Mestrado em Química
URI Permanente para esta coleção
Nível: Mestrado Acadêmico
Ano de início: 2006
Conceito atual na CAPES: 5
Ato normativo: Homologação da 85ª Reunião do CTC-ES, Parecer CNE/CES nº 163/2005.
Processo nº 23001.000081/2005-56 do Ministério da Educação.
Publicado no DOU 28/07/2005, seção 1, página 11)
Periodicidade de seleção: Anual
Área(s) de concentração: Química
Url do curso: https://quimica.vitoria.ufes.br/pt-br/pos-graduacao/PPGQ/detalhes-do-curso?id=954
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Submissões Recentes
- ItemEfeito dos substituintes p-fenil nas propriedades luminescentes de novos complexos de európio(III) e gadolínio(III) com hidrazidas(Universidade Federal do Espírito Santo, 2019-05-17) Brandão, Samira Gomes; Luz, Priscilla Paiva; Borges, Alex dos Santos; Ribeiro, Marcos AntonioNew lanthanides (Eu3+ and Gd3+) complexes with hydrazides were successfully synthesized and the effect of the p-phenyl substituent on the Eu3+ luminescent properties was evaluated. Crystals of Gd-amino was obtained and its structure was elucidated by single-crystal X-ray diffraction, revealing Gd3+ centered in a distorted tricapped trigonal-prismatic molecular geometry. IR spectroscopy and the elucidated structure confirmed hydrazides acting as bidentate ligands binding to Ln3+ ions through the oxygen of carbonyl group and the nitrogen of terminal amine, forming a five-membered ring. The CHN indicated the molecular formulas [Gd(amino)4(H2O)](NO3)3·(C2H5OH) and [Eu(toluic)3(H2O)3](NO3)3, the Gd3+ complex had its structure also confirmed by X-ray diffraction in single crystal. Lower T1 state energies were observed for ligands p-substituted with higher electron donating capacity groups and higher oscillator strength, such as p-OH and p-NH2. In contrast, higher lifetimes and quantum efficiencies were obtained for Eu-complexes with p-H and p-CH3 substituents, which are not deactivator groups and weaker oscillators.
- ItemSíntese e docking de novas 2-amino-4-fenil-pirimidinas substituídas no C6 por carbono/heterociclos aromáticos com potencial atividade biológica(Universidade Federal do Espírito Santo, 2019-04-01) Pina, Jorge Welton de Souza; Greco, Sandro José; Taranto, Alex Gutterres; Kuster, Ricardo MachadoCurrently, the synthesis of organic compounds represents a significant part in the process of discovery and development of new bioactive compounds. Among this range highlightthe pyrimidine ring, one of the key substances that sustain life as coenzymes, vitamins and nucleic acids. Over the last few decades, studies have reported on ways to synthesize corethat mimic functions and cells in our body to facilitate the interaction of these potential drugs with the affected cells. Further discussions are focusedon the pyrimidine coregiven their familiarity with our organism. Based on this it was aimed to synthesize and characterize new C6 substituted 2-amino-4-phenyl-pyrimidines by carbo/heterocycles in order to evaluate possible antiviral, anti-inflammatory and anticancer activities. In this studythe phenyl-triazole aldehyde was synthesized in a three-stepsequence with considerable yields. This aldehyde and other carbo / heterocycles were then used to synthesize substituted chalcones by the classical Claisen-Schimidt condensation methodology which served as a starting material in the synthesis of the desired molecules. Pyrimidine structures were synthesized through the multicomponent reaction of Biginelli and the Biginelli reaction modified by Atwal. Yields were considerable, ranging from 20-82% for pyrimidine synthesis. Molecular anchorage studies show great potentials for antiviral and anticancer activities. Pyrimidines 123a and 123c presented better performance among the synthesized molecules, and all the synthesized pyrimidines obtained values of receptor/ligand interaction energy at the most significant binding site when compared to control crystallographic structures for the proteins studied. In addition, two new crystallographic structures for pyrimidines 118and 121can be reported confirming and defining the structural position of each atom ofthese cores. All the pyrimidine structures synthesized presented relevant results through the molecular anchorage study for the proposed biological activities, thus showing a potential probability of inhibition of these sites.
- ItemUso da RMN no estudo da despolimerização de poliuretano rígido(Universidade Federal do Espírito Santo, 2019-03-26) Maioli, Juliana Proliciano; SILVA FILHO, Eloi Alves da; Cunha Neto, Álvaro; Freitas, Marcos Benedito José Geraldo de; Almeida, Luiz Carlos PimentelPolyurethanes (PUs) have been widely used in several trade sections. Thereby, large amounts of waste are produced and need to be correctly disposed off. Research on this theme has been helping industries to apply recycling processes that are cheap and efficient. In this work, the glycolysis of a rigid PU was performed using different catalysts. The catalysts used was: a tensoactive (CTAB), the NaOH, two ionics liquids (1-butyl-3-methylimidazole trichloromanganate and 1-butyl-3-methylimidazole trichlorozincate), and four Niobium salts (niobium pentoxide, niobium oxidehydrated, niobium pentachloride and niobium ammoniacal oxalate). 1H NMR technique was used to obtain the rate of PU depolymerization. Also was used the technique diffusion ordered spectroscopy 1H NMR (DOSY-NMR) that assisted in the identification composition of the mixture of products. In the glycolysis, glycerol (GCL) and diethylene glycol (DEG) were tested as glycolysis agents. The PU was synthesized to be free of additives in the depolymerization process, and its characterization was performed using infrared spectroscopy (FTIR) and 1H NMR spectroscopy analyses. The conversion rate provides information about which catalyst has the better catalytic activity. The use of NaOH as a catalyst presented conversion rate of 100 % in 30 min of reaction, as is already known in the literature, and the DOSY-NMR spectrum provided information about products that didn’t perceptible only by 1H NMR spectrum. Ionic liquids (LIs) as catalysts, presented conversion near of 80 % in 1h of reaction, which can be improved by modifying the reaction conditions. To determine the composition of the mixture of products in the depolymerization reaction, diffusion ordered spectroscopy 1H NMR (DOSY-NMR) was used. The Niobium salts had non-catalytic behavior, because they showed conversion rate lower than uncatalyzed reaction. DOSY-NMR indicated a complex mixture of reaction by-products, differently from the 1H NMR data, which indicated the formation of a simple diamine-terminated by-product.
- ItemSíntese de novo composto imínico com atividade antioxidante e anticorrosiva aplicado em biodiesel de soja(Universidade Federal do Espírito Santo, 2019-05-14) Martins, Lucas Ferreira; Silveira, Vivian Chagas da; Lacerda Junior, Valdemar; Romão, Wanderson; Aquije, Glória Maria de Farias Viégas; Santos, Reginaldo Bezerra dosBiodiesel is a renewable biofuel produced from transesterification of vegetable oils and animal fats with short-chain alcohols. Despite being environmentally friendly, biodiesel has low oxidative stability and is gradually degraded by autooxidation reactions. Furthmore, metallic structures are corroded whenimmersed in biodiesel, for being a higher electric conductive (compared with petro diesel) and hygroscopic medium. To rise oxidative stability and not damage fuel engines and storage tanks, antioxidants (reduce catalytic radical reactions) and corrosion inhibitors (adsorbs on metallic surface) are added in biodiesel. In this dissertation are discussed the synthesis of the new phenolic-iminic compound N,N’-bis-(4-hexadecanoate)salicylidene-ethylenedimaine,named IM, to play as multifunctional molecule, exhibiting antioxidative and corrosion inhibition activity. IM reduced carbon steel AISI 1020 coupons immersed in biodiesel, at room temperature and under heating and showed better results than commercial compounds butylated hydroxytoluene (BHT), tert-butylhydroquinone (TBHQ) and pyrogallol (PY). IM also increased oxidative stability of biodiesel contaminated with cooper ions, working as metal chelator, and reduced dissolved oxygen in biodiesel, working as oxygen scavenger. Corrosion was evaluated by light microscopy, scanning electron microscopy and atomic force microscopy. Oxidative stability tests were made by PetroOXY method
- ItemExtração de elementos traços da água do mar por coprecipitaçao e determinação por ICP-MS(Universidade Federal do Espírito Santo, 2019-03-29) Conceição, Vitor Nunes da; Lima, Maria Tereza Weitzel Dias Carneiro; Ribeiro, Araceli Verónica Flores Nardy; Athayde, Geisamanda Pedrini BrandãoThe quality of the oceans has been constantly changing at different scales, as a consequence of natural and mainly anthropic factors. The industrial, mining and agricultural activities have contributed significantly to the increase of trace element concentration in marine environments, impacting directly on its ecosystem and public health. In view of the above, the determination and monitoring of trace elements insea water is of great importance. Inductively coupled plasma mass spectrometry (ICP-MS) is widely used for the determination of trace elements in sea water, however, there is a great challenge because the salt matrix is considered complex, causing numerous spectral and non-spectral Thus, it is necessary to study trace element extraction methodologies in this matrix. In this sense, the present work initially aimed at the determination of As, Cr, Cu, Mn and Pb in sea water by ICP-MS in the standard mode (without reaction cell and collision) after the precipitation of the present Mg2+ion in the seawater with ammonia, forming Mg(OH)2, and coprecipitation of some trace elements. Multivariate statistical tools such as central composite planning, desirability function and response surface methodology were used to optimize the coprecipitation procedure. The optimal values obtained for 45 mL of sample were 1200 µL of concentrated aqueous ammonia, 30 minutes of centrifugation time and 400 µL of concentrated nitric acid. After the optimization, extraction tests were performed with other trace elements with coprecipitation, where good results were obtained for Co, thus, the element was included in the following studies. The obtained procedure had low detection limits in the sample (0.02 to 3.71 ng L-1), since good preconcentration factors were obtained. Accuracy of the method was verified by Trace Metals 1 certified reference material in seawater analyzes and the recovery percentage test (60.5 to 105.8%). Thus, the proposed procedure can be considered a good strategy for the determination of As, Co, Cr, Cu, Mn and Pb in sea water by ICP-MS, due to its simplicity and low cost, besides the good sensitivity and accuracyachieved.