Publicaciones 2011-2020

@article{RN165,
title = {Lewis Molecular Acidity of Ionic Liquids from Empirical Energy-Density Models},
author = { R. Contreras and A. Aizman and R.A. Tapia and A. Cerda-Monje},
url = {/brokenurl#<Go to ISI>://WOS:000315181600051},
doi = {10.1021/jp3114946},
issn = {1520-6106},
year = {2013},
date = {2013-01-01},
journal = {Journal of Physical Chemistry B},
volume = {117},
number = {6},
pages = {1911-1920},
abstract = {Two complementary models of Lewis molecular acidity are introduced and tested in a wide series of 45 room temperature ionic liquids (RTIL). They are defined in the context of the conceptual density functional theory. The first one, which we tentatively call the excess electronic chemical potential, assesses the electron accepting power of the RTIL by relating the H-bond donor acidity with the charge transfer associated to the acidic H-atom migration at the cation of the RTIL considered as a HB-donor species. This global index accounts for the molecular acidity of the cation moiety of the ionic liquid that takes into account the perturbation of the anionic partner. The second index is defined in terms of the local charge capacity modeled through the maximum electronic charge that the cation, in its valence state, may accept from an unspecified environment. Each model is compared with the experimental HB-donor acidity parameter of the Kamlet Taft model. The best comparison is obtained for a combination of both the excess electronic chemical potential and the local charge capacity. As expected, the correlations with the Kamlet Taft alpha parameter do not lead to a universal model of HB-donor acidity. Reduced correlations for limited series of structurally related RTIL are obtained instead. Finally, we illustrate the reliability and usefulness of the proposed model of RTIL molecular acidity to explain the cation-dependent solvent effects on the reactivity trends for cycloaddition, Kemp elimination, and Menschutkin reactions, for which experimental rate coefficients are available from literature.},
keywords = {ab-initio, dielectric-constant, diels-alder elimination, kemp polarity, reaction, scale solvents, static},
pubstate = {published},
tppubtype = {article}
}

@article{RN106,
title = {Solvent Effects in Ionic Liquids: Empirical Linear Energy-Density Relationships},
author = { A. Cerda-Monje and A. Aizman and R.A. Tapia and C. Chiappe and R. Contreras},
url = {/brokenurl#<Go to ISI>://WOS:000305890300028},
doi = {10.1039/c2cp40619e},
issn = {1463-9076},
year = {2012},
date = {2012-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {14},
number = {28},
pages = {10041-10049},
abstract = {Multiparameter linear energy-density relationships to model solvent effects in room temperature ionic liquids (RTILs) are introduced and tested. The model incorporates two solvent dependent and two specific solute-solvent parameters represented by a set of electronic indexes derived from the conceptual density functional theory. The specific solute-solvent interactions are described in terms of the electronic chemical potential for proton migration between the anion or cation and the transition state structure of a specific reaction. These indexes provide a quantitative estimation of the hydrogen bond (HB) acceptor basicity and the hydrogen bond donor acidity of the ionic solvent, respectively. A sound quantitative scale of HB strength is thereby obtained. The solvent dependent contributions are described by the global electrophilicity of the cation and nucleophilicity of the anion forming the ionic liquid. The model is illustrated for the kinetics of cycloaddition of cyclopentadiene towards acrolein. In general, cation HB acidity outweighs the remaining parameters for this reaction.},
keywords = {ab-initio, catalysis, dielectric-constant, diels-alder electrophilicity field-theory, functional index, models molecular-dynamics, reaction, solvation, static theory},
pubstate = {published},
tppubtype = {article}
}

@article{RN34e,
title = {Nmr Assignment in Regioisomeric Hydroquinones},
author = { J.A. Dobado and J.C. Gomez-Tamayo and F.G. Calvo-Flores and H. Martinez-Garcia and W. Cardona and B. Weiss-Lopez and O. Ramirez-Rodriguez and H. Pessoa-Mahana and R. Araya-Maturana},
url = {/brokenurl#<Go to ISI>://WOS:000291114500009},
doi = {10.1002/mrc.2745},
issn = {0749-1581},
year = {2011},
date = {2011-01-01},
journal = {Magnetic Resonance in Chemistry},
volume = {49},
number = {6},
pages = {358-365},
publisher = {2011 John Wiley & Sons, Ltd.},
abstract = {A set of regioisomeric pairs of tricyclic hydroquinones, analogues of antitumor 9,10-dihydroxy-4,4-dimethyl-5,8dihydroanthracen- 1(4H)-one (1) and other derivatives, were synthesized and their regiochemistry and NMR spectra assigned by using 1H-detected one-bond(C-H) HMQC and long-range C-HHMBC, in good agreement with theoretical O3LYP/Alhrichs-pVTZ calculations. The 5-hydroxymethyl derivatives (11, 15, 19) showed a 3 integral H,H coupling constant of methylene protons evidencing the presence of a seven-membered intramolecular hydrogen bonded ring, not observed for the 8-hydroxymethyl isomers.},
keywords = {basis-sets, c-13 calculations, chemical-shifts, coupling-constants, derivatives, dft, diels-alder giao, h, h-1 hmbc, hmqc, hydroquinone, nmr, o3lyp, organic-molecules, reaction, respiration, sensitivity, spin theoretical tumor-cell},
pubstate = {published},
tppubtype = {article}
}