Publications associées à Electron crystallography

Beyond the coupled distortion model: structural analysis of the single domain cupredoxin AcoP, a green mononuclear copper centre with original features

Cupredoxins are widely occurring copper-binding proteins with a typical Greek-key beta barrel fold. They are generally described as electron carriers that rely on a T1 copper centre coordinated by four ligands provided by the folded polypeptide. The discov ...

Royal Soc Chemistry2024

Dual Photoredox and Copper Catalysis: Enantioselective 1,2-Amidocyanation of 1,3-Dienes

Qian Wang, Jieping Zhu, Dan Forster, Weisi Guo

Dual photoredox−transition-metal catalysis has emerged as a powerful tool for the development of chemical transformations. However, its application in the selective difunctionalization of 1,3-dienes remains essentially unexploited. By the synergistic actio ...

2023

Diverting the 5-exo-Trig Oxypalladation to Formally 6-endo-Trig Fluorocycloetherification Product through 1,2-O/Pd(IV) Dyotropic Rearrangement

Qian Wang, Jieping Zhu, Jing Gong

Pd-catalyzed cyclizative functionalization of γ-hydroxyalkenes affords tetrahydrofuran derivatives via a key 5-exo-trig oxypalladation step. Herein, we report a palladium(II)-catalyzed, Selectfluor-mediated formal 6-endo-trig fluorocycloetherification of γ ...

2023

Reconstruction of Angstrom resolution exit-waves by the application of drift-corrected phase-shifting off-axis electron holography

Thierry Meyer, Victor Carle Adrien Boureau

Phase-shifting electron holography is an excellent method to reveal electron wave phase information with very high phase sensitivity over a large range of spatial frequencies. It circumvents the limiting trade-off between fringe spacing and visibility of s ...

Elsevier2023

Synthesis, isolation and application of a sila-ketenyl anion

Rosario Scopelliti, Shiori Fujimori

Ynolates or ketenyl anions, [RCCO]-, are negatively charged reactive intermediates, which can be generated in situ and used for divergent chemical transformations. Ynolates can react either at the oxygen or carbon centres or across the C-C triple bond, mak ...

Springernature2023

Atomic-level structure determination of amorphous molecular solids by NMR

David Lyndon Emsley, Arthur César Pinon, Pinelopi Moutzouri, Manuel Cordova

Structure determination of amorphous materials remains challenging, owing to the disorder inherent to these materials. Nuclear magnetic resonance (NMR) powder crystallography is a powerful method to determine the structure of molecular solids, but disorder ...

Nature Portfolio2023

Many-body screening effects in liquid water

Alfredo Pasquarello, Igor Reshetnyak, Arnaud Guillaume Lorin

The screening arising from many-body excitations is a crucial quantity for describing absorption and inelastic X-ray scattering (IXS) of materials. Similarly, the electron screening plays a critical role in state-of-the-art approaches for determining the f ...

Nature Portfolio2023

New Cu (I) complexes as catalyst for "click" reaction: An experimental and computational study

Farzaneh Fadaei Tirani

In this work, two novel well-defined Cu (I) complexes of a Schiff base ligand are described. For this purpose, N, N '-bis (trans-cinnamaldehyde) ethylenediimine [C20H20N2] (L) and Cu (I) complex of the type [CuC20H20N2)PPh3Cl] (C1) and [Cu(C20H20N2)PPh3Br] ...

WILEY2023

Direct Observation of the Phase Transition in C60 Fullerene

Chengcheng Yan

In the third study, the order-disorder phase transition of single-crystal C60 is studied using time-resolved electron microscopy. Solid C60 undergoes a first-order phase transition upon heating to 260 K. This is a structural transition from the low-tempera ...

EPFL Infoscience2023

In Situ and Time-Resolved Transmission Electron Microscopy of Nanoscale Processes

Chengcheng Yan

Observing the fast dynamics of nanoscale systems is crucial in order to understand and ultimately control their behavior. Characterizing these dynamic processes requires techniques with atomic spatial resolution and a temporal resolution that matches the t ...

EPFL2023

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

Apparent 6-endo-trig Carbofluorination of Alkenes Enabled by Palladium-Based Dyotropic Rearrangement

Qian Wang, Jieping Zhu, Jing Gong

Alkene difunctionalization featuring an intramolecular carbometallation step has been developed into a powerful transformation in organic synthesis. The 5-exo-trig carbometallation is in general highly favored over the alternative 6-endo-trig cyclization. ...

Wiley-VCH Verlag GmbH2022

Landing Proteins on Graphene Trampoline Preserves Their Gas-Phase Folding on the Surface

Klaus Kern, Stephan Rauschenbach, Sven Alexander Szilagyi, Hannah Julia Ochner

Molecule-surface collisions are known to initiate dynamics that lead to products inaccessible by thermal chemistry. These collision dynamics, however, have mostly been examined on bulk surfaces, leaving vast opportunities unexplored for molecular collision ...

AMER CHEMICAL SOC2023

Quantifying the Solution Structure of Metal Nanoclusters Using Small-Angle Neutron Scattering

Francesco Stellacci, Stefan Guldin, Zhi Luo, Ye Yang, Huayan Yang

Metal nanoclusters are a unique class of synthetic material, as their crystal structures can be resolved using X-ray diffraction, and their chemical formula can be precisely determinated from mass spectroscopy. However, a complete structure characterizatio ...

Wiley-VCH Verlag GmbH2022

Structure analysis of beta dicalcium silicate via scanning transmission electron microscope (STEM)

Franco Alberto Zunino Sommariva, Qiao Wang, Junying Zhao, Chaoqi Shi

Beta-dicalcium silicate (beta-C2S), one of the main phases in Portland cement clinker, offers some promising overviews regarding CO2 and energy savings potential compared to alite. Understanding the crystalline structure and reactive sites on beta-C2S surf ...

ELSEVIER SCI LTD2022

Computational Studies of the Proton-Coupled Metal Ion Transport in the SLC11/NRAMP Family of Transporters

Maria Letizia Merlini

In the last years, it has been demonstrated a link between the overload of metal ions inside nervous system cells and the onset of severe neurodegenerative diseases. This prompted the investigation of the structural and functional properties of transporter ...

EPFL2022

Photochemical Alkynylations with Hypervalent Iodine Reagents

Stephanie Grace Elizabeth Amos

Over the past twenty years, photochemical transformations have gained in importance in organic chemistry. Indeed, the development of photocatalysts has allowed the use of visible light as an energy source for chemical transformations. More specifically, ph ...

EPFL2022

Low-Loss Anisotropic Image Polaritons in van der Waals Crystal alpha-MoO3

Sergejs Boroviks

Orthorhombic molybdenum trioxide (alpha-MoO3), a newly discovered polaritonic van der Waals crystal, is attracting significant attention due to its strongly anisotropic mid-infrared phonon-polaritons. At the same time, coupling of polariton with its mirror ...

WILEY-V C H VERLAG GMBH2022

Concrete cancer : characterization of Alkali Silica Reaction early stage products by electron microscopy

Solène Anne-Lise Albinski

Concrete deterioration is a natural process, which has to be carefully monitored over a the service life of a structure. The Alkali-Silica Reaction (ASR) is a slow-process degradation, which devel-ops over decades and is therefore difficult to predict. Sin ...

EPFL2022

Deformation twinning mechanism in magnesium at the microscale: strain rate, temperature and orientation effects

Nicolò Maria Della Ventura

The project aims to validate some recent theoretical developments on the deformation twinning nucleation mechanism in HCP metals through small-scale mechanic experiments. To this end, a systematic investigation of the mechanical response of pure magnesium ...

EPFL2022