CNRS Angers Institute of Molecular Science and Technology

Angers, France

CNRS Angers Institute of Molecular Science and Technology

Angers, France

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Pop F.,CNRS Angers Institute of Molecular Science and Technology | Pop F.,CNRS French National High Magnetic Field Laboratory | Auban-Senzier P.,University Paris - Sud | Canadell E.,Campus Universitari Of Bellaterra | And 2 more authors.
Nature Communications | Year: 2014

So far, no effect of chirality on the electrical properties of bulk chiral conductors has been observed. Introduction of chiral information in tetrathiafulvalene precursors represents a powerful strategy towards the preparation of crystalline materials in which the combination of chirality and conducting properties might allow the observation of the electrical magnetochiral anisotropy effect. Here we report the synthesis by electrocrystallization of both enantiomers of a bulk chiral organic conductor based on an enantiopure tetrathiafulvalene derivative. The enantiomeric salts crystallize in enantiomorphic hexagonal space groups. Single crystal resistivity measurements show metallic behaviour for the enantiopure salts down to 40 K, in agreement with band structure calculations. We describe here the first experimental evidence of electrical magnetochiral anisotropy in these crystals, confirming the chiral character of charge transport in our molecular materials. © 2014 Macmillan Publishers Limited. All rights reserved.


Toma O.,CNRS Angers Institute of Molecular Science and Technology | Mercier N.,CNRS Angers Institute of Molecular Science and Technology | Botta C.,CNR Institute for Macromolecular Studies
European Journal of Inorganic Chemistry | Year: 2013

Three bismuth complexes based on N-methyl-4,4′-bipyridinium (hMV +), (hMV)[Bi(hMV)Cl5] (1), and N-methyl-N′-oxide-4, 4′-bipyridinium (MVO+), [Bi(MVO)X4(dmso)] ·dmso [X = Cl (2), Br (3)], are reported. All three compounds show luminescence in the solid state with maxima at 545 nm (yellow for 1) and 560 nm (orange for 2 and 3) with quantum yields up to 10 %. Upon UV irradiation, 1 undergoes a color change from white to blue accompanied by a reduction of the photoluminescence intensity. The analysis of the crystal structure of the three complexes points to a photoinduced charge-transfer (PICT) process at the origin of the photochromism in 1. Three bismuth complexes based on N-methyl-4,4′- bipyridinium (hMV+), (hMV)[Bi(hMV)Cl5] (1), and N-methyl-N′-oxide-4,4′-bipyridinium (MVO+), [Bi(MVO)X4(dmso)]·dmso [X = Cl (2), Br (3)], show strong photoluminescence in the solid state. Upon UV irradiation, 1 undergoes a photoinduced charge-transfer (PICT) process resulting in a color change from white to blue. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Menanteau T.,CNRS Angers Institute of Molecular Science and Technology | Levillain E.,CNRS Angers Institute of Molecular Science and Technology | Breton T.,CNRS Angers Institute of Molecular Science and Technology
Chemistry of Materials | Year: 2013

A simple strategy to avoid the formation of polyaryl layer during the functionalization of carbon surface by diazonium electroreduction is presented. The approach proposes to directly act on the polymerization mechanism by the use of a radical scavenger. The kinetic gap between the surface coupling and the multilayer formation is exploited to prevent the growth of the layer without interfering with the grafting. The well-known 4-nitrobenzenediazonium electrografting was used to demonstrate the possibility of reaching a monolayer surface coverage with an excess of DPPH (2,2-diphenyl-1-picrylhydrazyl). Experimental conditions were varied to validate the efficiency of the grafting limitation and the radical capture was confirmed by isolation of the aryl radical/DPPH coupling product. © 2013 American Chemical Society.


Hudhomme P.,CNRS Angers Institute of Molecular Science and Technology
Synlett | Year: 2010

The reaction of di-tert-butyl dicarbonate (Boc2O) in the presence of the acylation catalyst 4-dimethylaminopyridine (DMAP) was examined with N-Boc or N-acyl cyanoglycinate. The couple Boc2O/DMAP was found to act as an efficient agent for selective C-tert-butoxycarbonylation affording multifunctional carbon compounds. © 2010 Georg Thieme Verlag Stuttgart New York.


Croue V.,CNRS Angers Institute of Molecular Science and Technology | Goeb S.,CNRS Angers Institute of Molecular Science and Technology | Salle M.,CNRS Angers Institute of Molecular Science and Technology
Chemical Communications | Year: 2015

The metal-driven self-assembly strategy is well-established for the construction of discrete architectures featuring a cavity. The resulting molecular rings and cages are potentially useful as hosts for complementary guests. Recent years have seen growing interest in the introduction of given functionalities, including redox properties which, among others, allow modulating the ionic charge of the cavity. Depending on which subunit is electroactive, various situations can be encountered, with a global redox activity which is ligand- and/or metal-centered and which involves or not electronic interactions between the constituting units. In this feature article, we propose to survey those different situations by exploring some recent examples of the growing family of redox-active self-assembled rings and cages. © The Royal Society of Chemistry 2015.


Biet T.,CNRS Angers Institute of Molecular Science and Technology | Avarvari N.,CNRS Angers Institute of Molecular Science and Technology
CrystEngComm | Year: 2014

Electroactive ligands picoline-1,2,3-triazole-5-DM-TTF and lutidine-bis(1,2,3-triazole-5-DM-TTF) are synthesized by click chemistry following the ruthenium catalyzed azide-alkyne cycloaddition strategy. In the solid state structure of the bis(triazole) derivative, a tweezer conformation is observed, with the two TTF units arranged in a parallel manner. Cyclic voltammetry measurements show a splitting of the first oxidation wave, demonstrating sequential oxidation of the TTF donors in the intramolecular in through space mixed valence radical cation and then dication, suggesting that the tweezer conformation is maintained also in solution. A cobalt(ii) complex based on the chelating picoline-triazole ligand is described. The lutidine-bis-triazole ligand shows no chelating behavior in the two structurally reported cadmium(ii) complexes. In one of the complexes, the Cd(ii) center is coordinated by four triazole rings from four different ligands, while the other four triazole units establish hydrogen bonds with one axially coordinated water molecule. The second complex is a one-dimensional coordination polymer, containing the CdCl2 fragment, in which the repeating motif is a pentanuclear "Cd5Cl10" unit decorated with two TTF ligands coordinated in a ditopical mode through the triazole units. The TTF donors establish intra- and intermolecular S⋯S contacts. This journal is © the Partner Organisations 2014.


Hardouin-Lerouge M.,CNRS Angers Institute of Molecular Science and Technology | Hudhomme P.,CNRS Angers Institute of Molecular Science and Technology | Salle M.,CNRS Angers Institute of Molecular Science and Technology
Chemical Society Reviews | Year: 2011

Intense current interest in supramolecular chemistry is devoted to the construction of molecular assemblies displaying controlled molecular motion associated to recognition. On this ground, molecular clips and tweezers have focused an increasing attention. This tutorial review points out the recent advances in the construction of always more sophisticated molecular clips and tweezers, illustrating their remarkably broad structural variety and focusing on their binding ability towards neutral guests. A particular attention is brought to recent findings in dynamic molecular tweezers whose recognition ability can be regulated by external stimuli. Porphyrin-based systems will not be covered here as this very active field has been recently reviewed. © 2011 The Royal Society of Chemistry.


Roncali J.,CNRS Angers Institute of Molecular Science and Technology
Advanced Energy Materials | Year: 2011

An overview of various approaches for the realization of single-material organic solar cells (SMOCs) is presented. Fullerene-conjugated systems dyads, di-block copolymers, and self-organized donor-acceptor molecules all represent different possible approaches towards SMOCs. Although each of them presents specific advantages and poses specific problems of design and synthesis, these different routes have witnessed significant progress in the past few years and SMOCs with efficiencies in the range of 1.50% have been realized. These performances are already higher than those of bi-component bulk heterojunction solar cells some ten years ago, demonstrating that SMOCs can represent a credible approach towards efficient and simple organic solar cells. Possible directions for future research are discussed with the aim of stimulating further research on this exciting topic. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Chrysos M.,CNRS Angers Institute of Molecular Science and Technology | Verzhbitskiy I.A.,CNRS Angers Institute of Molecular Science and Technology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

The particularly weak isotropic spectrum of the recently reported nearly depolarized collision-induced Raman scattering band SF6(ν1)+N2(ν1) at room temperature was obtained and is presented here. The spectrum was extracted from high-quality measurements of two independent incident-field polarization scattering components. Its zero-order moment was found to be about 200 times smaller than that of its anisotropic counterpart. Agreement, both in spectral shape and in intensity, was found with predictions based on the dipole-induced dipole polarization model once corrected for the very substantial back-induction, dispersion, and dipole-induced quadrupole-induced dipole interaction mechanisms, all of which were considered within the model framework of two point-polarizable molecules. Quantum-mechanical calculations revealed a large contribution from bound and predissociating dimers that amounts to more than one-third of the total isotropic scattering intensity. © 2010 The American Physical Society.


Aleveque O.,CNRS Angers Institute of Molecular Science and Technology | Levillain E.,CNRS Angers Institute of Molecular Science and Technology | Sanguinet L.,CNRS Angers Institute of Molecular Science and Technology
Electrochemistry Communications | Year: 2015

We present a spectroelectrochemical bench involving an electrochemical/spectrophotometric coupling dedicated to probe electroactive self-assembled monolayers (SAMs). This bench is validated by the study of the oxidation of a 5,5′-disubstituted-2,2′-bithiophene immobilized on Au substrate, producing a reversible dimerization of the radical cation (i.e. ECDim process) leading to a dimer. A direct comparison between thin layer spectroelectrochemistry in solution and spectroelectrochemistry on SAMs shows that a SAM could be viewed as a highly concentrated solution. © 2014 Elsevier B.V.

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