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Concept

Isomer

Publications associées (31)

Carboxylic acid isomer-directed synthesis of CdS nanocluster isomers

Mingyang Liu

Selective synthesis of nanocluster (NC) isomers with tailored structures holds significant importance for enhancing their applications. Here, we develop an effective strategy for the selective synthesis of CdS NC isomers through the judicious choice of a p ...

Royal Soc Chemistry2024

Investigations about the Chemistry of Tetraarylethene- and Iridium-Based Luminophores

Anastasia Gitlina

The work described in this thesis focuses on two classes of luminophores: tetraarylethene-based polymers and Ir(III) complexes with orthometalated ligands. Tetraarylethene-based polymers show aggregation-induced emission (AIE) and they are of interest for ...

EPFL2024

The acid-mediated isomerization of iridium(iii) complexes with cyclometalated NHC ligands: kinetic vs. thermodynamic control

Kay Severin, Farzaneh Fadaei Tirani, Anastasia Gitlina

The isomerization of iridium(III) complexes with metalated N-heterocyclic carbene (NHC) ligands was studied. The fac isomers of complexes with 1-phenyl-3-methylbenzimidazolin-2-ylidene or 1-phenyl-3-benzylbenzimidazolin-2-ylidene ligands are transformed cl ...

2023

Influence of structural dynamics on cell uptake investigated with single-chain polymeric nanoparticles

Francesco Stellacci, Lixia Wei, Suiyang Liao, Arthur Eliot Bouchez

Most nanoparticles' parameters affect their interactions with cells. To date, all the parameters studied are basically static (e.g., size, shape, ligands, and charge). This is unfortunate, because proteins have struc-tural dynamics that most nanoparticles ...

CELL PRESS2023

New Approach for the Identification of Isobaric and Isomeric Metabolites

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr

The structural elucidation of metabolite molecules is important in many branches of the life sciences. However, the isomeric and isobaric complexity of metabolites makes their identification extremely challenging, and analytical standards are often require ...

2023

Probing Water Dissociation and Oxygen Replacement on Partially Oxygen-Covered Cu(111) by Reflection Absorption Infrared Spectroscopy

Rainer Beck, Harmina Vejayan, Mateusz Suchodol

The presence of chemisorbed oxygen on the Cu(111) surface is known to strongly reduce the activation barrier for water dissociation as compared to bare Cu(111). Here, we present direct experimental evidence for the hydrogen abstraction mechanism responsibl ...

2023

Advancing Glycan Analysis: Cryogenic Ion Spectroscopy for Database-Driven Identification

Ali H Abikhodr

Glycans play a pivotal role in both physiological processes; however, the field of glycobiology remains relatively understudied within biochemistry. The intricate complexity of glycans, coupled with their abundance of isomeric forms, presents formidable ch ...

EPFL2023

Identification of N-glycan positional isomers by combining IMS and vibrational fingerprinting of structurally determinant CID fragments

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Priyanka Bansal

While glycans are present on the surface of cells in all living organisms and play key roles in most biological processes, their isomeric complexity makes their structural characterization challenging. Of particular importance are positional isomers, for w ...

ROYAL SOC CHEMISTRY2022

Acid-base-induced fac → mer isomerization of luminescent iridium(iii) complexes

Kay Severin, Farzaneh Fadaei Tirani, Albert Ruggi, Anastasia Gitlina

Luminescent Ir(C^N)3 complexes (C^N = cyclometalated arylpyridine ligand) exist in the form of two stable isomers with distinct photophysical and electrochemical properties: fac and mer. Herein, we show that fac-Ir(C^N)3 complexes can be converted into the ...

2022

Identification of Mobility-Resolved N-Glycan Isomers

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Priyanka Bansal, Robert Paul Pellegrinelli

Glycan analysis has evolved considerably during the last decade. The advent of high-resolution ion-mobility spectrometry has enabled the separation of isomers with only the slightest of structural differences. However, the ability to separate such species ...

AMER CHEMICAL SOC2022

Mechanistic Insight into Supramolecular Polymerization in Water Tunable by Molecular Geometry

Lukas Pfeifer

Supramolecular self-assembly in water based on non-covalent bonding is attracting major attention due to the potential of hydrogels and aqueous polymers in biomedical applications. Although supramolecular polymerization in organic solvents is well establis ...

CHINESE CHEMICAL SOC2022

Combining multi-stage ion mobility spectrometry with cryogenic infrared spectroscopy for glycan analysis

Priyanka Bansal

Structural analysis of biomolecules is essential to understanding biological processes. Among the various classes of biomolecules, glycans have gained significant attention recently due to their ubiquitous roles in biological systems. However, study of gly ...

EPFL2022

A New Strategy Coupling Ion-Mobility-Selective CID and Cryogenic IR Spectroscopy to Identify Glycan Anomers

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Eduardo Carrascosa Casado, Priyanka Bansal, Robert Paul Pellegrinelli, Lei Yue

Determining the primary structure of glycans remains challenging due to their isomeric complexity. While high-resolution ion mobility spectrometry (IMS) has recently allowed distinguishing between many glycan isomers, the arrival-time distributions (ATDs) ...

2022

High-Throughput Multiplexed Infrared Spectroscopy of Ion Mobility-Separated Species Using Hadamard Transform

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr, Vasyl Yatsyna

Coupling vibrational ion spectroscopy with highresolution ion mobility separation offers a promising approach for detailed analysis of biomolecules in the gas phase. Improvements in the ion mobility technology have made it possible to separate isomers with ...

AMER CHEMICAL SOC2022

A new approach for identifying positional isomers of glycans cleaved from monoclonal antibodies

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Priyanka Bansal, Vasyl Yatsyna, Natalia Yalovenko

Glycosylation patterns in monoclonal antibodies (mAbs) can vary significantly between different host cell types, and these differences may affect mAbs safety, efficacy, and immunogenicity. Recent studies have demonstrated that glycan isomers with the termi ...

2021

Is a Single Conformer Sufficient to Describe the Reorganization Energy of Amorphous Organic Transport Materials?

Anne-Clémence Corminboeuf, Kun-Han Lin, Jacob Terence Blaskovits, Raimon Fabregat I De Aguilar-Amat, Iwona Swiderska

The reorganization energy (lambda), which quantifies the structural rearrangement of a molecule when accommodating a charge, is a key parameter in the evaluation of charge mobility in molecular solids. However, it is unclear how lambda is influenced by con ...

AMER CHEMICAL SOC2021

Constraining the response factors of an extractive electrospray ionization mass spectrometer for near-molecular aerosol speciation

Julia Schmale

Online characterization of aerosol composition at the near-molecular level is key to understanding chemical reaction mechanisms, kinetics, and sources under various atmospheric conditions. The recently developed extractive electrospray ionization time-of-f ...

2021

Photoisomerization of Linear and Stacked Isomers of a Charged Styryl Dye: A Tandem Ion Mobility Study

Eduardo Carrascosa Casado

The photoisomerization behavior of styryl 9M, a common dye used in material sciences, is investigated using tandem ion mobility spectrometry (IMS) coupled with laser spectroscopy. Styryl 9M has two alkene linkages, potentially allowing for four geometric i ...

AMER CHEMICAL SOC2021

Identifying Mixtures of Isomeric Human Milk Oligosaccharides by the Decomposition of IR Spectral Fingerprints

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Vasyl Yatsyna, Ali H Abikhodr

The analysis of glycans presents a significant challenge that arises from their isomeric heterogeneity. While high-resolution ion mobility spectrometry (IMS) has shown the ability to resolve subtly different glycan isomers, their unambiguous assignment rem ...

2021

Natural Product Synthesis Enabled by Domino Processes Incorporating a 1,2-Rearrangement Step

Jieping Zhu, Qian Wang, Bastien Delayre

The art of natural product total synthesis is closely associated with two major determinants: the development/application of novel chemical reactions and the innovation in strategic use of classic organic reactions. While purposely seeking/applying a new s ...

2021