-01-01

    Background\\ud An ageing population, the increasing specialisation of clinical services and diverse health-care provider ownership make the co-ordination and continuity of complex care increasingly problematic. The way in which the provision of complex health care is co-ordinated produces – or fails to produce – six forms of continuity of care (cross-sectional, longitudinal, flexible, access, informational and relational). Care co-ordination is accomplished by a combination of activities by pa...

  18. Engineering the oxygen coordination in digital superlattices

    Science.gov (United States)

    Cook, Seyoung; Andersen, Tassie K.; Hong, Hawoong; Rosenberg, Richard A.; Marks, Laurence D.; Fong, Dillon D.

    2017-12-01

    The oxygen sublattice in complex oxides is typically composed of corner-shared polyhedra, with transition metals at their centers. The electronic and chemical properties of the oxide depend on the type and geometric arrangement of these polyhedra, which can be controlled through epitaxial synthesis. Here, we use oxide molecular beam epitaxy to create SrCoOx:SrTiO3 superlattices with tunable oxygen coordination environments and sublattice geometries. Using synchrotron X-ray scattering in combination with soft X-ray spectroscopy, we find that the chemical state of Co can be varied with the polyhedral arrangement, with higher Co oxidation states increasing the valence band maximum. This work demonstrates a new strategy for engineering unique electronic structures in the transition metal oxides using short-period superlattices.

  19. Custom Coordination Environments for Lanthanoids: Tripodal Ligands Achieve Near-Perfect Octahedral Coordination for Two Dysprosium-Based Molecular Nanomagnets.

    Science.gov (United States)

    Lim, Kwang Soo; Baldoví, José J; Jiang, ShangDa; Koo, Bong Ho; Kang, Dong Won; Lee, Woo Ram; Koh, Eui Kwan; Gaita-Ariño, Alejandro; Coronado, Eugenio; Slota, Michael; Bogani, Lapo; Hong, Chang Seop

    2017-05-01

    Controlling the coordination sphere of lanthanoid complexes is a challenging critical step toward controlling their relaxation properties. Here we present the synthesis of hexacoordinated dysprosium single-molecule magnets, where tripodal ligands achieve a near-perfect octahedral coordination. We perform a complete experimental and theoretical investigation of their magnetic properties, including a full single-crystal magnetic anisotropy analysis. The combination of electrostatic and crystal-field computational tools (SIMPRE and CONDON codes) allows us to explain the static behavior of these systems in detail.

  20. Antecedents of individuals' interteam coordination: Broad functional experiences as a mixed blessing

    NARCIS (Netherlands)

    Vries, T.A. de; Walter, F.; Vegt, G.S. van der; Essens, P.J.M.D.

    2014-01-01

    This manuscript investigates the role of individual team members' breadth of functional experience for their interteam coordination behavior. Integrating personal construct and social identity theories, we examine interpersonal cognitive complexity as a mediating variable and organizational

  1. On coordinates and coordinate transformation in Einstein's theory of gravitation

    International Nuclear Information System (INIS)

    Chou Peiyuan

    1983-01-01

    This investigation is a further exposition of the significance of coordinates and their transformation in Einstein's theory of gravitation. The author considers the static axisymmetric field as an example, starts with its metric in the cylindrical coordinates, transforms this metric and the field equations into the Weyl-Levi-Civita system of coordinates, and supplements them with the harmonic condition. Both of the field equations and the harmonic condition are then transformed back to the original Cartesian system. Solutions for the static fields of an infinite plane with uniform surface density and an infinite rod with uniform linear density of matter, and of a body with spherical symmetry, are obtained again to show the necessity of the harmonic condition in their solutions. The fact that under the harmonic condition the solutions of the field equations for these problems contain their corresponding Newtonian potentials as approximations, is a strong support to the argument that the harmonic condition should be a physical supplement to Einstein's theory of gravitation. (Auth.)

  2. Information needs of physicians, care coordinators, and families to support care coordination of children and youth with special health care needs (CYSHCN).

    Science.gov (United States)

    Ranade-Kharkar, Pallavi; Weir, Charlene; Norlin, Chuck; Collins, Sarah A; Scarton, Lou Ann; Baker, Gina B; Borbolla, Damian; Taliercio, Vanina; Del Fiol, Guilherme

    2017-09-01

    Identify and describe information needs and associated goals of physicians, care coordinators, and families related to coordinating care for medically complex children and youth with special health care needs (CYSHCN). We conducted 19 in-depth interviews with physicians, care coordinators, and parents of CYSHCN following the Critical Decision Method technique. We analyzed the interviews for information needs posed as questions using a systematic content analysis approach and categorized the questions into information need goal types and subtypes. The Critical Decision Method interviews resulted in an average of 80 information needs per interview. We categorized them into 6 information need goal types: (1) situation understanding, (2) care networking, (3) planning, (4) tracking/monitoring, (5) navigating the health care system, and (6) learning, and 32 subtypes. Caring for CYSHCN generates a large amount of information needs that require significant effort from physicians, care coordinators, parents, and various other individuals. CYSHCN are often chronically ill and face developmental challenges that translate into intense demands on time, effort, and resources. Care coordination for CYCHSN involves multiple information systems, specialized resources, and complex decision-making. Solutions currently offered by health information technology fall short in providing support to meet the information needs to perform the complex care coordination tasks. Our findings present significant opportunities to improve coordination of care through multifaceted and fully integrated informatics solutions. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  3. The potential roles of T-type Ca2+ channels in motor coordination

    Directory of Open Access Journals (Sweden)

    Young-Gyun ePark

    2013-10-01

    Full Text Available Specific behavioral patterns are expressed by complex combinations of muscle coordination. Tremors are simple behavioral patterns and are the focus of studies investigating motor coordination mechanisms in the brain. T-type Ca2+ channels mediate intrinsic neuronal oscillations and rhythmic burst spiking, and facilitate the generation of tremor rhythms in motor circuits. Despite substantial evidence that T-type Ca2+ channels mediate pathological tremors, their roles in physiological motor coordination and behavior remain unknown. Here, we review recent progress in understanding the roles that T-type Ca2+ channels play under pathological conditions, and discuss the potential relevance of these channels in mediating physiological motor coordination.

  4. Effect of reinforcement learning on coordination of multiangent systems

    Science.gov (United States)

    Bukkapatnam, Satish T. S.; Gao, Greg

    2000-12-01

    For effective coordination of distributed environments involving multiagent systems, learning ability of each agent in the environment plays a crucial role. In this paper, we develop a simple group learning method based on reinforcement, and study its effect on coordination through application to a supply chain procurement scenario involving a computer manufacturer. Here, all parties are represented by self-interested, autonomous agents, each capable of performing specific simple tasks. They negotiate with each other to perform complex tasks and thus coordinate supply chain procurement. Reinforcement learning is intended to enable each agent to reach a best negotiable price within a shortest possible time. Our simulations of the application scenario under different learning strategies reveals the positive effects of reinforcement learning on an agent's as well as the system's performance.

  5. Report on July 2015 Additional Protocol Coordinators Best Practices Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Gitau, Ernest T.N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burbank, Roberta L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finch, Valerie A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-07-31

    After 10 years of implementation experience, the Office of Nonproliferation and Arms Control (NPAC) within the Department of Energy/National Nuclear Security Administration (DOE/NNSA) conducted the Additional Protocol (AP) Coordinators Best Practices Workshop at Oak Ridge National Laboratory from July 29-30, 2015. The goal of this workshop was to identify implementation best practices, lessons learned, and compliance challenges from the various Additional Protocol Coordinators (APCs) at each laboratory in the DOE/NNSA complex and associated sites. The workshop provided the opportunity for participants to share their insights and establish networks that APCs can utilize to continue to discuss challenges (new and old), identify best practices, and enhance communication and coordination for reporting multi-lab research projects during review activities. Workshop participants included DOE/NNSA HQ, laboratory and site APCs, seasoned experts, members of the original implementation outreach team, and Field Element and site security representatives.

  6. TURNAROUND COORDINATOR. YES OR NOT?

    Directory of Open Access Journals (Sweden)

    Martin HROMÁDKA

    2013-12-01

    Full Text Available Both low cost carriers ‘fresh wind’ and liberalisation of ground handling market makes airlines to be cost-wise in every single field. Thus, ground handling contract are cutting down in terms of their costs. Handling companies struggle with pressure being put from the market environment, they rush 25 minutes turnaround with couple of people. This can be potentially dangerous from the safety point of view. One of possible solutions seems to be introducing turnaround coordinator, person who would supervise the ramp handling procedures. This paper discusses the role of turnaround coordinator within the aircraft turnaround process. Duties and responsibilities of this person are described. However, not every airport is staffing this position. The survey shows that smaller airports pay much more attention to this issue than the big ones.

  7. A coordination language for databases

    DEFF Research Database (Denmark)

    Li, Ximeng; Wu, Xi; Lluch Lafuente, Alberto

    2017-01-01

    We present a coordination language for the modeling of distributed database applications. The language, baptized Klaim-DB, borrows the concepts of localities and nets of the coordination language Klaim but re-incarnates the tuple spaces of Klaim as databases. It provides high-level abstractions...... and primitives for the access and manipulation of structured data, with integrity and atomicity considerations. We present the formal semantics of Klaim-DB and develop a type system that avoids potential runtime errors such as certain evaluation errors and mismatches of data format in tables, which are monitored...... in the semantics. The use of the language is illustrated in a scenario where the sales from different branches of a chain of department stores are aggregated from their local databases. Raising the abstraction level and encapsulating integrity checks in the language primitives have benefited the modeling task...

  8. Coordinating talk and practical action

    DEFF Research Database (Denmark)

    Oshima, Sae; Streeck, Jürgen

    2015-01-01

    This paper investigates how talk and practical action are coordinated during one type of activity involving professional communication: the service-assessment sequence in hair salons. During this activity, a practical inspection of the haircut must be coupled with sequentially produced verbal acts....... Our analysis of four examples reveals that there is no fixed relationship between the organization of talk and practical action. Instead, people manipulate this relationship on a moment-by-moment basis, often coordinating the two into a single, integral package, or relying on one stream of action...... to achieve progress in the other. These findings imply that some multimodal activities that are brought into alignment may have their own, separate and independent procedural logic and sequencing patterns and that these can be brought into play to create or deal with constraints in each other....

  9. Complex manifolds in relativity

    International Nuclear Information System (INIS)

    Flaherty, E.J. Jr.

    1975-01-01

    Complex manifold theory is applied to the study of certain problems in general relativity. The first half of the work is devoted to the mathematical theory of complex manifold. Then a brief review of general relativity is given. It is shown that any spacetime admits locally an almost Hermitian structure, suitably modified to be compatible with the indefinite metric of spacetime. This structure is integrable if and only if the spacetime admits two geodesic and shearfree null congruences, thus in particular if the spacetime is type D vacuum or electrified. The structure is ''half-integrable'' in a suitable sense if and only if the spacetime admits one geodesic and shearfree null congruence, thus in particular for all algebraically special vacuum spacetimes. Conditions for the modified Hermitian spacetime to be Kahlerian are presented. The most general metric for such a modified Kahlerian spacetime is found. It is shown that the type D vacuum and electrified spacetimes are conformally related to modified Kahlerian spacetimes by a generally complex conformal factor. These latter are shown to possess a very rich structure, including the existence of Killing tensors and Killing vectors. A new ''explanation'' of Newman's complex coordinate transformations is given. It is felt to be superior to previous ''explanations'' on several counts. For example, a physical interpretation in terms of a symmetry group is given. The existence of new complex coordinate transformations is established: Nt is shown that any type D vacuum spacetime is obtainable from either Schwarzschild spacetime or ''C'' spacetime by a complex coordinate transformation. Finally, some related topics are discussed and areas for future work are outlined. (Diss. Abstr. Int., B)

  10. Improving Channel Coordination Through Franchising

    OpenAIRE

    Rajiv Lal

    1990-01-01

    In this paper, we explore the role of franchising arrangements in improving coordination between channel members. In particular we focus on two elements of the franchising contract, namely, the royalty structure and the monitoring technology. We begin with a simple analysis where a manufacturer distributes its product through a retailer and the retail demand is affected by the retail price and the service provided by the retailer. In this context we show that neither royalty payments nor moni...

  11. Coordination in the European Union

    OpenAIRE

    Martin Feldstein

    2013-01-01

    This paper examines the sources of current conflict within the EU and the EMU. The topics discussed include the recent ECB policy of bond buying (the OMT policy), the attempts to advance the "European Project" of stronger political union (the fiscal compact, the banking union, and the proposals for budget supervision). Contrary to the claims of the European leadership, the progress that has been made has been by individual countries and not by coordinated action. The special problems of Franc...

  12. Coordination strategies of crew management

    Science.gov (United States)

    Conley, Sharon; Cano, Yvonne; Bryant, Don

    1991-01-01

    An exploratory study that describes and contrasts two three-person flight crews performing in a B-727 simulator is presented. This study specifically attempts to delineate crew communication patterns accounting for measured differences in performance across routine and nonroutine flight patterns. The communication patterns in the two crews evaluated indicated different modes of coordination, i.e., standardization in the less effective crew and planning/mutual adjustment in the more effective crew.

  13. Monetary and Fiscal Policy Coordination

    OpenAIRE

    Hanif, Muhammad N.; Arby, Muhammad Farooq

    2003-01-01

    Macroeconomic policies are meant to achieve non-inflationary, stable growth. There are two major groups of policy instruments to achieve the purpose; one is related to monetary conditions and the other to fiscal conditions. Monetary instruments are employed by the central bank and fiscal instruments are employed by ministry of finance. The objectives and implications of policy measures taken by the two institutions often conflict with each other and thus call for policy coordination for effec...

  14. Inorganic, coordination and organometallic compounds

    International Nuclear Information System (INIS)

    Jursik, F.

    1978-01-01

    Separation of cations and anions of inorganic, coordination and metalloorganic compounds by the method of liquid column chromatography is considered. Common scheme of multicomponent cation mixture is suggesteed. Separation conditions, adsrbents, eluents, pH value solution concenstration, elution rate are also suggested. Separation of rare earth elements Cs, Be, Cd, Te, Th, U, Mo, Re, V, Ru, Zr, In compounds is considered as an example of liquid column chromatography application. Data on column chromatography application are summarized in a table

  15. Porphyrin coordination polymer nanospheres and nanorods

    Science.gov (United States)

    Wang, Zhongchun; Shelnutt, John A.; Medforth, Craig J.

    2012-12-04

    A porphyrin coordination polymer nanostructure comprising a network of pyridyl porphyrin molecules and coordinating metal ions coordinatively bound through the pyridyl groups. In some embodiments, the porphyrins are metalloporphyrins. A variety of nanostructures are formed by the network polymer, including nanospheres, polygonal nanostructures, nanorods, and nanofibers, depending on a variety of factors including coordination metal ion, porphyrin type, metal of the metalloporphyrin, and degree of agitation during nanostructure formation. Reduction of coordinating metal ions may be used to form metal nanoparticles on the coordination polymer nanostructure.

  16. Rare earth niobate coordination polymers

    Science.gov (United States)

    Muniz, Collin N.; Patel, Hiral; Fast, Dylan B.; Rohwer, Lauren E. S.; Reinheimer, Eric W.; Dolgos, Michelle; Graham, Matt W.; Nyman, May

    2018-03-01

    Rare-earth (RE) coordination polymers are infinitely tailorable to yield luminescent materials for various applications. Here we described the synthesis of a heterometallic rare-earth coordination compound ((CH3)2SO)3(RE)NbO(C2O4)3((CH3)2SO) = dimethylsulfoxide, DMSO, (C2O2= oxalate), (RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb). The structure was obtained from single crystal X-ray diffraction of the La analogue. The Nb˭O and DMSO terminal-bonding character guides assembly of an open framework structure with noncentrosymmetric RE-coordination geometry, and large spacing between the RE centers. A second structure was observed by PXRD for the smaller rare earths (Dy, Ho, Er, Yb); this structure has not yet been determined. The materials were further characterized using FTIR, and photoluminescence measurements. Characteristic excitation and emission transitions were observed for RE = Nd, Sm, Eu, and Tb. Quantum yield (QY) measurements were performed by exciting Eu and Tb analoges at 394 nm (QY 66%) and 464 nm (QY 71%) for Eu; and 370 nm (QY=40%) for Tb. We attribute the high QY and bright luminescence to two main structure-function properties of the system; namely the absence of water in the structure, and absence of concentration quenching.

  17. Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

    Directory of Open Access Journals (Sweden)

    Jakub Ehrenberger

    2017-09-01

    Full Text Available This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordination is designed, in which not only some, but all the required types of short-circuit contributions are taken into account. In radial systems, if the pickup currents are correctly chosen, protection coordination for maximum contributions is enough to ensure selectivity times for all the required short-circuit types. In distributed generation systems, due to different contributions flowing through the primary and selective protections, coordination for maximum contributions is not enough, but all the short-circuit types must be taken into account, and the protection coordination becomes a complex problem. A possible solution to the problem, based on an appropriately designed optimization, has been proposed in the paper. By repeating a simple optimization considering only one short-circuit type, the protection coordination considering all the required short-circuit types has been achieved. To show the importance of considering all the types of short-circuit contributions, setting optimizations with one (the highest and all the types of short-circuit contributions have been performed. Finally, selectivity time values are explored throughout the entire protected section, and both the settings are compared.

  18. Numerical construction of the p(fold) (committor) reaction coordinate for a Markov process.

    Science.gov (United States)

    Krivov, Sergei V

    2011-10-06

    To simplify the description of a complex multidimensional dynamical process, one often projects it onto a single reaction coordinate. In protein folding studies, the folding probability p(fold) is an optimal reaction coordinate which preserves many important properties of the dynamics. The construction of the coordinate is difficult. Here, an efficient numerical approach to construct the p(fold) reaction coordinate for a Markov process (satisfying the detailed balance) is described. The coordinate is obtained by optimizing parameters of a chosen functional form to make a generalized cut-based free energy profile the highest. The approach is illustrated by constructing the p(fold) reaction coordinate for the equilibrium folding simulation of FIP35 protein reported by Shaw et al. (Science 2010, 330, 341-346). © 2011 American Chemical Society

  19. Coordination chemistry of technetium as related to nuclear medicine

    International Nuclear Information System (INIS)

    Srivastava, S.C.; Richards, P.

    1982-01-01

    Significant advances have been made in the area of technetium coordination chemistry during the last five years. The main driving force behind this recent surge of interest in the field has been due to the practical application of technetium-99m in the rapidly growing speciality of nuclear medicine. Technetium-99 is one of the products of nuclear fission reactions, but it was the development of the molybdenum-99-technetium-99m generator about two decades ago that provided the basis for the development of radiopharmaceuticals routinely used in modern diagnostic applications. The chemistry of this element has proven to be quite rich owing to its multiple oxidation states and variable geometry. This can be attributed to its position in the middle of the periodic table. Diagnostic radiopharmaceuticals comprise predominantly III, IV and V oxidation states of Tc and involve a variety of coordination complexes. Even though the chemistry of Tc has been slow to evolve, recent synthetic advances have provided a more scientific basis for the study of a number of compounds with diverse coordination geometries and structures. Ligands with oxygen, nitrogen and sulfur donor atoms have been utilized to elucidate various aspects of the coordination chemistry of Tc. Single crystal X-ray structural analysis has been extensively used to characterize Tc complexes and thus construct a firm foundation for the study of synthetic and mechanistic aspects of the chemistry of this element. (author)

  20. Coordination of frontline defense mechanisms under severe oxidative stress.

    Science.gov (United States)

    Kaur, Amardeep; Van, Phu T; Busch, Courtney R; Robinson, Courtney K; Pan, Min; Pang, Wyming Lee; Reiss, David J; DiRuggiero, Jocelyne; Baliga, Nitin S

    2010-07-01

    Complexity of cellular response to oxidative stress (OS) stems from its wide-ranging damage to nucleic acids, proteins, carbohydrates, and lipids. We have constructed a systems model of OS response (OSR) for Halobacterium salinarum NRC-1 in an attempt to understand the architecture of its regulatory network that coordinates this complex response. This has revealed a multi-tiered OS-management program to transcriptionally coordinate three peroxidase/catalase enzymes, two superoxide dismutases, production of rhodopsins, carotenoids and gas vesicles, metal trafficking, and various other aspects of metabolism. Through experimental validation of interactions within the OSR regulatory network, we show that despite their inability to directly sense reactive oxygen species, general transcription factors have an important function in coordinating this response. Remarkably, a significant fraction of this OSR was accurately recapitulated by a model that was earlier constructed from cellular responses to diverse environmental perturbations--this constitutes the general stress response component. Notwithstanding this observation, comparison of the two models has identified the coordination of frontline defense and repair systems by regulatory mechanisms that are triggered uniquely by severe OS and not by other environmental stressors, including sub-inhibitory levels of redox-active metals, extreme changes in oxygen tension, and a sub-lethal dose of gamma rays.

  1. Power grid complexity

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Shengwei; Zhang, Xuemin [Tsinghua Univ., Beijing, BJ (China). Dept. of Electrical Engineering; Cao, Ming [Groningen Univ. (Netherlands). Faculty of Mathematics and Natural Sciences

    2011-07-01

    ''Power Grid Complexity'' introduces the complex system theory known as self-organized criticality (SOC) theory and complex network theory, and their applications to power systems. It studies the network characteristics of power systems, such as their small-world properties, structural vulnerability, decomposition and coordination strategies, and simplification and equivalence methods. The book also establishes four blackout models based on SOC theory through which the SOC of power systems is studied at both the macroscopic and microscopic levels. Additionally, applications of complex system theory in power system planning and emergency management platforms are also discussed in depth. This book can serve as a useful reference for engineers and researchers working with power systems. (orig.)

  2. Multisites Coordination in Shared Multicast Trees

    National Research Council Canada - National Science Library

    Dommel, H-P; Garcia-Luna-Aceves, J. J

    1999-01-01

    .... The protocol supports Internet-wide coordination for large and highly interactive groupwork, relying on transmission of coordination directives between group members across a shared end-to-end multicast tree...

  3. International Coordination of Lunar Polar Volatiles Exploration

    Science.gov (United States)

    Gruener, J. E.; Suzuki, N. H.; Carpenter, J. D.

    2015-10-01

    The International Space Exploration Coordination Group (ISECG) has established a study team to coordinate the worldwide interest in lunar polar volatiles, and in particular water ice, in an effort to stimulate cooperation and collaboration.

  4. The Imperative for Improved Global Economic Coordination

    OpenAIRE

    Stiglitz, Joseph E.

    2009-01-01

    While global coordination is absolutely essential, success in achieving it may prove difficult because economic globalization has outpaced political globalization. If we are to succeed, we will have to manage coordination better than we have in the past.

  5. Dreams: a framework for distributed synchronous coordination

    NARCIS (Netherlands)

    Proença, J.; Clarke, D.; Vink, de E.P.; Arbab, F.

    2012-01-01

    Synchronous coordination systems, such as Reo, exchange data via indivisible actions, while distributed systems are typically asynchronous and assume that messages can be delayed or get lost. To combine these seemingly contradictory notions, we introduce the Dreams framework. Coordination patterns

  6. Reusable coordinator modules for massively concurrent applications

    NARCIS (Netherlands)

    F. Arbab (Farhad); C.L. Blom (Kees); F.J. Burger (Freek); C.T.H. Everaars (Kees)

    1998-01-01

    htmlabstractIsolating computation and communication concerns into separate pure computation and pure coordination modules enhances modularity, understandability and reusability of parallel and/or distributed software. MANIFOLD is a pure coordination language that encourages this separation. We use

  7. Coordinator, Evaluation Unit | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Job Summary The Evaluation Unit Coordinator is expected to: ... with Centre policies and procedures and disseminates information to Unit staff on changes ... Coordinates the planning and organization of technical and administrative meetings ...

  8. Process Coordination & Policy Officer | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Such liaison aims to ensure that the operational aspects and requirements are taken into account. ... Business Process Coordination and Change Management ... plan and coordinating the update of the Division's work plan by all managers; ...

  9. An in-depth analysis of theoretical frameworks for the study of care coordination

    Directory of Open Access Journals (Sweden)

    Sabine Van Houdt

    2013-06-01

    Full Text Available Introduction: Complex chronic conditions often require long-term care from various healthcare professionals. Thus, maintaining quality care requires care coordination. Concepts for the study of care coordination require clarification to develop, study and evaluate coordination strategies. In 2007, the Agency for Healthcare Research and Quality defined care coordination and proposed five theoretical frameworks for exploring care coordination. This study aimed to update current theoretical frameworks and clarify key concepts related to care coordination. Methods: We performed a literature review to update existing theoretical frameworks. An in-depth analysis of these theoretical frameworks was conducted to formulate key concepts related to care coordination.Results: Our literature review found seven previously unidentified theoretical frameworks for studying care coordination. The in-depth analysis identified fourteen key concepts that the theoretical frameworks addressed. These were ‘external factors’, ‘structure’, ‘tasks characteristics’, ‘cultural factors’, ‘knowledge and technology’, ‘need for coordination’, ‘administrative operational processes’, ‘exchange of information’, ‘goals’, ‘roles’, ‘quality of relationship’, ‘patient outcome’, ‘team outcome’, and ‘(interorganizational outcome’.Conclusion: These 14 interrelated key concepts provide a base to develop or choose a framework for studying care coordination. The relational coordination theory and the multi-level framework are interesting as these are the most comprehensive.

  10. 2D co-ordinate transformation based on a spike timing-dependent plasticity learning mechanism.

    Science.gov (United States)

    Wu, QingXiang; McGinnity, Thomas Martin; Maguire, Liam; Belatreche, Ammar; Glackin, Brendan

    2008-11-01

    In order to plan accurate motor actions, the brain needs to build an integrated spatial representation associated with visual stimuli and haptic stimuli. Since visual stimuli are represented in retina-centered co-ordinates and haptic stimuli are represented in body-centered co-ordinates, co-ordinate transformations must occur between the retina-centered co-ordinates and body-centered co-ordinates. A spiking neural network (SNN) model, which is trained with spike-timing-dependent-plasticity (STDP), is proposed to perform a 2D co-ordinate transformation of the polar representation of an arm position to a Cartesian representation, to create a virtual image map of a haptic input. Through the visual pathway, a position signal corresponding to the haptic input is used to train the SNN with STDP synapses such that after learning the SNN can perform the co-ordinate transformation to generate a representation of the haptic input with the same co-ordinates as a visual image. The model can be applied to explain co-ordinate transformation in spiking neuron based systems. The principle can be used in artificial intelligent systems to process complex co-ordinate transformations represented by biological stimuli.

  11. Situational awareness of a coordinated cyber attack

    Science.gov (United States)

    Sudit, Moises; Stotz, Adam; Holender, Michael

    2005-03-01

    As technology continues to advance, services and capabilities become computerized, and an ever increasing amount of business is conducted electronically the threat of cyber attacks gets compounded by the complexity of such attacks and the criticality of the information which must be secured. A new age of virtual warfare has dawned in which seconds can differentiate between the protection of vital information and/or services and a malicious attacker attaining their goal. In this paper we present a novel approach in the real-time detection of multistage coordinated cyber attacks and the promising initial testing results we have obtained. We introduce INFERD (INformation Fusion Engine for Real-time Decision-making), an adaptable information fusion engine which performs fusion at levels zero, one, and two to provide real-time situational assessment and its application to the cyber domain in the ECCARS (Event Correlation for Cyber Attack Recognition System) system. The advantages to our approach are fourfold: (1) The complexity of the attacks which we consider, (2) the level of abstraction in which the analyst interacts with the attack scenarios, (3) the speed at which the information fusion is presented and performed, and (4) our disregard for ad-hoc rules or a priori parameters.

  12. Modeling Coordination Problems in a Music Ensemble

    DEFF Research Database (Denmark)

    Frimodt-Møller, Søren R.

    2008-01-01

    This paper considers in general terms, how musicians are able to coordinate through rational choices in a situation of (temporary) doubt in an ensemble performance. A fictitious example involving a 5-bar development in an unknown piece of music is analyzed in terms of epistemic logic, more...... to coordinate. Such coordination can be described in terms of Michael Bacharach's theory of variable frames as an aid to solve game theoretic coordination problems....

  13. Parenting Coordinators' Practices Recommendations: A Qualitative Study

    OpenAIRE

    Hirsch, Barbara Phyllis

    2016-01-01

    This qualitative study used a phenomenological approach to understand the experiences of seven parenting coordinators in using parenting coordination practices that they have found to be effective and would recommend to other parenting coordinators to achieve the following goals: educating parents, increasing the quality of parenting and co-parenting, managing conflict, and involving children and other family members in the process of parenting coordination. Data were collected with semi-str...

  14. Global Ocean Carbon and Biogeochemistry Coordination

    Science.gov (United States)

    Telszewski, Maciej; Tanhua, Toste; Palacz, Artur

    2016-04-01

    The complexity of the marine carbon cycle and its numerous connections to carbon's atmospheric and terrestrial pathways means that a wide range of approaches have to be used in order to establish it's qualitative and quantitative role in the global climate system. Ocean carbon and biogeochemistry research, observations, and modelling are conducted at national, regional, and global levels to quantify the global ocean uptake of atmospheric CO2 and to understand controls of this process, the variability of uptake and vulnerability of carbon fluxes into the ocean. These science activities require support by a sustained, international effort that provides a central communication forum and coordination services to facilitate the compatibility and comparability of results from individual efforts and development of the ocean carbon data products that can be integrated with the terrestrial, atmospheric and human dimensions components of the global carbon cycle. The International Ocean Carbon Coordination Project (IOCCP) was created in 2005 by the IOC of UNESCO and the Scientific Committee on Oceanic Research. IOCCP provides an international, program-independent forum for global coordination of ocean carbon and biogeochemistry observations and integration with global carbon cycle science programs. The IOCCP coordinates an ever-increasing set of observations-related activities in the following domains: underway observations of biogeochemical water properties, ocean interior observations, ship-based time-series observations, large-scale ocean acidification monitoring, inorganic nutrients observations, biogeochemical instruments and autonomous sensors and data and information creation. Our contribution is through the facilitation of the development of globally acceptable strategies, methodologies, practices and standards homogenizing efforts of the research community and scientific advisory groups as well as integrating the ocean biogeochemistry observations with the

  15. A Dynamic Coordination Mechanism Using Adjustable Autonomy

    NARCIS (Netherlands)

    Neef, R.M.; Vecht, B. van der; Dignum, F.; Meyer, J.J.C.

    2008-01-01

    Agents in an organization need to coordinate their actions in order to reach the organizational goals. This research describes the relation between types of coordination and the autonomy of actors. In an experimental setting we show that there is not one best way to coordinate in all situations. The

  16. A Dynamic Coordination Mechanism Using Adjustable Autonomy

    NARCIS (Netherlands)

    Vecht, B. van der; Dignum, F.; Meyer, J.J.C.; Neef, R.M.

    2007-01-01

    Agents in an organization need to coordinate their actions in order to reach the organizational goals. This research describes the relation between types of coordination and the autonomy of actors. In an experimental setting we show that there is not one best way to coordinate in all situations. The

  17. 45 CFR 1310.23 - Coordinated transportation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Coordinated transportation. 1310.23 Section 1310... START PROGRAM HEAD START TRANSPORTATION Special Requirements § 1310.23 Coordinated transportation. (a) Each agency providing transportation services must make reasonable efforts to coordinate transportation...

  18. The unified coordination language UnCL.

    NARCIS (Netherlands)

    F.S. de Boer (Frank); J.V. Guillen Scholten (Juan); J.F. Jacob (Joost)

    2005-01-01

    textabstractIn this paper we show how to use a (subset) of UML as an Unified Coordination Language (UnCL) that is based on a separation of concerns between coordination and computation. As such UnCL provides a general language for the coordination of, in particular, object-oriented applications. The

  19. A Note on the Dipole Coordinates

    OpenAIRE

    Kageyama, Akira; Sugiyama, Tooru; Watanabe, Kunihiko; Sato, Tetsuya

    2004-01-01

    A couple of orthogonal coordinates for dipole geometry are proposed for numerical simulations of plasma geophysics in the Earth's dipole magnetic field. These coordinates have proper metric profiles along field lines in contrast to the standard dipole coordinate system that is commonly used in analytical studies for dipole geometry.

  20. Optimization of strong and weak coordinates

    NARCIS (Netherlands)

    Swart, M.; Bickelhaupt, F.M.

    2006-01-01

    We present a new scheme for the geometry optimization of equilibrium and transition state structures that can be used for both strong and weak coordinates. We use a screening function that depends on atom-pair distances to differentiate strong coordinates from weak coordinates. This differentiation

  1. 47 CFR 27.57 - International coordination.

    Science.gov (United States)

    2010-10-01

    ... COMMUNICATIONS SERVICES Technical Standards § 27.57 International coordination. (a) WCS operations in the border areas shall be subject to coordination with those countries and provide protection to non-U.S... 47 Telecommunication 2 2010-10-01 2010-10-01 false International coordination. 27.57 Section 27.57...

  2. 40 CFR 109.6 - Coordination.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Coordination. 109.6 Section 109.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS CRITERIA FOR STATE, LOCAL AND REGIONAL OIL REMOVAL CONTINGENCY PLANS § 109.6 Coordination. For the purposes of coordination...

  3. 49 CFR 214.325 - Train coordination.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD WORKPLACE SAFETY Roadway Worker Protection § 214.325 Train coordination. Working limits established by a roadway worker through the use of train coordination shall comply with the... 49 Transportation 4 2010-10-01 2010-10-01 false Train coordination. 214.325 Section 214.325...

  4. Computation at a coordinate singularity

    Science.gov (United States)

    Prusa, Joseph M.

    2018-05-01

    Coordinate singularities are sometimes encountered in computational problems. An important example involves global atmospheric models used for climate and weather prediction. Classical spherical coordinates can be used to parameterize the manifold - that is, generate a grid for the computational spherical shell domain. This particular parameterization offers significant benefits such as orthogonality and exact representation of curvature and connection (Christoffel) coefficients. But it also exhibits two polar singularities and at or near these points typical continuity/integral constraints on dependent fields and their derivatives are generally inadequate and lead to poor model performance and erroneous results. Other parameterizations have been developed that eliminate polar singularities, but problems of weaker singularities and enhanced grid noise compared to spherical coordinates (away from the poles) persist. In this study reparameterization invariance of geometric objects (scalars, vectors and the forms generated by their covariant derivatives) is utilized to generate asymptotic forms for dependent fields of interest valid in the neighborhood of a pole. The central concept is that such objects cannot be altered by the metric structure of a parameterization. The new boundary conditions enforce symmetries that are required for transformations of geometric objects. They are implemented in an implicit polar filter of a structured grid, nonhydrostatic global atmospheric model that is simulating idealized Held-Suarez flows. A series of test simulations using different configurations of the asymptotic boundary conditions are made, along with control simulations that use the default model numerics with no absorber, at three different grid sizes. Typically the test simulations are ∼ 20% faster in wall clock time than the control-resulting from a decrease in noise at the poles in all cases. In the control simulations adverse numerical effects from the polar

  5. Solid-state polymerisation via [2+2] cycloaddition reaction involving coordination polymers.

    Science.gov (United States)

    Medishetty, Raghavender; Park, In-Hyeok; Lee, Shim Sung; Vittal, Jagadese J

    2016-03-14

    Highly crystalline metal ions containing organic polymers are potentially useful to manipulate the magnetic and optical properties to make advanced multifunctional materials. However, it is challenging to synthesise monocrystalline metal complexes of organic polymers and single-phase hybrid materials made up of both coordination and organic polymers by traditional solution crystallisation. This requires an entirely different approach in the solid-state by thermal or photo polymerisation of the ligands. Among the photochemical methods available, [2+2] cycloaddition reaction has been recently employed to generate cyclobutane based coordination polymers from the metal complexes. Cyclobutane polymers have also been integrated into coordination polymers in this way. Recent advancements in the construction of polymeric chains of cyclobutane rings through photo-dimerisation reaction in the monocrystalline solids containing metal complexes, coordination polymers and metal-organic framework structures are discussed here.

  6. On multidimensional item response theory -- a coordinate free approach

    OpenAIRE

    Antal, Tamás

    2007-01-01

    A coordinate system free definition of complex structure multidimensional item response theory (MIRT) for dichotomously scored items is presented. The point of view taken emphasizes the possibilities and subtleties of understanding MIRT as a multidimensional extension of the ``classical'' unidimensional item response theory models. The main theorem of the paper is that every monotonic MIRT model looks the same; they are all trivial extensions of univariate item response theory.

  7. Integration and coordination in a cognitive vision system

    OpenAIRE

    Wrede, Sebastian; Hanheide, Marc; Wachsmuth, Sven; Sagerer, Gerhard

    2006-01-01

    In this paper, we present a case study that exemplifies general ideas of system integration and coordination. The application field of assistant technology provides an ideal test bed for complex computer vision systems including real-time components, human-computer interaction, dynamic 3-d environments, and information retrieval aspects. In our scenario the user is wearing an augmented reality device that supports her/him in everyday tasks by presenting information tha...

  8. Application coordination in pervasive systems

    CERN Document Server

    Majuntke, Verena Elisabeth

    2013-01-01

    Pervasive applications are designed to support users in their daily life. For this purpose, applications interact with their environment, i.e. their context. They are able to adapt themselves to context changes or to explicitly change the context via actuators. If multiple applications are executed in the same context, interferences are likely to occur. To manage interferences, a coordination framework is presented in this thesis. Interferences are detected using a context model and information about applications' interaction with the context. The resolution of interference is achieved through

  9. Coordination compounds in nuclear medicine

    International Nuclear Information System (INIS)

    Jurisson, S.; Berning, D.; Wei Jia; Dangshe Ma

    1993-01-01

    Radiopharmaceuticals, drugs containing a radionuclide, are used routinely in nuclear medicine departments for the diagnosis of disease and are under investigation for use in the treatment of disease. Nuclear medicine takes advantage of both the nuclear properties of the radionuclide and the pharmacological properties of the radiopharmaceutical. Herein lies the real strength of nuclear medicine, the ability to monitor biochemical and physiological functions in vivo. This review discusses the coordination chemistry that forms the basis for nuclear medicine applications of the FDA-approved radiopharmaceuticals that are in clinical use, and of the most promising diagnostic and therapeutic radiopharmaceuticals that are in various stages of development. 232 refs

  10. Coordinated hybrid automatic repeat request

    KAUST Repository

    Makki, Behrooz

    2014-11-01

    We develop a coordinated hybrid automatic repeat request (HARQ) approach. With the proposed scheme, if a user message is correctly decoded in the first HARQ rounds, its spectrum is allocated to other users, to improve the network outage probability and the users\\' fairness. The results, which are obtained for single- and multiple-antenna setups, demonstrate the efficiency of the proposed approach in different conditions. For instance, with a maximum of M retransmissions and single transmit/receive antennas, the diversity gain of a user increases from M to (J+1)(M-1)+1 where J is the number of users helping that user.

  11. An introduction to the chemistry of complex compounds

    CERN Document Server

    Grinberg, Aleksander Abramovich; Trimble, R F

    1962-01-01

    An Introduction to the Chemistry of Complex Compounds discusses the fundamental concepts that are essential in understanding the underlying principles of complex compounds. The coverage of the book includes the compounds of the hexa, penta, and tetrammine type; compounds of the tri, dl, monoamine and hexacido types for the coordination number of 6; and complex compounds with a coordination number of 4. The text also covers the effects and chemical properties of complex compounds, such as the nature of the force of complex formation; the mutual effects of coordinated groups; and acid-base prope

  12. Biological activities of some Fluoroquinolones-metal complexes

    African Journals Online (AJOL)

    McRoy

    DNA cleavage studies of some synthesized metal complexes of fluoroquinolone ... Although the FQs are generally characterized by a broad antimicrobial spectrum ..... six Coordinate 3rd metal complexes with N- (5 –Phenyl-3,4- thiadiazol-2-yl).

  13. Transition Manifolds of Complex Metastable Systems

    Science.gov (United States)

    Bittracher, Andreas; Koltai, Péter; Klus, Stefan; Banisch, Ralf; Dellnitz, Michael; Schütte, Christof

    2018-04-01

    We consider complex dynamical systems showing metastable behavior, but no local separation of fast and slow time scales. The article raises the question of whether such systems exhibit a low-dimensional manifold supporting its effective dynamics. For answering this question, we aim at finding nonlinear coordinates, called reaction coordinates, such that the projection of the dynamics onto these coordinates preserves the dominant time scales of the dynamics. We show that, based on a specific reducibility property, the existence of good low-dimensional reaction coordinates preserving the dominant time scales is guaranteed. Based on this theoretical framework, we develop and test a novel numerical approach for computing good reaction coordinates. The proposed algorithmic approach is fully local and thus not prone to the curse of dimension with respect to the state space of the dynamics. Hence, it is a promising method for data-based model reduction of complex dynamical systems such as molecular dynamics.

  14. Unpacking Coordination Benefits in Supply Networks

    DEFF Research Database (Denmark)

    Petrick, Irene J.; Maitland, Carleen; Pogrebnyakov, Nicolai

    2016-01-01

    This paper examines how coordination among firms in supply networks generates benefits in the short and long terms for firms. It focuses on information technology (IT) and process improvement coordination. Analysis was performed on quantitative and qualitative data from a sample of SMEs in plastics...... manufacturing in Pennsylvania. Results indicate that coordination on both IT and process improvement leads to short- and long-term benefits. These relationships were mediated by the adoption of innovations (when coordinating on IT) and access to new capabilities (in process improvement coordination......). These results extend the understanding of how participation in supply networks benefits individual firms....

  15. Coordination features and use of aspartic acid in chelatometry

    International Nuclear Information System (INIS)

    Sergeev, G.M.; Korenman, I.M.

    1978-01-01

    Considered are coordination peculiarities and application of aspartic and as selective reagent for Be(2) and Mo(6) in chelatometry. pH range of the complexes with aspartic acid for Be(2), pH 4-9, for Mo(6), pH 3-9 are determined. Stability constants of the complexes are found. These values can serve as the basis for selective determination of Be(2) and Mo(6) with asparic acid, which are not always successful with EDTA and DTPA

  16. Coordinated research projects (CRP). Coordinated research project (CRP)

    International Nuclear Information System (INIS)

    Takagi, Hidekazu; Koike, Fumihiro; Nakamura, Nobuyuki

    2013-01-01

    In the present paper, the contribution of Japanese scientists in coordinated research projects on thermonuclear fusion. Representative subjects taken in seven projects are the precise computation of theoretical data on electron-molecule collisions in the peripheral plasma, the computation of spectroscopic data of multi-charged tungsten ions, the spectroscopic measurement of multi-charged tungsten ions using an ion trap device, the development of collisional-radiative model for plasmas including hydrogen and helium, the computational and theoretical studies on the behavior of tungsten and beryllium in the plasma-wall interaction, the study on the property of dusts generated in fusion devices. These subjects are those of most important issues in ITER. (author)

  17. Mixed Metal Complexes of Isoniazid and Ascorbic Acid: Chelation ...

    African Journals Online (AJOL)

    HP

    these ligands and their metal complexes have revealed the bi-dentate coordination of isoniazid ligand to ... of the drugs on coordination with a metal is enhanced ..... James, O.O., Nwinyi, C.O. and. Allensela, M.A. (2008). Cobalt(II) complexes of mixed antibiotics: Synthesis,. Characterization, antimicrobial potential and their.

  18. Synthesis and spectral studies of some lanthanide(III) complexes ...

    African Journals Online (AJOL)

    ... compounds were characterized through various physico-chemical studies. The coordinating ligand DABAAPS behave as tridentate N,N,O-donors. The central metal ion displays the coordination number nine in these complexes. Thermal stabilities of these complexes were also studied through thermogravimetric analysis.

  19. Coordination chemistry with phosphine and phosphine oxide-substituted hydroxyferrocenes.

    Science.gov (United States)

    Atkinson, Robert C J; Gibson, Vernon C; Long, Nicholas J; White, Andrew J P

    2010-08-28

    New unsymmetrical hydroxyferrocenes were synthesised from dibromoferrocene. The oxygen heteroatom was introduced via lithiation and quenching with bis-trimethylsilylperoxide followed by hydrolysis to unmask the hydroxyl functionality. The coordination chemistry of 1'-(diphenylphosphino)-1-hydroxyferrocene 2 was explored with palladium and rhodium precursors. A dinuclear palladium methyl complex with bridging ferrocenyloxo groups was obtained from the reaction between 2 and (cyclooctadiene)methylchloropalladium(II). With tetracarbonyldichlorodirhodium(I), two complexes were isolated. The major product was a bis ligand cis phosphine ligated complex with one ligand bound in a chelating mode and one with a pendant hydroxyl group. A minor product was crystallographically characterised as a dinuclear ferrocenyloxo-bridged rhodium carbonyl complex. The coordination chemistry of 2 and the corresponding phosphine oxide 3 was examined with group 4 metals and the resulting complexes examined as ethylene polymerisation catalysts. The ligands were found to bind in either a chelating fashion or with pendant phosphine donors. In all cases, low to moderately active ethylene polymerisation catalysts were found. The catalysts were very unstable and catalyst residues were observed in the isolated polymer indicating a short catalyst lifetime.

  20. Testing multiple coordination constraints with a novel bimanual visuomotor task.

    Directory of Open Access Journals (Sweden)

    Helene M Sisti

    Full Text Available The acquisition of a new bimanual skill depends on several motor coordination constraints. To date, coordination constraints have often been tested relatively independently of one another, particularly with respect to isofrequency and multifrequency rhythms. Here, we used a new paradigm to test the interaction of multiple coordination constraints. Coordination constraints that were tested included temporal complexity, directionality, muscle grouping, and hand dominance. Twenty-two healthy young adults performed a bimanual dial rotation task that required left and right hand coordination to track a moving target on a computer monitor. Two groups were compared, either with or without four days of practice with augmented visual feedback. Four directional patterns were tested such that both hands moved either rightward (clockwise, leftward (counterclockwise, inward or outward relative to each other. Seven frequency ratios (3∶1, 2∶1, 3∶2, 1∶1, 2∶3. 1∶2, 1∶3 between the left and right hand were introduced. As expected, isofrequency patterns (1∶1 were performed more successfully than multifrequency patterns (non 1∶1. In addition, performance was more accurate when participants were required to move faster with the dominant right hand (1∶3, 1∶2 and 2∶3 than with the non-dominant left hand (3∶1, 2∶1, 3∶2. Interestingly, performance deteriorated as the relative angular velocity between the two hands increased, regardless of whether the required frequency ratio was an integer or non-integer. This contrasted with previous finger tapping research where the integer ratios generally led to less error than the non-integer ratios. We suggest that this is due to the different movement topologies that are required of each paradigm. Overall, we found that this visuomotor task was useful for testing the interaction of multiple coordination constraints as well as the release from these constraints with practice in the presence of

  1. SENR /NRPy + : Numerical relativity in singular curvilinear coordinate systems

    Science.gov (United States)

    Ruchlin, Ian; Etienne, Zachariah B.; Baumgarte, Thomas W.

    2018-03-01

    We report on a new open-source, user-friendly numerical relativity code package called SENR /NRPy + . Our code extends previous implementations of the BSSN reference-metric formulation to a much broader class of curvilinear coordinate systems, making it ideally suited to modeling physical configurations with approximate or exact symmetries. In the context of modeling black hole dynamics, it is orders of magnitude more efficient than other widely used open-source numerical relativity codes. NRPy + provides a Python-based interface in which equations are written in natural tensorial form and output at arbitrary finite difference order as highly efficient C code, putting complex tensorial equations at the scientist's fingertips without the need for an expensive software license. SENR provides the algorithmic framework that combines the C codes generated by NRPy + into a functioning numerical relativity code. We validate against two other established, state-of-the-art codes, and achieve excellent agreement. For the first time—in the context of moving puncture black hole evolutions—we demonstrate nearly exponential convergence of constraint violation and gravitational waveform errors to zero as the order of spatial finite difference derivatives is increased, while fixing the numerical grids at moderate resolution in a singular coordinate system. Such behavior outside the horizons is remarkable, as numerical errors do not converge to zero near punctures, and all points along the polar axis are coordinate singularities. The formulation addresses such coordinate singularities via cell-centered grids and a simple change of basis that analytically regularizes tensor components with respect to the coordinates. Future plans include extending this formulation to allow dynamical coordinate grids and bispherical-like distribution of points to efficiently capture orbiting compact binary dynamics.

  2. Coordinating International Response to Emergencies

    International Nuclear Information System (INIS)

    Bice, S. D.

    2007-01-01

    Pandemic disease, natural disasters and terrorism can affect thousands of people in a relatively short period of time anywhere in the world. Our recent international experience with hurricanes, earthquakes, tsunamis and infectious diseases (AIDS, TB and highly pathogenic avian influenza) show us that we must respond with a coordinated approach or we will fail the very people we intend to help. Nations from around the world are often eager to send assistance to the site of a disaster, but coordinating the incoming aid is more often flawed and imprecise than it must be in order to save lives and mitigate suffering. How can any one country, suffering from a horrendous calamity coordinate the incoming aid from around the world? Can any one agency hope to coordinate the myriad nation's response let alone that of the hundreds of non-governmental organizations? Currently, the answer is sadly, no. The purpose of this presentation is not to recommend one over the many international bodies which claim to oversee humanitarian assistance; the purpose of this presentation is to discuss the elements of only one aspect of the overall response effort: public health and medical response coordination. Public health response is of course different than a purely medical response. Traditionally, in a natural disaster, immediate public health concerns center around water, sewerage/waste disposal, potential for disease outbreaks, etc, whereas medical response concentrates on triage, saving those who can be saved, patching up the injured, and to a lesser extent, primary care to the survivors. In order to avoid political controversy, this presentation will use the example of Hurricane Iniki in Hawaii, September 1992, to illustrate key concepts. The State of Hawaii is no stranger to natural disasters. Their emergency response mechanisms are well honed, exercised and quite capable. However, the local community leaders on Kauai Island went thru each of the following phases before they

  3. Optimal Coordination of Distance and Directional Overcurrent Relays Considering Different Network Topologies

    Directory of Open Access Journals (Sweden)

    Y. Damchi

    2015-09-01

    Full Text Available Most studies in relay coordination have focused solely on coordination of overcurrent relays while distance relays are used as the main protection of transmission lines. Since, simultaneous coordination of these two types of relays can provide a better protection, in this paper, a new approach is proposed for simultaneous coordination of distance and directional overcurrent relays (D&DOCRs. Also, pursued by most of the previously published studies, the settings of D&DOCRs are usually determined based on a main network topology which may result in mis-coordination of relays when changes occur in the network topology. In the proposed method, in order to have a robust coordination, network topology changes are taken into account in the coordination problem. In the new formulation, coordination constraints for different network topologies are added to those of the main topology. A complex nonlinear optimization problem is derived to find the desirable relay settings. Then, the problem is solved using hybridized genetic algorithm (GA with linear programming (LP method (HGA. The proposed method is evaluated using the IEEE 14-bus test system. According to the results, a feasible and robust solution is obtained for D&DOCRs coordination while all constraints, which are due to different network topologies, are satisfied.

  4. Anion-Dependent Exocyclic Mercury(II) Coordination Polymers of Bis-dithiamacrocycle

    Energy Technology Data Exchange (ETDEWEB)

    Siewe, Arlette Deukam; Kim, Seul Gi; Choi, Kyu Seong [Kyungnam University, Changwon (Korea, Republic of); Lee, Shim Sung [Gyeongsang National University, Jinju (Korea, Republic of)

    2014-09-15

    Synthesis and structural characterization of mercury(II) halides and perchlorate complexes of bis-OS{sub 2}-Synthesis and structural characterization of mercury(II) halides and perchlorate complexes of bis-OS{sub 2}- macrocycle (L) are reported. L reacts with mercury(II) chloride and bromide to yield an isostructural 2D coordination polymers with type [Hg(L)X{sub 2}]n (1: X = Cl and 2: X = Br). In 1, each Hg atom which lies outside the cavity is six-coordinate with a distorted octahedral geometry, being bound to four adjacent ligands via monodentate Hg-S bonds and two remaining sites are occupied by two terminal chlorido ligands to form a fishnet-like 2D structure. When reacting with mercury(II) iodide, L afforded a 1D coordination polymer [Hg{sub 2}(L)I{sub 4}]·CHCl{sub 3}n in which each exocyclic Hg atom is four-coordinate, being bound to two sulfur donors from different ligands doubly bridging the ligand molecules in a head-to-tail mode. The coordination sphere in 3 is completed by two iodo terminal ligands, adopting a distorted tetrahedral geometry. On reacting with mercury(II) perchlorate, L forms solvent-coordinated 1D coordination polymer ([Hg{sub 2}(L)(DMF){sub 6}](ClO{sub 4}){sub 4}·2DMF)n instead of the anion-coordination. In 4, the Hg atom is five-coordinate, being bound to two sulfur donors from two different ligands doubly bridging the ligand molecules in a side-by-side mode to form a ribbon-like 1D structure.. The three remaining coordination sites in 4 are completed by three DMF molecules in a monodentate manner. Consequently, the different structures and connectivity patterns for the observed exocyclic coordination polymers depending on the anions used are influenced not only by the coordination ability of the anions but also by anion sizes macrocycle (L) are reported. L reacts with mercury(II) chloride and bromide to yield an isostructural 2D coordination polymers with type [Hg(L)X{sub 2}]n (1: X = Cl and 2: X = Br). In 1, each Hg atom which lies

  5. Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Plapp, Bryce V.; Savarimuthu, Baskar Raj; Ferraro, Daniel J.; Rubach, Jon K.; Brown, Eric N.; Ramaswamy, S. (Iowa)

    2017-07-07

    During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a nearby glutamate residue, as suggested by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs. Zinc coordination and participation of water in the enzyme mechanism were investigated by X-ray crystallography. The apoenzyme and its complex with adenosine 5'-diphosphoribose have an open protein conformation with the catalytic zinc in one position, tetracoordinated by Cys-46, His-67, Cys-174, and a water molecule. The bidentate chelators 2,2'-bipyridine and 1,10-phenanthroline displace the water and form a pentacoordinated zinc. The enzyme–NADH complex has a closed conformation similar to that of ternary complexes with coenzyme and substrate analogues; the coordination of the catalytic zinc is similar to that found in the apoenzyme, except that a minor, alternative position for the catalytic zinc is ~1.3 Å from the major position and closer to Glu-68, which could form the alternative coordination to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide or N-benzylformamide (or with NAD+ and fluoro alcohols) have the classical tetracoordinated zinc, and no water is bound to the zinc or the nicotinamide rings. The major forms of the enzyme in the mechanism have a tetracoordinated zinc, where the carboxylate group of Glu-68 could participate in the exchange of water and substrates on the zinc. Hydride transfer in the Michaelis complexes does not involve a nearby water.

  6. Dithiolato complexes of molybdenum and tungsten

    International Nuclear Information System (INIS)

    Nieuwpoort, A.

    1975-01-01

    The synthesis of eight-coordinated and six-coordinated tungsten and molybdenum complexes with dithioligands is described. Molecular and crystal structures are determined and bond angles, bond lengths and structural parameters tabulated. Infrared spectra of dithiocarbamato complexes are discussed more extensively. Redox reactions are studied by voltammetry and electron transfer properties derived. Properties of the d electrons of the metal ion are interpreted in the ligand field model with data from electronic and e.s.r. spectra and magnetic susceptibilities. The result of molecular orbital calculations with the extended Hueckel-LCAO method are presented for eight-coordinated d 1 and d 2 systems, the six-coordinated complexes, and the free ligands

  7. BRAND program complex

    International Nuclear Information System (INIS)

    Androsenko, A.A.; Androsenko, P.A.

    1983-01-01

    A description is given of the structure, input procedure and recording rules of initial data for the BRAND programme complex intended for the Monte Carlo simulation of neutron physics experiments. The BRAND complex ideology is based on non-analogous simulation of the neutron and photon transport process (statistic weights are used, absorption and escape of particles from the considered region is taken into account, shifted readouts from a coordinate part of transition nucleus density are applied, local estimations, etc. are used). The preparation of initial data for three sections is described in detail: general information for Monte Carlo calculation, source definition and data for describing the geometry of the system. The complex is to be processed with the BESM-6 computer, the basic programming lan-- guage is FORTRAN, volume - more than 8000 operators

  8. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  9. Coordinated control of electrical drives

    International Nuclear Information System (INIS)

    Keresztely, S.

    1983-01-01

    The control system developed for the fuel handling machine of nuclear power plants contains seven microcomputers. Redundant hardware and software structure ensures high reliability and availability. The sensors are doubled and each set is connected to its own microcomputer for evaluation of measurements. The control program, coordinating seven electrical drives, is run on two identical microcomputers, and has access to both sets of measurement results. Two control desks are provided. The seventh microcomputer generates the digital picture of the working site around the actual position and the picture is sent to color TV monitors at the control desks. System reliability: failure of any part of the system causes an error message and no action. System availability: for emergency purposes, one of every pair of the identical subsystems must be operational. In this emergency mode unconditional reliability is lost. (author)

  10. Coordination control of distributed systems

    CERN Document Server

    Villa, Tiziano

    2015-01-01

    This book describes how control of distributed systems can be advanced by an integration of control, communication, and computation. The global control objectives are met by judicious combinations of local and nonlocal observations taking advantage of various forms of communication exchanges between distributed controllers. Control architectures are considered according to  increasing degrees of cooperation of local controllers:  fully distributed or decentralized control,  control with communication between controllers,  coordination control, and multilevel control.  The book covers also topics bridging computer science, communication, and control, like communication for control of networks, average consensus for distributed systems, and modeling and verification of discrete and of hybrid systems. Examples and case studies are introduced in the first part of the text and developed throughout the book. They include: control of underwater vehicles, automated-guided vehicles on a container terminal, contro...

  11. Coordinating towards a Common Good

    Science.gov (United States)

    Santos, Francisco C.; Pacheco, Jorge M.

    2010-09-01

    Throughout their life, humans often engage in collective endeavors ranging from family related issues to global warming. In all cases, the tragedy of the commons threatens the possibility of reaching the optimal solution associated with global cooperation, a scenario predicted by theory and demonstrated by many experiments. Using the toolbox of evolutionary game theory, I will address two important aspects of evolutionary dynamics that have been neglected so far in the context of public goods games and evolution of cooperation. On one hand, the fact that often there is a threshold above which a public good is reached [1, 2]. On the other hand, the fact that individuals often participate in several games, related to the their social context and pattern of social ties, defined by a social network [3, 4, 5]. In the first case, the existence of a threshold above which collective action is materialized dictates a rich pattern of evolutionary dynamics where the direction of natural selection can be inverted compared to standard expectations. Scenarios of defector dominance, pure coordination or coexistence may arise simultaneously. Both finite and infinite population models are analyzed. In networked games, cooperation blooms whenever the act of contributing is more important than the effort contributed. In particular, the heterogeneous nature of social networks naturally induces a symmetry breaking of the dilemmas of cooperation, as contributions made by cooperators may become contingent on the social context in which the individual is embedded. This diversity in context provides an advantage to cooperators, which is particularly strong when both wealth and social ties follow a power-law distribution, providing clues on the self-organization of social communities. Finally, in both situations, it can be shown that individuals no longer play a defection dominance dilemma, but effectively engage in a general N-person coordination game. Even if locally defection may seem

  12. The Coordinated School Health Program: Implementation in a Rural Elementary School District

    Science.gov (United States)

    Miller, Kim H.; Bice, Matthew R.

    2014-01-01

    Child health is a complex issue that requires a comprehensive approach to address the many factors that influence it and are influenced by it. In light of the complexity of children's health, the Coordinated School Health Program (CSHP) was developed as a framework for a systems approach to planning and implementing school-based children's health…

  13. Drawing from Memory: Hand-Eye Coordination at Multiple Scales

    Science.gov (United States)

    Spivey, Michael J.

    2013-01-01

    Eyes move to gather visual information for the purpose of guiding behavior. This guidance takes the form of perceptual-motor interactions on short timescales for behaviors like locomotion and hand-eye coordination. More complex behaviors require perceptual-motor interactions on longer timescales mediated by memory, such as navigation, or designing and building artifacts. In the present study, the task of sketching images of natural scenes from memory was used to examine and compare perceptual-motor interactions on shorter and longer timescales. Eye and pen trajectories were found to be coordinated in time on shorter timescales during drawing, and also on longer timescales spanning study and drawing periods. The latter type of coordination was found by developing a purely spatial analysis that yielded measures of similarity between images, eye trajectories, and pen trajectories. These results challenge the notion that coordination only unfolds on short timescales. Rather, the task of drawing from memory evokes perceptual-motor encodings of visual images that preserve coarse-grained spatial information over relatively long timescales as well. PMID:23554894

  14. The role of the Australian workplace return to work coordinator: essential qualities and attributes.

    Science.gov (United States)

    Bohatko-Naismith, Joanna; James, Carole; Guest, Maya; Rivett, Darren A

    2015-03-01

    In the Australian context, a return to work (RTW) Coordinator assists an injured worker with workplace-based support and regulatory guidance for the duration of their injury. Coordinating the RTW process has been considered an effective approach for managing workplace injuries, however few studies have described the skills, traits or characteristics required to fulfil the role of workplace RTW Coordinator. This study aims to provide insight as to the skills and attributes needed for the role of the workplace RTW Coordinator from their experience and perception. Focus groups were conducted with workplace RTW Coordinators from six major Australian cities. Twenty five participants were recruited through a national RTW Coordinator website, and professional RTW interest groups using a snowballing technique. Participating workplace RTW Coordinators were required to have a minimum 2 years' experience and to have been involved with the development and implementation of workplace policies and procedures. Thematic analysis was performed to identify meaningful patterns and themes. The data analysed provided clear insight as to the specific role requirements necessary for working as an Australian workplace RTW Coordinator. Three key themes clearly emerged; communication skills, RTW Coordinator characteristics, and managing the RTW process. The findings indicate that RTW Coordinators require a wide range of traits, skills, and attributes to successfully perform this role. Effective management by the RTW Coordinator of the complex RTW process is essential to facilitate a smooth transition for the injured worker, alongside maintaining a professional relationship with the employer and external stakeholders. The results of this study can be utilised to further improve the selection of future RTW Coordinators.

  15. Pleomorphic copper coordination by Alzheimer's disease amyloid-beta peptide.

    Science.gov (United States)

    Drew, Simon C; Noble, Christopher J; Masters, Colin L; Hanson, Graeme R; Barnham, Kevin J

    2009-01-28

    Numerous conflicting models have been proposed regarding the nature of the Cu(2+) coordination environment of the amyloid beta (Abeta) peptide, the causative agent of Alzheimer's disease. This study used multifrequency CW-EPR spectroscopy to directly resolve the superhyperfine interactions between Cu(2+) and the ligand nuclei of Abeta, thereby avoiding ambiguities associated with introducing point mutations. Using a library of Abeta16 analogues with site-specific (15)N-labeling at Asp1, His6, His13, and His14, numerical simulations of the superhyperfine resonances delineated two independent 3N1O Cu(2+) coordination modes, {N(a)(D1), O, N(epsilon)(H6), N(epsilon)(H13)} (component Ia) and {N(a)(D1), O, N(epsilon)(H6), N(epsilon)(H14)} (component Ib), between pH 6-7. A third coordination mode (component II) was identified at pH 8.0, and simulation of the superhyperfine resonances indicated a 3N1O coordination sphere involving nitrogen ligation by His6, His13, and His14. No differences were observed upon (17)O-labeling of the phenolic oxygen of Tyr10, confirming it is not a key oxygen ligand in the physiological pH range. Hyperfine sublevel correlation (HYSCORE) spectroscopy, in conjunction with site-specific (15)N-labeling, provided additional support for the common role of His6 in components Ia and Ib, and for the assignment of a {O, N(epsilon)(H6), N(epsilon)(H13), N(epsilon)(H14)} coordination sphere to component II. HYSCORE studies of a peptide analogue with selective (13)C-labeling of Asp1 revealed (13)C cross-peaks characteristic of equatorial coordination by the carboxylate oxygen of Asp1 in component Ia/b coordination. The direct resolution of Cu(2+) ligand interactions, together with the key finding that component I is composed of two distinct coordination modes, provides valuable insight into a range of conflicting ligand assignments and highlights the complexity of Cu(2+)/Abeta interactions.

  16. The coordination chemistry of macrocyclic ligands II

    International Nuclear Information System (INIS)

    Klimes, J.; Knoechel, A.; Rudolph, G.

    1977-01-01

    Compounds of UO 2 (NO 3 ) 2 .6H 2 0 or Th(NO 3 ) 4 .5H 2 0 with five selected crown ethers were prepared according to the method described in Knoeckel et al., Inorg.Nucl.Chem.Lett.; 11:787 (1975). The products were characterized by chemical analysis, NMR, IR and Raman spectroscopy. The results are analyzed and discussed. It is shown that the NO 3 groups remain free after combination, and the H 2 0 groups form the bonds to the polyether. It is concluded that the polyether molecule is attached to two units of UO 2 (NO 3 ) 2 .2H 2 0 (or Th(NO 3 ) 4 .3H 2 0), one each side of the polyether. This would be contrary to the assumption in previous publications, that the U0 2 2+ and Th 4+ ions were coordinated inside the macrocyclic ligand structure. The present hypothesis, however, agrees with a recently published x-ray structure for the uranium compound. In view of the new proposed structure it is suggested that the compounds should be regarded as adducts rather than complexes. (U.K.)

  17. Control coordination abilities in shock combat sports

    Directory of Open Access Journals (Sweden)

    Natalya Boychenko

    2014-12-01

    Full Text Available Purpose: optimize the process control level of coordination abilities in martial arts. Material and Methods: analysis and compilation of scientific and methodological literature, interviews with coaches of drum martial arts, video analysis techniques, teacher observations. Results: identified specific types of coordination abilities in shock combat sports. Pod branny and offered specific and nonspecific tests to monitor the level of species athletes coordination abilities. Conclusion: it is determined that in order to achieve victory in the fight martial artists to navigate the space to be able to assess and manage dynamic and spatio-temporal parameters of movements, maintain balance, have a high coordination of movements. The proposed tests to monitor species coordination abilities athletes allow an objective assessment of not only the overall level of coordination, and the level of specific types of manifestations of this ability.

  18. Photoactive devices including porphyrinoids with coordinating additives

    Science.gov (United States)

    Forrest, Stephen R; Zimmerman, Jeramy; Yu, Eric K; Thompson, Mark E; Trinh, Cong; Whited, Matthew; Diev, Vlacheslav

    2015-05-12

    Coordinating additives are included in porphyrinoid-based materials to promote intermolecular organization and improve one or more photoelectric characteristics of the materials. The coordinating additives are selected from fullerene compounds and organic compounds having free electron pairs. Combinations of different coordinating additives can be used to tailor the characteristic properties of such porphyrinoid-based materials, including porphyrin oligomers. Bidentate ligands are one type of coordinating additive that can form coordination bonds with a central metal ion of two different porphyrinoid compounds to promote porphyrinoid alignment and/or pi-stacking. The coordinating additives can shift the absorption spectrum of a photoactive material toward higher wavelengths, increase the external quantum efficiency of the material, or both.

  19. Design of coordinated controller in nuclear power plant based on digital instrument and control technology

    International Nuclear Information System (INIS)

    Cheng Shouyu; Peng Minjun; Liu Xinkai; Zhao Qiang; Deng Xiangxin

    2014-01-01

    Nuclear power plant (NPP) is a multi-input and multi-output, no-linear and time-varying complex system. The conventional PID controller is usually used in NPP control system which is based on analog instrument. The system parameters are easy to overshoot and the response time is longer in the control mode of the conventional PID. In order to improve this condition, a new coordinated control strategy which is based on expert system and the original controllers in the digital instrument and control technology was presented. In order to verify and validate it, the proposed coordinated control technology was tested by the full-scope real-time simulation system. The results prove that using digital instrument and control technology to achieve coordinated controller is feasible, the coordinated controller can effectively improve the dynamic operating characteristics of the system, and the coordinated controller is superior to the conventional PID controller in control performance. (authors)

  20. Experimental substantiation of methodic of 11-13 years old boxers’ coordination development

    Directory of Open Access Journals (Sweden)

    Yong Qiang Liu

    2015-06-01

    Full Text Available Purpose: experimental substantiation of methodic of junior boxers’ coordination training. Material: in the research 18 boxers of 11-13 year old age participated. In total, during 4 months 42 trainings were conducted. Total time of coordination load’s fulfillment at each training was 15-45 minutes. Results: dynamic of results in control tests was statistically confident in the tested parameters of movements. It proves effectiveness of usage the tasks with complex-coordination orientation, accented on impact on sensor-informational and motor systems of movements in junior boxers’ trainings. Conclusions: coordination training in boxing at initial stage shall include specialized varied means and methods, which would facilitate formation of motor condition and skills’ basis. Motor condition and skills are a reserve for further rising of coordination abilities’ level of junior sportsmen.