Electronic Spectroscopy
Mostrando 1-12 de 297 artigos, teses e dissertações.
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1. CLOROFILA EXTRAÍDA DE RESÍDUO INDUSTRIAL DA ERVA-MATE (Ilex paraguaiensis) UMA POSSIBILIDADE DE ECONOMIA CIRCULAR
Chlorophyll is the most abundant green pigment on the planet, it is unstable and decomposes naturally. Mate-herb is a traditional native plant in the southern region of South America, and its tea is part of the local culture and extractive agriculture. The mate-herb industry generates as a by-product a resinous material rich in chlorophyll whose use is propo
Química Nova. Publicado em: 2022
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2. EFFECT OF REACTION CONDITIONS ON PARTICLE SIZE OF ZNO NANOPARTICLES VIA CONTROLLED PRECIPITATION METHOD AND IN-VITRO ANTIBACTERIAL CAPACITY
High-yield ZnO spheroidal nanoparticles with an average diameter around 23 nm (≈ 25% frequency) and 30 nm (≈ 28% frequency) were obtained by controlled semicontinuous precipitation at low temperatures. This synthesis was obtained from hydrozincite (Zn5(CO3)2(OH)6) as primary nanoparticles. The Zn5(CO3)2(OH)6 nanoparticles were synthesized by hydrolysis o
Química Nova. Publicado em: 2022
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3. Dextran Sulfate/Pramlintide Polyelectrolyte Nanoparticles as a Promising Delivery System: Optimization, Evaluation of Supramolecular Interactions and Effect on Conformational Stability of the Peptide Drug
In this study, we investigated the feasibility to obtain nanoparticles (NPs) by assembling pramlintide (Pram) with dextran sulfate (DexS), as a new approach for mucosal peptide delivery. DexS/Pram NPs were prepared by dropwise addition of a Pram solution to a DexS solution under magnetic stirring. The physicochemical characteristics of NPs and molecular inte
J. Braz. Chem. Soc.. Publicado em: 2021-08
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4. Complexes with Furyl-Substituted 3-Hydroxychromone: Synthesis, Characterization and Fluorescence Studies
2-(2-Furyl)-3-hydroxychromone (HL) reacts with MII ions in the formation of quadratic [Cu(L)2] (3), octahedral [M(L)2(OH2)2] (M = Co (1), Ni (2), Zn (4), Mn (5)) and seesaw [M(L)2] (M = Sn (6), Pb (7)) complexes. Recrystallization of complexes 1-3 in presence of pyridine lead to [M(L)2(py)2] (1a-3a) aducts. All compounds were characterized by Fourier transfo
J. Braz. Chem. Soc.. Publicado em: 2021-08
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5. Nickel-Cerium Layered Double Hydroxide as Electrocatalyst for Glycerol Oxidation
A new nickel based layered double hydroxide nanomaterial, Ni0.8Ce0.2-LDH, constituted by about 3 nm large nanoparticles exhibiting enhanced electrocatalytic properties towards oxidation of glycerol in alkaline media, was prepared by incorporation of 20 wt.% of CeIII ions into α-nickel hydroxide. This can be oxidized to CeIV, as demonstrated by X-ray photoel
J. Braz. Chem. Soc.. Publicado em: 2020-11
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6. COVID-19 and stroke: a thromboembolic hypothesis
A new nickel based layered double hydroxide nanomaterial, Ni0.8Ce0.2-LDH, constituted by about 3 nm large nanoparticles exhibiting enhanced electrocatalytic properties towards oxidation of glycerol in alkaline media, was prepared by incorporation of 20 wt.% of CeIII ions into α-nickel hydroxide. This can be oxidized to CeIV, as demonstrated by X-ray photoel
Rev. Assoc. Med. Bras.. Publicado em: 2020-11
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7. Absolute Configuration of (−)-Cubebin, a Classical Lignan with Pharmacological Potential, Defined by Means of Chiroptical Spectroscopy
This work describes the first determination of the absolute configuration (AC) of (−)-cubebin by means of electronic circular dichroism (ECD), supported by quantum chemical calculations. The comparison of experimental ECD with the corresponding quantum chemical prediction for the proper diastereoisomer resulted in the definitive assignment of the AC of the
J. Braz. Chem. Soc.. Publicado em: 2020-10
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8. Calcium oxalate content from two Amazonian amilaceous roots and the functional properties of their isolated starches
Abstract The calcium oxalate content from two Amazonian amilaceous roots, Xanthosoma sagittifolium and Pachyrhizus tuberosus, before and after cooking were studied in the present work. Calcium oxalate raphides were observed by light microscopy in longitudinal sections from fresh tubers. The functional properties and physicochemical characteristics of isolate
Food Sci. Technol. Publicado em: 2020-09
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9. INTERAÇÕES COMPETITIVAS DE COMPLEXOS DE RUTÊNIO CONTENDO DIMETILSULFÓXIDO E LIGANTES N-HETEROCÍCLICOS COM ALBUMINA DE SORO HUMANO
Two ruthenium complexes of the type [RuCl(dmso)(L)2]Cl {L = 4,4’-dimethyl-2,2’-bipyridine (dmbpy); 4,4’-dinonyl-2,2’-bipyridine (dnbpy)} have been synthesized and characterized by elemental analysis, 1H NMR, FTIR, electronic spectra, and molar conductivity. The IR spectral studies revealed that the DMSO molecule is S-bound ( νSO= 1100 cm-1; 1079 cm-
Quím. Nova. Publicado em: 2020-03
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10. Well Defined Rich Electronic Structure: Facile Approach for Nido-Carborane Fused Azaspirodecaniums in Water Solution
A novel bis-dumbbell shape of a multi cation around a azaspirodecanium combined with nido-carborane was prepared in a single step in good yield starting from pyrrolidine and 1,3-dichloropropane to give one compound and from piperidine and 1,4-dichlorobutane to give the other. This is the first report of an electrolyte azaspirodecanium-boron-cluster structure
J. Braz. Chem. Soc.. Publicado em: 2020-01
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11. RAMAN STUDIES OF BIS(PHENYLTERPYRAZINE)IRON(II) AND SUPRAMOLECULAR SPECIES WITH PENTACYANIDOFERRATE(II) IONS
The chemistry and spectroscopy of the iron(II) phenylterpyrazine complex, [Fe(phtpz)2]2+, were investigated in comparison with the analogous phenylterpyridine species, Fe(phtpy)2]2+, and the results indicated a strong electronic delocalization on the Fe(II) terimine chromophore encompassing the lateral pyrazyl groups. The delocalized nature of the molecular
Quím. Nova. Publicado em: 05/12/2019
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12. UNRAVELING THE SOLVATOCHROMISM OF A TRIARYLMETHANE DYE BY RESONANCE RAMAN SPECTROSCOPY
The effect of the solvent on the electronic properties of the triarylmethane dye rosolic acid (RA) is investigated by means of UV-VIS and resonance Raman (RR) spectroscopies. The comparison of the solvatochromic behavior of both neutral and dianionic species of RA in acetonitrile, dimethylsulfoxide, and methanol illustrates the effect of polarity and hydroge
Quím. Nova. Publicado em: 05/12/2019