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  • P. Bayat, D. Lesage, et R. B. Cole, « Tutorial: Ion activation in tandem Mass spectrometry using ultra-high resolition spectroscopy », Mass Spectrometry Reviews, p. mas.21623, févr. 2020.

  • A. Benchohra, C. Méthivier, J. Landoulsi, D. Kreher, et R. Lescouëzec, « Electrospray ionization: an efficient approach to deposit polymetallic molecular switches onto gold surfaces », Chemical Communications, vol. 56, nᵒ 48, p. 6587-6589, 2020.
    Résumé : Electrospray ionization (EI) deposition is proven efficient in obtaining monolayers of a polymetallic charge transfer complex on gold surfaces. , Electrospray ionization (EI) deposition is proven efficient in obtaining monolayers of a polymetallic charge transfer complex on gold surfaces. The molecule's integrity is monitored by using PM-IRRAS and XPS. This approach broadens the perspective of molecular magnetic switch deposition, which is currently dominated by the thermal evaporation of monometallic spin crossover (SCO) complexes.
    Mots-clés : ERMMES, POLE 2.

  • A. Cartier, E. Levernier, A. - L. Dhimane, T. Fukuyama, C. Ollivier, I. Ryu, et L. Fensterbank, « Synthesis of Aliphatic Amides through a Photoredox Catalyzed Radical Carbonylation Involving Organosilicates as Alkyl Radical Precursors », Advanced Synthesis & Catalysis, vol. 362, nᵒ 11, p. 2254-2259, 2020.
    Résumé : Alkyl radicals, from primary to tertiary, formed by photocatalyzed oxidation of organosilicates, are involved efficiently in radical carbonylation with carbon monoxide (CO), in the presence of various amines and CCl4, leading to a variety of amides in moderate to good yields.
    Mots-clés : Carbonylation, MACO, multi-component reaction, photooxidative catalysis, POLE 1, radical/polar, silicates.
    Pièce jointe Full Text PDF 4.8 Mo (source)

  • F. Coumes, M. Balarezo, J. Rieger, et F. Stoffelbach, « Biobased Amphiphilic Block Copolymers by RAFT-Mediated PISA in Green Solvent », Macromolecular Rapid Communications, vol. 41, nᵒ 9, p. 2000002, 2020.
    Résumé : Biobased amphiphilic diblock copolymers are prepared thanks to the combination of reversible addition–fragmentation transfer (RAFT) polymerization and polymerization-induced self-assembly (PISA) in an eco-friendly solvent mixture. First, the formation of a poly(acrylic acid) macroRAFT agent (PAA-TTC) is performed in water at 70 °C. Then, in a series of experiments, the PAA-TTC macroRAFT agent is used directly, without purification, as both chain transfer agent and stabilizing agent in the RAFT-PISA of menthyl acrylate (MnA) in dispersion in an ethanol/water mixture. The polymerizations of MnA are fast with high final conversions and well-controlled amphiphilic diblock copolymers are synthesized. Stable, sub-micrometric spherical particles composed of the diblock copolymers are formed. The influence of the monomer concentration and the length of the solvophobic block on the diameter of the self-assemblies is studied by means of dynamic light scattering and cryogenic transmission electron-microscopy.
    Mots-clés : amphiphilic copolymers, biobased monomers, dispersion polymerization, PISA, POLE 4, POLYMERES, RAFT.
    Pièce jointe Full Text PDF 1.3 Mo (source)

  • L. Cunningham, Y. Wang, C. Nottingham, J. Pagsulingan, G. Jaouen, M. McGlinchey, et P. J. Guiry, « Enantioselective Synthesis of Planar Chiral Ferrocifens that Show Chiral Discrimination in Antiproliferative Activity on Breast Cancer Cells », ChemBioChem, vol. n/a, nᵒ n/a, 2020.
    Résumé : The design and first enantioselective synthesis of a series of chiral ferrocifens and ferrociphenols was realised via enantioselective palladium-catalysed intramolecular direct C?H bond activation followed by McMurry coupling. Biological evaluation revealed moderate anticancer activities on breast cancer cells and evidence of chiral discrimination between enantiomers. Treatment of these novel ferrocifens with Ag 2 O revealed that these systems are unable to form a neutral quinone methide, yet still demonstrate marked antiproliferative properties versus both the hormone-dependent MCF-7 and hormone-independent MDA-MB-231 cell lines. This bioactivity arises from two mechanisms: Fenton-type chemistry and the anti-estrogenic activity associated with the tamoxifen-like structure.
    Mots-clés : anti-cancer activity, asymmetric synthesis, CHEMBIO, Ferrocene, McMurry coupling, POLE 3.
    Note Note
    <p>doi: 10.1002/cbic.202000311</p>

  • F. D'Agosto, J. Rieger, et M. Lansalot, « RAFT-Mediated Polymerization-Induced Self-Assembly », Angewandte Chemie International Edition, vol. 59, nᵒ 22, p. 8368-8392, 2020.
    Résumé : After a brief history that positions polymerization-induced self-assembly (PISA) in the field of polymer chemistry, this Review will cover the fundamentals of the PISA mechanism. Furthermore, this Review will also give an overview of some of the features and limitations of RAFT-mediated PISA in terms of the choice of the components involved, the nature of the nanoobjects that can be obtained and how the syntheses can be controlled, as well as some potential applications.
    Mots-clés : block copolymers, heterogeneous polymerization, morphology, PISA, POLE 4, POLYMERES, RAFT.
    Pièce jointe Full Text PDF 4.4 Mo (source)

  • H. Du, F. A. de Oliveira, L. J. C. Albuquerque, G. Tresset, E. Pavlova, C. Huin, P. Guégan, et F. C. Giacomelli, « Polyglycidol-Stabilized Nanoparticles as a Promising Alternative to Nanoparticle PEGylation: Polymer Synthesis and Protein Fouling Considerations », Langmuir, vol. 36, nᵒ 5, p. 1266-1278, févr. 2020.
    Résumé : We herein demonstrate the outstanding protein-repelling characteristic of star-like micelles and polymersomes manufactured from amphiphilic block copolymers made by poly(butylene oxide) (PBO) hydrophobic segments and polyglycidol (PGL) hydrophilic outer shells. Although positively charged proteins (herein modeled by lysozyme) may adsorb onto the surface of micelles and polymersomes where the assemblies are stabilized by short PGL chains (degree of polymerization smaller than 15), the protein adsorption vanishes when the degree of polymerization of the hydrophilic segment (PGL) is higher than ∼20, regardless the morphology. This has been probed by using three different model proteins which are remarkably different concerning molecular weight, size, and zeta potential (bovine serum albumin (BSA), lysozyme, and immunoglobulin G (IgG)). Indeed, the adsorption of the most abundant plasma protein (herein modeled as BSA) is circumvented even by using very short PGL shells due to the highly negative zeta potential of the produced assemblies which presumably promote protein–nanoparticle electrostatic repulsion. The negative zeta potential, on the other hand, enables lysozyme adsorption, and the phenomenon is governed by electrostatic forces as evidenced by isothermal titration calorimetry. Nevertheless, the protein coating can be circumvented by slightly increasing the degree of polymerization of the hydrophilic segment. Notably, the PGL length required to circumvent protein fouling is significantly smaller than the one required for PEO. This feature and the safety concerns regarding the synthetic procedures on the preparation of poly(ethylene oxide)-based amphiphilic copolymers might make polyglycidol a promising alternative toward the production of nonfouling spherical particles.
    Mots-clés : POLE 4, POLYMERES.
    Pièce jointe Full Text PDF 4.1 Mo (source)

  • L. El Khoury, F. Célerse, L. Lagardère, L. - H. Jolly, E. Derat, Z. Hobaika, R. G. Maroun, P. Ren, S. Bouaziz, N. Gresh, et J. - P. Piquemal, « Reconciling NMR Structures of the HIV-1 Nucleocapsid Protein NCp7 Using Extensive Polarizable Force Field Free-Energy Simulations », Journal of Chemical Theory and Computation, vol. 16, nᵒ 4, p. 2013-2020, avr. 2020.
    Résumé : Using polarizable (AMOEBA) and nonpolarizable (CHARMM) force fields, we compare the relative free energy stability of two extreme conformations of the HIV-1 nucleocapsid protein NCp7 that had been previously experimentally advocated to prevail in solution. Using accelerated sampling techniques, we show that they differ in stability by no more than 0.75–1.9 kcal/mol depending on the reference protein sequence. While the extended form appears to be the most probable structure, both forms should thus coexist in water explaining the differing NMR findings.
    Mots-clés : MACO, POLE 1.
    Pièce jointe Full Text PDF 1.7 Mo (source)

  • R. El-Hnayn, L. Canabady-Rochelle, C. Desmarets, L. Balan, H. Rinnert, O. Joubert, G. Medjahdi, H. Ben Ouada, et R. Schneider, « One-Step Synthesis of Diamine-Functionalized Graphene Quantum Dots from Graphene Oxide and Their Chelating and Antioxidant Activities », Nanomaterials, vol. 10, nᵒ 1, p. 104, janv. 2020.
    Résumé : 2,2&rsquo;-(Ethylenedioxy)bis(ethylamine)-functionalized graphene quantum dots (GQDs) were prepared under mild conditions from graphene oxide (GO) via oxidative fragmentation. The as-prepared GQDs have an average diameter of ca. 4 nm, possess good colloidal stability, and emit strong green-yellow light with a photoluminescence (PL) quantum yield of 22% upon excitation at 375 nm. We also demonstrated that the GQDs exhibit high photostability and the PL intensity is poorly affected while tuning the pH from 1 to 8. Finally, GQDs can be used to chelate Fe(II) and Cu(II) cations, scavenge radicals, and reduce Fe(III) into Fe(II). These chelating and reducing properties that associate to the low cytotoxicity of GQDs show that these nanoparticles are of high interest as antioxidants for health applications.
    Mots-clés : 2, 2’-(ethylenedioxy)bis(ethylamine), ARC, graphene quantum dots, optical properties, POLE 1, redox-active nanoparticles.
    Pièce jointe Full Text PDF 3.9 Mo (source)

  • G. Falco, L. Simonin, S. Pensec, F. Dalmas, J. - M. Chenal, L. Bouteiller, et L. Chazeau, « Linear and nonlinear viscoelastic properties of segmented silicone-urea copolymers: Influence of the hard segment structure », Polymer, vol. 186, p. 122041, janv. 2020.
    Résumé : The linear and non-linear viscoelastic behaviors of 5 segmented silicone copolymers - with low fraction of 1,6-hexamethylene diisocyanate (HDI), 4,4′-methylenebis (cyclohexyl isocyanate) (HMDI), 1,3-bis(1-isocyanato-1-methylethyl)benzene (TMXDI), 2,4-tolylene diisocyanate (TDI) or isophorone diisocyanate (IPDI) as hard segments (HS) - are compared, in relation with their microstructure. When the HS are non-symmetrical, the materials nanostructuration is weak and has a limited impact on the mechanical response: two mechanical relaxations occur after the α relaxation of the polydimethylsiloxane (PDMS), the first related to the “unfreezing” of the HS-HS bonds, and the second one to the sticky reptation of the polymer chains. Conversely, when the HS are symmetrical, their self-organization is favored and the long range ordering of the HS is possible. The materials are then semi-crystalline like, with a low crystallinity (due to the low weight percentage of HS) and their flow, possible above their melting temperature (Tm), depends also on the HS dynamics, which is the most rapid for HDI.
    Mots-clés : Mechanical relaxations, Nanostructure, POLE 4, POLYMERES, Segmented copolymers.

  • Y. T. L. Guen, T. L. Gall, P. Midoux, P. Guégan, S. Braun, et T. Montier, « Gene transfer to skeletal muscle using hydrodynamic limb vein injection: current applications, hurdles and possible optimizations », The Journal of Gene Medicine, vol. 22, nᵒ 2, p. e3150, 2020.
    Résumé : Hydrodynamic limb vein injection is an in vivo locoregional gene delivery method. It consists of administrating a large volume of solution containing nucleic acid constructs in a limb with both blood inflow and outflow temporarily blocked using a tourniquet. The fast, high pressure delivery allows the musculature of the whole limb to be reached. The skeletal muscle is a tissue of choice for a variety of gene transfer applications, including gene therapy for Duchenne muscular dystrophy or other myopathies, as well as for the production of antibodies or other proteins with broad therapeutic effects. Hydrodynamic limb vein delivery has been evaluated with success in a large range of animal models. It has also proven to be safe and well-tolerated in muscular dystrophy patients, thus supporting its translation to the clinic. However, some possible limitations may occur at different steps of the delivery process. Here, we have highlighted the interests, bottlenecks and potential improvements that could further optimize non-viral gene transfer following hydrodynamic limb vein injection.
    Mots-clés : gene transfer, hydrodynamic delivery, locoregional, non-viral gene delivery, optimizations, POLE 4, POLYMERES, skeletal muscle.
    Pièce jointe Full Text PDF 6.4 Mo (source)
    Note Note
    <p>e3150 JGM-19-0364.R1</p>

  • H. Guo, D. Hourdet, A. Marcellan, F. Stoffelbach, J. Lyskawa, L. de Smet, A. Vebr, R. Hoogenboom, et P. Woisel, « Dual Responsive Regulation of Host–Guest Complexation in Aqueous Media to Control Partial Release of the Host », Chemistry – A European Journal, vol. 26, nᵒ 6, p. 1292-1297, janv. 2020.
    Résumé : Abstract The regulation of the concentration of a wide range of small molecules is ubiquitous in biological systems because it enables them to adapt to the continuous changes in the environmental conditions. Herein, we report an aqueous synthetic system that provides an orchestrated, temperature and pH controlled regulation of the complexation between the cyclobis(paraquat-p-phenylene) host (BBox) and a 1,5-dialkyloxynaphthalene (DNP) guest attached to a well-defined dual responsive copolymer composed of N-isopropylacrylamide as thermoresponsive monomer and acrylic acid as pH-responsive monomer. Controlled, partial release of the BBox, enabling control over its concentration, is based on the tunable partial collapse of the copolymer. This colored supramolecular assembly is one of the first synthetic systems providing control over the concentration of a small molecule, providing great potential as both T and pH chromic materials and as a basis to develop more complex systems with molecular communication.
    Mots-clés : host–guest systems, molecular recognition, POLE 4, POLYMERES, polymers, supramolecular chemistry.

  • S. Han, G. Mellot, S. Pensec, J. Rieger, F. Stoffelbach, E. Nicol, O. Colombani, J. Jestin, et L. Bouteiller, « Crucial Role of the Spacer in Tuning the Length of Self-Assembled Nanorods », Macromolecules, vol. 53, nᵒ 1, p. 427-433, janv. 2020.
    Résumé : Polymeric supramolecular nanorods were prepared in toluene by self-assembly of tris(urea) stickers connected on both sides through alkyl spacers of different lengths to short polystyrene (PS) arms. Several tris(urea) initiators or chain transfer agents were synthesized straightforwardly and used to grow well-defined PS arms via atom transfer radical polymerization (ATRP) or reversible addition fragmentation chain transfer (RAFT) polymerization. Self-assembly was investigated by means of Fourier-transform infrared (FTIR) spectroscopy and light/neutron scattering. A dramatic impact of the spacer separating the tris(urea) sticker from the PS arms on the extent of self-assembly was observed in toluene as long as the degree of polymerization of the PS arms (x) was kept short (x ∼ 10). Indeed, supramolecular nanorods several hundreds of nanometers in length for a few nanometers in radius were obtained with a spacer consisting of nine atoms, whereas five times shorter nanorods were obtained for a spacer of only five atoms, and spherical particles were found in the absence of any spacer, all other parameters remaining unchanged. These results reveal the possibility to tune the length of polymer-decorated supramolecular nanorods with minimal modification of the assembling sticker and without affecting the functionality of the rods.
    Mots-clés : POLE 4, POLYMERES.
    Pièce jointe Full Text PDF 1.9 Mo (source)

  • D. Jamroz, N. Fischer-Durand, M. Palusiak, S. Wojtulewski, S. Jarzyński, M. Stępniewska, M. Salmain, et B. Rudolf, « Inverse electron-demand Diels-Alder (iEDDA) bioorthogonal conjugation of half-sandwich transition metallocarbonyl entities to a model protein », Applied Organometallic Chemistry, vol. 34, nᵒ 4, p. e5507, 2020.
    Résumé : Novel transition metallocarbonyl complexes carrying a norbornene or an oxanorbornene group were synthesized by [4 + 2] cycloaddition between the organometallic maleimide dienophiles and cyclopentadiene or furan, respectively. The oxanorbornene adduct was obtained as a mixture of endo and exo isomers as confirmed by X-ray diffraction and NMR spectroscopy. The (oxa)norbornene groups further provided convenient chemical reporters to carry out inverse electron demand Diels-Alder (iEDDA) reactions with tetrazine derivatives. Detailed kinetic studies with a model tetrazine revealed that faster rates of reaction were determined with both isomers of the oxanorbornene complex with respect to the norbornene complexes. Eventually, incorporation of metallocarbonyl entities into bovine serum albumin equipped with tetrazine handles was achieved as shown by IR spectroscopy of the protein conjugates.
    Mots-clés : bioconjugation, CHEMBIO, iEDDA, metallocarbonyl complex, norbornene, POLE 3, tetrazine.
    Note Note
    <p>doi: 10.1002/aoc.5507</p>

  • J. ‐R. Jiménez, J. Glatz, A. Benchohra, G. Gontard, L. ‐M. Chamoreau, J. ‐F. Meunier, A. Bousseksou, et R. Lescouëzec, « Electron Transfer in the Cs⊂{Mn <sub>4</sub> Fe <sub>4</sub> } Cubic Switch: A Soluble Molecular Model of the MnFe Prussian‐Blue Analogues », Angewandte Chemie International Edition, vol. 59, nᵒ 21, p. 8089-8093, mai 2020.

  • E. Levernier, C. Lévêque, E. Derat, L. Fensterbank, et C. Ollivier, « Towards Visible-Light Photocatalytic Reduction of Hypercoordinated Silicon Species », Helvetica Chimica Acta, vol. 103, nᵒ 1, p. e1900238, 2020.
    Résumé : Nowadays, the quest of new radical precursors based on heteroatom complexes occupies an increasingly prominent position in contemporary research. Herein, we investigated the behavior and the limitations of hexa- or pentacoordinated organochlorosilanes and related pentacoordinated silyliums as new families of complexes for the generation of radicals under photocatalytic reductive conditions. Particularly, treatment of chlorophenylbis[N,S-pyridine-2-thiolato(−)]silicon(IV) or the related silylium derivative with the fac-Ir(ppy)3 (5 mol-%)/NEt3 (1.5 equiv.) system under blue LEDs irradiation generates a thiopyridyl radical which can participate in the formation of a carbon−sulfur bond by reaction with an allylsulfone. Computational studies supported this experimental finding, and particularly by showing that homolytic fragmentation of C−Ts bond is favored over the fragmentation of thiopyridyl radical.
    Mots-clés : allylation, chlorosilane, cyclic voltammetry, C−S bond, hypercoordinated silicon compounds, MACO, photoreduction, POLE 1, radicals, silylium.
    Pièce jointe Full Text PDF 8.3 Mo (source)

  • Y. Li, A. Hammoud, L. Bouteiller, et M. Raynal, « Emergence of Homochiral Benzene-1,3,5-tricarboxamide Helical Assemblies and Catalysts upon Addition of an Achiral Monomer », Journal of the American Chemical Society, vol. 142, nᵒ 12, p. 5676-5688, mars 2020.
    Résumé : Chirality amplification refers to the ability of a small chiral bias to fully control the main chain helicity of polymers and assemblies. Further implementation of functional chirally amplified helices as switchable asymmetric catalysts, chiral sensors, and circularly polarized light emitters will require a greater control of the energetics governing these chirality amplification effects. In this work, we report on the counterintuitive ability of an achiral molecule to suppress conformational defects in supramolecular helices, thus leading to the emergence of homochirality in a system containing a very small chiral bias. We focus our investigation on supramolecular helices composed of an achiral benzene-1,3,5-tricarboxamide (BTA) ligand, coordinated to copper, and an enantiopure BTA comonomer. Amplification of chirality as probed by varying the amount (sergeants and soldiers effect) or the optical purity (diluted majority-rules effect) of the enantiopure comonomer are modest in this initial system. However, both effects are hugely enhanced upon addition of a second achiral BTA monomer, leading to a perfect control of the helicity either by means of a remarkably low amount of sergeants (0.5%) or a small bias from a racemic mixture of enantiopure comonomers (10% ee). Such an enhancement in the amplification of chirality is only achieved by mixing the three components, i.e. the two achiral and the enantiopure comonomers, highlighting a synergistic effect upon coassembly of the three monomers. Investigation of the role of the achiral additive by multifarious analytical techniques supports its ability to stabilize the helical coassemblies and suppress helix reversals: i.e., conformational defects. Implementation of these helical copper precatalysts in the hydrosilylation of 1-(4-nitrophenyl)ethanone confirms that the effect of the achiral BTA additive is also operative under the conditions of the catalytic experiment. A highly enantioenriched product (90% ee) is produced by a supramolecular catalyst operating with ppm levels of chiral species.
    Mots-clés : POLE 4, POLYMERES.
    Pièce jointe Full Text PDF 5.5 Mo (source)

  • X. Liu, X. Su, C. Livache, L. - M. Chamoreau, S. Sanaur, L. Sosa-Vargas, J. - C. Ribierre, D. Kreher, E. Lhuillier, E. Lacaze, et F. Mathevet, « Investigation of charge transport properties of [1]Benzothieno[3,2-b][1]-benzothiophene single-crystals in field-effect transistor configuration », Organic Electronics, vol. 78, p. 105605, mars 2020.
    Résumé : Single-crystals of unsubstituted [1]Benzothieno[3,2-b][1]-benzothiophene (BTBT) were prepared by physical vapor transport deposition (VTP). The packing structure and morphology of the crystals were studied by X-ray diffraction (XRD), polarized optical microscopy (POM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The charge transport properties of BTBT single-crystals were also investigated via bottom contact/bottom gate (BC/BG) organic field-effect transistors (OFETs) on both SiO2 and n-octadecyltrichlorosilane (OTS) treated surfaces. A maximum hole mobility value of 0.032 cm2V−1s−1 was measured on the OTS substrate. In addition, single-crystal OFETs with ion gel top gate (TG) configuration were also investigated for low voltage operation. This work represents the first investigation of charge carrier mobility of a simple BTBT in transistor configuration and highlights the essential role of the BTBT substitution in charge transport properties.
    Mots-clés : Organic field effect transistors, POLE 4, POLYMERES, Semiconducting materials, Single crystals, Thienoacene derivative.

  • Y. Liu, J. Oble, A. Pradal, et G. Poli, « Catalytic Domino Annulations through η <sup>3</sup> -Allylpalladium Chemistry: A Never-Ending Story: Catalytic Domino Annulations through η <sup>3</sup> -Allylpalladium Chemistry: A Never-Ending Story », European Journal of Inorganic Chemistry, vol. 2020, nᵒ 11-12, p. 942-961, mars 2020.

  • Y. Liu, J. Oble, A. Pradal, et G. Poli, « Catalytic Domino Annulations through η3-Allylpalladium Chemistry: A Never-Ending Story », European Journal of Inorganic Chemistry, vol. 2020, nᵒ 11-12, p. 942-961, 2020.
    Résumé : Annulative η3-allylpalladium chemistry has been a longstanding trending research topic since the 80's. Nowadays, this research area is still providing challenges to the catalysis community leading to the development original and brand-new transformations. Several reaction partners have been used as precursors for η3-allylpalladium species, namely allyl diacetates, allyl monoacetates, 3-acetoxy-2-trimethylsilylmethyl-1-propene (ASMP), alkylidene cyclopropanes (ACPs), vinyl cyclopropanes (VCPs), vinyl aziridines, and vinyl epoxides. This minireview is intended to show the recent developments in the field of annulative η3-allylpalladium chemistry with emphasis on new reactivity, enantioselective transformations as well as potential applications in total synthesis.
    Mots-clés : POLE 1, ROCS.

  • T. Martinez, I. Alahyen, G. Lemière, V. Mouriès-Mansuy, et L. Fensterbank, « Straightforward Access to 2-Iodoindolizines via Iodine-Mediated Cyclization of 2-Pyridylallenes », Organic Process Research & Development, vol. 24, nᵒ 5, p. 817-821, mai 2020.
    Résumé : A metal-free access to 2-iodo-1,3-disubstituted indolizines has been developed. The proposed synthesis is relatively simple and efficient and involves the iodine-triggered 5-endo-trig cyclization of 2-pyridylallene precursors. While it can be conducted on a gram scale, the preparation of the precursors is straightforward and does not always require intermediate purifications. The obtained 2-iodoindolizines can be further functionalized through cross-coupling reactions.
    Mots-clés : MACO, POLE 1.
    Pièce jointe Full Text PDF 848 ko (source)

  • Š. Nováková Lachmanová, L. Pospíšil, J. Šebera, B. Talbi, M. Salmain, et M. Hromadová, « Electrochemical characterization of the artificial metalloenzyme papain-[(η6-arene)Ru(1,10-phenanthroline)Cl]+ », Journal of Electroanalytical Chemistry, vol. 859, p. 113882, 2020.
    Résumé : Electrochemical pro

    perties were studied for [(η6-arene)Ru(1,10-phenanthroline)Cl]Cl (arene = C6H5(CH2)2NHCOCH2Cl) organometallic complex 1, protein Papain PAP and its conjugate with organometallic complex 1-PAP. The latter can serve as an artificial metalloenzyme with catalytic activity in transfer hydrogenation. This work demonstrates that AC voltammetry and electrochemical impedance spectroscopy can be used as fast tools to screen the catalytic ability of 1-PAP electrochemically by studies of the catalytic hydrogen evolution reaction (HER). Proteins are known to catalyze this process, but we have shown that additional HER signal associated with the catalytic activity of 1 is observed for its conjugate with Papain 1-PAP.
    Mots-clés : Artificial metalloenzyme, CHEMBIO, Electrochemical admittance and impedance techniques, Papain, POLE 3, Ruthenium(II) complexes.

  • L. Plet, G. Delecourt, M. Hanafi, N. Pantoustier, G. Pembouong, P. Midoux, V. Bennevault, et P. Guégan, « Controlled star poly(2-oxazoline)s: Synthesis, characterization », European Polymer Journal, vol. 122, p. 109323, janv. 2020.
    Résumé : Poly(2-methyl-2-oxazoline) and poly(2-ethyl-2-oxazoline) star polymers with 3, 4 and 6 arms are synthesized from pluritriflate initiators. Characterization of the topology was achieved by NMR, SEC and kinetic studies. The initiation step of 2-ethyl-2-oxazoline being slow, heterogeneous star polymers in arm molar masses are obtained for low molar mass polymers. However, for both monomers, high molar mass homogeneous star polymers are obtained. A fast initiation is observed for the polymerization of 2-methyl-2-oxazoline, providing a control of the topology even at low molar mass. In the studied molar mass range, linear kinetic first order plots and linear molar mass as a function of conversion are obtained for both monomers, suggesting living polymerizations.
    Mots-clés : 2oxazoline polymerization, Pluritriflate initiators, POLE 4, POLYMERES, Star polymers.

  • V. Puchelle, H. Du, N. Illy, et P. Guégan, « Polymerization of epoxide monomers promoted by tBuP4 phosphazene base: a comparative study of kinetic behavior », Polymer Chemistry, vol. 11, nᵒ 21, p. 3585-3592, juin 2020.
    Résumé : The kinetics of the anionic ring-opening polymerizations (AROP) of epoxide monomers, 1,2-epoxybutane (BO), 1,2-epoxypropane (PO), tert-butyl glycidyl ether (tBuGE), allyl glycidyl ether (AGE), benzyl glycidyl ether (BnGE), and ethoxyethyl glycidyl ether (EEGE), was investigated using benzyl alcohol/tBuP4 as the initiating system. All the polymerizations proceed in a controlled manner following a first order kinetics with respect to the monomer. The influence of the side chains borne by the oxirane ring was evidenced. Propagating centers derived from epoxide bearing heretoatom-containing side chains display higher reactivities and propagation rates. A reactivity scale has been established and is as follows, kp,BnGE > kp,AGE > kp,EEGE ≫ kp,tBuGE ≈ kp,PO > kp,BO. Using BO as the model monomer and different initiator concentrations, the nature of the propagating species has been identified as ion pairs. The influence of a Lewis acid addition on the monomer reactivities and on the control of the polymerization was also investigated. In the presence of triisobutylaluminum (iBu3Al), polymerization kinetics was faster but led to a broadening of the molar mass distributions. The monomer reactivity scale was also strongly modified with kp,PO > kp,BO > kp,EEGE ≈ kp,AGE > kp,BnGE ≈ kp,tBuGE. The polymerizations of PO, BO and tBuGE follow zero order kinetics which is not the case for the other oxirane monomers.
    Mots-clés : pole 4, POLYMERES.
    Pièce jointe Full Text PDF 923.5 ko (source)

  • C. Qin, T. Matsushima, W. J. Potscavage, A. S. D. Sandanayaka, M. R. Leyden, F. Bencheikh, K. Goushi, F. Mathevet, B. Heinrich, G. Yumoto, Y. Kanemitsu, et C. Adachi, « Triplet management for efficient perovskite light-emitting diodes », Nature Photonics, vol. 14, nᵒ 2, p. 70-75, févr. 2020.
    Résumé : Perovskite light-emitting diodes are promising for next-generation lighting and displays because of their high colour purity and performance1. Although the management of singlet and triplet excitons is fundamental to the design of efficient organic light-emitting diodes, the nature of how excitons affect performance is still not clear in perovskite2–4 and quasi-two-dimensional (2D) perovskite-based devices5–9. Here, we show that triplet excitons are key to efficient emission in green quasi-2D perovskite devices and that quenching of triplets by the organic cation is a major loss path. Employing an organic cation with a high triplet energy level (phenylethylammonium) in a quasi-2D perovskite based on formamidinium lead bromide yields efficient harvesting of triplets. Furthermore, we show that upconversion of triplets to singlets can occur, making 100% harvesting of electrically generated excitons potentially possible. The external quantum and current efficiencies of our green (527 nm) devices reached 12.4% and 52.1 cd A−1, respectively.
    Mots-clés : POLE 4, POLYMERES.

  • J. P. Rada, J. Forté, G. Gontard, V. Corcé, M. Salmain, et N. A. Rey, « Isoxazole-Derived Aroylhydrazones and Their Dinuclear Copper(II) Complexes Show Antiproliferative Activity on Breast Cancer Cells with a Potentially Alternative Mechanism Of Action », ChemBioChem, vol. n/a, nᵒ n/a, 2020.
    Résumé : Abstract This paper reports the design, synthesis and cytotoxicity studies of two new isoxazole-derived aroylhydrazone ligands and their dinuclear copper(II) complexes. Compounds were fully characterized by various spectroscopic and analytical techniques. The molecular structures of four derivatives were confirmed by X-ray crystallography. The stability of the ligands and the complexes in aqueous medium was monitored spectroscopically. Both the ligands and the complexes were shown to interact with calf thymus DNA (ct-DNA). Additionally, structures containing a phenol pendant arm were significantly more cytotoxic than those carrying a pendant pyridine substituent, reaching sub-micromolar IC50 values on the triple-negative human breast cancer cell line MDA-MB-231. The metal chelation and transchelation ability of the compounds towards FeII, FeIII and ZnII ions was explored as a possible mechanism of action of these compounds.
    Mots-clés : antitumor agents, aroylhydrazonic ligands, CHEMBIO, copper(II) complexes, cytotoxicity, DNA, POLE 3.
    Note Note
    <p>doi: 10.1002/cbic.202000122</p>

  • B. Rasolonjatovo, N. Illy, V. Bennevault, J. Mathé, P. Midoux, T. L. Gall, T. Haudebourg, T. Montier, P. Lehn, B. Pitard, H. Cheradame, C. Huin, et P. Guégan, « Temperature-Sensitive Amphiphilic Non-Ionic Triblock Copolymers for Enhanced In Vivo Skeletal Muscle Transfection », Macromolecular Bioscience, vol. 20, nᵒ 3, p. 1900276, 2020.
    Résumé : It is reported that low concentration of amphiphilic triblock copolymers of pMeOx-b-pTHF-b-pMeOx structure (TBCPs) improves gene expression in skeletal muscle upon intramuscular co-injection with plasmid DNA. Physicochemical studies carried out to understand the involved mechanism show that a phase transition of TBCPs under their unimer state is induced when the temperature is elevated from 25 to 37 °C, the body temperature. Several lines of evidences suggest that TBCP insertion in a lipid bilayer causes enough lipid bilayer destabilization and even pore formation, a phenomenon heightened during the phase transition of TBCPs. Interestingly, this property allows DNA translocation across the lipid bilayer model. Overall, the results indicate that TBCPs exhibiting a phase transition at the body temperature is promising to favor in vivo pDNA translocation in skeletal muscle cells for gene therapy applications.
    Mots-clés : amphiphilic copolymers, in vivo transfection, LCST, POLE 4, poly(2-methyl-2-oxazoline), POLYMERES, skeletal muscle.
    Pièce jointe Full Text PDF 1.3 Mo (source)

  • Y. Ren, J. Forte, K. Cheaib, N. Vanthuyne, L. Fensterbank, H. Vezin, M. Orio, S. Blanchard, et M. Desage-El Murr, « Optimizing Group Transfer Catalysis by Copper Complex with Redox-Active Ligand in an Entatic State », Iscience, vol. 23, nᵒ 3, p. UNSP 100955, mars 2020.
    Résumé : Metalloenzymes use earth-abundant non-noble metals to perform high-fidelity transformations in the biological world. To ensure chemical efficiency, metalloenzymes have acquired evolutionary reactivity-enhancing tools. Among these, the entatic state model states that a strongly distorted geometry induced by ligands around a metal center gives rise to an energized structure called entatic state, strongly improving the reactivity. However, the original definition refers both to the transfer of electrons or chemical groups, whereas the chemical application of this concept in synthetic systems has mostly focused on electron transfer, therefore eluding chemical transformations. Here we report that a highly strained redox-active ligand enables a copper complex to perform catalytic nitrogen- and carbon-group transfer in as fast as 2 min, thus exhibiting a strong increase in reactivity compared with its unstrained analogue. This report combines two reactivity-enhancing features from metalloenzymes, entasis and redox cofactors, applied to group-transfer catalysis.
    Mots-clés : aziridination, cu, E-POM, galactose-oxidase, generation, MACO, metal-complexes, models, oxidation, POLE 1, POLE 2, radicals, reactivity, site.
    Pièce jointe Texte intégral 19.8 Mo (source)

  • M. Roy, V. Berezhnaia, M. Villa, N. Vanthuyne, M. Giorgi, J. - V. Naubron, S. Poyer, V. Monnier, L. Charles, Y. Carissan, D. Hagebaum‐Reignier, J. Rodriguez, M. Gingras, et Y. Coquerel, « Stereoselective Syntheses, Structures, and Properties of Extremely Distorted Chiral Nanographenes Embedding Hextuple Helicenes », Angewandte Chemie International Edition, vol. 59, nᵒ 8, p. 3264-3271, 2020.
    Résumé : We report a molecular design and concept using π-system elongation and steric effects from helicenes surrounding a triphenylene core toward stable chiral polycyclic aromatic hydrocarbons (PAHs) with a maximal π-distortion to tackle their aromaticity, supramolecular and molecular properties. The selective syntheses, and the structural, conformational and chiroptical properties of two diastereomeric large multi-helicenes of formula C90H48 having a triphenylene core and embedding three [5]helicene units on their inner edges and three [7]helicene units at their periphery are reported based on diastereoselective and, when applicable, enantiospecific Yamamoto-type cyclotrimerizations of racemic or enantiopure 9,10-dibromo[7]helicene. Both molecules have an extremely distorted triphenylene core, and one of them exhibits the largest torsion angle recorded so far for a benzene ring (twist=36.9°).
    Mots-clés : aromaticity, helicenes, POLE 1, polycyclic aromatic hydrocarbons, ROCS, stereoselectivity, strained molecules.

  • R. Salles, B. Abécassis, E. Derat, D. Brouri, A. Bernard, Q. Zhang, A. Proust, C. Desmarets, et G. Izzet, « Hierarchical Self-Assembly of Polyoxometalate-Based Organo Palladium(II) Metallomacrocycles via Electrostatic Interactions », Inorganic Chemistry, vol. 59, nᵒ 4, p. 2458-2463, févr. 2020.
    Résumé : The design and synthesis of a supramolecular square composed of polyoxometalate-based hybrid donors and ethylenediamine palladium(II) nodes are reported. The structure of the metallomacrocycle scaffold was inferred by diffusion NMR, small-angle X-ray scattering (SAXS), and molecular modeling. The metallomacrocycle scaffold that contains negatively and positively charged subunits can further self-assemble owing to a competition between the solvation energy of the discrete species and intermolecular electrostatic interactions. When the dissociating character of the solvent was lowered or when in the presence of a protic solvent, different types of multiscale organizations (vesicles and pseudo-1D structures) were selectively formed and were characterized by SAXS and transmission electron microscopy.
    Mots-clés : ARC, E-POM, MACO, POLE 1, POLE 2.
    Pièce jointe Full Text PDF 2.1 Mo (source)

  • M. Salmain, N. Fischer-Durand, et B. Rudolf, « Bioorthogonal Conjugation of Transition Organometallic Complexes to Peptides and Proteins: Strategies and Applications », European Journal of Inorganic Chemistry, vol. 2020, nᵒ 1, p. 21-25, 2020.
    Résumé : The advent of bioorthogonal chemistry has revolutionized the common practices in protein bioconjugation and contributed to a large extent to the development of chemical biology, a discipline aimed at studying biological/biochemical processes/events in their natural setting (living cells, whole organisms) using dedicated chemical tools. This minireview intends to provide an up-to-date overview on the various bioorthogonal strategies implemented for the conjugation of transition organometallic entities to peptides, peptide nucleic acids and proteins with a focus on targeted applications, i.e. fluorescence- or radio-labeling for imaging, controlled delivery of therapeutic agents and bioanalysis.
    Mots-clés : CHEMBIO, Click chemistry, Cycloaddition, Ferrocene, Manganese, Peptide nucleic acids, POLE 3.
    Note Note
    <p>doi: 10.1002/ejic.201900810</p>
    Note Note
    <p>doi: 10.1002/ejic.201900810</p>

  • Y. Shi, Y. Li, et T. Coradin, « Magnetically-oriented type I collagen-SiO2@Fe3O4 rods composite hydrogels tuning skin cell growth », Colloids and Surfaces B: Biointerfaces, vol. 185, p. 110597, 2020.

  • C. Tugny, N. del Rio, M. Koohgard, N. Vanthuyne, D. Lesage, K. Bijouard, P. Zhang, J. Meijide Suárez, S. Roland, E. Derat, O. Bistri-Aslanoff, M. Sollogoub, L. Fensterbank, et V. Mouriès-Mansuy, « β-Cyclodextrin–NHC–Gold(I) Complex (β-ICyD)AuCl: A Chiral Nanoreactor for Enantioselective and Substrate-Selective Alkoxycyclization Reactions », ACS Catalysis, vol. 10, nᵒ 11, p. 5964-5972, juin 2020.
    Résumé : NHC-capped β-cyclodextrin (β-ICyD) was used as a ligand for gold-catalyzed alkoxycyclization reactions. The cavity was found to be responsible for a triple selectivity: (i) the asymmetric shape of the cavity of β-ICyD induced highly stereoselective cyclizations, (ii) the shape of the interior favored the formation of a six-membered ring in the absence of a nucleophile, and finally, (iii) the encapsulation of the metal inside the cavity disfavored the addition of sterically hindered alcohols. Highly enantioselective and substrate-selective alkoxycyclizations of enynes are therefore promoted by the cavity-based molecular reactor (β-ICyD)AuCl.
    Mots-clés : CSOB, GOBS, MACO, POLE 1, POLE 3.
    Pièce jointe Full Text PDF 2.2 Mo (source)

  • Z. Wang, D. Landy, C. Sizun, C. Cézard, A. Solgadi, C. Przybylski, L. de Chaisemartin, L. Herfindal, G. Barratt, et F. - X. Legrand, « Cyclodextrin complexation studies as the first step for repurposing of chlorpromazine », International Journal of Pharmaceutics, vol. 584, p. 119391, 2020.

  • K. Wu, B. Pudasaini, J. Y. Park, S. Top, G. Jaouen, M. - H. Baik, et W. E. Geiger, « Oxidation of Cymantrene-Tagged Tamoxifen Analogues: Effect of Diphenyl Functionalization on the Redox Mechanism », Organometallics, 2020.
    Résumé : The oxidations of 1,1′-di-p-anisolyl-2-cymantrenylbutene (3b) and 1,1′-di-p-hydroxyphenyl-2-cymantrenylbutene (3c) were investigated by electrochemical and spectroscopic experiments and by density functional theory (DFT) calculations. Both compounds undergo a reversible one-electron oxidation followed closely by a partially chemically reversible second oxidation (E1/2 values vs ferrocene: 0.60 and 0.74 V for 3b; 0.63 and 0.78 V for 3c). In comparison to the nonphenyl-functionalized parent, 1,1′-diphenyl-2-cymantrenylbutene (3a), 3b,c have lower and more closely spaced oxidation potentials and more rapid follow-up reactions of their dications, 3b2+ and 3c2+. Shifts in the calculated charge distributions of the neutral compounds and their singly and doubly oxidized products corroborated trends in the measured shifts of Mn–CO νCO frequencies in assigning the redox sites primarily to the diarylbutene fragment. Upon removal of electrons, the lost charge density is partially compensated by the polarizable cymantrenyl tag. The half-lives of the dications 3b2+ and 3c2+ are about 10 s at room temperature in dichloromethane/0.05 M [NBu4][B(C6F5)4]. Their follow-up reactions are initiated by loss of a proton either from a hydroxyl group or from the CH2 group of the diarylbutene unit, giving rise to two products having quinone methide structures. Although the initial oxidation sites of cymantrene-tagged diarylbutenes are primarily ligand based and those of ferrocene-tagged diarylbutenes are metal-based, the ultimate oxidation products of their p-OH- or p-OMe-functionalized derivatives are very similar.
    Mots-clés : CHEMBIO, POLE 3.
    Note Note
    <p>doi: 10.1021/acs.organomet.9b00822</p>

  • G. Xu, S. Leloux, P. Zhang, J. M. Suárez, Y. Zhang, E. Derat, M. Ménand, O. Bistri‐Aslanoff, S. Roland, T. Leyssens, O. Riant, et M. Sollogoub, « Capturing the Monomeric (L)CuH in NHC-Capped Cyclodextrin: Cavity-Controlled Chemoselective Hydrosilylation of α,β-Unsaturated Ketones », Angewandte Chemie International Edition, vol. 59, nᵒ 19, p. 7591-7597, 2020.
    Résumé : The encapsulation of copper inside a cyclodextrin capped with an N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal C−H bonds of the cyclodextrin.
    Mots-clés : cavities, copper hydride, cyclodextrins, GOBS, hydrosilylation, MACO, N-heterocyclic carbenes, POLE 1, POLE 3, α, β-unsaturated ketones.
    Pièce jointe Full Text PDF 3.2 Mo (source)


  • « 15 Silicates in Photocatalysis », in Photocatalysis in Organic Synthesis, 2019ᵉ éd., Stuttgart: Thieme Verlag, 2019, p. 427.
    Résumé : Thieme E-Books & E-Journals
    Mots-clés : CHEMBIO, MACO, POLE 1, POLE 3.

  • F. Abbassi, M. Mbarek, D. Kreher, et K. Alimi, « Cross linking-dependent properties of PVK-MEH-PPV bi-block copolymer: Vibrational, thermal and optical properties », Journal of Physics and Chemistry of Solids, vol. 126, p. 274-279, mars 2019.
    Résumé : Despite its interesting optoelectronic properties, the insolubility of poly (N-vinylcarbazole-poly [2-methoxy-5-2 (ethylhexyloxy)-1,4-phenylenevinylene] (PVK-MEH-PPV) bi-block copolymer has caused some difficulties especially for the elaboration of new composites based on this copolymer and [6,6]-phenyl-C61-butanoate of methyl (PCBM). To solve the problem of insolubility, we first modify quantitatively a main parameter in the chemical synthesis, namely the oxidant agent and then replaced with a new one. Dramatic changes in the vibrational and optical properties are founded by varying the FeCl3 amount in the synthesis way due to the cross-linking of PVK units. This is induces the modulation of copolymers properties particularly theirs emissive proprieties due to the modulation of PVK and MEH-PPV contribution. A red shifting of the maximum of photoluminescence and a quenching was observed with increasing of the oxidation yields. Composite based PCBM and copolymer was elaborated due the solubility of one of copolymer by changing the oxidant agent.
    Mots-clés : Chemical synthesis, Infrared spectroscopy, Optical properties, POLYMERES, Polymers, Thermogravimetric analysis (TGA).

  • U. Alali, A. Vallin, A. Bil, T. Khanchouche, D. Mathiron, C. Przybylski, R. Beaulieu, J. Kovensky, M. Benazza, et V. Bonnet, « The uncommon strong inhibition of α-glucosidase by multivalent glycoclusters based on cyclodextrin scaffolds », Organic & Biomolecular Chemistry, vol. 17, nᵒ 30, p. 7228-7237, 2019.
    Résumé : New inhibitors of α-glucosidase based on perglycosylated cyclodextrins were synthesized via click-chemistry and compared to acarbose. , The homeostasis disruption of d -glucose causes diabetes, a dramatic chronic disease worldwide. Type 1 diabetes is a successfully treatable form, where blood d -glucose is regulated by insulin treatment. In contrast type 2 diabetes, the non-insulin dependent kind, is problematic. The control of the d -glucose blood level via intestinal α- d -glucosidase inactivation can be achieved by using competitive inhibitors, such as iminosugars ( e.g. acarbose) or sulfonium sugar derivatives ( e.g. salacinol). Recently, an unprecedented result showed that multivalent diamond nanoparticles grafted with unmodified sugars displayed α-glucosidase inhibition at low micromolar concentrations. Herein we describe the synthesis of multivalent glycoclusters using cyclodextrins (CDs) as scaffolds and an assessment of their role as inhibitors of α- d -glucosidase. The glycoclusters were efficiently obtained from per-azido α, β and γ-CD derivatives and propargyl glycosides using click-chemistry under microwave irradiation. The methodology was successfully applied to various protected and non-protected propargylated monosaccharides, including both O - and S -glycosides, giving clear evidence of its versatility. The targeted 6- per -glycosylated CDs were isolated in moderate to excellent yields (30–90%) by silica gel chromatography. The results showed inhibition of α-glucosidase from Saccharomyces cerevisiae with IC 50 values in the 32–132 μM range, lower than that of acarbose (IC 50 = ∼250 μM), a well-known competitive inhibitor used in the clinical treatment of type 2 diabetes. Preliminary experiments suggest a mixed-type non-competitive inhibition mode for these new glycoclusters.
    Mots-clés : CSOB, POLE 3.

  • Q. Arnoux, C. Blouzon, D. Li, Y. J. Dappe, A. Smogunov, P. Bonville, L. Tortech, et J. - B. Moussy, « Controlling the magnetic exchange coupling in hybrid heterojunctions via spacer layers of π-conjugated molecules », Physical Review B, vol. 99, nᵒ 14, p. 144405, avr. 2019.
    Résumé : Mastering and understanding the magnetic couplings between magnetic electrodes separated by organic layers are crucial for developing new hybrid spintronic devices. We study the magnetic exchange interactions in organic-inorganic heterojunctions and unveil the possibility of controlling the strength of the magnetic exchange coupling between two ferromagnetic electrodes across π-conjugated molecules’ (α-sexithiophene or para-sexiphenyl) ultrathin film. In Fe3O4/π-conjugated molecules/Co magnetic tunnel junctions, an antiferromagnetic interlayer exchange coupling with variable strength is observed according to the nature of the aromatic rings (thiophene or phenyl groups). The underlying physical mechanism is revealed by ab initio calculations relating the strength of magnetic coupling to the spin moment penetration into a molecular layer at the molecule/Co interface. The prospect that magnetic coupling between two ferromagnetic electrodes can be mediated and tuned by organic molecules opens different perspectives in the way magnetization of organic tunnel junctions or spin valves can be driven.
    Mots-clés : E-POM, POLE 2.
    Pièce jointe Full Text PDF 4.6 Mo (source)

  • M. Auffray, D. H. Kim, J. U. Kim, F. Bencheikh, D. Kreher, Q. Zhang, A. D'Aléo, J. - C. Ribierre, F. Mathevet, et C. Adachi, « Dithia[3.3]paracyclophane Core: A Versatile Platform for Triplet State Fine-Tuning and Through-Space TADF Emission », Chemistry – An Asian Journal, vol. 14, nᵒ 11, p. 1921-1925, 2019.
    Résumé : Thermally activated delayed fluorescence (TADF) based on through-space donor and acceptor interactions constitute a recent and promising approach to develop efficient TADF emitters. Novel TADF isomers using a dithia[3.3]-paracyclophane building block as a versatile 3D platform to promote through-space interactions are presented. Such a 3D platform allows to bring together the D and A units into close proximity and to probe the effect of their orientation, contact site and distance on their TADF emission properties. This study provides evidence that the dithia[3.3]paracyclophane core is a promising platform to control intramolecular through-space interactions and obtain an efficient TADF emission with short reverse-intersystem crossing (RISC) lifetimes. In addition, this study demonstrates that this design can tune the energy levels of the triplet states and leads to an upconversion from 3CT to 3LE that promotes faster and more efficient RISC to the 1CT singlet state.
    Mots-clés : cyclophanes, donor-acceptor molecules, POLYMERES, TADF lifetime, thermally activated delayed fluorescence, through-space interactions.
    Pièce jointe Full Text PDF 799.4 ko (source)

  • V. Ayzac, Q. Sallembien, M. Raynal, B. Isare, J. Jestin, et L. Bouteiller, « A Competing Hydrogen Bonding Pattern to Yield a Thermo-Thickening Supramolecular Polymer », Angewandte Chemie International Edition, vol. 58, nᵒ 39, p. 13849-13853, 2019.
    Résumé : Introduction of competing interactions in the design of a supramolecular polymer (SP) creates pathway complexity. Ester–bis-ureas contain both a strong bis-urea sticker that is responsible for the build-up of long rod-like objects by hydrogen bonding and ester groups that can interfere with this main pattern in a subtle way. Spectroscopic (FTIR and CD), calorimetric (DSC), and scattering (SANS) techniques show that such ester–bis-ureas self-assemble into three competing rod-like SPs. The previously unreported low-temperature SP is stabilized by hydrogen bonds between the interfering ester groups and the urea moieties. It also features a weak macroscopic alignment of the rods. The other structures form isotropic dispersions of rods stabilized by the more classical urea-urea hydrogen bonding pattern. The transition from the low-temperature structure to the next occurs reversibly by heating and is accompanied by an increase in viscosity, a rare feature for solutions in hydrocarbons.
    Mots-clés : hydrogen bonds, pathway complexity, POLYMERES, self-assembly, supramolecular polymers, urea.

  • K. Baatout, F. Saad, A. Baffoun, B. Mahltig, D. Kreher, N. Jaballah, et M. Majdoub, « Luminescent cotton fibers coated with fluorescein dye for anti-counterfeiting applications », Materials Chemistry and Physics, vol. 234, p. 304-310, août 2019.
    Résumé : A simple,

    rapid and green method to develop fluorescent cotton yarns was established. We report the application of fluorescein (FL) into textile support by impregnation method while keeping the original cotton yarn properties for anti-counterfeiting applications. The FL-coated yarns were characterized by Scanning Electron Microscopy, reflectance and fluorescence spectroscopy. The CIE chromaticity diagram showed a yellowish green emission with a weak yellow coloration of cotton fiber. Mechanical characterization of samples shows that the application of fluorescein did not alter significantly the breaking strength and elongation at break of the fibers, even when using resins. In contrast, to resin-free impregnation process the color fastness test demonstrates that the use of resins as binder is required. The obtained results showed that cotton samples release slowly its contents and fluorescein remains more than five washing cycles.
    Mots-clés : Anti-counterfeiting, Cotton fiber, Fluorescein dye, Fluorescence, POLYMERES, Resin, Washing fastness.

  • G. Basuyaux, A. Desmarchelier, G. Gontard, N. Vanthuyne, J. Moussa, H. Amouri, M. Raynal, et L. Bouteiller, « Extra hydrogen bonding interactions by peripheral indole groups stabilize benzene-1,3,5-tricarboxamide helical assemblies », Chemical Communications, vol. 55, nᵒ 59, p. 8548-8551, juill. 2019.
    Résumé : Benzene-1,3,5-tricarboxamide monomers derived from alkyl esters of tryptophan (BTA Trp) self-assemble into helices with an inner threefold hydrogen bond network surrounded by a second network involving the indole N–H groups. As a consequence of this extra stabilization of its helical assemblies, BTA Trp forms more viscous solutions than a range of ester and alkyl BTAs.
    Mots-clés : ARC, POLE 1, POLYMERES.
    Pièce jointe Full Text PDF 2.4 Mo (source)

  • P. Bayat, D. Gatineau, D. Lesage, S. Marhabaie, A. Martinez, et R. B. Cole, « Investigation of activation energies for dissociation of host-guest complexes in the gas phase using low-energy collision induced dissociation », Journal of Mass Spectrometry, vol. 54, nᵒ 5, p. 437-448, 2019.

  • L. Ben Haj Hassen, S. Dhifaoui, Y. Rousselin, V. Marvaud, C. Stern, C. E. Schulz, et H. Nasri, « New insights on the electronic, magnetic, electric and molecular structure of a bis-(4-cyanopyridine) iron(III) complex with the meso-tetrakis(4-methoxyphenyl)porphyrin », Inorganica Chimica Acta, vol. 486, p. 675-683, févr. 2019.
    Résumé : We have successfully synthesized and characterized a new low-spin iron(III) bis(4-cyanopyridine) complex with a meso-porphyrin substituted in the para positions of the phenyls by the methoxy group, namely the bis(4-cyanopyridine)[(meso-tetrakis(4-metoxyphenylporphyrinato)]iron(III) trifluoromethanesulfonate chlorobenzene monosolvate complex with the formula [FeIII(TMPP)(4-CNpy)2]SO3CF3.C6H5Cl (I). This species was characterized through ultraviolet–visible, Fourier-transform infrared and Mössbauer spectroscopy as well as by SQUID magnetometry, cyclic voltammetry, and X-ray crystallography. These characterizations indicated that our synthetic heme model is a low-spin (S = 1/2) coordination compound and especially shows that the structural, electronic and the magnetic properties of complex (I) are closely dominated by the presence of the methoxy σ-donor group at the para positions of the meso-porphyrin.
    Mots-clés : Cyclic voltammetry, E-POM, Iron(III) porphyrin, Magnetic properties, POLE 2, X-ray Molecular structure.

  • R. Benchouaia, N. Cissé, B. Boitrel, M. Sollogoub, S. Le Gac, et M. Ménand, « Orchestrating Communications in a Three-Type Chirality Totem: Remote Control of the Chiroptical Response of a Möbius Aromatic System », Journal of the American Chemical Society, vol. 141, nᵒ 29, p. 11583-11593, juill. 2019.

  • L. Benda, B. Doistau, C. Rossi-Gendron, L. - M. Chamoreau, B. Hasenknopf, et G. Vives, « Substrate-dependent allosteric regulation by switchable catalytic molecular tweezers », Communications Chemistry, vol. 2, nᵒ 1, p. 144, 2019.

  • K. Bernardino, J. Świergiel, J. Jadżyn, L. Bouteiller, et A. F. de Moura, « Bulkiness as a design element to increase the rigidity and macrodipole of supramolecular polymers », Journal of Molecular Liquids, vol. 286, p. 110937, juill. 2019.
    Résumé : N,N′-dialkyl ureas in non-polar solvents self-assemble as hydrogen bonded chains. Infrared and dielectric spectroscopy show that more sterically crowded monomers form shorter chains but also larger macrodipoles. This unexpected effect is due to the enhanced rigidity of the bulky assemblies, as confirmed by molecular dynamics simulations.
    Mots-clés : POLYMERES.

  • J. Besnardiere, B. Ma, A. Torres-Pardo, G. Wallez, H. Kabbour, J. M. González-Calbet, H. J. Von Bardeleben, B. Fleury, V. Buissette, C. Sanchez, T. Le Mercier, S. Cassaignon, et D. Portehault, « Structure and electrochromism of two-dimensional octahedral molecular sieve h’-WO3 », Nature Communications, vol. 10, nᵒ 1, p. 327, janv. 2019.
    Résumé : Octahedral molecular sieves (OMS) are built of transition metal-oxygen octahedra that delimit sub-nanoscale cavities. Compared to other microporous solids, OMS exhibit larger versatility in properties, provided by various redox states and magnetic behaviors of transition metals. Hence, OMS offer opportunities in electrochemical energy harnessing devices, including batteries, electrochemical capacitors and electrochromic systems, provided two conditions are met: fast exchange of ions in the micropores and stability upon exchange. Here we unveil a novel OMS hexagonal polymorph of tungsten oxide called h’-WO3, built of (WO6)6 tunnel cavities. h’-WO3 is prepared by a one-step soft chemistry aqueous route leading to the hydrogen bronze h’-H0.07WO3. Gentle heating results in h’-WO3 with framework retention. The material exhibits an unusual combination of 1-dimensional crystal structure and 2-dimensional nanostructure that enhances and fastens proton (de)insertion for stable electrochromic devices. This discovery paves the way to a new family of mixed valence functional

    materials with tunable behaviors.
    Mots-clés : ERMMES, POLE 2.

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