11 research outputs found

    Synthesis, electrochemical behavior and X-ray crystal and molecular structures of [Fe(diene)(CO)(2)PPh3] (diene = chalcone, sorbic acid)

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    The compounds [Fe(ch)(CO)(2)PP3] (1) (ch = chalcone) and [Fe(sba)(CO)(2)PPh3] (2) (sba = sorbic acid) were prepared by irradiating the tetracarbonyltriphenylphosphineiron(0) complex in benzene in the presence of ch or sba. The compounds were characterized by infrared and P-31 NMR spectroscopies. Their electrochemical behavior was investigated by cyclic voltammetry and the results suggest that their oxidations occur by more than one electrochemical step, producing free ch and sba, free PPh3 and solvated Fe(III). It was observed that sba ligand contributes more effectively to the stabilization of metal center in these complexes, the X-ray crystal and molecular structures of 1 and 2 were determined; it was shown that the Fe atom adopts a distorted octahedral coordinated geometry in which three of the sites are occupied by the ch or sba ligand. The [Fe(ch)(CO)(2)PPh3] complex is a monomer and the unit cell of complex 2 contains exist two identical and crystallographically independent molecules of [Fe(sba)(CO)(2)PPh3] which are linked by short hydrogen bonds O-H . . .O (C) 2001 Published by Elsevier B.V. Ltd

    Mono- and dinuclear palladium(II) compounds containing nitrogen ligands. Crystal and molecular structure of [Pd(N,C-dmba)(NCO)(2,3-lut)] and [Pd(H2CCOMe)Cl(2,2 '-bipy)]

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    The cyanate-bridged cyclopalladated compound [Pd(N,C-dmba)(mu-NCO)](2) (1) (dmba = PhCH2NMe2) reacts in CH2Cl2 with 2,3-lutidine (2,3- lut), 3,4-lutidine (3,4-lut), 2,2'-bipyridine (2,2'-bipy) and 4,4'-bipyridine (4,4'-bipy), to give [Pd(N, C-dmba)(NCO)(2,3-lut)] (2), [Pd(N,C-dmba)(NCO)(3,4-lut)] (3), [{Pd(N,C-dmba)(NCO)}(2)(mu-2,2'-bipy)] .CH2Cl2 (4) and [{Pd(N,C-dmba)(NCO)}(2)(mu-4,4'-bipy)] . CH2Cl2 (5), respectively. The compounds were characterized by elemental analysis, i.r. and n. m. r. spectroscopy and also by t.g.a. The i.r. spectra of (2 - 5) display typical bands of monodentate N-bonded cyanate groups, whereas the n. m. r. data of (4) are consistent with the presence of a bridging 2,2'-bipyridine ligand. Complex (4) decomposes slowly in acetone. One of the products formed, [Pd(H2CCOMe) Cl(2,2'-bipy)] (6), was characterized by X-ray diffraction. As inferred from the t.g.a., the thermal stability decreases in the order: [{Pd(N,C-dmba)(NCO)}(2) (mu-4,4'-bipy)]. CH2Cl2 (5) > [Pd(N,C-dmba)(2,3-lut)( NCO)] (2) = [Pd(N, C-dmba)(3,4-lut)(NCO)] (3) > [{Pd(N,C-dmba)(NCO)}(2)(mu- 2,2'-bipy)] .CH2Cl2 (4). According to thermal analysis and X-ray diffraction patterns compounds (2 - 3) decompose into metallic palladium Pd(0), whereas (4 - 5) decompose with the formation of PdO. The X-ray crystal and molecular structure of [Pd(N, C-dmba)( NCO)(2,3-lut)] (2) was determined. The lutidine unit is perpendicular to the coordination plane

    Thermal decomposition and stability of [Fe(eta(4)-enone)(CO)(2)L] complexes (L=CO and PPh3)

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    The compounds [Fe(bda)(CO)(2)L] and [Fe(ch)(CO)(2)L], (bda=benzylideneacetone; ch=chalcone; L=CO, PPh3) were investigated by thermogravimetry and derivative thermogravimetry (TG and DTG). The fragmentation patterns suggest that the iron atom protects the enone fragment, so that the organic ligands break up with the loss of the pendant aromatic rings

    Investigação por espectroscopia Mössbauer de compostos de ferro(0) contendo dissulfeto de carbono

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    Neste trabalho são apresentados resultados proveniente da aplicação da Espectroscopia Mössbauer na investigação de compostos carbonilferro contendo o ligante CS2, [Fe(CO)2(h²-CS2 )(PPh3)2] e [Fe(CO)2(h²-CS2) {P(OPh)3}2]. Nas sínteses dessas espécies, a utilização de TMNO (trimetilaminóxido) como agente descarbonilante mostrou-se bastante eficiente, superando aquelas descritas na literatura que requerem inclusive preparação de compostos precursores. Os resultados de espectroscopia Mössbauer, juntamente com dados no IV e de RMN de 31P, foram conclusivos na proposição da geometria octaédrica distorcida ao redor do átomo de ferro para ambos os compostos investigados.The one pot syntheses of the compounds of general formula [Fe(CO)2(h²-CS2 )(L)2] (L = PPh3, P(OPh)3), were carried out in high yields by using trimethylaminoxide (TMNO) as decarbonilating agent. The compounds were investigated by Mössbauer spectroscopy which afforded indicative data of an octahedral geometry around the iron atom in the species [Fe(CO)2(h²-CS2)(PPh3) 2] e [Fe(CO)2(h²-CS2 ){P(OPh)3}2].Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    An Extensible Architecture for the Integration of Remote and Virtual Laboratories in Public Learning Tools

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    Remote laboratories are software and hardware tools that allow students to remotely access real equipment located in universities. The integration of remote laboratories in learning tools (learning management systems, content man- agement systems, or personal learning environments) has been achieved to integrate remote laboratories as part of the learning curricula. A cross-institutional initiative called gateway4labs has been created to perform this integration extensible to multiple remote laboratories in multiple learning tools. This contribution focuses on describing this initiative and, in particular, how opening it to public systems (where users do not need to be registered) produces new technical and organizational challenges due to the public availability of labs. In addition, this contribution shows integrations of systems that were not previously addressed in this initiative, such as PhET or ViSH, as well as a new approach for integrating supported laboratories in external specifications such as the smart device one through OpenSocial

    A Federation of VISIR remote laboratories through the PILAR Project

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    This paper describes how a new Erasmus Plus project, PILAR, (Platform Integration of Laboratories based on the Architecture of visiR), is being developed and how the startup of the partnership and the project is reinforcing the VISIR (Virtual Instrument Systems in Reality) network and the Special Interest Group of VISIR under the Global Online Laboratory Consortium (GOLC) of the International Association of Online Engineering (IAOE). The Spanish University for Distance Education (UNED) coordinates the project that aims to federate the existing (or new) VISIR systems in order to use the resources more effectively and in a more efficient way, making transparent to the final user the election of the shared resources.N/

    A saúde neonatal na perspectiva de atenção contínua à saúde da mulher e da criança La atención neonatal en la perspectiva de la atención continua a la salud de las mujeres y niños The neonatal care from the perspective of continuous attention to woman and child's health

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    O estudo é uma revisão narrativa de teses e dissertações concluídas no período de 2000 a 2009 produzidas pelo Grupo de Pesquisa Enfermagem Obstétrica e Neonatal e pelo Núcleo de Estudos e Pesquisa em Aleitamento Materno da Escola de Enfermagem da Universidade de São Paulo que focalizaram os fatores maternos e perinatais que repercutem na saúde neonatal. A produção científica evidencia alinhamento com as diretrizes estabelecidas pelos órgãos de saúde nacionais e internacionais para a promoção da saúde neonatal e infantil.<br>El estudio es una revisión de la literatura de tesis y disertaciones producidas en el periodo de 2000 hasta 2009 por el Grupo de Investigación de Enfermería Obstétrica y Neonatal y por el Centro de Estudios y Investigación en Lactancia Materna de la Escuela de Enfermería de la Universidad de São Paulo, que se centró en las repercusiones maternas y perinatales en la salud del recién nacidos. La producción científica se muestra de acuerdo con las directrices para promover la salud neonatal y infantil establecidas por los organismos de salud nacionales e internacionales.<br>The study is a literature review of theses and dissertations concluded from 2000 to 2009 developed by the Obstetric and Neonatal Nursing Research Group and Breastfeeding Center for Studies and Research of Nursing School, University of São Paulo, which focused on the maternal and perinatal impact on neonatal health. The scientific production shows agreement with the guidelines to promote neonatal and infant health established by national and international health agencies
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