Deprotonation
Mostrando 1-12 de 113 artigos, teses e dissertações.
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1. FACILE SYNTHESIS, CHARACTERIZATION AND DFT CALCULATIONS OF 2-ACETYL PYRIDINE DERIVATIVES
Deprotonation of 2-acetylpyridine was carried out in the presence of NaH as a phase transfer catalyst instead of NaOH to minimize side products formation. The products were then treated with two equivalents of alkyl/aryl halide to synthesize a variety of acetyl pyridine derivatives. The compounds were structurally characterized by 1H- and 13C-NMR spectroscop
Quím. Nova. Publicado em: 2017-09
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2. Lime and calcium-magnesium silicate in the ionic speciation of an Oxisol
ABSTRACT Plant residues and certain fertilizers accelerate soil acidification and increase the levels of aluminum-Al+3 in soils under no-tillage (NT). Silicates act as acidity amendments and as a source of silicon as in H4SiO4. An increase in the pH of soil solution causes the deprotonation of H4SiO4 and generates the anionic form (H3SiO4−). The aim of thi
Sci. agric. (Piracicaba, Braz.). Publicado em: 2017-08
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3. Influence of Supporting Electrolytes on RO 16 Dye Electrochemical Oxidation Using Boron Doped Diamond Electrodes
The influence of different supporting electrolytes as well as of different current densities on RO16 dye electrochemical oxidation using BDD electrodes has been systematically studied. The RO16 azo-dye electrooxidation experiments were performed at different current densities and three different supporting electrolytes: H2SO4 0.1 mol L-1, HClO4 0.1 mol L-1 a
Mat. Res.. Publicado em: 13/03/2017
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4. SYNTHESIS AND BIOLOGICAL ACTIVITY OF NEW SERIES OF ORGANOTIN(IV) ESTERS WITH N,N-DIACETYLGLYCINE
A bioactive N,N-diacetylglycine (NNDAG) and new organotin(IV) complexes (OTCs) (1-7) were synthesized. Spectroscopic techniques were employed to characterize NNDAG and OTCs. FTIR was employed to verify N,N protection of glycine by acetyl groups. The disappearance of υ(OH) at 3000-2600 cm-1 showed de-protonation of free ligand. The Δυ 150<200 cm-1 of OTCs
Quím. Nova. Publicado em: 2016-01
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5. 4-(Pyren-1-ylimino)methylphenol and its Silylated Derivative as Chromogenic Chemosensors Highly Selective for Fluoride or Cyanide
Two novel compounds, 4-(pyren-1-ylimino)methylphenol and 4-[(triisopropylsilyl)oxy]phenylmethylenepyren-1-amine) were synthesized. Solutions of 4-(pyren-1-ylimino)methylphenol in dimethyl sulfoxide (DMSO) are colorless, but on addition of cyanide and fluoride they become colored due to the deprotonation of the chemosensor. The system is highly selective towa
J. Braz. Chem. Soc.. Publicado em: 2015-12
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6. ADSORÇÃO DE 5 FLUOROURACIL E 5 CLOROURACIL SOBRE HOPG: um estudo da importância do estado de protonação via microscopia de varredura por tunelamento. / ADSORPTION OF 5-FLUOROURACIL AND 5 CLOROURACIL ON HOPG: a study of the importance of the state of protonation via scanning tunneling microscopy.
Neste trabalho foi explorada a adsorção de moléculas orgânicas para realizar modificação em superfícies. Neste contexto foi proposta a adsorção das moléculas orgânicas de derivados halogenados do uracil, o 5 Fluorouracil e o 5 Clorouracil no, substrato monocristalino do HOPG (Grafite Pirolítico Altamente Orientado do inglês, Highly Oriented Pyro
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/06/2011
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7. Atividade eletrocatalítica de sistemas biomiméticos da enzima catalase
In this work, we describe the immobilization of the dinuclear compound [Cu2(apyhist)2Cl2](ClO4)2 (1) and its derived cations complexes, obtained in water solution or by deprotonation of the imidazolate moiety in the ligand leading to a cyclic tetranuclear species, in the Nafion® membrane on glass carbon electrode surface. After that, we studied the influenc
Química Nova. Publicado em: 2011-09
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8. Aspects of protonation and deprotonation of humic scid durface on molecular conformation
As densidades superficiais de carga de ácidos húmicos foram determinadas por titulação potenciométrica e condutimétrica simultâneas. Também foi observada a influência do pH na conformação molecular através de espectroscopia de UV-Vis e microscopia eletrônica de varredura (MEV). A densidade de carga superficial para todas as amosftras de ácido h
Journal of the Brazilian Chemical Society. Publicado em: 2011-08
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9. SÍNTESE E ARRANJOS SUPRAMOLECULARES DE COMPLEXOS BIS(TRIAZENIDO) MACROCÍCLICOS E TRIAZENIDO 1-ÓXIDO COM OS CÁTIONS Cu2+, Ni2+, Cu+, K+. / SYNTHESIS AND SUPRAMOLECULAR ARRANGEMENTS OF BIS(TRIAZENIDE) MACROCYCLIC AND TRIAZENIDE 1-OXIDE COMPLEXES WITH Cu2+, Ni2+, Cu+, K+ CATIONS.
This work elaborates on the determination of crystal and molecular structures of four pro-ligands, emphasizing bis(triazenes), triazene 1-oxide and a new class of bis(triazenes) macrocyclic, and eight complexes involving Cu+, Cu2 +, Ni2 + and K+. Pro-ligands triazenes 1-oxide are relatively small and simple molecules. When they are deprotonated they presen a
Publicado em: 2010
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10. Estudo da interação do vanádio (V) com ácidos [beta]-alaninoidroxâmico, glicinoidroxâmico e [alfa]-alaninoidroxâmico em solução aquosa $h [manuscrito] : $b uma abordagem a partir da DFT
The discovery of the potential insulin-mimetic properties of vanadium compounds has stimulated research about the clinical use of these compounds. The effects of different organic groups in the geometry, electronic structure and chemical properties of the vanadium coordination compounds are of fundamental importance to understand the chemical reactivity and
Publicado em: 2009
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11. Modelagem multiescala do acoplamento eletro-químico em um meio poroso argiloso com dependência do PH / Multiscale modeling of eletro-chemical couplings in clays including PH dependence
In this work we develop a three-scale mathematical modeling to describe electro-chemical couplings in clays using the asymptotic homogenization procedure of periodic structures. We consider the porous medium composed of kaolinite particles saturated by an electrolyte solution of water-solvent and four ionic solutes monovalents Na+, H+, Cl-, OH-At the nanosca
Publicado em: 2007
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12. The saccharinate anion: a versatile and fascinating ligand in coordination chemistry
The saccharinate anion, obtained by deprotonation of the N-H moiety of saccharin (o-sulfobenzimide) is a very versatile and polyfunctional ligand in coordination chemistry. In this review the different forms of metal-to-ligand interactions involving this anion and some other coordination peculiarities are briefly discussed on the basis of some selected examp
Química Nova. Publicado em: 2005-03