Christelle Gautier's research while affiliated with University of Angers and other places

Publications (29)

Article
The results reported in this study clearly show that it is possible to easily control the formation of a functional monolayer by spontaneous reduction of an aryldiazonium salt on gold...
Article
This work reports the first in-situ and real-time resolved spectroelectrochemical monitoring of a diazonium electrografting. Exploiting the 4-nitrobenzene diazonium salt reduction, we provide a spectral characterization of the adsorption kinetic...
Article
Full-text available
The surface modification by organics has been booming over the past twenty years in the context of the development of 2D nanomaterials for a wide range of applications. The diazonium salt chemistry represents a valued approach since it allows the covalent attachment, under mild experimental conditions, of functional moieties to various substrates....
Article
A new method to follow in‐situ grafting kinetics of diazonium compounds, based on the imposing of small amplitude high frequency AC oscillations at grafting potential, is outlined. This enables the time‐resolved measurements of capacitive impedance, concomitantly with the growth of the organic layer at the working electrode. The impedance values we...
Article
Stable mixed organic films were formed on glassy carbon electrode surface via a two-step functionalization, using the electroreduction of a diazonium cation. First, the grafting of 4-azidobenzenediazonium was performed in the presence of a redox inhibitor, leading to the formation of an azido monolayer. Then, this monolayer was used as a platform a...
Article
The synthesis of a redox-active helical foldamer and its immobilization onto a gold electrode are described. These large molecular architectures are grafted in a reproducible manner and provide foldamer-based self-assembled...
Article
Tetrathiafulvalene redox units were grafted at both extremities of an oligopyridine-dicarboxamide foldamer through a straightforward copper-catalyzed azide-alkyne cycloaddition. The present work demonstrates that the hybridization equilibrium of foldamers can be...
Article
High-sensitivity charge coupled-device (CCD)cameras, efficient fibre optic bundles, high stable light source and 3D printing technologies now open large possibilities to probe redox species in solution and on confined surface by real-time absorption spectroelectrochemistry. This short review aims at providing an overview of the first work of absorp...
Article
A global and extremely simple strategy to prepare covalently attached monolayered organic film on carbon surface is presented. The approach is centered on the strict control of the radical polymerization traditionally observed when aryldiazonium salts are reduced. By exploiting the reductive properties of superoxide ions generated from atmospheric...
Article
The electrochemical and spectroelectrochemical studies of thienylene vinylene (TV) derivatives in the immobilized state are compared with the ones obtained in solution. The results highlight the exaltation of the dimerization...
Article
The study of mixed self-assembled monolayers of perylenediimide and hexanethiol by cyclic voltammetry and absorption spectroelectrochemistry shows a non-linearity of absorbance maxima as a function of the surface coverage. This surprising result could be supported by an increase in the average tilt angle at low coverage, suggesting that the dilutio...
Article
Mainly based on electrochemical investigations, this work provides evidence of discrimination between self-assembled monolayers (SAMs) prepared from alkanethiols or symmetrical dialkyl disulfides on gold. Gravimetric experiments carried out by quartz crystal microbalance during the elaboration of ferrocene based SAMs (from alkanethiols FcC15SH and...
Article
Perylenediimide (PDI) based self-assembled monolayers (SAMs) have been studied by quartz crystal microbalance, X-ray photoelectron spectroscopy, cyclic voltammetry and spectroelectrochemistry (SEC). The high stability of PDI based SAMs has allowed probing very low signals by absorption and emission SEC and extracting voltabsorptograms. The waveleng...
Article
Electrochemical transduction without covalent links between redox and complexant units in a complexing self-assembled monolayer has been established. The results demonstrate that transduction depends on the crown ether/ferrocene ratio and appears to be tunable.
Article
This work establishes an experimental estimation of the full steady-state coverage of redox centers on self-assembled monolayers. The results demonstrate that the assessment of the full surface coverage and the adsorption kinetic from a Langmuir model impose drastic experimental conditions.
Article
Full-text available
This work reports the first example of electrochemical cation bindingtransductionvia nitroxylgroups. It shows the possibility to transduce a complexation without a π-conjugated bridge between the redox and the host moieties. As expected, we confirm that the host/redoxprobe distance is a key point for transduction.
Article
A methodology is proposed to provide direct access in good yields to peptide residues-appended perylenediimides PDI-(Cl(4))-[Gly-Ala(OEt)](2), 2a, PDI-(Cl(4))-[Gly-Val(OEt)](2), 2b and PDI-(Cl(4))-[Gly-Gly(OEt)](2), 2c from a generic perylenediimide (PDI) platform symmetrically functionalized with carboxylic acids at the imide sites, PDI-(Cl(4))-[G...
Article
Herein, we evaluated the influence of hydrogen interactions in bithiophene self-assembled monolayers on gold. We have elaborated SAMs from different thiol derivatives in which the number and position of amide functionality is varied to compare their electrochemical behavior. Preliminary, optimal conditions of the monolayer formation from our synthe...
Article
Full-text available
Electrocatalysis: The molecular distribution of redox centers on mixed nitroxyl SAMs strongly influences the electrocatalytic reactivity (see picture).
Article
Full-text available
The elaboration of mixed self-assembled monolayers (SAMs) of tetrathiafulvalene derivatives allows the modulation of intermolecular interactions and provides evidence of segregated distribution of redox centers.
Article
Full-text available
A numerical method is proposed in order to differentiate a random distribution from a phase segregation of redox centers on (mixed) SAMs. This approach is compared to Laviron's interactions model and voltammetric data of nitroxylalkanethiolate SAMs.
Article
Nitroxyl radical SAMs on gold afford a noteworthy electrochemical stability in both aqueous and organic media (see figure). The control of the redox center accessibility using mixed SAMs is illustrated by the electrocatalytic activities towards benzyl-alcohol oxidation in CH2Cl2 and H2O.
Article
Mixed SAMs of nitroxyl radical derivative and alkanethiol have been studied by cyclic voltammetry in both aqueous and non-aqueous solvents. Cyclic voltammograms exhibit shapes as a function of surface coverage deviating from an “ideal system”. Confronted to Laviron’s interaction model, the agreement observed between theory and experiments provides...

Citations

... Whereas HBLMs have traditionally been developed on gold surfaces with thiol alkyl modifications [7,10,21,36,41], carbon ones are yet to be extensively applied to construct HBLMs [42][43][44][45] despite the fact that they provide a relatively inert and stable surface [46]. Diazonium salts are excellent candidates for the covalent modification of carbon surfaces [47][48][49][50][51][52][53][54][55]. One of the earliest examples of using diazonium salts to electrochemically modify glassy carbon electrodes (GCE) was reported by Bélanger et al. [48], who electrodeposited the diazonium analogues of 4-nitrophenyl and 4-carboxyphenyl. ...
... As a reminder, the capacity of a film is C ∝ εε°/th, where ε and ε°a re the electrical permittivities of the medium and vacuum, respectively, and th is the thickness of the film; therefore, a thicker film should have a lower capacity if the structure is the same (same ε). 55 Optimization of Changing Monomers. The following experiments involved three diazonium salts and four monomers ( Figure 15A). ...
... -Due to its spontaneous oxidation into Cu(II), copper(I) is not stable under atmospheric conditions, which justifies that the reaction is often carried out under argon or nitrogen. 120,130,138,151,155,170,172,182 It can be obtained from three main routes. The first one, the most usual one, involves the chemical reduction (by L-ascorbic acid or L-sodium ascorbate) of various Cu(II) salts (generally sulfate or acetate) to form Cu(I). 114,117,118,120,[129][130][131]133,136,141,152,153,156,159,161,170,171,182 Large excess in reducing agent (molar ratios [reducing agent/Cu(II)] varying from 1 114,133 to 50 171 ) guarantees a sufficient Cu(I) concentration in the medium, even when the reaction mixture is not kept under inert atmosphere. ...
... A pyridinecarboxamide (PDCA) pentamer, derivatized with a thiol anchoring point at the central residue and two tetrathiafulvalene units as electroactive probes, was synthesized with the aim of recognizing anions inside the cavity by using cyclic voltammetry [167]. Experimental variables were chosen in order to minimize double helices formation and maximize the coverage of the gold electrode by helices, which lay parallel to the surface. ...
... The radical-paired dimers can be extended to linear oligomers or polymers, leading to redox-switchable oligomeric 186,187 or polymeric foldamers 188,189 . In 2015, Zhang, Li and colleagues reported 187 two TTF-BIPY 2+ alternating polymers that can each be switched between two folded states by chemically regulating the intramolecular donor-acceptor and radical-pairing interactions. ...
... From this contemporary viewpoint, key concepts and selected contributions over the past 10 years are highlighted. The reader is referred to excellent reviews in the field including those on catalytic applications of MOFs, [28] SEC in the solution state, [29,30] and SEC of adsorbed molecular species relevant to surface-enhanced Raman scattering (SERS), as well as SEC of polymeric thin films for electronics and spintronics, [31] sol-gel films, [32] membranes, sensors, [26] self-assembled monolayers, [33] and even single molecules at an electrochemical interface. [34] In the field of MOF research, which is a focus herein, SEC techniques have received limited attention with only in situ powder X-ray diffraction (PXRD), [35,36] XAS, [37] UV-Vis-NIR, and EPR spectroscopy [38][39][40][41][42][43][44][45] measurements reported to date in the literature. ...
... The strength and nature of the diazonium-substrate bond depend as well on the nature of the grafted substrate. Several kinds of surfaces have been successfully modified with diazonium salts, ranging from carbon-based materials 41,[47][48][49][50][51][52] , to semiconductors 40,53 , to metals 42,44,46,54,55 . Specifically, TOF-SIMS spectrometric analyses showed that diazonium grafting on carbonaceous materials usually proceeds towards the formation of either C-C bonds (with the carbon surface) or C-O bonds (with its superficial oxides) 48 . ...
... [85] Les méthodes utilisant l'électrochimie de surface (voltammétrie cyclique et autres) sont beaucoup plus employées, et le ferrocène est un groupe très représenté pour ce type d'analyse dans la littérature. [86], [87], [88], [89], [90] Étant donné qu'il dispose d'une oxydation électrochimique réversible et stable dans de nombreux milieux, il est normal qu'il ait été utilisé comme « sonde » pour attester du fonctionnement d'une stratégie d'accroche en surface. Ainsi l'équipe de M. Chisdey a beaucoup étudié la possibilité de clicker sur une surface un motif ferrocène. ...
... De cette façon, cette équipe a pu démontrer que la molécule se comporte différemment vis-à-vis de la réaction de dimérisation selon qu'elle soit en solution ou immobilisée sur un substrat. [10] Cette différence de comportement entre système en solution et système condensé à l'échelle de la monocouche soulève la question de celui qu'aurait un système électrofluorochrome également greffé sous la forme d'une monocouche. En effet, dans une telle configuration, la diffusion, qui joue un rôle prépondérant lorsque la sonde électroactive et fluorescente est en solution, n'intervient plus. ...
... Typically, the surface coverage of the layer, controlled by the incubation time, the concentration in solution and the co-presence on the surface of different thiol species, has an important impact on the properties and reactivity of the whole metal-layer system. For instance, absorption spectroelectrochemical experiments on perylenediimide-derived SAMs evidenced the influence of the molecular surface coverage over the sample optical properties 32 . A non-linear shift in the absorbance maxima was indeed recorded (Figure 1.4a) when the pure perylenediimide layer was "diluted" by co-adsorbing shorter hexanethiol chains, which altered the original intermolecular interactions and generated higher tilting angles inside the layer. ...