This thesis reports the synthesis and characterization of two new copper(II) halide complexes with deprotonated N-(2-hydroxyethyl)ethylenediamine behaving as a bidentate. The magnetic properties of the new copper(II) complexes were studied from room temperature to liquid nitrogen temperatures. The magnetic data show that both complexes exhibit antiferromagnetic interactions with a singlet ground state and a thermally accessible triplet excited state. Magnetic data and infrared spectra indicate the complexes are halogenbridged. Deprotonation at an amine nitrogen is based on the presence of a hydroxyl stretching band in the infrared spectra. Electronic spectra and infrared spectra indicate the complexes are square planar. Elemental analyses, infrared spectra, electronic spectra, electron spin resonance spectra, and magnetic data are reported and discussed.

In this study a bidentate ligand containing two ferrocenyl moieties, N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine, was prepared by condensation reaction of ferrocenecarboxyaldehyde and ethylenediamine on refluxing in benzene. The molecule was identified by IR, Raman, UV-Vis, 1H-, 13C-NMR spectroscopies. Then, this bidentate molecule was reacted with tetracarbonyl(bicyclo[2.1.1] hepta-2,5-diene)molybdenum(0). The ligand substitution reaction in toluene yielded the new complex, tetracarbonyl[N,N&acute / -bis(ferrocenylmethylene)ethylenediamine] molybdenum(0). This new complex could be isolated from the reaction solution in the form of orange crystals and fully characterized by elemental analysis, IR, UV-Vis, MS, 1H- and 13C-NMR spectroscopies. As a bidentate ligand, N,N&acute / -bis(ferrocenylmethylene)ethylenediamine binds the metal atom in the two cis positions in the pseudooctahedral geometry of the molybdenum-complex. Electrochemistry of the tetracarbonyl[N,N&acute / -bis(ferrocenylmethylene) ethylenediamine]molybdenum(0) was studied by cyclic voltammetry, chronoamperometry and controlled potential electrolysis combined with the UV-Vis or infrared spectroscopy. One irreversible oxidation and three reversible oxidations were observed in the cyclic voltammogram. Irreversible and a reversible oxidations are attributed to molybdenum and the other two reversible oxidation to iron centers. It is found that the two ferrocene groups started communication with each other after formation of molybdenum-complex.

In this study a bidentate ligand containing two ferrocenyl moieties, N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine, was prepared by condensation reaction of ferrocenecarboxyaldehyde and ethylenediamine on refluxing in benzene. The molecule was identified by IR, Raman, UV-VIS, 1H-, 13C-NMR spectroscopies. Then, this bidentate ligand was reacted with pentacarbonylbis-(trimethyl)silylethyne)tungsten(0). The ligand substitution reaction in dichloromethane yielded the new complex, tetracarbonyl [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) (W(CO)4(BFEDA)). This new complex was isolated from the reaction solution in the form of orange crystals and fully characterized by elemental analysis, IR, UV-VIS, MS, 1H- and 13C-NMR spectroscopies. As a bidentate ligand, [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine] binds the metal atom in the two cis positions in the pseudooctahedral geometry of the tungsten-complex. Electrochemistry of the tetracarbonyl [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) was studied by cyclic voltammetry, and controlled potential electrolysis combined with the UV-VIS spectroscopy. One irreversible oxidation and three reversible oxidations were observed in the cyclic voltammogram. One of these reversible and the irreversible oxidations are attributed to tungsten and the other two reversible oxidations to iron centers. It is found that the two ferrocene groups started communication with each other after formation of tungsten-complex. N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine was also reacted with photogenerated pentacarbonyl(tetrahydrofuran)tungsten(0) complex and the pentacarbonyl [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) (W(CO)5(BFEDA)) as an intermediate on the route to the tetracarbonyl[N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) was isolated from the reaction medium in the form of red crystals and fully characterized by, IR, 1H- and 13C-NMR spectroscopies. The conversion of W(CO)5(BFEDA) to the W(CO)4(BFEDA) in dichloromethane by a ring closure mechanism was observed by IR spectroscopy.

Bibliography: leaves 282-354 / 354 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physiology, 1986

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 24, 2007) Includes bibliographical references.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O objetivo deste trabalho foi estudar a imobilizaÃÃo da lipase de Candida antarctica tipo B (CalB) atravÃs de ligaÃÃo covalente utilizando a resina hidrofÃlica Toyopearl como suporte. Avaliaram-se vÃrios protocolos de ativaÃÃo, utilizando como agentes ativantes: glicidol, glutaraldeÃdo e etilenodiamina (EDA), e seu efeito na atividade hidrolÃtica do biocatalisador obtido. A atividade hidrolÃtica dos derivados foi avaliada pela hidrÃlise do butirato de para-nitrofenila (PNPB) e utilizou-se como reaÃÃo de esterificaÃÃo, a sÃntese do butirato de butila, empregando Ãcido butÃrico e butanol como substratos. O suporte foi previamente caracterizado pela obtenÃÃo de imagens por microscopia eletrÃnica de varredura (MEV), difratogramas de raio-X (DRX) e espectros de infravermelho (FTIR). A Ãrea superficial e a porosidade do suporte foram avaliadas pelo mÃtodo BET. Determinaram-se a concentraÃÃo de proteÃna e a atividade enzimÃtica do sobrenadante antes e apÃs os processos de imobilizaÃÃo. O melhor resultado de atividade hidrolÃtica da enzima imobilizada foi de 894,17  43,29 U/g de suporte, utilizando o suporte Toyopearl-Glioxil-EDA-GlutaraldeÃdo (Toyo-GEG). Este valor de atividade foi 1,56 vezes maior que o obtido para o derivado comercial Novozym 435. A influÃncia de diferentes concentraÃÃes de proteÃna foi avaliada e observou-se a saturaÃÃo do suporte com uma concentraÃÃo de 40 mg/g e 2238,25  27,33U/g de atividade. A influÃncia dos tempos de incubaÃÃo na imobilizaÃÃo indicou que longos tempos de imobilizaÃÃo acarretam na diminuiÃÃo da atividade hidrolÃtica dos biocatalisadores. Nos estudos de estabilidade tÃrmica a 60 C, conseguiu-se um elevado grau de estabilizaÃÃo para o derivado, com estabilidade tÃrmica superior a da enzima solÃvel. Para o derivado obtido com 72 horas de imobilizaÃÃo o fator de estabilizaÃÃo em relaÃÃo à enzima solÃvel e ao derivado comercial, respectivamente, foi de 694,56 e 12,74. Quanto à estabilidade operacional, apÃs o sÃtimo ciclo de sÃntese do butirato de butila, o derivado Toyo-GEG reteve em torno de 76 % de sua atividade inicial. / The objective of this work was to study the immobilization of Candida antarctica type B lipase (CalB) by covalent bond using hydrophilic resin named Toyopearl as a support. The influence of activation agents (glycidol, glutaraldehyde and ethylenediamine) in the hydrolytic activity of the biocatalyst was investigated. The enzyme preparations were tested in the hydrolysis of para-nitrophenyl butyrate (PNPB) and in an esterification reaction, butyl butyrate synthesis from butyric acid and butanol. The support was previously characterized by scanning electronic microscopy (SEM), Xray diffraction (DRX) and Fourier transform infra red (FTIR). Superficial area and porosity were evaluated using BET method. Protein concentration and enzymatic activity in the supernatant were determined before and after immobilization process. Best results of hydrolytic activity were obtained using the enzyme immobilized in Toyopearl-Glyoxyl-EDA-Glutaraldehyde (Toyo-GEG), 894.17  43.29 U/g of support, which is 1.56-fold higher than the hydrolytic activity of Novozym 435. The influence of different loadings of protein and the incubation time in the immobilization were also studied. The saturation of support was observed with a load of 40 mg/g of support with 2238.25  27.33 U/g. A decrease in the hydrolytic activity of enzyme preparations was observed for long incubation times. However, thermal stability studies at 60 C, showed that this parameter was important for enzyme stabilization. Thermal stabilization by immobilization was achieved and the immobilized enzyme was more thermal stable than the soluble enzyme. The immobilized lipase prepared at incubation time of 72 hours was 694.59-fold more stable than soluble enzyme and 12.74 -fold than Novozym 435. In organic medium, cycles of synthesis of butyl butyrate was chosen to quantify operational stability. After the seventh cycle, Toyo-GEG retained around 76 % of the initial activity.

This dissertation describes the synthesis and antimicrobial use of a series of half-sandwich Ir(III), Rh(III), Co(III) amino acid and ethylenediamine complexes. This investigation focuses on the formulation (ηn-arene)M(L)X, (L = ethylenediamine or α-amino carboxylate), (M= Ir, Rh, Ru, Co). Arene, Ligand and metal center variations were designed to tailor antimicrobial activity specific for each organism studied (Staphylococcus aureus or Mycobacteria). Each of the D/L-amino acids formed a diasteromeric complex with chiral centers on both the metal center and amino acid ligand. The unique chirality of each center elicits different antimicrobial activity against the Mycobacteria studied. The metal center (M), arene ligand (ηn-arene), and amino acid (aa), were changed independently and studied for the antimicrobial activity. In a similar fashion, each of the complexes modified with ethylenediamine and diamine derivatives were studied for their antimicrobial activity against S.aureus. All complexes were synthesized,characterized by nuclear magnetic resonance (NMR), high-resolution mass spectroscopy (HRMS), single-crystal X-ray diffraction, and elemental analysis. During the course of this work it was found that the amino acid complexes with all metal centers were specific for antimicrobial activity against all types of Mycobacteria, while the diamine derivatives were active against different strains of S.aureus. Acitvity was measured to be as low as 2 ug/mL respectively depending on the complex used. A structure activity relationship was developed to determine what combinations of ligand, metal and arene were necessary to achieve the highest antimicrobial activity. The optimal arene R-chain length for CpR was determined to be R=hexyl for all complexes studied. The most active amino acidcomplex was determined to be that of L-phenylglycine for Mycobacteria, the cis-1,2-diaminocyclohexane complex is the most active ligand against S.aureus. Each metal center had similar activity levels. Toxicological studies were performed to test their viablity to be used in mammalian systems. The complexes with the highest activity were studied against several mammailan cell lines and revealed that mammailan cells were undergoing normal cellular processes at up to 40 times the minimal inhibitory concentration (MIC). A study of the MOA or mechanism of action revealed the ability of the amino acid complexes to affect the peptidyl transferase region on the 23s ribosomal subunit of M.smegmatis. This was accomplished by isolating resistant strains of M.smegmatis towards the most effective complex (Cp*hexyl)Ir(L-phenylglycine)-Cl. Cross drug resistance of these mutants was shown with clarithromycin. The DNA of the 23s ribosomal subunit was sequenced revealing a deletion/insertion mutation within domain V (bases 2057-2058). / Ph. D.

Made available in DSpace on 2015-05-14T13:21:15Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 1879228 bytes, checksum: 90c7da6ef56a230fab2ca924b5d230db (MD5) Previous issue date: 2012-08-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The clay mineral vermiculite was modified by intercalation of ethylenediamine (en) in acidic medium based on a 24 factorial design, the selected variables were: temperature of the intercalation reaction, concentration of en+, time under stirring and acid leaching of the vermiculite. Sixteen different experimental conditions were carried out and the evaluated response was the percentage of nitrogen in each sample. The pristine and modified matrices were characterized through the following techniques, elemental analysis of CHN, x-ray diffraction, infrared spectroscopy, nuclear magnetic resonance for 29Si nucleus. A chemometric study was performed by using the sixteen infrared spectra to investigate the effect of the experimental conditions in the modification of vermiculite. The results showed that temperature of the reaction and the leaching process of the solid have relevant influence in terms of structural properties of vermiculite. The elemental analysis data gave 0.54 mmol g-1 for the amount of organic groups, suggesting the effectiveness of the intercalation reaction of protonated ethylenediamine (en+) in the interlayer space of the material. The solid obtained under optimized conditions was applied to adsorption of the reactive dye Remazol Blue RN from aqueous solutions, by using a 22 factorial design, the variables studied were: temperature and time of reaction, and the response was given by the UV-Vis absorption of the dye typical band. The results showed that the modified vermiculite is an efficient adsorbent for removing of Remazol blue RN from aqueous solution and the application of experimental design is important for determining the best conditions for the experimental variables. / O argilomineral vermiculita foi modificado por intercalação de etilenodiamina (en) em meio ácido. Para isto, foi empregado um planejamento fatorial 24, cujos fatores escolhidos foram: temperatura da reação de intercalação, concentração de en+, tempo de agitação e lixiviação da vermiculita, no total foram obtidas 16 amostras de vermiculita preparadas em diversas condições experimentais. A resposta avaliada foi a percentagem de nitrogênio. As matrizes pura e modificadas foram caracterizadas através das técnicas de análise elementar de CHN; difração de raios X; espectroscopia na região do infravermelho e ressonância magnética nuclear de 29Si. Um estudo quimiométrico foi realizado utilizando os espectros na região do infravermelho das 16 amostras para investigar o efeito das condições experimentais na modificação de vermiculita. Os resultados mostraram que a temperatura de reação e o processo de lixiviação do sólido tem influência relevante em termos de propriedades estruturais da vermiculita. Os dados de análise elementar forneceram o valor de 0,54 mmol g-1 para a quantidade de grupos orgânicos, sugerindo a efetividade da reação de intercalação de etilenodiamina protonada (en+) no espaço interlamelar do material. O sólido otimizado foi aplicado em processo de adsorção do corante reativo azul de remazol RN em solução aquosa, utilizando o planejamento fatorial, na qual as variáveis foram: temperatura e tempo de agitação, as respostas foram dadas pela absorção no UV-VIS da banda característica do corante. Os resultados mostraram que a vermiculita modificada é um adsorvente eficiente para a remoção do corante reativo azul de remazol RN em solução aquosa e que a aplicação do planejamento experimental é importante para a determinação das melhores condições das variáveis experimentais.

The effects of some associated minerals on thiosulfate gold leaching were studied through thermodynamic analysis and leaching experiments on composite ore samples containing various minerals and a reference silicate gold ore. In the leaching test on the reference gold ore, about 93% of gold was extracted within 3.0 hours. The presence of various amount of pyrite, pyrrhotite, chalcopyrite, arsenopyrite, chalcocite, bornite, and some lead species, has significant detrimental effects. Under reduced oxygen conditions, the thiosulfate consumptions could be significantly reduced. High gold extractions (i.e. >= 90%) were observed in the leaching tests with reduced dissolved oxygen (i.e., 0.7% oxygen in the supplied gas) in the absence or in the presence of sulfide minerals such as pyrite, pyrrhotite, arsenopyrite and chalcopyrite. High copper concentration and a pre-aeration step was also found to largely increase the gold extractions under such conditions. Thiosulfate-copper-ethylenediamine system was found effective in the leaching of gold. The leaching kinetics was significantly slower than that of the conventional thiosulfate-copper-ammonia leaching. The consumption of thiosulfate, however, was largely reduced. This leaching system worked effectively on the reference gold ore within a wider pH range (e.g., 6-11), with or without ammonia. The presence of ammonia in a low concentration improved the leaching rate but also increase the consumption of thiosulfate. Comparable gold extractions were observed in the leaching of the composite ores containing various sulfide minerals, such as pyrite, pyrrhotite, chalcocite, galena and chalcopyrite. The leaching of gold in the presence of iron sulfides was also improved by applying chemical additives, such as, carbonate, calcium, galena, phosphate, and additional hydroxide anion. It is proposed that these additives either passivated the harmful surface of sulfide minerals or masked some detrimental aqueous species. Finally, some improved leaching methods concluded in this study were applied on a few industrial ore samples in order to demonstrate the effectiveness of these methods. It was found that by comprehensively applying these improved thiosulfate leaching strategies, satisfactory gold extractions and thiosulfate consumption results were archived on these ores. / Thesis (Ph.D, Mining Engineering) -- Queen's University, 2008-09-18 11:48:38.672

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The significant increase of carbon dioxide emissions in the atmosphere comes intensifying the global warming. The search for energetic source that turn emission down is of great importance, as well as the use of complementary actions like dioxide carbon capture process of the main emissions sources. From among some processes already very well-known industrially highlights chemical absorption with alkanolamine, which shows some disadvantages in being costly and generate waste derived from recovery. The use gas-solid selective in carbon dioxide adsorption has very advantages over absorption liquid amine such as easy handling without risks to the environment and recovering of adsorbent material, being possible to use industries plants with continuous flux. In this context were synthesized through hydrothermal method two materials of family M41S of type MCM-41 and MCM-48. Then the materials were impregnated with ethylenediamine by wet impregnation method. These materials were used for the carbon dioxide adsorption process and were characterized by several physic-chemical techniques. The powder X-ray diffraction patterns of the samples showed all peaks characteristics of MCM-41 and MCM-48 before and after impregnation with amines. The absorption spectrum in the infrared region showed bands due to Si-O and O-Si-O bonds in all materials and N-H bonds due to presence of amine in the supports after impregnation process. The thermogravimetric curves showed that stability of material containing amines is up to 100 °C. The materials showed N2 adsorption isotherms type IV, some with hysteresis type H1 and high surfaces areas (over 1000 m2 g-1). Carbon dioxide capture tests in flux system and atmosphere pressure showed significant drawbacks in the capture capacities of carbon dioxide for the materials impregnated with ethylenediamine in comparison to the values obtained with the MCM-41 and MCM-48 supports alone. Tests with closed system and pressure variation in the range of 0.5 to 30 bar allowed the construction of the isotherms to prepared materials of which were fitted using the Langmuir model. The results showed that the samples of MCM-41 and MCM-48 without impregnation are favorable for applications where high pressures are required. / O aumento significativo das emissões de dióxido de carbono na atmosfera vem acentuando o efeito do aquecimento global. A busca por fontes energéticas que minimizem as emissões é de grande importância, como também o uso de ações complementares como processos para captura deste gás das principais fontes emissoras. Dentre alguns processos já bem conhecidos industrialmente, destaca-se a absorção química com alcanolaminas, a qual apresenta algumas desvantagens por ser dispendiosa e gerar rejeitos da sua recuperação. O uso da adsorção gás-sólido seletiva de dióxido de carbono tem muitas vantagens sobre a absorção com aminas líquidas, tais como: fácil manipulação sem riscos ao ambiente, e recuperação do material adsorvente, podendo-se utilizar plantas industriais com fluxo contínuo. Neste contexto, foram sintetizados através do método hidrotérmico dois materiais da família M41S do tipo MCM-41 e MCM-48. Em seguida os materiais foram impregnados com etilenodiamina, através do método de impregnação por via úmida. Estes materiais foram utilizados para o processo de adsorção de dióxido de carbono e foram caracterizados por diversas técnicas físico-químicas. Os difratogramas de raios-X das amostras sintetizadas apresentaram os picos característicos do MCM-41 e do MCM-48 antes e após a impregnação com aminas. Os espectros de absorção na região do infravermelho mostraram bandas devido às ligações Si-O e O-Si-O em todos os materiais e de ligações N-H devido à presença da amina nos suportes após a impregnação. As curvas termogravimétricas mostraram que a estabilidade do material contendo aminas é de até 100 °C. Todos os materiais apresentaram isotermas de adsorção de N2 do tipo IV, alguns com histerese do tipo H1 e elevadas áreas superficiais (acima de 1000 m2 g-1). Os testes de captura de dióxido de carbono em sistema com fluxo e pressão atmosférica mostraram significativas reduções nas capacidades de captura para os materiais impregnados em comparação com os valores obtidos com os suportes MCM-41 e MCM-48. Testes com sistema fechado e variação de pressão na faixa de 0,5-30 bar permitiram o levantamento de isotermas de equilíbrio para os materiais preparados as quais foram ajustadas através do modelo de Langmuir. Os resultados mostraram que as amostras de MCM-41 e MCM-48 são favoráveis para aplicações onde altas pressões são requeridas.