Solvent
Mostrando 1-12 de 2730 artigos, teses e dissertações.
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1. Bimetallic Au-Pd/α-MoO3 Catalyst with High Oxygen Vacancies for Selective Oxidation of Cinnamyl Alcohol
Supported Au-Pd nanoparticles (NPs) have been extensively studied in alcohol oxidation reactions. However, few studies use reducible metal oxides as support, which can activate oxygen molecules and boost the selectivity of the reaction. In this work, Au-Pd NPs were supported on α-MoO3 and evaluated in the selective oxidation of cinnamyl alcohol without solv
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. GRAPHEN-PHENYL-NH2 AS NANOCARRIER: A DENSITY FUNCTIONAL THEORY STUDY
Recently, graphene and modified graphene as one of the most suitable and the most important carbon nanomaterials have been introduced for drug delivery. In this paper, we have studied the binding characteristics of the EDC-NHS cross-linking process of graphene-phenyl-NH2 and 5-aminolevulinic acid (ALA) drug in both gas and solvent phases by density functiona
Química Nova. Publicado em: 2022
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3. Temperature Dependent Emission Properties of ReI Tricarbonyl Complexes with Dipyrido-Quinoxaline and Phenazine Ligands
In this work, the emission properties of fac-[Re(CO)3(NN)(py)]+, NN = 1,10-phenanthroline (phen), dipyrido[3,2-f:2’,3’-h]quinoxaline (dpq) and dipyrido[3,2-a:2’3’-c]phenazine (dppz); py = pyridine were investigated in different temperatures, ranging from 80 to 300 K, and in different solvent mixtures and in polymethyl methacrylate. The changes observ
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. A New Synthetic Route and Comprehensive Topological Study of a Benzimidazole Derivative
Benzimidazole and its derivatives are molecules that have diverse biological properties, therefore we synthesized and studied a new benzimidazole to understand their physical/chemical properties. The compound was obtained through a new synthetic route, using graphite oxide, in the absence of solvent, with crystalline packaging supported by C-H…N and C-H…
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Supercritical Carbon Dioxide Effect on Lipase-Catalyzed Geranyl Acetate Synthesis
This work provides a general insight on lipase-catalyzed synthesis of geranyl acetate through esterification of geraniol with acetic acid. Although this reaction is relatively well known, the replacement of organic solvents by supercritical fluids is fairly recent and the role of CO2 is still not completely understood. Therefore, reactions were performed wit
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. Sustainable and Reusable Sulfonic Acid-Functionalized Task-Specific Ionic Liquid Catalysts for Multicomponent Reactions. A Review
Improvements in Sustainable Organic Synthesis are usually related to the investigation of less hazardous, non-corrosive and renewable materials, as well as waste prevention, energy efficiency, solvent-free reactions, and the development of efficient reusable catalysts. In this context, multicomponent reactions emerged as important strategies for the rapid an
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. SUPERCRITICAL EXTRACTION OF LYOPHILIZED STRAWBERRY ANTHOCYANINS WITH PULSED ELECTRIC FIELDS PRETREATMENT
The lyophilized strawberry anthocyanins were extracted using a supercritical extraction (SE) process. The effect of pulsed electric fields (PEF) as pretreatment and the influence of the addition of ethanol as a cosolvent on the percentage of extraction yield (EY) and the total anthocyanin concentration (TAC) were analyzed. The effect of PEF was evaluated at
Química Nova. Publicado em: 2022
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8. DESENVOLVIMENTO DE ACESSÓRIO PORTÁTIL DE CONTROLE DE TEMPERATURA PARA MEDIDAS ESPECTROSCÓPICAS
Temperature is a natural phenomenon that may modify the structure of chemical compounds and hence their properties. We aimed to develop a simple portable system based on the Peltier principle for spectral characterization of compounds with temperature-dependent structure. The device was constructed and adapted to three pieces of equipment: X-ray diffractomet
Química Nova. Publicado em: 2022
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9. Development of a Disposable Pipette Extraction Method Using Coffee Silverskin as an Adsorbent for Chromium Determination in Wastewater Samples by Solid Phase Extraction
A procedure using disposable pipette tips adapted for solid-phase extraction, known as DPX SPE, was used as an alternative way for the chromium determination in wastewater samples. DPX-SPE consists of a device which allows a dynamic contact between the sample and the solid-phase. A residue obtained from the processing of coffee beans, denominate coffee silve
Journal of the Brazilian Chemical Society. Publicado em: 2022
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10. A New Approach for Histamine Functionalized Nanoparticles as Sorbent Phase for Bar Adsorptive Microextraction (BAµE) and Determination of Parabens in Water by HPLC-DAD
In this study, for the first time, histamine-functionalized magnetic nanoparticles (HIS-MNP) were used as sorbent phase combined with bar adsorptive microextraction (BAµE) for the determination of methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) in water samples by high performance liquid chromatography coupled with diode arr
Journal of the Brazilian Chemical Society. Publicado em: 2022
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11. What is new in non-chromatographic flavonoid purification?
Flavonoids are metabolites occurring in all plant tissues and present different biological activities. They occur in a mixture of similar polarity with laborious separation and purification processes, usually furnishing low yields. Semi-preparative chromatographic methods are universally employed procedures for their isolation. This paper discusses the state
Química Nova. Publicado em: 2022
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12. Development and application of a test mixture for untargeted liquid chromatography-mass spectrometry analysis of urine samples
Metabolic profiling of complex biological matrices based on liquid chromatography-mass spectrometry (LC-MS) allows detecting a wide range of metabolites with distinct concentrations and physicochemical properties. Given the complexity of samples and the necessity of a comprehensive approach in untargeted metabolomics, quality control strategies are mandatory
Química Nova. Publicado em: 2022