Publications associées à Charge formelle

Adding Color to Mass Spectra of Biopolymers: Charge Determination Analysis (CHARDA) Assigns Charge State to Every Ion Peak

Yury Tsybin, Natalia Gasilova, Laure Menin, Anton Kozhinov, Konstantin Nagornov

Traditionally, mass spectrometry (MS) output is the ion abundance plotted versus the ionic mass-to-charge ratio m/z. While employing only commercially available equipment, Charge Determination Analysis (CHARDA) adds a third dimension to MS, estimating for ...

Amer Chemical Soc2024

cell2mol: encoding chemistry to interpret crystallographic data

Rubén Laplaza Solanas, Anne-Clémence Corminboeuf, Sergio Vela Llausi, Yuri Cho

The creation and maintenance of crystallographic data repositories is one of the greatest data-related achievements in chemistry. Platforms such as the Cambridge Structural Database host what is likely the most diverse collection of synthesizable molecules ...

NATURE PORTFOLIO2022

Using collective knowledge to assign oxidation states of metal cations in metal-organic frameworks

Berend Smit, Seyedmohamad Moosavi, Daniele Ongari, Kevin Maik Jablonka

Knowledge of the oxidation state of metal centres in compounds and materials helps in the understanding of their chemical bonding and properties. Chemists have developed theories to predict oxidation states based on electron-counting rules, but these can f ...

NATURE RESEARCH2021

Delivery of a Masked Uranium(II) by an Oxide-Bridged Diuranium(III) Complex

Marinella Mazzanti, Farzaneh Fadaei Tirani, Dieuwertje Katelijn Modder

Oxide is an attractive linker for building polymetallic complexes that provide molecular models for metal oxide activity, but studies of these systems are limited to metals in high oxidation states. Herein, we synthesized and characterized the molecular an ...

Wiley-VCH Verlag GmbH2021

Evaluating Charge Equilibration Methods To Generate Electrostatic Fields in Nanoporous Materials

Berend Smit, Daniele Ongari, Peter George Boyd, Amber Kashan Mace, Özge Kadioglu

Charge equilibration (Qeq) methods can estimate the electrostatic potential of molecules and periodic frameworks by assigning point charges to each atom, using only a small fraction of the resources needed to compute density functional (DFT)-derived charge ...

2019

Extrinsic Defects in Amorphous Oxides: Hydrogen, Carbon, and Nitrogen Impurities in Alumina

Alfredo Pasquarello, Francesco Ambrosio, Zhendong Guo

We present a procedure for addressing extrinsic defects in amorphous oxides, in which the most stable defect configurations are identified through ab initio molecular dynamics in various charge states and studied through hybrid functional calculations. The ...

American Physical Society (APS)2019

Transferable Machine-Learning Model of the Electron Density

Michele Ceriotti, Anne-Clémence Corminboeuf, Alberto Fabrizio, David Mark Wilkins, Benjamin André René Meyer, Andrea Grisafi

The electronic charge density plays a central role in determining the behavior of matter at the atomic scale, but its computational evaluation requires demanding electronic-structure calculations. We introduce an atom-centered, symmetry-adapted framework t ...

2019

Orientational ordering of water in extended hydration shells of cations is ion-specific and is correlated directly with viscosity and hydration free energy

Yixing Chen, Sylvie Roke, Halil Ibrahim Okur, Chung-Wen Liang

Specific ion effects in aqueous solutions are investigated at the molecular, nanoscopic and macroscopic levels. Femtosecond elastic second harmonic scattering (fs-ESHS) is used here to assess the chemical effects of ions on molecular and nanoscopic length ...

2017

Development of Accurate and Efficient Electronic Structure Approaches for the Description of Organic Systems

Riccardo Petraglia

The overarching objective of this thesis is extending and adapting the set of computational tools available for describing molecular precursors of organic semiconductors. The research presented within develops adhering to three principle goals: (1) provide ...

EPFL2016

Valence and conduction band tuning in halide perovskites for solar cell applications

Ursula Röthlisberger, Simone Meloni, Giulia Palermo, Negar Ashari Astani

We performed density functional calculations aimed at identifying the atomistic and electronic structure origin of the valence and conduction band, and band gap tunability of halide perovskites ABX(3) upon variations of the monovalent and bivalent cations ...

Royal Society of Chemistry2016

Dissociation of charge transfer states and carriers separation in bilayer organic solar cells - A time-resolved electroabsorption spectroscopy study

Jacques-Edouard Moser, Jelissa Risse, Roland Hany

Ultrafast optical probing of the electric field by means of Stark effect in planar heterojunction cyanine dye / fullerene organic solar cells enables to directly monitor the dynamics of free electron formation during the dissociation of interfacial charge ...

Amer Chemical Soc2015

Synthesis, structural determination, theoretical studies and catalytic activity of Mn(II) complex of N-isonicotinyl phosphoric triamide ligand

Kurt Schenk, Farzaneh Fadaei Tirani

synthesized and characterized by H-1, C-13, P-31 NMR and IR spectroscopies. The reaction of MnCl2 center dot 4H(2)O with L led to the formation of a new 3D system {MnL2Cl2}(n)center dot 34CH(3)OH (C-1). X-ray crystallographic data revealed that the ligand ...

Elsevier Science Sa2015

Charge Asymmetry at Aqueous Hydrophobic Interfaces and Hydration Shells

Sylvie Roke, Yixing Chen, Rüdiger Scheu, Kailash Chandra Jena

The solvation of ions in a dielectric continuum is symmetric with respect to the sign of the ionic charge. Yet, many phenomena show indirect evidence that water may have a preference for negative charge: the vast majority of biological membrane interfaces ...

Wiley-Blackwell2014

Chlorination of bromide-containing waters: Enhanced bromate formation in the presence of synthetic metal oxides and deposits formed in drinking water distribution systems

Urs von Gunten, Chao Liu

Bromate formation from the reaction between chlorine and bromide in homogeneous solution is a slow process. The present study investigated metal oxides enhanced bromate formation during chlorination of bromide-containing waters. Selected metal oxides enhan ...

Elsevier2013

Assessment of Intra- and Intermolecular Effects by Computational NMR

Daniel Filipe Dos Santos Alves Jana

This thesis addresses advances in the field of computational Nuclear Magnetic Resonance (NMR) with two specific objectives: 1) developing an approach enabling the direct probing of intramolecular electronic effects on molecular properties; 2) assessing and ...

EPFL2012

Understanding and Minimizing Density Functional Failures Using Dispersion Corrections

This thesis introduces original formalisms to achieve an accurate description of dispersion interactions within the framework of density functional theory. The presented research focuses on two specific objectives related to density functional approximatio ...

EPFL2012

IR spectroscopy of isolated metal-organic complexes of biocatalytic interest: Evidence for coordination number four for Zn2+(imidazole)(4)

Ulrich Lorenz

The characterization of the interactions of Zn2+ ions with imidazole ligands is vital for understanding the function of a plethora of zinc enzymes at the molecular level. The infrared multiple photon dissociation (IRMPD) spectrum of mass selected Zn2+(imid ...

2011

Formation of substoichiometric GeOx at the Ge-HfO2 interface

Alfredo Pasquarello, Peter Broqvist, Jan Felix Binder

The stability of oxygen vacancies across the Ge-HfO2 interface is studied through semilocal and hybrid density-functional calculations. On the semiconductor side, the formation energies are obtained for substoichiometric GeOx of varying x through the use o ...

American Institute of Physics2010

Tertiary Chiral Domains Assembled by Achiral Metal-Organic Complexes on Cu(110)

Klaus Kern, Giovanni Costantini

We report on the formation of chiral domains self-assembled from terephthalic acid (TPA) and iron on a Cu(110) surface. Using scanning tunnelling microscopy, we observe that the supramolecular structures are organized on successive hierarchical levels. Chi ...

2010

Charge state of the O-2 molecule during silicon oxidation through hybrid functional calculations

Alfredo Pasquarello, Peter Broqvist, Audrius Alkauskas

We study the charge state of the diffusing O-2 molecule during silicon oxidation through hybrid functional calculations. We calculate charge-transition levels of O-2 in bulk SiO2 and use theoretical band offsets to align these levels with respect to the Si ...

2008