Preparação de catalisadores por meio da imobilização de metalopofirinas e enzimas em hidróxidos duplos lamelares para reações catalíticas únicas e sequenciais

Orientadora: Profa. Dra. Shirley NakagakiCoorientador: Prof. Dr. Fernando WypychTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Química. Defesa: Curitiba, 29/03/2019Inclui referênciasResumo: Foram sintetizados sólidos de core shell de HDL e sílica a fim de averiguar uma possível interferência na morfologia do suporte de uma manganês porfirina na oxidação de substratos orgânicos como cicloocteno e cicloexano. Foram realizadas diversas sínteses para tentar distribuir homogêneamente às partículas de HDL sobre a esfera de sílica. Os sólidos foram caracterizados por diferentes técnicas e após essas caracterizações, o sólido que se assemelhou mais com a condição proposta, foi utilizado como suporte para a imobilização da [Mn(TDFSPP)]-MnP. e posteriormente foi avaliado como catalisador de processos heterogêneos frente a reações de oxidação do cicloocteno e cicloexano. Os sólidos demonstraram atividade catalítica para as reações de oxidação, e elevada seletividade para a produção cicloexanol quando o substrato empregado foi o cicloexano. Observou-se que para o sólido com a distribuição do HDL na sílica, têm-se rendimentos de reação superiores frente ao sólido que continha somente a MnP imobilizada no HDL. Outro objetivo dessa tese foi sintetizar um sólido HDL Zn/Al para posterior imobilização da MnP e da enzima GOD (no mesmo HDL) para produzir um sólido capaz de realizar uma reação sequencial. A reação sequencial proposta envolve a oxidação da glucose usando a enzima como catalisador da etapa 1. Nessa etapa, há a produção de H2O2 e esse deve atuar como oxidante para a etapa 2, que é a oxidação do cicloocteno pela MnP para produzir o epóxido correspondente. Foram feitos diversos teste com relação ao preparo do sólido GOD/HDL na tentativa de otimizar os rendimentos obtidos na atividade enzimática. Foram investigados diferentes condições experimentais tais como o modo de preparo (adsorção/ aprisionamento) e sensibilidade frente a diferentes % de solvente orgânico no meio de reação. Observou-se que os rendimentos da reação de oxidação do cicloocteno utilizando os catalisadores sólidos preparados com GOD e MnP trata-se de uma reação sequencial. Tais resultados foram promissores e, ainda que sob condições preliminares, o emprego catalítico das metaloporfirinas e da enzima GOD no suporte de HDL pode ser melhor investigado.Abstract: HDL and silica core shell solids were synthesized to investigate possible interference in the morphology of the support of a manganese porphyrin in the oxidation of organic substrates such as cyclooctene and cyclohexane. Several syntheses were performed to try to distribute homogeneously the LDH particles on the silica sphere. The solids were characterized by different techniques and after these characterizations the solid that most resembled the proposed condition was used as support for the immobilization of [Mn (TDFSPP)] - MnP. and was subsequently evaluated as a catalyst for heterogeneous processes of oxidation reactions of cyclooctene and cyclohexane. The solid showed catalytic activity for oxidation reactions, and high selectivity for cyclohexanol production when the substrate used was cyclohexane. It was observed that for the solid core shell, higher yields of reaction were obtained versus the solid containing only the MnP immobilized on LDH. Another objective of this thesis was to synthesize a solid of Zn/Al LDH for subsequent immobilization of MnP and the GOD enzyme (in the same LDH) to produce a solid to performing a sequential reaction. The proposed sequential reaction involves the oxidation of glucose using the GOD enzyme as the catalyst of step 1. At this step, there is the production of H2O2 and this should act as oxidant for step 2, for the oxidation of the cyclooctene by MnP to produce the corresponding epoxide. Several tests were carried out regarding the preparation of the GOD/HDL solid in an attempt to optimize the yields obtained in the enzymatic activity. Many experimental conditions such as the preparation (adsorption / entrapment) and sensitivity to different % of organic solvent in the reaction medium were investigated. It was observed that the yields of the cyclooctene oxidation reaction using the solid catalysts prepared with GOD and MnP is a sequential reaction. This results were promising and, under preliminary conditions, the catalytic use of the metalloporphyrins and the GOD enzyme on the LDH support can be investigated

Preparação de sólidos por meio da imobilização de metaloporfirinas em hidróxidos duplos lamelares (HDL) : estudo sistemático da influência da composição do HDL nos processos de imobilização e na atividade catalítica

Orientadora : Profª Drª Shirley NakagakiCo-orientador : Prof. Dr. Fernando WypychDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Química. Defesa: Curitiba, 02/03/2015Inclui referências : f. 70-74Área de concentração: Química inorgânicaResumo: O uso de metaloporfirinas com a finalidade de catalisar reações de oxidação tem sido explorado pela academia e estudos recentes revelaram que a imobilização de metaloporfirinas em suportes inorgânicos, tais como os hidróxidos duplos lamelares - HDL - tem levado a catalisadores eficientes na oxidação de hidrocarbonetos. Essa imobilização evita a desativação das espécies porfirínicas cataliticamente ativas, inibindo a sua destruição e/ou aglomeração, auxiliando no re-uso do catalisador. Pesquisas envolvendo suportes de espécies catalíticas despertam interesse, visto que resultados preliminares indicam a sua influência no desempenho catalítico de reações de oxidação de substratos orgânicos. Neste trabalho é relatado o uso catalítico em reação de oxidação, de sólidos preparados pela heterogenização da manganês porfirina, 5,10,15,20-tetrakis-2,6-difluor-3-sulfonatofenil porfirina manganês(III) (MP1) em diferentes hidróxidos duplos lamelares preparados a partir de sais de magnésio ou zinco (M2+) e alumínio (M3+) em diferentes proporções em quantidade de matéria e diferentes íons intercalantes averiguando a influência do suporte no desempenho catalítico. A preparação dos suportes HDL foi realizada a partir da metodologia de co-preciptação em pH crescente utilizando sais de Al(NO3)3, Zn(NO3)2 ou Mg(NO3)2, em diferentes proporções em quantidade de matéria dos metais (M+2:M+3) da ordem de 2:1, 3:1 e 4:1 e diferentes íons intercalantes (CO32- e NO31-). Por meio de diferentes métodos de caracterização, foi observado que no processo de imobilização da MP1 nos suportes HDL não houve a intercalação da MP1 no espaço interlamelar do HDL, sendo o complexo imobilizado provavelmente superficialmente às lamelas. Os sólidos provenientes da heterogenização da MP1 no HDL (MP1-HDLX) foram investigados como catalisadores na reação de oxidação de cicloocteno ao epóxido por iodosilbenzeno. Na reação utilizando a MP1 em solução (catálise homogênea) foi obtido 76% de rendimento do epóxido. Quando utilizado como catalisador o sólido MP1-HDLX, obteve-se resultados na faixa de 50 à 77% de rendimento, sugerindo que dependendo do HDL (variação de x) preparado a interação com a MP levou a sistemas catalíticos diferentes. Observou-se melhores rendimentos quando a MP1 foi imobilizada em suportes contendo Zn2+. Isto pode estar associado ao tamanho do raio iônico dos metais di valentes usados (Mg2+ e Zn2+). Com o aumento do raio iônico, supõem-se que as porfirinas estejam mais afastadas entre si, pois a distância entre as cargas positivas da lamela seria maior. Palavras chave: porfirina, oxidação, HDL, catálise heterogênea, manganês.Abstract: In the last 30 years the use of metalloporphyrins as catalyst for oxidation reactions has been explored by the academy research and recent studies revealed that the immobilization of metalloporphyrins on inorganic supports, such as layered double hydroxide (LDH), has shown efficient catalyst for hydrocarbons oxidation. The immobilization prevents the deactivation of porphyrin species catalytically active, inhibiting the self-destruction and agglomeration, supporting the re-use of the catalyst. Research involving support of catalytic species are interesting, as preliminary results have been indicate that the support present some influence in the catalytic performance of organic substrates oxidation reactions. This work, report the use of catalytic solids for oxidation reaction prepared by the heterogenization of the manganese porphyrin, 5,10,15,20-tetrakis-2,6-difluoro-3-sulfonate phenyl porphyrin manganese(III) (MP1) in different layered double hydroxides (LDH) prepared from magnesium or zinc salts (M2 +) and aluminum (M3 +) in different molar ratio conditions (4: 1, 3: 1, 2: 1) with different intercalating ions (CO32- and NO31-) in order to investigate the influence of the support on the catalytic performance of the resulted solid. The preparation of the LDH supports was made from the adaptation of the co-precipitation methodology at crescent pH conditions using Al (NO3) 3, Zn (NO3) 2 or Mg (NO3) 2 salts in different molar ratio of the amount of metal (M2+: M3+, 2: 1, 3: 1 and 4: ) and different intercalating ions (CO32- and NO31-). By using different characterization methods, it was observed that in the process of MP1 immobilization in the different supports LDH there was no intercalation of MP1 in the interlayer space of LDH, and probably the complex was immobilized on the layer surface of the LDH support. The solids resulted from the heterogenization process using the diferent LDH solids were investigated as catalysts in the oxidation reaction of cyclooctene to the correspondent epoxide by the iodosylbenzene. In the reaction using the MP1 in solution (homogeneous catalysis) it was obtained 76% yield of epoxide. When they were used the solid catalysts resulted by the immobilization process MP1-HDLX, the catalytic results ranging from 50 to 77% epoxide yield, suggesting that depending on the interaction of HDL prepared with MP, different catalyst systems were obtained. Best catalytic yields were observed when the MP1 was immobilized on LDH supports containing Zn2 + as M2+ ion. This fact may be associated with the size of the ionic radius of the divalent metal used (Mg2 + and Zn2 +): increasing the ionic radius, it is assume that the manganese porphyrin molecules are more distant from each other, because the distance between the positive charges of the layered on the LDH would be greater. Key words; porphyrin, oxidation, LDH, heterogeneous catalysis, manganese

Nb2O5/SBA-15 catalyzed propanoic acid esterification

A family of niobia (Nb2O5) functionalized SBA-15 solid catalysts have been prepared via wet impregnation with NbCl5 (2–32 wt% Nb) and subsequent thermal processing, for application in the acid catalyzed esterification of propanoic acid with methanol. Bulk and surface physicochemical characterization revealed that highly dispersed niobia species present at low loadings when calcined at 500 °C exhibit strong Brönsted acid character and associated activity for esterification. Increased calcination temperatures are found to result in a decrease in Brönsted:Lewis acid ratio associated with recrystallization of the niobia phase leading to a loss of catalyst activity. Esterification activity is found to be directly proportional to Brönsted:Lewis acid ratio, with the 2 wt% Nb/SBA-15 catalyst pre-calcined at 500 °C found to exhibit highest activity and excellent reusability without deactivation

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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