Browsing by Author "Grand, Andre"
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- ItemA Relation between Different Scales of Electrophilicity: Are the Scales Consistent Along a Chemical Reaction?(2012) Morell, Christophe; Herrera Pisani, Bárbara Andrea; Gutiérrez Oliva, Soledad; Ceron, Maria-Luisa; Grand, Andre; Toro Labbé, Alejandro
- ItemIs an elementary reaction step really elementary? Theoretical decomposition of asynchronous concerted mechanisms(2010) Labet, Vanessa; Morell, Christophe Jean-Rene; Toro Labbé, Alejandro; Grand, Andre
- ItemTheoretical Study of Cytosine Deamination from the Perspective of the Reaction Force Analysis(2008) Labet, Vanessa; Morell, Christophe; Grand, Andre; Toro Labbé, Alejandro
- ItemTowards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges(2015) Martinez-Araya, Jorge Ignacio; Grand, Andre; Glossman-Mitnik, DanielBy means of the Spin-Polarized Conceptual Density Functional Theory (SP-CDFT), three 2,6-bis(imino) pyridine catalysts based on iron(II), used for polymerization of ethylene, were studied. The catalysts differed by the substituent group, bearing either -H, -NO2 or -OCH3. To date, catalytic activity, a purely experimental parameter measuring the mass of polyethylene produced per millimole of iron per time and pressure unit at a fixed temperature, has not been explained in terms of local hyper-softness. The latter is a purely theoretical parameter designed for quantifying electronic effects; it is measured using the metal atom responsible for the coordination process with the monomer (ethylene). Because steric effects are not relevant in these kinds of catalysts and only electronic effects drive the catalytic process, an interesting link is found between catalytic activity and the local hyper-softness condensed on the iron atom by means of four functionals (B3LYP, BP86, B97D, and VSXC). This work demonstrates that the use of local hyper-softness, predicted by the SP-CDFT, is a suitable parameter for explaining order relationships among catalytic activity values, thus quantifying the electronic influence of the substituent group inducing this difference; the use of only net electric charges does not lead to clear conclusions. This finding can aid in estimating catalytic activities leading to a more rational design of new catalysts via computational chemistry.