Publicaciones 2011-2020

@article{RN305,
title = {Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells},
author = { R. Mera-Adasme and W.H. Xu and D. Sundholm and F. Mendizabal},
url = {/brokenurl#<Go to ISI>://WOS:000385180600020},
doi = {10.1039/c6cp04627d},
issn = {1463-9076},
year = {2016},
date = {2016-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {18},
number = {40},
pages = {27877-27884},
abstract = {Solar power is a strong alternative to the currently used fossil fuels in order to satisfy the world's energy needs. Among them, dye-sensitized solar cells (DSSC) represent a low-cost option. Efficient and cheap dyes are currently needed to make DSSCs competitive. Computational chemistry can be used to guide the design of new light-absorbing chromophores. Here, we have computationally studied the lowest excited states of ZnPBAT, which is a recently synthesized porphyrinoid chromophore with high light-absorption efficiency. The calculations have been performed at ab initio correlated levels of theory employing second-order coupled clusters (CC2) and algebraic diagrammatic construction using second order (ADC(2)) methods and by performing density functional theory (DFT) calculations using the time-dependent DFT (TDDFT) approach for excitation energies. The ultraviolet-visible (UV-vis) spectrum calculated at the ADC(2) and CC2 levels agrees well with the experimental one. The calculations show that ZnPBAT has six electronic transitions in the visible range of the absorption spectrum. The ab initio correlated calculations and previously reported experimental data have been used to assess the performance of several well-known density functionals that have been employed in the present TDDFT study. Solvent effects have been estimated by using the conductor-like screening model (COSMO). The influence of the addition of a TiO2 cluster to the chromophore systems has also been investigated. The results indicate that both CAM-B3LYP and Becke's "half-and-half'' (BHLYP) density functionals are appropriate for the studies of excitation energies in the blue range of the visible spectrum for these kinds of porphyrinoid chromophores, whereas the excitation energies of the Q band calculated at the ab initio correlated level are more accurate than those obtained in the present TDDFT calculations. The inclusion of solvent effects has a modest influence on the spectrum of the protonated form of the studied chromophores, whereas solvent models are crucial when studying the absorption spectrum of the anionic chromophore. The calculated UV-vis spectrum for the chromophore anion is not significantly affected by attaching a TiO2 cluster to it.},
keywords = {adsorption, approximation, basis-sets, correlation-energy, dft, efficiency hartree-fock, model, organic-dyes, performance, screening},
pubstate = {published},
tppubtype = {article}
}

@article{RN85,
title = {Computational Studies of the Metal-Binding Site of the Wild-Type and the H46r Mutant of the Copper, Zinc Superoxide Dismutase},
author = { R. Mera-Adasme and F. Mendizabal and M. Gonz\'{a}lez and S. Miranda-Rojas and C. Olea-Azar and D. Sundholm},
url = {/brokenurl#<Go to ISI>://WOS:000304215200011},
doi = {10.1021/ic202416d},
issn = {0020-1669},
year = {2012},
date = {2012-01-01},
journal = {Inorganic Chemistry},
volume = {51},
number = {10},
pages = {5561-5568},
abstract = {Impairment of the Zn(II)-binding site of the copper, zinc superoxide dismutase (CuZnSOD) protein is involved in a number of hypotheses and explanations for the still unknown toxic gain of function mutant varieties of CuZnSOD that are associated with familial forms of amyotrophic lateral sclerosis (ALS). In this work, computational chemistry methods have been used for studying models of the metal-binding site of the ALS-linked H46R mutant of CuZnSOD and of the wild-type variety of the enzyme. By comparing the energy and electronic structure of these models, a plausible explanation for the effect of the H46R mutation on the zinc site is obtained. The computational study clarifies the role of the D124 and D125 residues for keeping the structural integrity of the Zn(II)-binding site, which was known to exist but its mechanism has not been explained. Earlier results suggest that the explanation for the impairment of the Zn(II)-site proposed in this work may be useful for understanding the mechanism of action of the ALS-linked mutations in CuZnSOD in general.},
keywords = {amyotrophic-lateral-sclerosis, approximation, correlation-energy, crystal-structures, cu, density efficient, functionals, sod1, solvents zn},
pubstate = {published},
tppubtype = {article}
}

@article{RN28i,
title = {Influence of the Nature of the Absorption Band on the Potential Performance of High Molar Extinction Coefficient Ruthenium(Ii) Polypyridinic Complexes as Dyes for Sensitized Solar Cells},
author = { F. Gajardo and M. Barrera and R. Vargas and I. Crivelli and B. Loeb},
url = {/brokenurl#<Go to ISI>://WOS:000292010000012},
doi = {10.1021/ic1020862},
issn = {0020-1669},
year = {2011},
date = {2011-01-01},
journal = {Inorganic Chemistry},
volume = {50},
number = {13},
pages = {5910-5924},
abstract = {When tested in solar cells, ruthenium polypyridinic dyes with extended pi systems show an enhanced light-harvesting capacity that is not necessarily reflected by a high (collected electrons)/(absorbed photons) ratio. Provided that metal-to-ligand charge transfer bands, MLCT, are more effective, due to their directionality, than intraligand (IL) pi-pi* bands for the electron injection process in the solar cell, it seems important to explore and clarify the nature of the absorption bands present in these types of dyes. This article aims to elucidate if all the absorbed photons of these dyes are potentially useful in the generation of electric current. In other words, their potentiality as dyes must also be analyzed from the point of view of their contribution to the generation of excited states potentially useful for direct injection. Focusing on the assignment of the absorption bands and the nature of the emitting state, a systematic study for a series of ruthenium complexes with 4,4'-distyryl-2,2'-dipyridine (LH) and 4,4'-bis[p-(dimethylamino)-alpha-styryl]-2,2'-bipyridine (LNMe2) "chromophoric" ligands was undertaken. The observed experimental results were complemented with TDDFT calculations to elucidate the nature of the absorption bands, and a theoretical model was proposed to predict the available energy that could be injected from a singlet or a triplet excited state. For the series studied, the results indicate that the percentage of MLCT character to the anchored ligand for the lower energy absorption band follows the order [Ru(deebpy)(2)(LNMe2)](PF6)(2) > [Ru(deebpy)(2)(LH)] (PF6)(2) > [Ru(deebpy)(LH)(2)](PF6)(2), where deebpy is 4,4'-bis(ethoxycarbonyl)-2,2'-bipyridine, predicting that, at least from this point of view, their efficiency as dyes should follow the same trend.},
keywords = {charge-transfer conversion, correlation-energy, density, excited-states, films, light, nanocrystalline optical-properties, sensitizers, tio2},
pubstate = {published},
tppubtype = {article}
}