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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

[en] STUDY OF COMPLEXES OF CU (II) WITH THE LIGANDS TYROSINE AND PHOSPHOCREATINE IN SOLID PHASE / [pt] ESTUDO DE COMPLEXOS DE CU (II) COM OS LIGANTES TIROSINA E FOSFOCREATINA NO ESTADO SÓLIDO

ISMARCIA GONCALVES SILVA 01 August 2005 (has links)
[pt] O estudo da síntese e das propriedades de complexos de Cu (II) com aminoácidos e compostos de interesse biológico, tanto em solução aquosa como na fase sólida, pode permitir avaliar o comportamento desses complexos em organismos vivos. Assim, neste trabalho, realizou-se um estudo de complexos de Cu (II) com os ligantes fosfocreatina e tirosina na fase sólida. As sínteses foram realizadas em meio aquoso, utilizando-se soluções 0,2 mol.L-1 de cobre (II), de adenosina trifosfato (ATP) e de tirosina (Tyr), no sistema Cu(II)-ATP-Tyr, e de cobre (II), de fosfocreatina (PCr) e de tirosina (Tyr), no sistema Cu-PCr-Tyr, obtendo-se cristais e um sólido na forma de pó (ambos azuis), respectivamente. Esses compostos foram caracterizados pelas técnicas espectroscópicas de absorção atômica, de absorção na região do infravermelho e na região UV-visível, e ainda, por análises elementar e termogravimétrica. Os resultados indicam que, no sistema Cu(II)-ATP-Tyr, houve formação do complexo binário Cu-Tyr2, e que a complexação do cátion Cu (II) parece ter ocorrido pelos grupos carboxilato e amina das duas moléculas de tirosina. No sistema Cu(II)-PCr-Tyr, os resultados apontam para a formação de um complexo ternário, que pode ser representado pela fórmula Cu(II)-Tyr- H2O-PO3H2, no qual o cátion Cu (II) parece ter-se complexado pelos grupos carboxilato e amina da tirosina, e ainda, por um grupamento fosfito isolado proveniente da ruptura da molécula de fosfocreatina, além de se coordenar também com uma molécula de água. / [en] Studies on synthesis and properties of copper (II) complexes with aminoacids and compounds of biological interest, in either aqueous solution or solid phase, are important to evaluate behavior in living organisms. For this reason, copper (II) complexes with the ligands phosphocreatine, adenosine triphosphate and tyrosine were studied. The synthesis were carried out in aqueous phase using solution 0,2 mol.L-1 of Cu (II), adenosine triphosphate and tyrosine for the system Cu(II)-ATP-Tyr, and Cu (II), phosphocreatine and tyrosine for the system Cu(II)- PCr-Tyr. A crystal and a powder, both blue, were obtained, respectively: and were characterized by elemental and themogravimetric analyses and by atomic absorption, infrared and UV-vis spectroscopy. It may be inferred that the complex Cu(II)-Tyr2 was formed in the synthesis of Cu(II)-ATP-Tyr system, in which the copper (II) coordinates through the carboxyl and amine groups from both tyrosine molecules. In the synthesis of Cu(II)-PCr-Tyr system, the results may indicate the formation of the complex Cu(II)-Tyr-H2O-PO3H2, in which the copper (II) may coordinates through the carboxyl and amine groups from tyrosine, and through a phosphite group from a broken phosphocreatine molecule and also through a water molecule.
12

Synthesis and charaterisation of phosphorescent copper (I) complexes for light emitting devices

Andrés-Tomé, María Inmaculada January 2013 (has links)
Over the last decade, many significant developments have been made to improve the active materials in a new generation of organic light emitting devices (OLEDs). Current OLED technology is focused on organo-transition metal complexes, which emit from the triplet excited state and exhibit bright phosphorescence. Efficient in devices have been reported using these luminescent materials, such as iridium and platinum complexes, however, rare metal abundance concerns, high price and toxicology have inspired the study of alternative phosphorescent materials, such as copper or silver complexes. In this research, novel copper complexes have been synthesized, such as trinuclear and mononuclear copper (I) complexes, using a range of ligands, such as alkynyl, phosphine alkynyl and pyridine ligands. The synthesised complexes have been characterised by with a range of techniques, such as UV/Vis absorption and emission spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), cyclic voltammetry (CV) and scanning electron microscopy (SEM). Most of the copper complexes have shown very interesting luminescent properties in solution and solid state and some of them were studied for future application in a device.
13

Estudo de propriedades eletrônicas e estruturais de complexos de cobre / Electronic and structural properties study of copper complexes

Marcos Brown Gonçalves 07 December 2010 (has links)
Neste trabalho estudamos propriedades estruturais, magnéticas e eletrônicas de complexos de cobre em duas classes de ligantes semelhantes com potenciais aplicações nas áreas de nanotecnologia e farmacologia. A primeira classe de ligantes é do tipo bases de Schiff, conhecidas por sua vasta gama de aplicações em química e biologia, aqui estudadas como miméticos de sítios de proteínas e também como potenciais metalo-fármacos. Procuramos investigar as características estruturais e eletrônicas buscando correlacionar as informações obtidas experimentalmente com as obtidas através de cálculos de estrutura eletrônica. Em especial, no estudo da competição pelo íon Cu entre as bases de Schiff e a proteína albumina, mostramos a influência de diversos fatores como, por exemplo, a geometria dos ligantes e a sua estrutura eletrônica. A segunda classe estudada é constituída de bases modificadas de DNA com a habilidade de complexar metais (espécie [M-DNA]) e formar estruturas com acoplamento ferromagnético. Observamos para as espécies [M-DNA] que o acoplamento ferromagnético é estabilizado através de dois efeitos: a) diferentes estados de carga que podem gerar distorções na coordenação quadrado planar; b) a adição do backbone do DNA. Utilizamos neste estudo o método Projector Augmented Wave (PAW) e também bases locais dentro da Teoria do Funcional da Densidade, atrav´es dos c´odigos computacionais CP-PAW e Gaussian03. / We studied structural, electronic and magnetic properties of copper complexes with two similar classes of ligands with potential applications in nanotechnology or pharmacology. The first class of compounds consists of Schiff bases and corresponding copper complexes. We investigated structural and electronic properties of these complexes searching for correlations among the information obtained experimentally and by electronic structure calculations. In special, in the study of the competition for the Cu ion between Schiff bases and the albumin protein, we show the influence of different factors such as the geometry of the ligands and their electronic structure. The second class of ligands focused in our studies are modified DNA bases coordinated to copper, where EPR studies have shown ferromagnetic interactions among the metal centers. We studied in this case the influence of the charge state and of the backbone in the magnetization of the Cu chain. In all cases presented here, we used ab-initio electronic structure calculations in the framework of the Density Functional Theory (DFT). This has been done using the CP-PAW code and the Gaussian03 code.
14

Studies On Copper Complexes Showing DNA Cleavage Activity

Thomas, Anitha M 01 1900 (has links) (PDF)
No description available.
15

[en] SYNTHESIS,CHARACTERIZATION AND THEORETICAL STUDY OF ORTHO-SUBSTITUTED SCHIFF BASES AND THEIR COPPER(II) COMPLEXES AS POTENTIAL ANTITUMOR AGENTS / [pt] SÍNTESE, CARACTERIZAÇÃO E ESTUDO TEÓRICO DE BASES DE SCHIFF ORTO-SUBSTITUÍDAS E SEUS COMPLEXOS DE COBRE(II) COMO POTENCIAIS AGENTES ANTITUMORAIS

WELLINGTON DA SILVA CRUZ 23 May 2012 (has links)
[pt] Os processos neoplásicos têm sido no mundo atual uma das patologias mais preocupantes. A neoplasia maligna, também denominada de câncer, é o mais agravante processo patológico, que pode levar a morte do portador. Diante desse quadro, diversos medicamentos têm sido planejados com o objetivo de eliminar seletivamente as células cancerígenas, dentre eles, alguns complexos de coordenação, como a cisplatina, a carboplatina e as casiopeínas. No entanto, efeitos colaterais severos e toxicidades são fatores limitantes, sendo necessário, portanto, o desenvolvimento de moléculas mais seletivas, eficazes, menos tóxicas e com efeitos colaterais reduzidos. Este trabalho tem como objetivo a síntese de três ligantes imínicos binucleantes, derivados de aminas aromáticas orto-substituídas, um deles com substituinte doador de elétrons (L-NFT), já descrito na literatura, e os outros dois inéditos com substituintes retiradores de elétrons iodo (L-IDA) e nitro (L-NTA). Os ligantes foram caracterizados por ponto de fusão/decomposição, espectroscopia vibracional, espectroscopia eletrônica, análise elementar, análise termogravimétrica e modelagem molecular. Foi resolvida a estrutura cristalina de uma forma parcialmente hidrolisada do ligante L-IDA. Todos os ligantes foram submetidos a uma análise farmacológica in silico para a obtenção de seus parâmetros farmacocinéticos e farmacodinâmicos teóricos. A partir desses ligantes, foram sintetizados os respectivos complexos de cobre(II), todos eles inéditos, os quais foram caracterizados pelas seguintes técnicas: espectroscopia vibracional, espectroscopia eletrônica, análise elementar, análise termogravimétrica, espectroscopia de emissão ótica com plasma indutivamente acoplado, espectroscopia de ressonância paramagnética eletrônica e modelagem molecular. O complexo do ligante L-NFT é binuclear. Entretanto, os ligantes L-IDA e L-NTA sofreram hidrólise parcial no processo de complexação, gerando espécies mononucleares do tipo ML2 e geometria quadrática plana. Uma dessas espécies foi caracterizada por difração de raios X. Todas as moléculas obtidas serão submetidas futuramente a testes biológicos com o intuito de comprovar experimentalmente suas possíveis ações antineoplásicas. / [en] Nowadays, the neoplastic processes have been one of the most concern diseases. The malignance tumor, also called cancer, is the most aggravating pathological process, responsible for the death of the patient in most cases. In this context, several drugs have been designed with the objective to eliminate the cancer cells selectively; among them, some coordination complexes, like cisplatin, carboplatin and the casiopeins. However, severe side effects and the development of resistant tumors are limiting factors. For this reason, the search for new molecules (more selective and/or effective, less toxic and with reduced side effects) is a field of extensive research. The present work has as principal purpose the synthesis of three binucleating iminic ligands derived from ortho-substituted aromatic amines: one of them containing an electron-donor substituent (L-NFT), a compound already described in literature, and the others, both novel substances, containing electron-withdrawing substituents iodine (L-IDA) or nitro (L-NTA). The ligands were characterized by their fusion/decomposition point, vibrational and electronic spectroscopies, elemental and thermogravimetric analysis and also molecular modeling. The crystalline structure of a partially hydrolyzed form of the L-IDA ligand was resolved too. All of the ligands were submitted to an in silico pharmacological analysis to obtain pharmacokinetic and pharmacodynamic theoretical properties. From these ligands, three new copper(II) complexes were synthetized, which were characterized by the following techniques: vibrational and electronic spectroscopies, elemental and thermogravimetric analysis, ICP-OES, electron paramagnetic resonance spectroscopy, and molecular modeling. The complex of L-NFT ligand is dinuclear. However, the L-IDA and L-NTA ligands suffered partial hydrolysis during the complexation reaction producing mononuclear species of the ML2 type and with square planar geometry. One of these species was characterized by X-ray diffraction. All synthetized compounds will be submitted to biological tests in order to prove their possible anticancer activity.
16

Copper, Silver, and Gold Clusters: A Synthetic and Structural Investigation

Davis, Harrison Olivia 29 May 2019 (has links)
No description available.
17

Structure of organic molecular thin films vapour deposited on III-V semiconductor surfaces

Cox, Jennifer Jane January 1999 (has links)
No description available.
18

Synthèse de nouveaux composés phosphorés : vers de nouveaux additifs pour polymères et des complexes cuivreux luminescents innovants / Synthesis of new phosphorus compounds : towards new polymer additives and innovative luminescent copper complexes

Bissessar, Damien 07 December 2018 (has links)
Ce travail de thèse s’est inscrit dans le cadre d’un projet en relation étroite avec une industrie chimique. La problématique initiale concerne le développement de nouvelles molécules antioxydantes permettant de protéger les matériaux plastiques. Dans un premier temps, la stratégie envisagée s’appuie sur la synthèse de phosphines par hydrophosphination, réaction répondant aux principes de la chimie verte. La réaction est hautement régiosélective et la simplicité de la synthèse a permis d’obtenir de nombreuses nouvelles phosphines qui ont alors été testées pour leurs propriétés anti-oxydantes. Nous avons pu identifier plusieurs structures originales répondant au cahier des charges. Dans un second temps, nous avons étudié la faisabilité de développer de nouveaux additifs antioxydants secondaires à base de dérivés phénoliques, dont le cardanol qui est une molécule biosourcée. De nombreuses nouvelles molécules phosphorées ont été synthétisées, complètement caractérisées et évaluées pour leurs propriétés anti-oxydantes. Enfin, nous avons essayé de valoriser nos nouveaux composés pour d’autres applications. Les phosphines étant d’excellents ligands pour les métaux de transition, nous avons étudié la chimie de coordination avec le cuivre(I) en espérant former des complexes cuivreux luminescents. En effet, l’élaboration de diodes électroluminescentes stables reste un défi technologique malgré toutes les avancées actuelles. Dans ce contexte, de nombreux nouveaux complexes de type cubane ont été synthétisés et entièrement caractérisés. Ces complexes tétranucléaires sont des structures intéressantes, faciles à synthétiser, avec d’excellents rendements quantiques. Ces complexes présentent une stabilité élevée et des propriétés de luminescence qui en font de très bons candidats pour des dispositifs en optoélectronique. / This thesis work was part of a project in collaboration with a chemical industry. The topic is the development of new antioxidant molecules to protect plastic materials. Initially, the strategy envisaged was based on the synthesis of phosphines by hydrophosphination, reaction in accordance with the green chemistry principles. The reaction is highly regioselective and the simplicity of the synthesis allowed us to obtain many new phosphines which were then tested for their antioxidant properties. We were able to identify several original structures that meet the requirements. In a second step, we studied the feasibility of developing new secondary antioxidant additives based on phenolic derivatives, including cardanol, which is a biosourced molecule. Many new phosphorus molecules have been synthesized, completely characterized and evaluated for their antioxidant properties. Finally, we tried to apply our new compounds for other applications. Since phosphines are excellent ligands for transition metals, we studied coordination chemistry with copper (I), hoping to form luminescent copper complexes. Indeed, the development of stable light-emitting diodes remains a technological challenge despite all the current advances. In this context, many new cubane-type complexes have been synthesized and fully characterized. These tetranuclear complexes are interesting structures, easy to synthesize, with excellent quantum yields. These complexes exhibit high stability and luminescence properties, which make them very good candidates for optoelectronic devices.
19

Estudos espectrofotométricos e por quimiluminescência da autoxidação de complexos de Ni(II) ou Cu(II)/tetraglicina induzida por S(IV). Aplicações analíticas / Spectrophotometric and chemiluminescence studies of S(IV) induced autoxidation of Ni(II) or Cu(II)/tetraglycine complexes. Analytical applications.

Bonifacio, Rodrigo Leandro 13 May 2004 (has links)
O presente trabalho apresenta estudos da reação de autoxidação de Ni(II)/tetraglicina ou Cu(II)/tetraglicina induzida por S(IV). Estudos espectrofotométricos enfocaram a formação do respectivo íon metálico no estado de oxidação 3+. Verificou-se que S(IV) acelera a autoxidação de Ni(II)/tetraglicina em pH=9,2 (tampão borato), com a determinação de alguns parâmetros cinéticos desta reação. A autoxidação de Cu(II)/tetraglicina induzida por S(IV), caracterizada por efeito sinérgico positivo de Ni(II), foi empregada no desenvolvimento de método analítico para S(IV) na faixa de (0-0,12) milimolar. Este método foi utilizado para estudo da autoxidação de S(IV) catalisada por traços de íons metálicos de transição, em meio não-complexante. Estudos por quimiluminescência abordaram a interação das espécies geradas na autoxidação de Ni(II)/tetraglicina e Cu(II)/tetraglicina induzida por S(IV) com o íon tris-bipiridil-2,2´-rutênio(II). Foi avaliado o efeito de intensificação da radiação emitida, causado por tensoativos ou adições sucessivas de S(IV). A interação das espécies produzidas na autoxidação de Ni(II)/tetraglicina induzida por S(IV) com luminol foi aproveitada para desenvolvimento de método quimiluminescente para determinação de sulfito. O método proposto foi aplicado para determinação de S(IV) livre em amostras de bebidas, açúcar e água de chuva (limite de detecção 0,28 nanomolar). / The current work shows studies concerning the sulfite induced Ni(II)/tetraglycine (NiIIG4) and Cu(II)/tetraglycine (CuIIG4) autoxidation reaction in aqueous medium. Spectrophotometric studies focused on the formation of the correspondent metallic ion in the 3+ oxidation state. It was found that S(IV) accelerates NiIIG4 autoxidation at pH = 9.2 (borate buffer). Some kinetic parameters of this reaction have been successfully determined. S(IV) induced CuIIG4 autoxidation, which is characterized by the remarkable positive synergistic effect of Ni(II), was used in the development of a S(IV) analytical method in the range of (0-12)x10-5 mol L-1. This method was used to study the S(IV) catalyzed autoxidation of metallic transition ions, in non-complexing medium. Chemiluminescence studies approached the interaction between Ru(II)/bipy (tris-bipyridil-2,2´-ruthenium(II) ion) and the species generated in the S(IV) induced NiIIG4 autoxidation. The emitted radiation intensifying effect, which is caused by the presence of certain surfactants or consecutive additions of S(IV), was evaluated. The interaction between the species generated in the S(IV) induced NiIIG4 autoxidation and luminol was used in the development of a sulfite determination method by chemiluminescence. A flow system containing a gas-diffusion unit was used to separate S(IV) from the matrix. Free sulfite was determined in beverages, sugar and rainwater samples, with a detection limit of 2,8 x 10-8 mol L-1.
20

Estudos espectrofotométricos e por quimiluminescência da autoxidação de complexos de Ni(II) ou Cu(II)/tetraglicina induzida por S(IV). Aplicações analíticas / Spectrophotometric and chemiluminescence studies of S(IV) induced autoxidation of Ni(II) or Cu(II)/tetraglycine complexes. Analytical applications.

Rodrigo Leandro Bonifacio 13 May 2004 (has links)
O presente trabalho apresenta estudos da reação de autoxidação de Ni(II)/tetraglicina ou Cu(II)/tetraglicina induzida por S(IV). Estudos espectrofotométricos enfocaram a formação do respectivo íon metálico no estado de oxidação 3+. Verificou-se que S(IV) acelera a autoxidação de Ni(II)/tetraglicina em pH=9,2 (tampão borato), com a determinação de alguns parâmetros cinéticos desta reação. A autoxidação de Cu(II)/tetraglicina induzida por S(IV), caracterizada por efeito sinérgico positivo de Ni(II), foi empregada no desenvolvimento de método analítico para S(IV) na faixa de (0-0,12) milimolar. Este método foi utilizado para estudo da autoxidação de S(IV) catalisada por traços de íons metálicos de transição, em meio não-complexante. Estudos por quimiluminescência abordaram a interação das espécies geradas na autoxidação de Ni(II)/tetraglicina e Cu(II)/tetraglicina induzida por S(IV) com o íon tris-bipiridil-2,2´-rutênio(II). Foi avaliado o efeito de intensificação da radiação emitida, causado por tensoativos ou adições sucessivas de S(IV). A interação das espécies produzidas na autoxidação de Ni(II)/tetraglicina induzida por S(IV) com luminol foi aproveitada para desenvolvimento de método quimiluminescente para determinação de sulfito. O método proposto foi aplicado para determinação de S(IV) livre em amostras de bebidas, açúcar e água de chuva (limite de detecção 0,28 nanomolar). / The current work shows studies concerning the sulfite induced Ni(II)/tetraglycine (NiIIG4) and Cu(II)/tetraglycine (CuIIG4) autoxidation reaction in aqueous medium. Spectrophotometric studies focused on the formation of the correspondent metallic ion in the 3+ oxidation state. It was found that S(IV) accelerates NiIIG4 autoxidation at pH = 9.2 (borate buffer). Some kinetic parameters of this reaction have been successfully determined. S(IV) induced CuIIG4 autoxidation, which is characterized by the remarkable positive synergistic effect of Ni(II), was used in the development of a S(IV) analytical method in the range of (0-12)x10-5 mol L-1. This method was used to study the S(IV) catalyzed autoxidation of metallic transition ions, in non-complexing medium. Chemiluminescence studies approached the interaction between Ru(II)/bipy (tris-bipyridil-2,2´-ruthenium(II) ion) and the species generated in the S(IV) induced NiIIG4 autoxidation. The emitted radiation intensifying effect, which is caused by the presence of certain surfactants or consecutive additions of S(IV), was evaluated. The interaction between the species generated in the S(IV) induced NiIIG4 autoxidation and luminol was used in the development of a sulfite determination method by chemiluminescence. A flow system containing a gas-diffusion unit was used to separate S(IV) from the matrix. Free sulfite was determined in beverages, sugar and rainwater samples, with a detection limit of 2,8 x 10-8 mol L-1.

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