Publicaciones 2011-2020

@article{RN376,
title = {Iso-Solvation Effects in Mixtures of Ionic Liquids on the Kinetics of a Model Snar Reaction},
author = { J. Alarcon-Esposito and R. Contreras and P.R. Campodonico},
url = {/brokenurl#<Go to ISI>://WOS:000414440000030},
doi = {10.1039/c7nj03246c},
issn = {1144-0546},
year = {2017},
date = {2017-01-01},
journal = {New Journal of Chemistry},
volume = {41},
number = {22},
pages = {13435-13441},
abstract = {The SNAr reaction between 1-chloro-2,4-dinitrobenzene and morpholine was used as a model system to study solvation effects in a series of mixtures involving imidazolium based ionic liquids. Iso-solvation regimes (i.e. a solvent composition regime where the solute is being solvated by approximately the same number of different solvent molecules in the mixture) are reported for the first time in ionic liquid mixtures, for 4 mixtures including [EMIM][SCN][DCN], [BMIM][DCN][BF4], [BMIM][BF4][PF6] and [BMIM][PF6][FAP]. The results show that for significant changes in composition, the rate coefficients remain approximately constant. An additional interesting result is that the mixture [BMIM][BF4][PF6] (in the proportion of 0.9 for the molar fraction of BMIMBF4) shows a slightly better kinetic performance as compared to pure BMIMBF4 and BMIMPF6. Finally, for the [EMIM][SCN][DCN] mixture, an increasing proportion of EMIMSCN with respect to EMIMDCN results in a decrease in the rate coefficient within the range of (0.1-0.75) for the molar fraction of EMIMSCN. This result may be traced to competition between the anions [SCN-] and [DCN-] towards the reaction center driven by the basicity of the reaction medium.},
keywords = {alpha, aromatic behavior, binary-mixtures, comparison method, nucleophilic-substitution, parameters, preferential probes, scale solvation, solvatochromic solvents},
pubstate = {published},
tppubtype = {article}
}

@article{RN328,
title = {Gutmann's Donor Numbers Correctly Assess the Effect of the Solvent on the Kinetics of Snar Reactions in Ionic Liquids},
author = { J. Alarcon-Esposito and R. Contreras and R.A. Tapia and P.R. Campodonico},
url = {/brokenurl#<Go to ISI>://WOS:000383763200049},
doi = {10.1002/chem.201602237},
issn = {0947-6539},
year = {2016},
date = {2016-01-01},
journal = {Chemistry-a European Journal},
volume = {22},
number = {37},
pages = {13347-13351},
abstract = {We report an experimental study on the effect of solvents on the model SNAr reaction between 1-chloro-2,4dinitrobenzene and morpholine in a series of pure ionic liquids (IL). A significant catalytic effect is observed with reference to the same reaction run in water, acetonitrile, and other conventional solvents. The series of IL considered include the anions, NTf2-, DCN-, SCN-, CF3SO3-, PF6-, and FAP(-) with the series of cations 1-butyl-3-methyl-imidazolium ([BMIM]+), 1-ethyl-3-methyl-imidazolium ([ EMIM]+), 1-butyl2,3- dimethyl-imidazolium ([BM2(I)M](+)), and 1-butyl-1-methyl-pyrrolidinium ([BMPyr](+)). The observed solvent effects can be attributed to an "anion effect". The anion effect appears related to the anion size (polarizability) and their hydrogenbonding (HB) abilities to the substrate. These results have been confirmed by performing a comparison of the rate constants with Gutmann's donicity numbers (DNs). The good correlation between rate constants and DN emphasizes the major role of charge transfer from the anion to the substrate.},
keywords = {anion aromatic aryl azides, basicity, comparison conventional donicity effects, gutmann's ionic lewis liquids, method, nucleophilic-substitution, numbers, parameters, pi-star, polarities, preferential scale solvation, solvatochromic solvents},
pubstate = {published},
tppubtype = {article}
}