A5018337406- Analytical Chemistry and Chromatography
- Microfluidic and Capillary Electrophoresis Applications
- Drug Solubulity and Delivery Systems
- Spectroscopy and Quantum Chemical Studies
- Clay minerals and soil interactions
- Free Radicals and Antioxidants
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- Analytical chemistry methods development
- Molecular spectroscopy and chirality
- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Synthesis and Characterization of Heterocyclic Compounds
- Synthesis and biological activity
- Computational Drug Discovery Methods
- X-ray Diffraction in Crystallography
- Iron oxide chemistry and applications
- Synthesis and Catalytic Reactions
- Luminescence Properties of Advanced Materials
- Supramolecular Chemistry and Complexes
- Chemical Reaction Mechanisms
- High-pressure geophysics and materials
- Analytical Chemistry and Sensors
- Malaria Research and Control
- Hydrogels: synthesis, properties, applications
Federal University of São João del-Rei
2013-2024
University of Cologne
2019
Humboldt-Universität zu Berlin
2019
Marine Research Centre
2019
Universidade do Porto
2019
University of Minho
2019
Universidade Católica Dom Bosco
2007-2014
Universidade Federal de Minas Gerais
2006-2013
Institute of Solid State Chemistry
2010
TU Dresden
2007-2010
Halloysite is a clay mineral with stoichiometry Al2Si2O5(OH)4·nH2O that can grow into long tubules and chemically similar to kaolinite. In this work we present systematic study on the stability, electronic, mechanical properties of zigzag armchair single-walled halloysite nanotubes by means self-consistent charge density-functional tight-binding method (SCC-DFTB). The detailed analysis focused structural properties, strain energy, band gap as function tube radii Mulliken distribution. energy...
The aluminosilicate mineral imogolite is composed of single-walled nanotubes with stoichiometry (HO)3Al2O3SiOH and occurs naturally in soils volcanic origin. In the present work we study stability electronic mechanical properties zigzag armchair using density-functional tight-binding method. (12,0) tube has highest all tubes studied here. Uniquely for nanotubes, a minimum strain energy optimum structure. This agreement experimental data, as shown by comparison simulated X-ray diffraction...
The mechanism of neutral hydrolysis ester has long been explored by theoretical studies. However, reliable calculations show that the usual bifunctional catalysis reported different authors cannot explain experimental kinetics. An important advance was recently Gunaydin and Houk, suggesting ions are involved in process initiates water autoionization followed protonation (W(AI)A mechanism). this does not activated esters. In work, we have used ab initio calculations, continuum solvation...
We have investigated the structure and electronic of single- double-walled imogolite nanotubes with Ge Si as group IV element. While it is known from experiment, in case single-walled tubes confirmed by theory, are monodisperse diameter. show that also showing a preferred chirality (zigzag), resulting hydrogen-bond network on tube surfaces, there an exceptionally stable form intertube interaction supports formation nanotubes. The strongest stabilization has been found for indexes nine units...
Fe(III) hydrolysis in aqueous solution has been investigated using density-functional methods (DFT). All possible structures arising from different tautomers and multiplicities have calculated. The solvation energy estimated the UAHF−PCM method. free energies compared with available experimental data. species distinct geometries electronic structures. We shown that improvement of theory level calculating does not necessarily improve since is a simple method neglects specific interactions...
Structural, electronic, and mechanical properties of single-walled chrysotile nanotubes have been investigated using the self-consistent charge density-functional tight-binding method (SCC-DFTB). The naturally occurring (NTs) are composed brucite, Mg(OH)2, layer in outer side tridymite, SiO2, inner side. zigzag (17,0)–(45,0) armchair (9,9)–(29,29) nanotubes, which correspond to radii ranging from 16 47 Å, calculated. SCC-DFTB results good agreement with available experimental previously...
Elution order elucidation of 4-hydroxypropranolol by capillary electrophoresis and theoretical methods.
Coumarins have great pharmacotherapeutic potential, presenting several biological and pharmaceutical applications, like antibiotic, fungicidal, anti-inflammatory, anticancer, anti-HIV, healing activities, among others. These molecules are practically insoluble in water, for it became necessary to complex them with cyclodextrins (CDs), which influence their bioavailability the target organism. In this work, we studied two coumarins, was possible conclude that there were structural differences...
Imogolite is a single-walled aluminosilicate nanotube (NT) found in nature that can be easily synthesized, as well its analogue aluminogermanate NT. Based on geometrical assumptions and pKa values, species such H3PO4, H3PO3, H3AsO3, H3AsO4 could also candidates to form imogolite-like structures. In the present work, we provide insights about stability, electronic, structural mechanical properties of possible imogolite like NTs by means self-consistent charge density-functional tight-binding...
Structural and thermodynamic properties of the mononuclear Al/citrate complexes have been theoretically investigated aiming to understand coordination mechanism at an atomic level. GGA-DFT/PCM calculations performed for different conformations tautomers arising from Al(3+) citric acid (H3L) interaction in aqueous solution. The Gibbs reaction energies were estimated based on trigonal planar Al(OH)3 H3L form Al-citrate complexes. free [AlL], [AlHL](+), [Al(OH)L](-) species are good agreement...
Friedelin molecular conformers were obtained by Density Functional Theory (DFT) and ab initio structure determination from powder X-ray diffraction. Their with the five rings in chair-chair-chair-boat-boat, all chair, are energy degenerated gas-phase according to DFT results. The diffraction data reveals that A, B C of friedelin D E boat-boat, conformation. high correlation values among data, reported single-crystal indicate use conventional diffractometer can be applied routine laboratory...
Synthetic 3-alkylpyridine marine alkaloid (3-APA) analogues have shown good antimalarial activity against Plasmodium falciparum. However, despite their structural originality, molecular target was unknown. Herein, we report a proposal for the mechanism of action 3-APA through interference with process hemozoin (Hz) formation. The interaction between and heme groups investigated employing an in silico approach biophysical techniques such as ultraviolet-visible light (UV-vis) titration...