Publications associées à Hyperconjugaison

Controlling On-Surface Photoactivity: The Impact of π-Conjugation in Anhydride-Functionalized Molecules on a Semiconductor Surface

On-surface synthesis has become a prominent method for growing low-dimensional carbon-based nanomaterials on metal surfaces. However, the necessity of decoupling organic nanostructures from metal substrates to exploit their properties requires either trans ...

Wiley-VCH Verlag GmbH2024

High-Density Immobilization of TCEP on Silica Beads for Efficient Disulfide Reduction and Thiol Alkylation in Peptides

Christian Heinis

Tris-(2-carboxyethyl)phosphine (TCEP) linked to agarose beads is widely used for reducing disulfide bridges in proteins and peptides. The immobilization of TCEP on beads allows efficient removal after reduction to prevent its reaction with alkylating reage ...

2023

Light-Responsive Oligothiophenes Incorporating Photochromic Torsional Switches

Kevin Sivula, Emilie Baudat, Giuseppe Sforazzini, Muhammad Aiman Bin Rahmanudin Hamdan, Augustina Jozeliunaite

We present a quaterthiophene and sexithiophene that can reversibly change their effective pi-conjugation length through photoexcitation. The reported compounds make use of light-responsive molecular actuators consisting of an azobenzene attached to a bithi ...

WILEY-V C H VERLAG GMBH2022

Helical versus linear Jahn-Teller distortions in allene and spiropentadiene radical cations

Rubén Laplaza Solanas, Anne-Clémence Corminboeuf, Marc Hamilton Folkmann Garner

The allene radical cation can be stabilized both by Jahn-Teller distortion of the bond lengths and by torsion of the end-groups. However, only the latter happens and the allene radical cation relaxes into a twisted D-2 symmetry structure with equal double- ...

ROYAL SOC CHEMISTRY2022

Insights into the microbial reduction of pentavalent and hexavalent uranium species by Shewanella oneidensis MR-1

Margaux Camille Andréa Molinas

Decades of uranium-related activities such as ore mining, nuclear power generation, weapon manufacture, storage of nuclear wastes, have contributed to the release of U in the environment. U occurrence is concerning, since in surface environments, U is typi ...

EPFL2021

Trisubstituted geminal diazaalkene derived transient 1,2-carbodications

Shubhajit Das

The coulombic repulsion between two adjacent cation centres of 1,2-carbodications is known to decrease with pi- and/or n-donor substituents by a positive charge delocalization. Here we report the delocalization of the positive charge of transient 1,2-carbo ...

Royal Society of Chemistry2020

Crossed Molecular Beams and Theoretical Studies of the O(P-3)+1,2-Butadiene Reaction: Dominant Formation of Propene plus CO and Ethylidene plus Ketene Molecular Channels

Silvia Tanteri, Adriana Caracciolo

Detailed understanding of the mechanism of the combustion relevant multichannel reactions of O(P-3) with unsaturated hydrocarbons (UHs) requires the identification of all primary reaction products, the determination of their branching ratios and assessment ...

CHINESE PHYSICAL SOC2019

Why are sec-alkylperoxyl bimolecular self-reactions orders of magnitude faster than the analogous reactions of tert-alkylperoxyls? The unanticipated role of CH hydrogen bond donation

Ganna Gryn'ova

High-level ab initio calculations are used to identify the mechanism of secondary (and primary) alkylperoxyl radical termination and explain why their reactions are much faster than their tertiary counterparts. Contrary to existing literature, the decompos ...

Royal Soc Chemistry2016

Photochromic Torsional Switch (PTS): a Light-Driven Actuator for the Dynamic Tuning of π-Conjugation Extension

Anne-Clémence Corminboeuf, Pascal Miéville, Riccardo Petraglia, Emilie Baudat, Giuseppe Sforazzini, Adrien Georges Nicolai, Adam Antoni Sobczuk, Luca Cervini

Here we present a molecular architecture that can reversibly change the geometric conformation of its π-system backbone via irradiation with two different wavelengths. The proposed ‘molecular actuator’ consists of a photoswitchable azobenzene orthogonally ...

2016

Synthetic Approaches to Functional Derivatives of Cycl[3.2.2]Azine-1,2-Dicarboxylic Acid - Perspective Building Blocks for pi-Extended Macrocyclic Compounds

Fedor Zhurkin

One of the actual goals in the field of macrocyclic research is to provide accessible chemically robust compounds with absorption in the NIR spectral region. This requirement can be fulfilled in the case of tetrapyrrolic derivatives such as porphyrins, pht ...

Bentham Science Publ Ltd2015

Importance of Unpaired Electrons in Organic Electronics

Mariateresa Scarongella, Natalie Renuka Banerji

The first observation that PBBTPD, a low bandgap, ambipolar conjugated donor-acceptor (DA) polymer based on benzobisthiadiazole (BBT), possesses an open-shell singlet ground state as well as a thermally accessible triplet state is described. Similarly, int ...

Wiley-Blackwell2015

Long-Range π-Conjugation in Phenothiazine-containing Donor-Acceptor Dyes for Application in Dye-Sensitized Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jacques-Edouard Moser, Carole Graetzel, Jinhyun Kim, Thomas Moehl, Mateusz Barnaba Wielopolski, Yuxiang Yu

Four organic donor–π-bridge–acceptor dyes containing phenothiazine as a spacer and cyanoacrylic acid as an acceptor were synthesized and tested as sensitizers in dye-sensitized solar cells (DSCs). The influence of iodide- and cobalt-based redox electrolyte ...

Wiley-VCH Verlag Berlin2015

Solvent Effects on the Encapsulation of Divalent Ions by Benzo-18-Crown-6 and Benzo-15-Crown-5

Thomas Rizzo, Yoshiya Inokuchi

We measure UV photodissociation (UVPD) spectra of cold benzo-15-crown-5 (B15C5) and benzo-18-crown-6 (B18C6) complexes with divalent ions (M2+ = Ca2+, Sr2+, Ba2+, and Mn2+), solvated with an H2O or a CH3OH molecule: M2+·B15C5·H2O, M2+·B15C5·CH3OH, M2+·B18C ...

American Chemical Society2015

Direct Evaluation of the Hyperconjugative Interactions in 1,1,1-Trihaloethane (CH3CX3, X = F, Cl, and Br)

Anne-Clémence Corminboeuf, Zhenhua Chen

Following the computational strategy proposed by Mulliken in 1939 (J. Chem. Phys. 1939, 7 (5), 339-352), when the concept of hyperconjugation was coined, we evaluated the hyperconjugative stabilization energy in 1,1,1-trihaloethane using the block-localize ...

Amer Chemical Soc2014

Origin of the Spectral Shifts among the Early Intermediates of the Rhodopsin Photocycle

Ursula Röthlisberger, Ivano Tavernelli, Pablo Campomanes Ramos, Marilisa Neri, Stefano Vanni, Bruno Araujo Cautiero Horta

A combined strategy based on the computation of absorption energies, using the ZINDO/S semiempirical method, for a statistically relevant number of thermally sampled configurations extracted from QM/MM trajectories is used to establish a one-to-one corresp ...

2014

Structure-property relationships based on Hammett constants in cyclometalated iridium(III) complexes: their application to the design of a fluorine-free FIrPic-like emitter

Mohammad Khaja Nazeeruddin, Rosario Scopelliti, Ursula Röthlisberger, Ivano Tavernelli, Basile Curchod, Julien Edouard Frey

While phosphorescent cyclometalated iridium(III) complexes have been widely studied, only correlations between oxidation potential EOX and Hammett constant sigma, and between the redox gap (Delta E-REDOX = E-OX-E-RED) and emission or absorption wavelength ...

2014

Intricacies of Describing Weak Interactions involving Halogen Atoms within Density Functional Theory

Ursula Röthlisberger, Ivano Tavernelli, Manuel Dömer

In this work we assess the performance of different dispersion-corrected DFT approaches (M06, M06-2X, DFT-D3 and DCACP) in reproducing high-level wave function based benchmark calculations on the weakly bound halogen dimers (X2)2 and X2-Ar (for X=F,Cl,Br,I ...

Amer Chemical Soc2013

The biphenyl-monitored effective size of unsaturated functional or fluorinated ortho substituents

The size of a series of typical substituents has been probed by dynamic NMR measurements of the barriers to aryl-aryl rotation of the corresponding biphenyls. The resulting B values are meaningful because only mono-ortho substituted compounds were investig ...

2010

Structure and Bonding of Isoleptic Coinage Metal (Cu, Ag, Au) Dimethylaminonitrenes in the Gas Phase

Thomas Rizzo, Natalia Nagornova, Oleg Boyarkine, Peter Chen

Dimethylaminonitrene complexes of IMesM+ (IMes = 1,3-bis(2,4,6-trimethylphenyl)- imidazol-2-ylidene; M = Cu, Ag, Au) were prepared in the gas phase and structurally characterized by high-resolution infrared spectroscopy of the cold species, ion-molecule re ...

American Chemical Society2010

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