22 research outputs found
From symmetry breaking in the bulk to phase transitions at the surface: a quantum-mechanical exploration of Li6PS5Cl argyrodite superionic conductor
A DFT(-D) revisitation of MgCl2-supported Ziegler-Natta catalysts: the question of TiCl4 adsorption
Spectroscopic Evidences for TiCl4/Donor Complexes on the Surface of MgCl2-Supported Ziegler-Natta Catalysts
Conformational Behavior and Magnetic Properties of a Nitroxide Amino Acid Derivative in Vacuo and in Aqueous Solution
The Bond Analysis Techniques (ELF and Maximum Probability Domains) Application to a Family of Models Relevant to Bio-Inorganic ChemistryApplications of Density Functional Theory to Biological and Bioinorganic Chemistry
Electron Localization Function (ELF) and Maximum Probability
Domain (MPD) analyses have been applied to model metal–porphyrins and show
compatible and complementary results. ELF basins are quite different from MPDs,
but are a necessary starting point for optimizing them. The analyses of the bond
between the metal and porphyrin do not show significant differences between nontransition
and transition metals. In all the cases considered, we find signatures
characteristic of essentially ionic bonds
Theoretical Analysis of the Reactivity of Carbon Nanotubes: Local Versus Topological Effects
In carbon materials the mobile π electrons are situated in topologically different circumstances at edge sites, and their π electronic states, essentially controlled by the network structure of sp2 carbon, may be significantly affected. In this work, we derived topological indications about the reactivity of carbon nanotubes and fullerenes with the hydroxyl radical (OH•), the most important oxidizing species in the troposphere. For each molecular structure, we computed the local softness, the Mulliken charges of the reacting carbons of (n,n) and (n,0) clusters, and their Huckel-type aromaticity rules, as an index to determine topologically independent sites and predicting a certain grade of reactivity of the nanotube and fullerenic carbon atoms. Using local softness, closely related to the energy gap, it was possible to separate the periodical nanotubes in three families according to their reactivity. A connection between the reactivity index ΔE and the topology was established by means of the Fukui integrated function. It resulted that for (n,0) clusters, odd n implies aromaticity, whereas even n, non-aromaticity; (n,n) clusters are in any case non-aromatic. For a better understanding of some experimental results, we also discussed how edge effects can influence topological reactivity due to the increment of the number of benzene rings in some cluster arrangements
Disordered Chain Conformations of Poly(tetrafluoroethylene) in the High-Temperature Crystalline Form I
Electron Localization Function and Maximum Probability Domains analysis of semi-ionic oxides crystals, surfaces and surface defects
Maximum Probability Domain (MPD) analysis has been recently applied to
pure covalent and ionic crystals. The present study is devoted to a
first MPD analysis of semi ionic crystals, Silicon Oxide, Aluminum Oxide
and Titanium Oxide. These crystals are involved in important catalytic
and photo-catalytic processes occurring on their surfaces. For this
reason the study has been performed on bulk crystal and on surface slab
models. Also surface neutral oxygen vacancy, the F-0 surface defect, has
been considered. The Electron Localization Function (ELF) analysis has
also been performed, due to its holistic approach to electronic
structures. (C) 2015 Published by Elsevier BM