Browsing by Author "Mendizabal, Fernando"
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- ItemCatalytic activity of iron phthalocyanine for the oxidation of thiocyanate and L-cysteine anchored on Au(111) clusters(2019) Castro Latorre, Pablo; Miranda Rojas, Sebastián; Barrientos, Lorena; Mendizabal, Fernando
- ItemElectronic structure and optical properties calculation of Zn-porphyrin with N-annulated perylene adsorbed on TiO2 model for dye-sensitized solar cell applications: A DFT/TD-DFT study(2017) Paredes Gil, Katherine; Mendizabal, Fernando; Páez Hernández, Dayán; Arratia Pérez, Ramiro
- ItemImprovement of photovoltaic performance by substituent effect of donor and acceptor structure of TPA-based dye-sensitized solar cells(2016) Inostroza, Natalia; Mendizabal, Fernando; Arratia Perez, Ramiro; Orellana, Carlos; Linares Flores, Cristian
- ItemInteraction of LD14 and TiO2 in dye-sensitized solar-cells (DSSC) : A density functional theory study(2015) Mendizabal, Fernando; Lopéz, Alfredo; Arratia Pérez, Ramiro; Zapata-Torres, Gerald
- ItemInteraction of YD2 and TiO2 in dye-sensitized solar cells (DSSCs) : a density functional theory study(2015) Mendizabal, Fernando; Lopéz, Alfredo; Arratia Pérez, Ramiro; Inostroza, Natalia; Linares-Flores, Cristian
- ItemPalmitic acid and hexadecylamine molecules assdsorbed on titania surface in hybrid composites. Effect of surfactants using density functional theory(2017) Orellana, Carlos; Mendizabal, Fernando; Gonzalez, Guillermo; Miranda-Rojas, Sebastian; Barrientos, LorenaA complete theoretical characterization of the factors involved in the stabilization of hybrid laminar composites is reported, with the purpose of understanding the main interactions involved in the formation of these types of systems. The models were built using two different surfactants: hexadecylamine (HDA) and palmitic acid (PAc), on a cluster of titania (TiO2) which represents its anatase crystalline phase. We explored the relevance of the titania-surfactant and surfactant-surfactant interactions, and of the protonation state of the palmitic acid in the stabilization of the hybrid laminar composites. The results were rationalized using energy decomposition analysis (EDA) and the non-covalent interaction index (NIC). The interaction energies between HDA and the TiO2 surface without the contribution of the dispersion forces were -25 kcal/mol and -29 kcal/mol for the (1 0 0) and (1 01) surfaces, respectively. These results suggest the formation of a donor-acceptor bond between HDA-TiO2 allowing its stabilization. On the other hand, the interaction energy between PAc and the TiO2 (1 0 1) surface was about -45 kcal/mol without the dispersion term. Thus, the PAc-TiO2 model has a higher covalent character than the HDA-TiO2 interaction, as confirmed by the energy decomposition analyses. The results suggest new hybrid laminar composites which are better when carboxylic acid was used instead of amines. Therefore, the use of surfactants with the carboxyl functional group yielded more stable TiO2 hybrid composites. The interaction energy between surfactant chains was about -13 kcal/mol, confirming the importance of dispersion forces in the stabilization of these types of systems. The study of systems with palmitic acid was complemented by building some anionic models to show the importance of acid protons in those systems. However, when the acidic hydrogens were removed, the interaction energy between the PAc molecules considering the dispersion correction increased to 45 kcal/mol, with a highly repulsive character. These results suggest that the acid hydrogens of the PAc surfactants play a fundamental role in terms of correctly representing the carboxylic acid-TiO2 interface and the stabilization of the laminar hybrid composites. (C) 2017 Elsevier B.V. All rights reserved.
- ItemSubstituents role in zinc phthalocyanine derivatives used as dye-sensitized solar cells. A theoretical study using Density Functional Theory(2015) Linares Flores, Cristián; Mendizabal, Fernando; Arratia Pérez, Ramiro; Inostroza, Natalia; Orellana, Carlos
- ItemTailoring electroactive surfaces by non-template molecular assembly. Towards electrooxidation of L-cysteine(2017) Santander Nelli, Mireya; Silva, Carlos P.; Espinoza Vergara, Javier; Silva, Juan F.; Olguín, Camila F.; Cortés Arriagada, Diego; Zagal Moya, José Heráclito; Mendizabal, Fernando; Díez Pérez, Ismael; Pavez, Jorge
- ItemTheoretical insights into the adsorption of neutral, radical and anionic thiophenols on gold(111)(2013) Miranda-Rojas, S.; Munoz-Castro, Alvaro; Arratia-Perez, Ramiro; Mendizabal, FernandoThe interaction of thiol and thiolate containing molecules with gold (S-Au) has gained increasing interest because of its applications in molecular electronic devices and catalysis. In this context, the enhanced conductivity of thiophenol compared to alkanethiol represents an opportunity to develop more sensitive and selective gold-based devices by incorporating molecules with the aryl-thiol moiety into their structures. As has been proposed earlier, the thiol moiety is deprotonated after binding to gold, hence, we present here a comparative study of the S-Au bond strength between several neutral and deprotonated aromatic-sulfur systems in their anionic and radical forms with a detailed description of the nature of this interaction. The study was performed by means of computational chemistry methods, using a cluster of 42 Au atoms as a model of the Au(111) surface that allowed us to provide new chemical insights to control the S-Au interface interaction strength. Our results revealed that the thiophenols-gold interaction is mainly dispersive where the interaction energies range between 31 and 43 kcal mol(-1). The radical and anionic thiophenolates-gold interaction increases due to a strong charge transfer character, depicting interaction energies in the range of 50 to 55 kcal mol(-1) and 62 to 92 kcal mol(-1), respectively. These results suggest that for the anionic thiophenolate the binding strength can be tailored according to the electron-donor capabilities of the ligand which in turn can be finely tuned by several substituents. Our results are of possible impact for the design of new devices.
- ItemUnraveling the Nature of the Catalytic Power of Fluoroacetate Dehalogenase(2018) Miranda-Rojas, Sebastian; Fernandez, Israel; Kaestner, Johannes; Toro Labbé, Alejandro; Mendizabal, Fernando