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Concept

Effet anomérique

Publications associées (13)

Indication of 310-Helix Structure in Gas-Phase Neutral Pentaalanine

Vasyl Yatsyna

We investigate the gas-phase structure of the neutral pentaalanine peptide. The IR spectrum in the 340-1820 cm-1 frequency range is obtained by employing supersonic jet cooling, infrared multiphoton dissociation, and vacuum-ultraviolet action spectroscopy. ...

AMER CHEMICAL SOC2023

cgNA+: A sequence-dependent coarse-grain model of double-stranded nucleic acids

Rahul Sharma

DNA mechanics plays a crucial role in many biological processes, including nucleosome positioning and protein-DNA interactions. It is believed that nature employs epigenetic modifications in DNA to further regulate gene expression. Moreover, double-strande ...

EPFL2023

Low-energy stereodynamics of ion-forming reactions

Junwen Zou

In this thesis, an experimental study of low-temperature stereodynamics in the reactive scattering of Ne(3P2) + X collisions (X = Ar, Kr, Xe, CO and N2) is presented. The steric effect of Ne(3P2) in these reactions is observed experimentally using a contro ...

EPFL2021

Revealing Single-Bond Anomeric Selectivity in Carbohydrate-Protein Interactions

Oleg Boyarkine, Aleksandr Pereverzev, Ruslan Yamaletdinov, Viktoriia Aladinskaia

The noncovalent binding of proteins to glycans is amazingly selective to the isoforms of carbohydrates, including alpha/beta anomers that coexist in solution. We isolate in the gas phase and study at the atomic level the simplest model system: noncovalent ...

AMER CHEMICAL SOC2020

Rational Design of Hole Transport Materials: Tools and Structure-Packing-Property Relationships

Kun-Han Lin

The growing demand for low-cost, large-scale and flexible electronics has led to a boost in research on organic semiconductors (OSC). Understanding structure-packing-property relationships (SPPR) and the role of molecular building blocks in charge transpor ...

EPFL2020

Cryogenic Ion Spectroscopy for Identification of Monosaccharide Anomers

Thomas Rizzo, Valeriu Scutelnic

We combine conformer-selective, cryogenic infrared spectroscopy, quantum mechanical computations, and 18O substitution at the reducing end to determine the structural preferences of protonated glucosamine in the gas phase. Cryogenic infrared-infrared (IR-I ...

2019

Mixed-linker UiO-66: structure-property relationships revealed by a combination of high-resolution powder X-ray diffraction and density functional theory calculations

Berend Smit, Nicola Casati, Davide Tiana

The use of mixed-linker metal-organic frameworks (MIXMOFs) is one of the most effective strategies to modulate the physical-chemical properties of MOFs without affecting the overall crystal structure. In many instances, MIXMOFs have been recognized as soli ...

2017

Rotational barriers of biphenyls having heavy heteroatoms as ortho-substituents: experimental and theoretical determination of steric effects

The free energies of activation for the aryl-aryl rotation of 17 biphenyl derivatives, bearing a heavy heteroatom (S, Se, Te, P, Si, Sn) as ortho substituent, have been measured by variable temperature NMR. These numbers, so called B values, represent a me ...

2012

Conformational Preferences of Gas-Phase Helices: Experiment and Theory Struggle to Agree: The Seven-Residue Peptide Ac-Phe-(Ala)5-Lys-H+

Thomas Rizzo

The physical chemistry of bio molecules in the gas phase is progressing at a rapid pace. One of the most promising areas is the determination of the conformations of biologically important molecules. Quantitative determination of their relative energies is ...

Wiley-V C H Verlag Gmbh2012

Steric Effects in the Chemisorption of Vibrationally Excited Methane on Ni(100)

Rainer Beck, Régis Bisson, Bruce Yoder

Newly available, powerful infrared laser sources enable the preparation of intense molecular beams of quantum-state prepared and aligned molecules for gas/surface reaction dynamics experiments. We present a stereodynamics study of the chemisorption of vibr ...

American Association for the Advancement of Science2010

Metalation of 2-Heterosubstituted Naphthalenes at the 1- or 3-Position: Factors That May Determine the Regiochemistry

Upon metalation and subsequent electrophilic trapping, 2-fluoronaphthalene inevitably gives rise to regioisomeric mixtures in varying proportions, whereas 2-(trifluoromethyl) naphthalene undergoes deprotonation either at the 1- or the 3-position, depending ...

Georg Thieme Verlag2010

Synthesis and Conformational Analysis of (alpha-D-Galactosyl)phenylmethane and alpha-,beta-Difluoromethane Analogues: Interactions with the Plant Lectin Viscumin

Pierre Vogel, Maria Kolympadi

alpha-D-Galactosyl)phenylmethane (1). (alpha- and beta-D-galactosyl)-(difluoro)phenylmethane (2 and 3) have been prepared and their conformations in solution were described by using a combination of force-field calculations and NMR spectroscopic studies. G ...

2009

Recent Synthetic Approaches Toward Non-anomeric Spiroketals in Natural Products

Pierre Vogel, Sandrine Gerber, Sylvain Favre

Many natural products of biological interest contain [6,5]- and [6,6]-spiroketal moieties that can adopt various configurations, benefiting or not from anomeric conformation stabilizing effects. The spiroketal fragments are often important for the biologic ...

2008