A5044908281- Clay minerals and soil interactions
- Advanced Chemical Physics Studies
- Chemical Reaction Mechanisms
- Iron oxide chemistry and applications
- Free Radicals and Antioxidants
- Molecular Spectroscopy and Structure
- Soil and Unsaturated Flow
- Crystallography and molecular interactions
- High-pressure geophysics and materials
- Glass properties and applications
- Spectroscopy and Quantum Chemical Studies
- Zeolite Catalysis and Synthesis
- Organophosphorus compounds synthesis
- Crystal Structures and Properties
- Organic Chemistry Cycloaddition Reactions
- Chemical Thermodynamics and Molecular Structure
- Natural Products and Biological Research
- Phosphorus compounds and reactions
- Molecular spectroscopy and chirality
- Geological and Geochemical Analysis
- Analytical Chemistry and Chromatography
- Chemical synthesis and alkaloids
- Inorganic and Organometallic Chemistry
- Mesoporous Materials and Catalysis
- Synthesis and characterization of novel inorganic/organometallic compounds
Instituto Andaluz de Ciencias de la Tierra
2016-2025
Consejo Superior de Investigaciones Científicas
2008-2025
University of Maryland, Baltimore County
2024
Universidad de Granada
2009-2023
Universidad Autónoma Metropolitana
2008-2023
Novartis (Switzerland)
2020
Estación Experimental del Zaidín
1999-2010
Andalusian School of Public Health
2010
Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública
2010
Centro Nacional de Biopreparados (Cuba)
2008
Many properties of 2,4-dichlorophenoxyacetic acid (2,4-D) depend on its molecular environment, such as whether it is an isolated molecule, a dimer, or in crystalline state. The geometry, conformational analysis, and vibrational spectrum 2,4-D were theoretically calculated using Density Functional Theory (DFT) methods. A new slightly more stable conformer was found, which different to those previously reported. most shows dimer by means hydrogen bonds between the carboxylic groups both...
The structure of dioctahedral 2:1 phyllosilicates with different interlayer charge was studied theoretically using ab initio calculations. standard Kohn-Sham self-consistent density functional method used in the generalized gradient approximation (GGA), numerical atomic orbitals as basis set, by means SIESTA program. Once had been checked satisfactorily, theoretical study extended beyond systems for which there are experimental information, and structural characteristics were predicted....
Two different theoretical approaches are used to study the OH radical attack on toluene: Møller−Plesset perturbation theory and B3LYP density functional method. The critical points of potential energy surface for addition toluene determined, rate−equilibrium relationships discussed. A stable structure corresponding a prereactive complex which is formed when at about 2.5 Å from obtained. existence this loosely bound system necessary explain experimentally observed negative activation energy....
The adsorption of glycine on the surface montmorillonite was observed for first time by quantum mechanical calculations, finding zwitterions and glycinium cations.
The presence of antibiotics in soils is increasing drastically last decades due to the intensive farming industry and excessive human consumption. Clay minerals are one soil components with great adsorption capacity for organic pollutants. study interactions between mineral surfaces will give us scientific knowledge these pollutants through soils. In this work, we antibiotic ciprofloxacin clay fraction from Argentinian zone Santa Rosa (Corrientes), a collaborative research experiments...
The dehydroxylation of pyrophyllite involves the reaction OH groups and elimination water molecules through two possible mechanisms, one involving bridging hydroxyl an octahedral Al (3+) pair other reacting across dioctahedral vacancy. First-principles molecular dynamics simulations at density functional theory level are used together with metadynamics algorithm to explore free-energy surface (FES) initial step dehydroxylation. We observe that mechanisms yield similar activation energies 0...
The ordering of octahedral Al3+, Fe3+, and Mg2+ cations in dioctahedral 2:1 phyllosilicates was studied theoretically. Quantum mechanical calculations based on density functional theory (DFT) were performed for optimizing different cation distributions along the sheet. Three systems two species (Al3+/Mg2+, Al3+/Fe3+, Fe3+/Mg2+) to obtain exchange potentials Jn as first, second, third, fourth nearest neighbors. Monte Carlo (MC) simulations previously calculated these binary showed phase...
The geometrical features and electronic structure of molecular clusters models two octahedrally coordinated cations in edge-sharing octahedra were studied by means Hartree-Fock ab initio orbital calculations at LANL2DZ 6-31+G* levels. These represent the different cation pairs among Al3+, Fe3+, Mg2+ octahedral sheet clays. reproduce experimental values main corresponding minerals. vibrational frequencies bridging hydroxyl groups (M-OH-M') calculated compared with data. A good agreement...
Abstract The low-charge dioctahedral 2:1 phyllosilicates are an important group of clay minerals that have a low degree cation substitution and very weak interlayer interatomic interactions which difficult to reproduce with quantum mechanical calculations. In order study the crystallographic properties these compounds density functional theory (DFT) quantum-mechanical methods, optimization norm-conserving pseudopotentials Al, Si, O, H Na atoms has been carried out, cutoff radii basis sets...
Dolomite (CaMg(CO3)2) is a sedimentary mineral that found in the majority of natural carbonate rocks. has been used treatment polluting agents, and as potential adsorbent CO2. usually associated with oil deposits. Secondary recovery problem related to adsorption processes hydrocarbons onto rocks covering rock surface film. The aim present study investigate water several organic molecules (hexane, cyclohexane, cyclohexene, benzene) most stable (101̅4) dolomite by means Density Functional...
The ordering of Al3+, Fe3+, and Mg2+ cations along the octahedral sheet in dioctahedral 2:1 phyllosilicates was studied theoretically. distribution Fe3+/Mg2+ is compared with Al3+/Fe3+ Al3+/Mg2+ distributions. cation exchange interaction parameters Jn, as first, second, third, fourth nearest neighbors were calculated by means empirical interatomic potentials. Several compositions different interlayer cations, tetrahedral charge close to ferric smectites, illites, nontronites studied. From...
It is shown how the symmetry properties of linked groups in a molecule help to reduce number harmonics Fourier series expansions aggregate, mononuclear, and binuclear parameters as function dihedral angles. This provides rationalization for some well-known conformational dependences torsional potentials, hyperfine couplings, internuclear interactions helps predict these simple formulas break down when conformations become more complex.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe intrinsic basicity of 4(5)-2'-aminoethylimidazole (histamine)A. Hernandez-Laguna, J. L. M. Abboud, R. Notario, H. Homan, and Y. G. SmeyersCite this: Am. Chem. Soc. 1993, 115, 4, 1450–1454Publication Date (Print):February 1, 1993Publication History Published online1 May 2002Published inissue 1 February 1993https://pubs.acs.org/doi/10.1021/ja00057a031https://doi.org/10.1021/ja00057a031research-articleACS PublicationsRequest reuse...