Publicaciones 2011-2020

@article{RN134,
title = {Electron Paramagnetic Resonance Study of Copper-Ethylenediamine Complex Ion Intercalated in Bentonite},
author = { J.P. Donoso and C.J. Magon and J.F. Lima and O.R. Nascimento and E. Benavente and M. Moreno and G. Gonz\'{a}lez},
url = {/brokenurl#<Go to ISI>://WOS:000327110500067},
doi = {10.1021/jp408658d},
issn = {1932-7447},
year = {2013},
date = {2013-01-01},
journal = {Journal of Physical Chemistry C},
volume = {117},
number = {45},
pages = {24042-24055},
abstract = {This work reports on studies of two-dimensional networks of Cu2+ ions, built by exchanging Na-bentonite with Cu2+ aqueous or with the bis(ethylenecliamine) complex, [Cu(C2H4 (NH2))(2)](2+), at different concentrations of the paramagnetic center. Dilution of the magnetically active species is performed by the cointercalation of analogous diamagnetic zinc species, aqueous Zn2+, or complexed [Zn(C2H4 (NH2))(2)](2+) ions, with ethylenediamine in excess. Materials were characterized by X-ray diffraction, Fourier transform infrared (FT-IR) and UV-visible spectroscopy, and continuous-wave electron paramagnetic resonance (EPR). X-ray diffraction measurements indicated that the interlaminar distance in the bentonite decreases with the increase of Zn concentration in the composites. The observation of a two-component Cu2+ EPR spectrum imply the coexistence of isolated Cu2+ with a well-resolved hyperfine structure and spin-spin exchanged Cu2+ dimers or clusters with an unresolved hyperfine structure. EPR spin Hamiltonian parameters of the isolated species in Cu/ethylenediamine intercalated samples are typical of axially distorted sites, six-coordinated with bis(ethylenediamine) in the equatorial plane and with oxygen on the internal surfaces of the clay. Experimental facts indicate that the interaction between paramagnetic centers is mainly favored by two different phenomena: turbostratic disorder of clay sheets and segregation of the magnetic centers leading to interstratifications of layers.},
keywords = {aqueous-solutions, characterization, clay, cupric ion, magnetic-resonance, montmorillonite solid-surfaces, spectroscopic spin-resonance, thermal-stability},
pubstate = {published},
tppubtype = {article}
}

@article{sotodelgado2012catalytic,
title = {On the Catalytic Effect of Water in the Intramolecular Diels-Alder Reaction of Quinone Systems: A Theoretical Study},
author = { J. Soto-Delgado and A. Aizman and R. Contreras and L.R. Domingo},
url = {/brokenurl#<Go to ISI>://WOS:000311428400087},
doi = {10.3390/molecules171113687},
issn = {1420-3049},
year = {2012},
date = {2012-01-01},
journal = {Molecules},
volume = {17},
number = {11},
pages = {13687-13703},
abstract = {The mechanism of the intramolecular Diels-Alder (IMDA) reaction of benzoquinone 1, in the absence and in the presence of three water molecules, 1w, has been studied by means of density functional theory (DFT) methods, using the M05-2X and B3LYP functionals for exploration of the potential energy surface (PES). The energy and geometrical results obtained are complemented with a population analysis using the NBO method, and an analysis based on the global, local and group electrophilicity and nucleophilicity indices. Both implicit and explicit solvation emphasize the increase of the polarity of the reaction and the reduction of activation free energies associated with the transition states (TSs) of this IMDA process. These results are reinforced by the analysis of the reactivity indices derived from the conceptual DFT, which show that the increase of the electrophilicity of the quinone framework by the hydrogen-bond formation correctly explains the high polar character of this intramolecular process. Large polarization at the TSs promoted by hydrogen-bonds and implicit solvation by water together with a high electrophilicity-nucleophilicity difference consistently explains the catalytic effects of water molecules.},
keywords = {catalysis, characterization, chemistry density dft dft, diels-alder difference electrophilicity, functionals, index, indices, intramolecular local molecules, polar quantitative reactions, reactivity regioselectivity, solvent, thermochemistry, water},
pubstate = {published},
tppubtype = {article}
}

@article{RN89,
title = {Layered Graphitic Carbon Host Formation During Liquid-Free Solid State Growth of Metal Pyrophosphates},
author = { C. Diaz and M.L. Valenzuela and V. Lavayen and C. O'dwyer},
url = {/brokenurl#<Go to ISI>://WOS:000304728500029},
doi = {10.1021/ic300767h},
issn = {0020-1669},
year = {2012},
date = {2012-01-01},
journal = {Inorganic Chemistry},
volume = {51},
number = {11},
pages = {6228-6236},
abstract = {We report a successful ligand- and liquid-free solid state route to form metal pyrophosphates within a layered graphitic carbon matrix through a single step approach involving pyrolysis of previously synthesized organometallic derivatives of a cyclotriphosphazene. In this case, we show how single crystal Mn2P2O7 can be formed on either the micro- or the nanoscale in the complete absence of solvents or solutions by an efficient combustion process using rationally designed macromolecular trimer precursors, and present evidence and a mechanism for layered graphite host formation. Using in situ Raman spectroscopy, infrared spectroscopy, X-ray diffraction, high resolution electron microscopy, thermogravimetric and differential scanning calorimetric analysis, and near-edge X-ray absorption fine structure examination, we monitor the formation process of a layered, graphitic carbon in the matrix. The identification of thermally and electrically conductive graphitic carbon host formation is important for the further development of this general ligand-free synthetic approach for inorganic nanocrystal growth in the solid state, and can be extended to form a range of transition metals pyrophosphates. For important energy storage applications, the method gives the ability to form oxide and (pyro)phosphates within a conductive, intercalation possible, graphitic carbon as host-guest composites directly on substrates for high rate Li-ion battery and emerging alternative positive electrode materials.},
keywords = {characterization, nanocomposites, nanoparticles, nanotubes, nanowires precursor, pyrolysis, spectroscopic},
pubstate = {published},
tppubtype = {article}
}

@article{RN108,
title = {Bond Fukui Functions as Descriptor of the Electron Density Reorganization in Pi Conjugated Systems},
author = { M. Gonz\'{a}lez-Suarez and A. Aizman and J. Soto-Delgado and R. Contreras},
url = {/brokenurl#<Go to ISI>://WOS:000298827600008},
doi = {10.1021/jo201465g},
issn = {0022-3263},
year = {2012},
date = {2012-01-01},
journal = {Journal of Organic Chemistry},
volume = {77},
number = {1},
pages = {90-95},
abstract = {The bond Fukui function is introduced and tested as a new reactivity index capable of predicting the evolution of bond breaking and formation processes during an organic reaction involving pi conjugated systems. As an illustration, we examine many cases where substituted ethylenes and dienes may respond to different reagents to yield cycloaddition, Michael addition, and other reactions at double bonds.},
keywords = {characterization, cycloaddition diels-alder electrophilicity, hardness molecules, quantitative reactions, reactivity, regioselectivity},
pubstate = {published},
tppubtype = {article}
}