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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.
21

The dissolution of gold colloids in aqueous thiosulfate solutions

seanzhang06@hotmail.com, Xin-min Zhang January 2008 (has links)
The kinetics of the dissolution of gold and silver colloids in ammoniacal thiosulfate solutions has been studied using oxygen, copper(II) or oxygenated copper(II) as oxidants at pH 9 - 11 and temperature 22oC to 48oC. The effects of the concentration of the main reagents such as copper(II), ammonia and thiosulfate as well as various background reagents have been investigated. Gold and silver colloids have characteristic absorption peaks at 530 nm and 620 nm respectively. Thus, the extent of gold or silver dissolution in different lixiviant systems was monitored using an ultraviolet-visible spectrophotometer. A comparison of the behaviour of gold colloids and powders has also been made. The beneficial or detrimental effects of silver colloid, and background reagents such as silver nitrate, and sodium salts of nitrate, carbonate, sulfite, sulfate, trithionate, tetrathionate anions have also been investigated. Experimental results show that the relative rates and the extent of gold colloid dissolution at 25ºC in different lixiviant systems in a given time interval are in the order: oxygen-cyanide > copper(II)-ammonia-thiosulfate ≈ oxygen-copper(II)- ammonia-thiosulfate > oxygen ammonia-thiosulfate ≥ oxygen-ammonia > copper(II) ammonia. The analysis of electrode potentials shows that Au(S2O3)23- is the predominant gold(I) species in the lixiviant solutions containing oxygen or copper(II) as oxidant and thiosulfate or mixed ammonia-thiosulfate as ligands. During the reaction of copper(II) with thiosulfate in ammoniacal solution without oxygen, the measured potential using a platinum electrode represent the redox couple Cu(NH3)n2+/Cu(S2O3)m1-2m (n = 4 or 3, m = 3 or 2) depending on the concentrations of thiosulfate and ammonia. The initial dissolution rates of gold colloid by oxygen in copper-free solutions show a reaction order of 0.28 with respect to the concentration of dissolved oxygen, but independent of the concentration of ammonia and thiosulfate. The reaction activation energy of 25 kJ/mol in the temperature range 25°C to 48°C indicated a diffusion controlled reaction. The initial dissolution rates of gold colloid by oxidation with copper(II) in oxygenfree solutions show reaction orders of 0.41, 0.49, 0.60, 0.15 and 0.20 with respect to the concentrations of copper(II), thiosulfate, ammonia, chloride and silver respectively. The presence of silve (I) or chloride ions enhances the rate of gold dissolution, indicating their involvement in the surface reaction, possibly by interfering with or preventing a passivating sulfur rich film on gold surface. An activation energy of 40-50 kJ/mol for the dissolution of gold by oxidation with copper(II) in the temperature range 22°C to 48°C suggests a mixed chemically/diffusion controlled reaction. The dissolution of gold by oxidation with copper(II) in oxygen-free solutions appears to be a result of the reaction between gold, thiosulfate ions and the mixed complex Cu(NH3)p(S2O3)0. The half order reactions support electrochemical mechanisms in some cases. The initial dissolution rates of gold colloid, massive gold and gold-silver alloys by oxygenated copper(II) solutions also suggest a reaction that is first order with respect to copper(II) concentration. High oxygen concentration in solutions has a negative effect on the initial rate of gold dissolution and overall percentage of gold dissolution, indicating that oxygen affects the copper(II), copper(I) or sulfur species which in turn affects the gold dissolution. The surface reaction produces Au(NH3)(S2O3)- and Cu(NH3)p+. The mixed complexes Au(NH3)(S2O3)- and Cu(NH3)p+ re-equilibrate to the more stable complexes Au(S2O3)23- and Cu(S2O3)35- in solution. The dissolution of gold powder by oxidation with copper(II) in oxygen-free solutions shows the same trends as that of gold colloid. The presence of silver(I) or chloride ions enhances the initial rate and percentage dissolution of gold colloid and powder. The dissolution kinetics of gold powder and colloid follow a shrinking sphere kinetic model in solutions of relatively low concentrations of thiosulfate and ammonia, with apparent rate constants being inversely proportional to particle radius. The best system for dissolving gold based on the results of this work is the copper(II)-ammonia-thiosulfate solution in the absence of oxygen or in the presence of oxygen. In the absence of oxygen, copper(II) 1.5-4.5 mM, thiosulfate 20-50 mM, ammonia 120-300 mM and pH 9.3-10 are the best conditions. The presences of carbonate and sulfite have a significant negative effect on the dissolution of gold. The presence of sodium trithionate shows a beneficial effect in the first two hours, while sodium tetrathionate or lead nitrate have a small negative effect and sodium nitrate showed no effect on the dissolution of gold. Silver nitrate and sodium chloride also show beneficial effects. In the presence of oxygen, copper(II) 2.0-3.0 mM, thiosulfate 50 mM, ammonia 240 mM and pH 9.3-9.5 are the best conditions.
22

Carreadores lipídicos nanoestruturados para incorporação de complexos de cobre(ii) aplicáveis no estudo frente ao Mycobacterium tuberculosis / Nanostrutured lipid carriers to incorporation for copper(ii) complex applicable in the study against Mycobacterium tuberculosis

Sato, Mariana Rillo [UNESP] 03 February 2016 (has links)
Submitted by MARIANA RILLO SATO null (marillosato@gmail.com) on 2016-02-22T18:19:25Z No. of bitstreams: 1 Dissertação FINAL - COM FICHA.pdf: 2624639 bytes, checksum: 73f8b5a016f99a538e050ac383d48e8e (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-02-24T14:12:59Z (GMT) No. of bitstreams: 1 sato_mr_me_arafcf_par.pdf: 1019774 bytes, checksum: ef4be326766e21e326047c976e98d864 (MD5) / Made available in DSpace on 2016-02-24T14:12:59Z (GMT). No. of bitstreams: 1 sato_mr_me_arafcf_par.pdf: 1019774 bytes, checksum: ef4be326766e21e326047c976e98d864 (MD5) Previous issue date: 2016-02-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Tuberculosis (TB) is known worldwide as the leading infectious disease of chronic evolution in which the abandonment of treatment before the recommended period tends to cause the development of more severe disease, such as the appearance of resistant strains. Copper interacts with biologically active ligands developing copper(II) complex with activities antimicrobial. Nanostructured lipid carriers (NLCs) have gained prominence in the pharmaceutical field, since they have the ability to compartmentalize efficiently lipophilic drugs and modify their properties and behavior in the biological environment. The aims of this study was to evaluate the potential of copper(II) complexes-loaded NLCs applicable in the study against Mycobacterium tuberculosis. Copper(II) complexes containing isoniazid binder were obtained and they were entitled C1, C2, and C3 where they have co-binders anionic chloride, cyanate and thiocyanate, respectively. NLCs were obtained by fusion-emulsification technique, formulations were obtained by Ultra turrax at 5000 rpm for 10 minutes followed by sonicator at 8% amplitude for 20 minutes to obtain stable NLCs, those were incorporated of 3.50% and 0.50% to surfactant poloxamer 407 and cetrimonium bromide, respectively, and 2.07%, 2.50% and 0.88% of polyoxyethylene stearate lipids, triglycerides of capric acid/caprylic and ethoxylated hydrogenated castor oil 40 OE (F32) or castor oil (F38), respectively. Copper(II) complexes were incorporated into NLCs (F32.OE.C1, F32.OE.C2, F32.OE.C3 and F38.OR.C1, F38.OR.C2, F38.OR.C3) and characterized by diameter (Dmn) , polydispersivity index (PDI) and zeta potential (ZP) for 1, 15, 30, 45 and 60 days, which revealed homogeneous dispersion and excellent physical stability over the same period; the atomic force microscopy confirmed that developed NLCs are spherical particles dispersions at nanometer scales; differential scanning calorimetry revealed that the constituents used in the formulations interacted in the systems and confirmed that copper(II) complexes were incorporated in the NLCs. The antimicrobial activity of the complexes against M. tuberculosis H37Rv was determined by the resazurin microdilution assay demonstrated potential anti-TB when complexes were incorporated into NLCs. Cytotoxicity assay in murine macrophage-like cells J774A.1 (ATCC TIB-67) e MRC-5 (ATCC-CCL-171) for 24 h and acute toxicity of the complex against Artemia salina L (Artemiidae) showed the formulations have toxicity in all tested concentrations; although published reports indicated the safety of the components used of the formulations, studies should be conducted in animal models to assess the acute toxicity. These results suggest that NLCs have potential application in the study against Mycobacterium tuberculosis. / A Tuberculose (TB) é mundialmente conhecida como a principal doença infecto-contagiosa de evolução crônica, em que o abandono do tratamento antes do período recomendado tende a ocasionar o desenvolvimento de casos mais graves da doença, gerando o aparecimento de cepas resistentes. O cobre interage com ligantes biologicamente ativos desenvolvendo complexos de cobre(II) com ações antimicrobiana. Carreadores lipídicos nanoestruturados (CLNs) vêm se destacando na área farmacêutica, pois apresentam a capacidade de compartimentalizar, de maneira eficiente fármacos lipofílicos e de modificar suas propriedades e comportamento em meio biológico. O objetivo deste trabalho foi avaliar o potencial de CLNs acrescidos de complexos de cobre(II) aplicáveis no estudo frente ao Mycobacterium tuberculosis. Foram obtidos 3 complexos de cobre(II), intitulados C1, C2 e C3 que contem o ligante isoniazida e os co-ligantes aniônicos cloreto, tiocianato e cianato, respectivamente. Os CLNs foram obtidos pela técnica de fusão-emulsificação, testando-se diversas formulações por Ultra turrax a 5000 rpm por 10 minutos e por sonicador com amplitude 8% por 20 minutos até a obtenção de CLNs estáveis, que foram constituídos de 3,50% e 0,50 % de poloxamer 407 e brometo de cetrimônio, respectivamente, e de 2,07%, 2,50% e 0,88% de estearato de polioxietileno, triglicérides do ácido cáprico/caprílico e óleo de rícino hidrogenado e etoxilado 40 (F32) ou óleo de rícino (F38), respectivamente. Os complexos de cobre(II) foram incorporados nos CLNs (F32.OE.C1, F32.OE.C2, F32.OE.C3, e F38.OR.C1, F38.OR.C2, F38.OR.C3), e caracterizados por diâmetro hidrodinâmico médio (Dnm), índice de polidispersidade (IPD) e potencial zeta (PZ) por 1, 15, 30, 45 e 60 dias, revelando homogeneidade da dispersão e excelente estabilidade física; a microscopia de força atômica confirmou que os CLNs tratam-se de dispersões de partículas esféricas em escalas nanométricas; a calorimetria exploratória diferencial revelou que os componentes utilizados nas formulações interagiram para formação do sistema e que os complexos de cobre(II) foram incorporados nos CLNs. A atividade antimicrobiana dos complexos, frente ao M. tuberculosis H37Rv determinada pelo ensaio de microdiluição com Resazurina evidenciaram potencialização da ação anti-TB pela incorporação dos complexos nos CLNs. Os ensaios de citotoxicidade frente à linhagem de macrófagos J774A.1 (ATCC TIB-67) e de MRC-5 (ATCC-CCL-171) em 24 h e a toxicidade aguda dos complexos frente à Artemia salina L., mostraram que as formulações apresentaram toxicidade em todas as concentrações testadas; apesar de relatos da literatura indicarem a segurança dos componentes das formulações, estudos devem ser realizados em modelos animais para avaliar a toxicidade aguda. Os resultados sugerem que os CLNs apresentam aplicação potencial no estudo frente ao Mycobacterium tuberculosis.
23

Copper Grafted Titanium Dioxide in Hydrogels for Photocatalysts

Amsaaed, Salem 14 December 2018 (has links)
This study are based on the premise that the incorporation of metal ions into nano titania-PHEMA [poly (2-hydroxyethyl methacrylate)] hydrogels would enhance the desirable properties in the photodecomposition of pollutants. The investigation are centered in the use of Cu(II) as metal ion of interest. The development of TiO2-PHEMA-Cu hydrogels was conducted, and the characterization of the materials by FT-IR, XRD and fluorescence was performed. The absorption of copper(II) from the solution was monitored by UV-Vis. The FT-IR are found too, be the most effective tool too, analyze the interaction of Cu(II) with PHEMA in the nanocomposite hydrogels. The free carbonyl group has the IR band at 1715 cm-1 in the TiO2-PHEMA. Upon uptaking Cu(II), the hydrogels showed a new band at 1595 cm-1. Further examination establishes the relationship between the two bands. The time-dependent study revealed that the intensity of band at 1595 cm-1 would increase while that at 1715 cm-1 would decrease as the time for uptaking Cu(II) increased. A concentration-dependent study also demonstrated the same trend that showed the intensities of the two bands moved in the opposite directions.
24

\"Estudo experimental e teórico de compostos de bases de Schiff com cobre (II)\" / \"Experimental and theoretical studies on copper(II) Schiff Bases\"

Érica Tozzo 25 September 2006 (has links)
Neste trabalho inicialmente foi feita uma breve apresentação sobre a utilização de compostos de bases de Schiff e Cobre(II) como catalisadores na reação de oxidação de sulfetos. Foi feita a determinação das estruturas cristalinas dos compostos: N,N\'-bis(3-etoxisalicilideno)-(1,2etileno- diamina) Cu(II), sistema cristalino ortorrômbico grupo espacial Pbcn a = 7.639(5); b= 12.760(5); c= 19.733(5)Å; V = 1923.4(15) (3)Å3; Dcalc = 1.505 Mg/m3; MM = 435.96; e m = 1.170 mm-1, N,N\'-bis (4-dietilaminasalicilideno) - (1,2etilenodiamina) Cu(II), sistema monoclínico, C2/c, a = 19.571(2); b=9.8514(2)=; c=12.4552(4) Å; Beta = 93.705(9)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1, N,N\'-bis(3-metoxisalicilideno)-(1,2etilenodiamina)Cu(II), sistema ortorrômbico, Pna21, a = 7.5140(6); b= 9.2629(9); c= 24.721(3)Å; V =1720.6(3) Å3; Dcalc = 1.575 Mg,m-1; MM = 407.91; e m = 1.302 mm1 e (SALAHE)Cu(II), monoclínico, P21/C, a = 18.3216(2) Å; b=4.804(3) Å; c=19.801(2)Å; Beta = 98.908(6)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1. Os cálculos teóricos para as quatro moléculas foram efetuados partindo-se das coordenadas atômicas cristalográficas. Foram modeladas, para posterior estudo teórico, as moléculas de vinte e seis compostos de bases de Schiff e Cobre(II) análogos. Foram calculadas 104 variáveis para cada composto, e realizado o estudo de correlação estrutura-atividade catalítica através de métodos de Quimiometria. Foi obtido um modelo de correlação utilizando a classe de compostos de atividade catalítica pré-definida. Finalmente foi realizada a tentativa de previsão de atividade dos vinte e quatro compostos com atividade não conhecida, obtendo-se como resultado a probabilidade de vinte deles serem ativos como catalisadores da conversão sulfeto-sulfóxido . / Initially, in this work, a brief presentation about Schiff bases and their applications as catalysist. The crystalline structure determination was made for the compounds: N,N\'-bis(3-etoxysalicylidene)- (1,2ethylenediamine) Cu(II), crystal system orthorhombic spatial group Pbcn a = 7.639(5); b= 12.760(5); c= 19.733(5)Å; V = 1923.4(15) (3)Å3; Dcalc = 1.505 Mg/m3; MM = 435.96; e m = 1.170 mm-1, N,N\'-bis (4- diethylaminesalicilidene) - (1,2ethylenediamine) Cu(II), monoclinic, C2/c, a = 19.571(2); b=9.8514(2)=; c=12.4552(4) Å; B= 93.705(9)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1, N,N\'-bis(3-metoxysalicilidene)- (1,2ethylenediamine) Cu(II), orthorhombic, Pna21, a = 7.5140(6); b= 9.2629(9); c= 24.721(3)Å; V =1720.6(3) Å3; Dcalc = 1.575 Mg,m-1; MM = 407.91; e m = 1.302 mm1 e (SALAHE)Cu(II), monoclinic, P21/C, a = 18.3216(2) Å; b=4.804(3) Å; c=19.801(2)Å; B= 98.908(6)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1. The theoretical calculations for the four molecules had been effected starting of the crystallographic atomic coordinates. Twenty-six molecules without determined crystallographic structure had been shaped for theoretical study. 104 variables for each compound had been calculated, and carried through the correlation study structure-catalyst activity through chemometric methods. A separation model was gotten in one single class. Finally the attempt of forecast of activity of twenty four compounds with activity unknown was carried through, getting itself as resulted the probability of twenty in all to be able to become active.
25

Autoxidação dos complexos de tetra, penta e hexaglicina de Ni(II), Co(II) e Cu(II) induzida por S(IV). Determinação de S(IV) e aldeídos por quimiluminescência / Sulfite induced autoxidation of Ni(II), Co(II) and Cu(II) / tetra, penta and hexaglycine complexes. Chemiluminescent determination of S(IV) and acetaldehyde

Luciana Batista de Carvalho 05 March 2007 (has links)
A autoxidação dos complexos de Ni(II) e Co(II) com tetra, penta e hexaglicina, em meio de tampão borato, é acelerada por espécies de enxofre (IV) (H2S0<SUB3, HS03-e SO32-). A formação dos complexos de Ni(III) e Co(III) foi acompanhada espectrofotometricamente em 325 e 265 nm, respectivamente. A velocidade da reação de autoxidação do complexo de Ni(II)/Gn aumenta com a concentração de S(IV) e é máxima em pH &#926;8,5. O processo é autocatalítico com Ni(III)ou Co(III)atuando como iniciadores, forma~os pela oxidação espontânea de Ni(II) ou Co(II) pelo oxigênio molecular. A dependência da constante de velocidade observada com a oncentração de S(IV) evidenciou possíveis reações paralelas com formação de um complexo com ligantes mistos antes da etapa da oxidação. A autoxidação dos complexos de Cu(II)com penta e hexaglicina em pH =9 é muito lenta, na presença e na ausência de S(IV).A presença de S(IV) e de traços de Ni(II)ou Co(II) aumenta significativamente a velocidade e a eficiência da reação (período de indução de 0,5 s). O mecanismo envolve uma cadeia de reações e um ciclo redox dos complexos. Acetaldeído e formaldeído inibem parcialmente a reação de autoxidação de Ni(II)/G4 na presença de S(IV) e luminol.O método quimiluminescente desenvolvido pode ser empregado para determinação de formaldeído [(5,0.10-5 - 1,0.10-2) mol L-1] e acetaldeído [(1,0.10-4 - 0,10) mol L-1], não sendo possível detectar separadamente cada um desses aldeídos. Na autoxidação de Ni(OH)2 induzida por S(IV) na presença de luminol ocorre emissão de radiação, possibilitando a detecção de S(IV) na faixa de 5,0.10-8 a 1,0.10-5 mol L-1, com limite de detecção estimado de 1,3.10-8 mol L-1. / The autoxidation of Ni(lI) and Co(lI) complexes with tetra, penta and hexaglycine, in borate medium, is accelerated by sulfur (IV) species (H2S03, HS03- and SO32-). The formation of Ni(llI) and Co(lIl) complexes was followed spectrophotometrically at 325 and 265 nm, respectively. The autoxidation rate of Ni(II)/Gn complex increases with S(IV) concentration and is maximum at pH ~ 8.5. The process is autocatalytic with Ni(lIl) or Co(llI) acting as initiators, formed by spontaneous oxidation by oxygen. The dependence of the observed rate constant with S(IV) concentration showed evidences of back or parallel reactions with formation of mixed ligand complex prior to the oxidation step. The autoxidation of Cu(II)/penta and hexaglycine complexes at pH = 9, in the presence and absence of S(IV), is very slow. The presence of S(IV) and of small amounts of Ni(lI) or Co(lI) increases significantly the effectiveness and reaction rate (induction period = 0.5 s). The mechanism involves a radical chain and redox cycling of the metal íon complexes. Acetaldehyde and formaldehyde partially inhibit the autoxidation reaction of Ni(II)/G4 in the presence of S(IV) and luminol. The developed chemiluminescent method can be used for determination of formaldehyde [(5.0.10-5 - 1.0.10-2) mol L-1] and acetaldehyde [(1.0.10-4 - 0.10) mol L-1), being not possible their isolated detection. The S(IV) induced autoxidation of Ni(OH)2 in the presence of luminol, occurs with radiation emission, allowing S(IV) detection in the range 5.0.10-8 to 1.0.10,-5 mol L-1, with detection limit of 1.3.10-8 mol L-1.
26

Estudo dos complexos de cobre (ii) com triptofilglicina utilizando a técnica de ressonância paramagnética eletrônica / Study of complex the copper (II) with Trp-Gly by using the techinique of electronic paramagnetic resonance

Carlos Alberto Fonzar Pintao 24 February 1989 (has links)
Neste trabalho estudou-se os complexos formados pelo íon cobre (II) com o dipeptides triptofilglicina na faixa de pH=3,0 a 13,5. A caracterização dos mesmos foram realizadas através das técnicas de Ressonância Paramagnética Eletrônica (RPE) em duas temperaturas (ambiente e nitrogênio líquido) e Absorção Ótica no visível (350 a 1000 nm). As amostras em solução aquosa obedeceram a relação de 10 ligantes para 1 metal. Caracterizou-se três tipos de complexos nas faixas pHs: 4.0 a 6,0; 6,0 a 12,0 e acima de 12,0. Estes complexos foram propostos com base nos dados espectroscópicos e um conhecimento prévio dos pKs dos grupos desprotonáveis, são eles: CuL2, CuL(H2O) e CuL(OH) (H2O). Estudou-se a influência da cadeia lateral pesada nos parâmetros espectroscópicos e comparativamente ao complexo Gliciltriptofano estudado por Nascimento (1985) no mesmo intervalo de pH, foi possível mostrar que o modelo de não covalência (Brill e Bryce (1968)), é o mais adequado em explicar a diminuição da constante hiperfina Az, constatado em Ph elevado. O complexo tridentado CuL(H2O) foi cristalizado e medidas de RPE no monocristal permitiram obter o tensor giromagnético molecular. Interação de exchange e/ou dipolar, não permitiram a determinação do tensor hiperfino no complexo. Através das direções principais e valores das direções das componentes do tensor cristalino e as direções das normais aos planos de coordenação, foi possível detectar uma forte interação de exchange entre dois íons vizinhos. / In this work was studied the complex made by the ion copper(II) with the dipeptide tryptophilglicine in the area of pH between 3,0-13,5. The cacacterizations of them were realized by the electron paramagnet resonance (ERP) in two temperatures (room and liquid nitrogen) and Optics Absorption in the visible (between 350 - 1100 nm). The samples in aqueous solution got the rate of 10 ligand to one metal. Three species of complex were characterized: pHs between 4,0-6,0; 6,0-12,0 and above 12,0. These complexes were proposed with foundation in the spectroscope informations and a previous know of the pKs of the deprotanatable groups, they are: CuL2; CuL(H2O) and CuL(OH) (H2O). The influency of the lateral chain weighed in the spectroscopies parameter was studied, and in compere with the glyciltryptophan complex studied by Nascimentoi (1985) in the same intermission of the pH, it was possible to show that the model of no covalente (Brill and Bryce-1968) is the adequader to explain the hiperfine constant Az diminution, evidenced in heigh pH. The tridentate complex CuL(H2O) was crystallized and EPR mensures in the monocrystal allowed to get the molecular gyromagnetic tensor. Exchange and/or dipolar interaction didn\'t allow the determination of the hyperfine tensor of the complex. By the main directions and values of the component parts of the tensor g crystalline and the normal directions to the plans of coordination, it was possible to detect a strong interaction of exchange between to neighbour ions.
27

Synthèse et fonctionnalisation de bispidines pour la complexation du 64Cu en vue d’applications en imagerie médicale par tomographie à émission de positrons et en radiothérapie / Synthesis and functionnalisation of bifunctional chelates for 64Cu complexation for their applications by positron emission tomography (PET) imaging and radiotherapy

Roux, Amandine 07 November 2014 (has links)
Ce travail de thèse visait à développer une nouvelle famille de ligands de type bispidines pour la complexation du cuivre(II) en vue d’applications en tomographie par émission de positrons(TEP). En effet, le cuivre 64 est un radioélément dont l’étude dans le cadre de l’imagerie TEP est en plein essor. Les bispidines, quant à elles, présentent l’intérêt de posséder une structure rigide et pré-organisée permettant la complexation de nombreux métaux de transitions.Nous présentons ici la synthèse et l’optimisation de nouveaux ligands dont les propriétés structurales et physico-chimiques ont été étudiées. Un ligand a montré de très bons résultats puisqu’il possède tous les paramètres cinétiques et thermodynamiques nécessaires à un chélatant utilisé en imagerie TEP. Différentes voies de fonctionnalisation ont ensuite été étudiées afin d’obtenir divers chélatants bifonctionnels. Un ligand comportant une lysine a pu être couplé à une fonction maléimide (régiosélective des cystéines), à une biotine (possédant une forte interaction pour la streptavidine) ou encore à un motif Bodipy pour l’obtention d’une sonde bimodale (UV-visible et TEP). Enfin, nous présentons l’extension de cette famille de bispidines par l’augmentation du nombre de fonctions de coordination présentes ou encore par l’obtention de ligands tricycliques en vue de moduler la sélectivité de ces molécules. / This work aimed to develop a new family of bispidine-type ligands for copper(II) complexation with applications in Positron Emission Tomography (PET). Indeed, copper 64 is a radioelement whose study in PET imaging is booming. Bispidines have the benefit of having a rigid and preorganized structure for complexation of a large number of transition metals. In this work we present the synthesis and optimization of new ligands whose structural and physico-chemical properties have been studied. One ligand showed very good results because it possesses all of kinetic and thermodynamic parameters which are necessary for its application to PET imaging. Different strategies of functionalization have been studied to obtain bifunctional chelates. A lysine derivative has been coupled to a maleimide function (regioselective of cysteins), to abiotine (which displays a strong affinity for streptavidin) or to a Bodipy pattern for obtaining a bimodal probe (UV-visible and PET). Finally, we present an extension of this bispidine family by increasing the number of coordination functions or by synthesizing tricyclic compounds to modulate the selectivity of these molecules.
28

Synthèse et caractérisation de bispidines, chélatants du 64Cu, en vue d’applications pour la tomographie à émission de positrons / Synthesis and characterization of bispidine-based 64Cu chelating agents for application in positron emission tomography

Gillet, Raphaël 13 October 2017 (has links)
Ce travail de thèse avait pour objectif de développer de nouveaux chélatants du cuivre(II) de type bispidine pour des applications en Tomographie à Emission de Positrons. Le 64Cu est un radioisotope métallique dont les propriétés sont intéressantes pour la TEP. Les bispidines sont des chélatants dont la structure est préorganisée et rigide. Cette propriété confère au bispidine de bonnes propriétés de coordination vis-à-vis des métaux de transition, en particulier le cuivre(II). Ce travail présente le développement d’un ligand de type bispidine possédant un groupement phosphonate ainsi que le développement de bispidines permettant la synthèse de nouvelles familles de chélatants pour le cuivre(II). La bispidine phosphonatée a ensuite fait l’objet d’une étude physico-chimique par différentes techniques, révélant ainsi qu’elle possède les caractéristiques requises pour des applications en TEP. Le radiomarquage en présence de 64Cu a été étudié pour une sélection de plusieurs chélatants et montre le fort potentiel des ligands de type bispidine pour la complexation du 64Cu. Enfin, diverses stratégies de fonctionnalisation ont été étudiées pour l’obtention d’un chélatant bifonctionnel basé sur la bispidine phosphonatée. Ces stratégies démontrent la possibilité d’obtenir deux ligands bifonctionnels. De surcroît, deux plateformes bifonctionnelles peuvent faire l’objet de point de départ pour le développement de nouvelles familles de bispidines bifonctionnelles. / This PhD work aimed at developing new bispidine-based copper(II) chelating agents for applications in Positron Emission Tomography (PET). On one hand, 64Cu is a metallic radioisotope which possesses interesting properties for PET imaging and on the other hand, bispidines have a pre-organized and rigid structure. This property makes them good chelating agents for numerous transition metals, particularly copper(II). This work presents the development of a new bispidine-based ligand having a phosphonate pendant arm as well as the development of bispidines allowing the synthesis of new chelating agents for copper(II). The physico-chemical properties of the phosphonated bispidine were thoroughly studied by different techniques, showing that it would be adequat for PET applications. Radiolabeling experiments were also done in the presence of 64Cu for various bispidines and show the high potential of bispidine ligands for the complexation of 64Cu. Finally, several functionalization strategies were studied in order to get bifunctional chelates based on the phosphonated bispidines. This study proved the possibility to develop two bifunctional bispidines based on the phosphonated one and also it allowed us to develop two bifunctional bispidines as synthon for the synthesis of new families of bifunctional bispidines.
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Synthesis and Characterization of Copper(II) Complexes

Amani, Saeid 12 1900 (has links)
A series of dihydroxy bridged copper(II) complexes of the type [(L)Cu(OH)₂Cu(L)]x₂ * nH₂0, where L is 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine or 1,10-phenanthroline, x is a counter ion, and n is the number of water molecules, was synthesized. In the case of monohydroxy bridged copper(II) complexes, we have found a new method of synthesis for [ (L)₂Cu(OH)Cu(L)₂ ] (ClO₄)₃, where L is 2,2'-bipyridine or 1,10-phenanthroline. We have synthesized five new monohydroxy bridged copper(II) complexes, thus increasing the number of monohydroxy bridged copper(II) complexes to nine. All complexes have been characterized by infrared spectroscopy, UV-visible spectroscopy, magnetic moments, and elemental analysis. The electron spin resonance results establish that the fulvic acids contain organic free radicals as an internal part of their molecular structure. The concentration of unpaired electrons will increase by increasing the pH. The unpaired electron in fulvic acid interacts with the unpaired electron on copper(II) through the Π system, and this will decrease the spin concentration of fulvic acid complexed with copper(II). The displacement of titration curve from a free ligand (fructose-1,6-diphosphate, ribulose-1,5-diphosphate, phospherine, phosphothreonine, and 3-phosphoglyceric acid, to a ligand plus copper(II) (1:1 ratio) shows there is a strong interaction between copper(II) and the corresponding ligand. All complexes absorb UV-visible at 250-300 nm. The absorption intensity changes as a function of pH. Copper (II) forms a complex with fructose-1,6-diphosphate, ribulose-1,5-diphosphate, phosphoserine, phosphothreonine, and 3-phosphoglyceric acid by the ratio of 1:3, 1:3, 1:1, 1:1, and 1:2, respectively.
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Síntese e caracterização de nanopartículas de sílica contendo íons cobre (II) para aplicação agroquímica / Synthesis and characterization of silica nanoparticles containing copper (II) ions to agrochemical application

Belini, Tábita Cristina, 1985- 22 August 2018 (has links)
Orientadores: Fernando Aparecido Sígoli, Italo Odone Mazali / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T05:10:39Z (GMT). No. of bitstreams: 1 Belini_TabitaCristina_M.pdf: 4357833 bytes, checksum: f01ca369956da0ce911ee6541c29da11 (MD5) Previous issue date: 2012 / Resumo: Nanopartículas de sílica foram obtidas, via método sol-gel, a partir de silicato de sódio em pH alcalino. A reação de precipitação foi conduzida por 24 h, mediante aquecimento sob refluxo, obtendo-se assim um sol de sílica 1 % m/v, podendo ser concentrado a 3 % m/v mediante destilação. Amostras em fase sólida foram preparadas removendo-se a água da suspensão com o auxílio de um spray dryer. As partículas presentes nos sóis apresentam morfologia esferoidal, diâmetro médio de 15 nm e potencial zeta de -28 mV. Já as amostras secas em spray dryer foram caracterizadas como não-cristalinas, o potencial zeta variou para -33,5 mV sendo observado a possibilidade de aglomeração de partículas. A distribuição de tamanho de partículas mostrou-se bimodal, com a primeira população centrada em aproximadamente 15 nm e a segunda, em 100 nm. O processo de adsorção dos íons cobre(II) foi conduzido a partir da suspensão de nanopartículas de sílica 1 % m/v. Adicionou-se cloreto de cobre(II) à suspensão de modo a se obter as concentrações de 1 e 5 mol % de íons cobre(II) em relação à sílica. Esta suspensão final foi processada em spray dryer, obtendo-se amostras em fase sólida. Estas são não-cristalinas, apresentam morfologia esferoidal, potencial zeta de -43 mV para as amostras contendo 1 mol % de íons cobre(II), e -33,7 mV, para 5 mol % de íons cobre(II). A ação biológica das nanopartículas de sílica contendo íons cobre(II) teve foi testada com relação as bactérias Xanthomonas axonopodis e Ralstonia solanacearum e nos fungos Alternaria solani e Colletotrichum gloeosporioides, mostrando eficácia no controle destes quatro patógenos. / Abstract: Silica nanoparticles were obtained by sol-gel method from sodium silicate in alkaline medium. The precipitation reaction was conducted by heating the solution under reflux for 24 h, obtaining a silica sol 1 % w/v, that may be concentrated to 3 % w/v by distillation. Dried samples were obtained removing water in a spray-dryer equipment. The obtained nanoparticles are spheroidal, with an average size of 15 nm and zeta potential of -28 mV. The dried samples were characterized as noncrystalline, the zeta potential of re-dispersed have changed to -33,5 mV and its possible to observe some agglomerated particles after drying. The size distribution is bimodal, being the first population around 15 nm and the second one around 100 nm. The adsorption of copper(II) ions was conducted from 1 % w/v the silica sol. Copper(II) chloride was added silica nanoparticles suspension in order to achieve the concentrations of 1 and 5 mol % of copper(II) ions by silica mol. This final suspension was dried in spray-dryer to obtain solid samples. The latter are noncrystalline, spheroidal, with a zeta potential around -43 mV (samples with copper(II) 1 mol %) and -33,7 mV (samples with copper(II) 5 mol %). The biological activities of the silica nanoparticles containing copper(II) ions were tested against the bacterias, Xanthomonas axonopodis and Ralstonia solanacearum and the fungus, Alternaria solani and Colletotrichum gloeosporioides showing efficacy against these four targets. / Mestrado / Quimica Inorganica / Mestra em Química

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