As imidas naftálicas (INs) compõe uma classe de moléculas orgânicas aromáticas derivadas, geralmente, de um anidrido naftálico e uma amina primária. São de grande interesse na área de materiais devido a uma série de propriedades físicas e químicas, mas principalmente devido à suas propriedades fotofísicas. Derivados de INs são compostos fluorescentes com propriedades fotofísicas interessantes como fotoestabilidade, emissão de fluorescência variável (dependendo dos ligantes, pH, temperatura e solvente), solvatocromismo e halocomismo. O estudo de compostos de coordenação formados por imidas naftálicas e metais de transição abre um leque interessante no que tange a pesquisa e desenvolvimento de novos materiais. Esta tese descreve a síntese da imida 4-amino-N-piridina-1,8-naftalimida (NF2), da diimida N,N\'-Bis-(4-piridil)piromelítica (DI1), a determinação dos valores de pKa (2,75 e 3,49), absortividade molar (3537 L.mol-1.cm-1), efeito solvatocrômico (positivo) e rendimento quântico (0,27) de NF2; absortividade molar (18246 L.mol-1.cm-1) e solvatocromismo negativo para DI1. Foram sintetizados compostos de coordenação entre o ligante DI1 e os íons Fe3+; Ru3+ e Co2+, porém a formação de complexos com o ligante NF2 não foi observada por meio das técnicas aplicadas / Naphthalic imides (INs) comprise a class of aromatic organic molecules generally derived from a naphthalic anhydride and primary amine. They are of great interest in the field of materials chemistry due to a number of physical and chemical properties, but mainly to their photophysical properties. Derivatives of INs are fluorescent compounds with several interesting photophysical properties such as photostability, variable fluorescence emission (depending on ligands, pH, temperature and solvent), solvatochromism and halochromism. The study of coordination compounds formed between naphthalic imides and transition metals opens up an interesting range of research and development of new materials. This thesis describes the synthesis of 4-amine-N-pyridine-1,8-naphthalimide (NF2) and N, N\'-Bis- (4-pyridyl) pyromellitic diimide (DI1) , measurement of pKa values (2.75 and 3.49), molar absorptivity (3537 L:mol1:cm1), solvatochromic e_ect (positive) and quantum yield (0.27) of NF2; Molar absorptivity (18246 L.mol-1.cm-1) and solvatochromic efect (negative) for DI1. Coordination compounds with DI1 and Fe3+; Ru3+ and Co2+ ions were synthesized; but complexes with NF2 was not observed by the applied techniques

Na montagem de um farol automobilístico são utilizados diversos materiais, tais como insertos metálicos nas fixações, vidros nas lâmpadas, materiais poliméricos nas lentes, carcaças, molduras, vedações e refletores, além de vernizes, tintas, película de metal para reflexão do feixe luminoso. Há cerca de quatro décadas foi iniciada a confecção dos refletores utilizando o BMC (bulk moulding compound), sigla em inglês para composto para moldagem em forma de massa, que é um compósito polimérico termofixo. Este material apresenta inúmeras vantagens sobre o metal, tal como forma e geometria que podem se integrar facilmente ao desenho do carro, elevada produtividade, baixo custo e da elevada resistência térmica. Contudo, apresentam o inconveniente de não poderem ser reciclados. Uma opção ao BMC tem sido o PEI [poli (éter imida)], que é um material polimérico termoplástico de alto desempenho que apresenta propriedades atrativas para essa utilização. Oferece também elevada produtividade, porém com um custo elevado se comparado ao BMC. Tem a vantagem de pode ser reciclado. De modo a analisar o potencial dos dois materiais e extrair deles suas vantagens competitivas, bem como determinar suas possíveis limitações, o presente trabalho apresenta os resultados de caracterização mecânica, análise térmica, ensaios de impacto, ensaios de temperatura de deflexão térmica (HDT) e reaproveitamento de resíduos de BMC, incorporando-o ao PVC [poli (cloreto de vinila)], resultando uma nova blenda polimérica. O estudo conclui que ambos os materiais podem ser utilizados para fabricação de refletores automobilísticos. No entanto, o preço do PEI é maior que o do BMC, o que desestimula sua utilização em produtos de alta escala de produção, como, por exemplo, o produto do presente trabalho. O BMC por sua vez não pode ser reciclado, exigindo um custo adicional para seu reaproveitamento de maneira a evitar seu descarte em aterro sanitário. / For assembly of an automobile headlight a lot of materials are used such as metallic inserts anchors, glass in the lamps, lens of polymeric materials, bezels, frames, fences and reflectors as well as paints, metallic sheet for reflection of the luminous beam. About four decades ago begun the manufacturing of BMC reflectors, which is a thermoset composite material. This material presents countless advantages on the metal, such as shape and geometry that can easily integrate the designing of cars, high productivity, low cost and high heat resistance. However, they have the disadvantage of not being able to be recycled. An option to the BMC has been the PEI [poly (ether imide)], which is a high performance polymeric thermoplastic material which brings attractive properties for the production of reflectors. It also offers high productivity, however with a high cost compared to BMC. It also has the advantage of being recycled. In order to analyze the potential of both materials and extract their competitive advantages, as well as determine their possible limitations, this study presents the results of mechanical characterization, thermal analysis, impact tests, tests on heat deflection temperature (HDT) and the reuse of BMC waste, incorporating it to PVC [poly (vinyl chloride)], resulting in a new polymeric blend. The study concludes that both materials can be used for manufacturing automobile reflectors. However, the price of PEI is higher than the one of BMC, which discourages their use in high-scale production products, as the one of this work. The BMC for your time can not be recycled, demanding an extra cost for their reuse, avoiding its disposal in landfill.

Na montagem de um farol automobilístico são utilizados diversos materiais, tais como insertos metálicos nas fixações, vidros nas lâmpadas, materiais poliméricos nas lentes, carcaças, molduras, vedações e refletores, além de vernizes, tintas, película de metal para reflexão do feixe luminoso. Há cerca de quatro décadas foi iniciada a confecção dos refletores utilizando o BMC (bulk moulding compound), sigla em inglês para composto para moldagem em forma de massa, que é um compósito polimérico termofixo. Este material apresenta inúmeras vantagens sobre o metal, tal como forma e geometria que podem se integrar facilmente ao desenho do carro, elevada produtividade, baixo custo e da elevada resistência térmica. Contudo, apresentam o inconveniente de não poderem ser reciclados. Uma opção ao BMC tem sido o PEI [poli (éter imida)], que é um material polimérico termoplástico de alto desempenho que apresenta propriedades atrativas para essa utilização. Oferece também elevada produtividade, porém com um custo elevado se comparado ao BMC. Tem a vantagem de pode ser reciclado. De modo a analisar o potencial dos dois materiais e extrair deles suas vantagens competitivas, bem como determinar suas possíveis limitações, o presente trabalho apresenta os resultados de caracterização mecânica, análise térmica, ensaios de impacto, ensaios de temperatura de deflexão térmica (HDT) e reaproveitamento de resíduos de BMC, incorporando-o ao PVC [poli (cloreto de vinila)], resultando uma nova blenda polimérica. O estudo conclui que ambos os materiais podem ser utilizados para fabricação de refletores automobilísticos. No entanto, o preço do PEI é maior que o do BMC, o que desestimula sua utilização em produtos de alta escala de produção, como, por exemplo, o produto do presente trabalho. O BMC por sua vez não pode ser reciclado, exigindo um custo adicional para seu reaproveitamento de maneira a evitar seu descarte em aterro sanitário. / For assembly of an automobile headlight a lot of materials are used such as metallic inserts anchors, glass in the lamps, lens of polymeric materials, bezels, frames, fences and reflectors as well as paints, metallic sheet for reflection of the luminous beam. About four decades ago begun the manufacturing of BMC reflectors, which is a thermoset composite material. This material presents countless advantages on the metal, such as shape and geometry that can easily integrate the designing of cars, high productivity, low cost and high heat resistance. However, they have the disadvantage of not being able to be recycled. An option to the BMC has been the PEI [poly (ether imide)], which is a high performance polymeric thermoplastic material which brings attractive properties for the production of reflectors. It also offers high productivity, however with a high cost compared to BMC. It also has the advantage of being recycled. In order to analyze the potential of both materials and extract their competitive advantages, as well as determine their possible limitations, this study presents the results of mechanical characterization, thermal analysis, impact tests, tests on heat deflection temperature (HDT) and the reuse of BMC waste, incorporating it to PVC [poly (vinyl chloride)], resulting in a new polymeric blend. The study concludes that both materials can be used for manufacturing automobile reflectors. However, the price of PEI is higher than the one of BMC, which discourages their use in high-scale production products, as the one of this work. The BMC for your time can not be recycled, demanding an extra cost for their reuse, avoiding its disposal in landfill.

The flexible substrate was fabricated by BaTi4O9 mixed with O-Cresol Novolac Epoxy, polyether imide or surface active agents. The electrical and physical characteristic measured had been finished. The dielectric property influence of substrate was changed from percentage of BaTi4O9. The dielectric constant model was used by Jayasundere and Smith equation (J. S. eq.) and Lichtenecker equation (L. eq.) The study of crystalline grain, orientation and phase transfer temperature was used by SEM, XRD, and DSC, respectively. The dielectric constant and dielectric loss tangent of the composite was measured using an HP4294A impedance analyzer. The TM mode calculated by resonate frequency of the composite was measured using an HP4156C network analyzer. The dielectric constant was obtained to TM mode at high frequency. The result was showed that dielectric constant at low frequency of BaTi4O9, OCN Epoxy and PEI are 57, 5.8 and 3.65, respectively. OCN Epoxy is better than PEI of electrical characteristic. However, OCN Epoxy is not flexible. For this reason, the PEI was focused on electrical property at high frequency. The BaTi4O9 exhibited a dielectric constant of 39 at frequency during 3~10 GHz. The dielectric constant was measured of 10 at frequency during 2~16 GHz with 70 wt% PEI composite. The dielectric constant is higher than FR-4 substrate to 6.4 of the composite. The low dielectric constant is obtaining to reduce stuffing.

Anthraquinone (AQ) derivatives with relatively high reduction potentials have been synthesized to afford good candidates for electron transfer studies in DNA. Electron withdrawing groups on the anthraquinone ring gave derivatives with less negative reduction potentials. The anthraquinone imide (AQI) derivatives had reduction potentials less negative than AQ derivatives. The AQI ring system was subject to base-induced hydrolysis. Water-soluble sulfonated tetraarylporphyrins have been studied in a wide variety of contexts. Herein, we report the first synthesis of a pentasulfonated porphyrin bearing an internal cyclic sulfone ring. Treatment of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS4) with fuming H2SO4 gave a structure consistent with initial sulfonation followed by dehydration to give a sulfone bridge between an ortho-position of one of the phenyl groups and a β-pyrrole position on the porphine ring (TPPS4Sc). The structure was established by ESI-MS and 1HNMR. The Soret absorption is red shifted by about 32 nm compared to that of TPPS4. Streptococcus pyogenes obtains iron by taking up heme from the environment during infection. One of the heme uptake pathways is the Sia or Hts pathway. The initial protein in this pathway is Shr, which has two heme-binding NEAT domains, NEAT1 nearer the N-terminus, and NEAT2 nearer the C-terminus. We report biophysical characteristics of these two NEAT domains. To assess stability of this domain towards heme release, denaturation studies of the Fe(II) and Fe(III) forms were performed. For each domain, both the Fe(II) and the Fe(III) forms behave similarly in thermal denaturation and guanidinium denaturation. Overall, NEAT2 is more stable than NEAT1. Spectral signatures, sequence alignment and homology modeling for both domains suggest that one of the axial ligands is methionine. NEAT2 autoreduces as the pH increases and autooxidizes as the pH decreases. Heme uptake from the host environment is the only iron acquisition pathway in S. pyogenes; inhibition of this pathway might be an approach to infection control. Compounds that might inhibit the heme uptake pathway were selected via virtual screening.

NONE.

No description available.

abstract: A lack of adequate energy storage technologies is arguably the greatest hindrance to a modern sustainable energy infrastructure. Chemical energy storage, in the form of batteries, is an obvious solution to the problem. Unfortunately, today’s state of the art battery technologies fail to meet the desired metrics for full scale electric grid and/or electric vehicle role out. Considerable effort from scientists and engineers has gone into the pursuit of battery chemistries theoretically capable of far outperforming leading technologies like Li-ion cells. For instance, an anode of the relatively abundant and cheap metal, magnesium, would boost the specific energy by over 4.6 times that of the current Li-ion anode (LiC6). The work presented here explores the compatibility of magnesium electrolytes in TFSI–-based ionic liquids with a Mg anode (TFSI = bis(trifluoromethylsulfonyl)imide). Correlations are made between the Mg2+ speciation conditions in bulk solutions (as determined via Raman spectroscopy) and the corresponding electrochemical behavior of the electrolytes. It was found that by creating specific chelating conditions, with an appropriate Mg salt, the desired electrochemical behavior could be obtained, i.e. reversible electrodeposition and dissolution. Removal of TFSI– contact ion pairs from the Mg2+ solvation shell was found to be essential for reversible electrodeposition. Ionic liquids with polyethylene glycol chains pendent from a parent pyrrolidinium cation were synthesized and used to create the necessary complexes with Mg2+, from Mg(BH4)2, so that reversible electrodeposition from a purely ionic liquid medium was achieved. The following document discusses findings from several electrochemical experiments on magnesium electrolytes in ionic liquids. Explanations for the failure of many of these systems to produce reversible Mg electrodeposition are provided. The key characteristics of ionic liquid systems that are capable of achieving reversible Mg electrodeposition are also given. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2016

As imidas naftálicas (INs) compõe uma classe de moléculas orgânicas aromáticas derivadas, geralmente, de um anidrido naftálico e uma amina primária. São de grande interesse na área de materiais devido a uma série de propriedades físicas e químicas, mas principalmente devido à suas propriedades fotofísicas. Derivados de INs são compostos fluorescentes com propriedades fotofísicas interessantes como fotoestabilidade, emissão de fluorescência variável (dependendo dos ligantes, pH, temperatura e solvente), solvatocromismo e halocomismo. O estudo de compostos de coordenação formados por imidas naftálicas e metais de transição abre um leque interessante no que tange a pesquisa e desenvolvimento de novos materiais. Esta tese descreve a síntese da imida 4-amino-N-piridina-1,8-naftalimida (NF2), da diimida N,N\'-Bis-(4-piridil)piromelítica (DI1), a determinação dos valores de pKa (2,75 e 3,49), absortividade molar (3537 L.mol-1.cm-1), efeito solvatocrômico (positivo) e rendimento quântico (0,27) de NF2; absortividade molar (18246 L.mol-1.cm-1) e solvatocromismo negativo para DI1. Foram sintetizados compostos de coordenação entre o ligante DI1 e os íons Fe3+; Ru3+ e Co2+, porém a formação de complexos com o ligante NF2 não foi observada por meio das técnicas aplicadas / Naphthalic imides (INs) comprise a class of aromatic organic molecules generally derived from a naphthalic anhydride and primary amine. They are of great interest in the field of materials chemistry due to a number of physical and chemical properties, but mainly to their photophysical properties. Derivatives of INs are fluorescent compounds with several interesting photophysical properties such as photostability, variable fluorescence emission (depending on ligands, pH, temperature and solvent), solvatochromism and halochromism. The study of coordination compounds formed between naphthalic imides and transition metals opens up an interesting range of research and development of new materials. This thesis describes the synthesis of 4-amine-N-pyridine-1,8-naphthalimide (NF2) and N, N\'-Bis- (4-pyridyl) pyromellitic diimide (DI1) , measurement of pKa values (2.75 and 3.49), molar absorptivity (3537 L:mol1:cm1), solvatochromic e_ect (positive) and quantum yield (0.27) of NF2; Molar absorptivity (18246 L.mol-1.cm-1) and solvatochromic efect (negative) for DI1. Coordination compounds with DI1 and Fe3+; Ru3+ and Co2+ ions were synthesized; but complexes with NF2 was not observed by the applied techniques

Nesse trabalho obtiveram-se membranas de poli(imida) ramifricada com tamanho de poro ajustável usando melamina como agente de ramificação e indutor da formação de poros. Estas poli(imidas) foram sulfonadas usando-se ácido sulfúrico concentrado eficazmente. Finalmente, obtivemos membranas de carbono molecular por pirólise sob atmosfera inerte das poli(imidas) ramificadas. Estas membranas apresentam canais micrométricos paralelos à superfície e uma estrutura assimétrica constituída de uma camada densa filtrante e uma camada com canais micrométricos paralelos à superfície altamente ordenados. A membrana apresentou boa estabilidade química frente ao ataque por radicais hidroxila gerados via reação de Fenton. / In this work was obtained branched poly(imides) with tuned pore size using melamine as branching and pore induction agent. The poly(imides) with were efficiently sulfonated with concentrated sulfuric acid. Finally, the molecular sieve carbon membranes were obtained by pyrolysis under inert atmosphere of the branched poly(imides). These membranes have an asymmetric structure with a dense filtering layer and a porous layer with highly ordered channels standing parallel to the surface. These membranes display good chemical stability toward hydroxyl radical attack produced by Fenton reaction.