Interconversion
Mostrando 1-12 de 332 artigos, teses e dissertações.
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1. INSIGHT INTO THE CONFORMATIONAL SPACE OF N-BENZYL-N-(FURAN-2-YLMETHYL)ACETAMIDE BY NMR SPECTROSCOPY AND DFT CALCULATIONS
In this study, the conformational behavior of N-benzyl-N-(furan-2-ylmethyl) acetamide in chloroform was addressed by using a combined experimental/theoretical strategy using NMR spectroscopy and quantum chemical calculations. The 1H and 13C one-dimensional NMR spectra, as well as the two-dimensional HSQC-DEPT and HMBC-DEPT NMR spectra, evinced the presence o
Quím. Nova. Publicado em: 2021-01
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2. CHROMATOGRAPHIC INVESTIGATION OF RUTHENIUM NITROSYL COMPLEX: NO INTERCONVERSION AND REACTIONS WITH BIOLOGICAL REDUCTANTS
One experimental strategy to prepare a nitrosyl metal complex is based on the acid-base conversion of NO2- into NO+. Here, we employed UV-vis absorption and FTIR spectroscopies to investigate the reaction of cis-[Ru(NO2)(bpy)2(imN)]PF6 with H3O+, which produced cis-[Ru(NO)(bpy)2(imN)](PF6)3 complex. Chromatographic studies were carried out and showed that im
Quím. Nova. Publicado em: 2018-04
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3. Computational Study of Electronic Effects from β-Substituents on the Tautomerism of Naphthazarin Derivatives
In this work, semi-empirical AM1 and DFT B3LYP/6-31G** calculations were applied in the study of the interconversion among tautomers of several naphthazarin and 5-amino-8-hydroxy-1,4-naphthoquinone β-substituted derivatives bearing electron-donor or electron-withdrawing groups. Using a semi-empirical method, detailed potential energy landscapes for proton t
J. Braz. Chem. Soc.. Publicado em: 2017-04
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4. Phaeophytins from Thyrsacanthus ramosissimus Moric. with inhibitory activity on human dna topoisomerase II-α
Our study reports the extraction and isolation of a new phaeophytin derivative 15¹-hydroxy-(15¹-S)-porphyrinolactone, designated anamariaine (1) herein, isolated from the chloroform fraction of aerial parts of Thyrsacanthus ramosissimus Moric. along with the known 15¹-ethoxy-(15¹-S)-porphyrinolactone (2). These compounds were identified by usual spectros
Quím. Nova. Publicado em: 2012
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5. Especiação, quantificação, distribuição e transporte de mercúrio em solos contaminados do município de Descoberto, Minas Gerais
In 2002, the blooming of metallic mercury in an area of the soil of Descoberto was observed. Municipal and state health representatives, besides research centers, performed several actions to evaluate the situation and guarantee the populations safety. The obtained results for soil superficial layer indicated Hg concentrations above the level in which there
Publicado em: 2010
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6. CaracterizaÃÃo ViscoelÃstica Linear de Misturas AsfÃlticas: OperacionalizaÃÃo Computacional e AnÃlise pelo MÃtodo dos Elementos Finitos / Linear Viscoelastic Characterization of Asphalt Mixes: Computational Operationalization and Analysis using the Finite Element Method
Uma mistura asfÃltica apresenta um comportamento mecÃnico complexo que pode ser idealizado por um modelo viscoelastoplÃstico, que considera a existÃncia de deformaÃÃes recuperÃveis (elÃstico e viscoelÃstico) e nÃo recuperÃveis (plÃstico e viscoplÃstico). No entanto, o estado da arte da pesquisa brasileira tem considerado um modelo mais restrito,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/12/2009
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7. Analysis of experiments involving Chemistry in science teaching textbooks for 1st to 4th grades of elementary school evaluated by PNLD - 2007 / Análise de experimentos que envolvem química presentes nos livros didáticos de ciências de 1ª a 4ª séries do ensino fundamental avaliados no PNLD/2007
This work analyses experiments dealing with chemical transformations proposed in science teaching textbooks for 1st to 4th grades of elementary school. The textbooks chosen were that evaluated in the Brazilian Program of Textbooks (Programa Nacional do Livro Didático) - PNLD/2007. The analysis emphasizes the characterization of the textbooks as didactic res
Publicado em: 2009
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8. Optically induced valence tautomeric interconversion in cobalt dioxolene complexes
A descoberta de que vários complexos de cobalto-dioxoleno exibem bi-estabilidade magnética foto induzida foi descrita recentemente. Este fenômeno encontra-se sempre associado a processos de interconversão de tautômeros de valência entre espécies de cobalto(III) baixo spin e de cobalto(II) alto spin. Enfatiza-se, nesta revisão, a forte correlação fo
Journal of the Brazilian Chemical Society. Publicado em: 2006-12
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9. Uso da reação de Baylis-Hillman : sintese assimetrica do efaroxan e analogos / The Baylis-Hillman reaction : assymetric synthesis of efaroxan and derivates
tes melitus é uma patologia que acomete milhões de pessoas em todo o mundo e aproximadamente 4% da população brasileira. Alguns fármacos são disponibilizados no mercado para o tratamento dessa doença, como as sulfoniluréias e as biguanidas, porém apresentam uma série de problemas com o uso prolongado, e várias contra-indicações assim como efeito
Publicado em: 2006
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10. The solid-state and solution-state reassigned structures of tagitinin A, a 3,10-epoxy-germacrolide from Tithonia diversifolia, and the interconversion of 3,10-epoxy-germacrolide conformational families via a ring-atom flip mechanism
Tagitinina A(2), uma 3,10-epoxi-germacrolida-6,7-trans-lactona conhecida e isolada de Tithonia diversifolia foi estudada através de difração de raios-X de monocristal. Verificou-se que a mesma apresenta a configuração relativa 1beta,4alfa,6alfa,7beta,8beta que difere da orientação 1alfa em C(1) proposta originalmente na literatura e que foi determinad
Journal of the Brazilian Chemical Society. Publicado em: 2005-06
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11. Clonagem do cDNA que codifica a enzima UDP-glicose pirofosforilase de batata (Solanum tuberosum L.). / Cloning of cdna encoding potato (Solanum tuberosum L.) udp-glucose pyrophosphorylase.
Biotechnology is revolutionazing human activity in several fields. In forestry, new technologies like transgenies, genomics, proteomics and bioinformatics have been quickly consolidated. Assossiating these technologies with conventional forestry breeding will accelerate the process of obtaining new trees with specific wood properties for the paper and pulp i
Publicado em: 2004
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12. A semiempirical study of the conformational behavior of cinchonidine and its interaction with methyl pyruvate
Hydrogenation of methyl pyruvate on a palladium or platinum surface in the presence of cinchona alkaloids leads to a high degree of enantiodifferentiation. In the present study, the semiempirical AM1 and PM3 methods are employed to perform a detailed analysis of the conformational behavior of cinchonidine and to study its interaction with methyl pyruvate. Ni
Brazilian Journal of Chemical Engineering. Publicado em: 2001-09