Browsing by Author "XX617897"
Now showing items 41-60 of 90
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Mendizábal Emaldía, Fernando; Contreras Ramos, Renato; Aizman, Arie (1997)The electronic structure of 1T-TiS2 intercalated with lithium is analysed within a molecular approach that uses a finite-size cluster to represent the solid. Electronic descriptors such as the electronic chemical potential, ...
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Miño Galaz, Germán; Contreras Ramos, Renato (Elsevier, 2010)Hydrogen bond shortening and strengthening induced by confinement within fullerenes for a series of hydrogen bonded bihalides were studied. Significant increase in the electron localizability at the hydrogen bond region ...
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Campodónico, Paola R.; Andrés, Juan; Aizman, Arie; Contreras Ramos, Renato (2007)We propose that a specific property of a chemical fragment, its regional electrophilicity, be taken as defining its nucleofugality index nu(PG) in alpha-elimination reactions. We tabulate this quantity for a series of ...
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Cedillo, A.; Contreras Ramos, Renato; Galván, M.; Aizman, Arie; Andrés, Juan; Safont, Vincent S. (2007)We introduce and test a nucleophilicity index as a new descriptor of chemical reactivity. The index is derived from a perturbation model for the interaction between the nucleophile and a positive test charge. The computational ...
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Soto Delgado, Jorge; Aizman, Arie; Contreras Ramos, Renato; Domingo, Luis R. (2012)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 ...
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Pérez Méndez, Claudio; Fuentealba, Claudio; Contreras Ramos, Renato (2009)In the process of evaluating intrinsic electronic chemical potentials and related properties of anions in the gas phase, positive values for this quantity often arise. We herein examine in detail this result in terms of ...
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Gallardo Fuentes, Sebastián; Contreras Ramos, Renato; Isaacs, Mauricio; Honores, Jessica; Quezada, Diego; Landaeta, Esteban; Ormazábal Toledo, Rodrigo (Elsevier, 2016)We herein present a systematic study on the mechanism of CO2 electro-cycloaddition to propylene oxide, using both experimental and theoretical procedures. The study considers the analysis of mild and sustainable conditions ...
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Miño, German; Contreras Ramos, Renato (2009)The electronic properties of a chemical model that mimics the His-57 ••• Asp-102 catalytic residues of α-chymotrypsine during the transition from normal hydrogen bond to short and strong hydrogen-bond regimes are presented. ...
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Contreras Ramos, Renato; Aizman, Arie (1986)Further developments in the local reaction field (LRF) model of solvent effects are presented. The improved formalism, including dielectric saturation effects, permits a better description of the solvent polarization vector. ...
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Contreras Ramos, Renato; Aizman Rosemblum, Arie (Wiley, 1985)The introduction of local dielectric effects within the SCF theory of continuum solvent effects representation is examined at a semiempirical level. The formalism is developed in the frame of the reaction field theory ...
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On the variations of electronic chemical potential and chemical hardness induced by solvent effects Meneses, L.; Fuentealba Rosas, Patricio; Contreras Ramos, Renato (ELSEVIER, 2006-12-29)The effects that a polarizable medium exerts on the electronic chemical potential and the chemical hardness of neutral and charged molecules are discussed in detail, using the continuum approach based on the polarizable ...
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Gallardo Fuentes, Sebastian; Contreras Ramos, Renato; Ormazabal Toledo, Rodrigo (ROYAL SOC CHEMISTRY, 2016)The mechanism of the ANRThe mechanism of the ANRORC-like ring transformation of nitroimidazole derivatives towards aniline has been studied by fully exploring the potential energy surface (PES). For this purpose the reaction ...
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Campodónico, Paola R.; Ormazábal Toledo, Rodrigo; Aizman, Arie; Contreras Ramos, Renato (Elsevier, 2010)We herein report on the group electrophilicity of molecular fragments present in the title compounds to describe leaving group abilities in reactions of aryl benzoates toward CN . It is found that the presence ...
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González Suárez, Mauricio; Aizman, Arie; Contreras Ramos, Renato (Springer-Verlag, 2010)We present herein a model to deal with the chemical reactivity, selectivity and site activation concepts of p electron systems derived by merging the classical Coulson–Longuet-Higgins response function theory based on ...
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Domingo, Luis R.; Pérez López, Patricia; Contreras Ramos, Renato (WILEY-V C H VERLAG GMBH, 2006-01-16)Small cycloalkynes possess a pi-strain-induced electrophilicity related to the bending of the C-SP3-C-SP-C-SP bond angle. For cyclopentyne and benzyne, the electrophilicity index defined in the context of density functional ...
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Ormazábal Toledo, Rodrigo; Castro, Enrique A.; Santos, José G.; Millán, Daniela; Cañete, Alvaro; Contreras Ramos, Renato; Campodónico, Paola R. (2012)In nucleophilic substitution reactions at carbonyl centres, there are two possible channels. The first one occurs when the attack of nucleophilic agents takes place simultaneously with the departure of the nucleofuge. This ...
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Rivas, Pilar; Zapata Torres, Gerald; Melin, Junia; Contreras Ramos, Renato (2004)The hydride transfer process between the isoalloxazine moiety of flavins and the nicotinamide moiety of NAD(P)H has been explored by using density functional theory based reactivity index in the 1-methylnicotinamide-lumiflavine ...
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Contreras Ramos, Renato; Gómez Jeria, Juan (American Chemical Society, 1984)SCF-CNDO/2 calculations, including the continuum solvent effects via an extended version of the generalized Born formula, have been performed for H30+.-.(H20),..a-ndO H(-H 20),..-H.3O0Ht--s p.ec ies (n = 0, 1,2). The ...
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Contreras Ramos, Renato; Gómez Jeria, Juan (American Chemical Society, 1983-07-19)SCF-CNDO/2 calculations, including the continuum solvent effects via an extended version of the generalized Born formula, have been performed for H30+··.(H20) •.•. OH- and (H20) •... Hp+ ... OH- species (n = 0,1,2). The ...
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Campodónico, Paola R.; Andrés, Juan; Aizman, Arie; Contreras Ramos, Renato (Elsevier, 2008-10-23)Experimental observations show that for the gas phase isomerization of protonated molecules, a third body can transport a proton from a high-energy site to a lower energy-site of the substrate, thereby catalyzing the ...