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排序方式: 共有680条查询结果,搜索用时 156 毫秒
1.
Antoine Busseau Dr. Carmen Villegas Dr. Sylvie Dabos‐Seignon Dr. Clément Cabanetos Prof. Piétrick Hudhomme Dr. Stéphanie Legoupy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(25):8452-8456
New penta(organo)fullerenes donor–acceptor systems bearing five tetrathiafulvalene recognition units have been synthesized to promote self‐assemblies similar in appearance to shuttlecocks nested into each other thanks to the conical host cavity created around the fullerene together with the π–π and electronic interactions. 相似文献
2.
Nickel(II) meso‐Hydroxyporphyrin Complexes Revisited: Palladium‐Catalysed Synthesis,Electronic Structures of Derived Oxy Radicals,and Oxidative Coupling to a Dioxoporphodimethene Dyad 下载免费PDF全文
Dr. Louisa J. Esdaile Dr. Llew Rintoul Mean See Goh Khalissa Merahi Dr. Nathalie Parizel Dr. R. Mark Wellard Dr. Sylvie Choua Prof. Dennis P. Arnold 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3430-3446
We report the synthesis and characterisation of new examples of meso‐hydroxynickel(II) porphyrins with 5,15‐diphenyl and 10‐phenyl‐5,15‐diphenyl/diaryl substitution. The OH group was introduced by using carbonate or hydroxide as nucleophile by using palladium/phosphine catalysis. The NiPor?OHs exist in solution in equilibrium with the corresponding oxy radicals NiPor?O.. The 15‐phenyl group stabilises the radicals, so that the 1H NMR spectra of {NiPor?OH} are extremely broad due to chemical exchange with the paramagnetic species. The radical concentration for the diphenylporphyrin analogue is only 1 %, and its NMR line‐broadening was able to be studied by variable‐temperature NMR spectroscopy. The EPR signals of NiPor?O. are consistent with somewhat delocalised porphyrinyloxy radicals, and the spin distributions calculated by using density functional theory match the EPR and NMR spectroscopic observations. Nickel(II) meso‐hydroxy‐10,20‐diphenylporphyrin was oxidatively coupled to a dioxo‐terminated porphodimethene dyad, the strongly red‐shifted electronic spectrum of which was successfully modelled by using time‐dependent DFT calculations. 相似文献
3.
Green solvent approach for printable large deformation thermoplastic elastomer based piezoresistive sensors and their suitability for biomedical applications 下载免费PDF全文
Bruna F. Gonçalves Pedro Costa Juliana Oliveira Sylvie Ribeiro Vitor Correia Gabriela Botelho Senentxu Lanceros‐Mendez 《Journal of Polymer Science.Polymer Physics》2016,54(20):2092-2103
Composites based on biocompatible thermoplastic elastomer styrene‐ethylene/butylene‐styrene (SEBS) as matrix and multi‐walled carbon nanotubes (MWCNT) as nanofillers show excellent mechanical and piezoresistive properties from low to large deformations. The MWCNT/SEBS composites have been prepared following a green solvent approach, to extend their range of applicability to biomedical applications. The obtained composites with 2, 4, and 5 wt % MWCNT content provide suitable piezoresistive response up to 80% deformation with a piezoresistive sensibility near 2.7, depending on the applied strain and MWCNT content. Composite sensors were also developed by spray and screen printing and integrated with an electronic data acquisition system with RF communication. The possibility to accurately control the composites properties and performance by varying MWCNT content, viscosity, and mechanical properties of the polymer matrix, shows the large potential of the system for the development of large deformation printable piezoresistive sensors. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2092–2103 相似文献
4.
Dr. Julie Martin Dr. Mohammad Wehbi Dr. Cécile Echalier Dr. Sylvie Hunger Dr. Audrey Bethry Prof. Xavier Garric Dr. Coline Pinese Prof. Jean Martinez Dr. Lubomir Vezenkov Prof. Gilles Subra Prof. Ahmad Mehdi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(56):12839-12845
A simple and efficient way to synthesize peptide-containing silicone materials is described. Silicone oils containing a chosen ratio of bioactive peptide sequences were prepared by acid-catalyzed copolymerization of dichlorodimethylsilane, hybrid dichloromethyl peptidosilane, and Si(vinyl)- or SiH-functionalized monomers. Functionalized silicone oils were first obtained and then, after hydrosilylation cross-linking, bioactive polydimethylsiloxane (PDMS)-based materials were straightforwardly obtained. The introduction of an antibacterial peptide yielded PDMS materials showing activity against Staphylococcus aureus. PDMS containing RGD ligands showed improved cell-adhesion properties. This generic method was fully compatible with the stability of peptides and thus opened the way to the synthesis of a wide range of biologically active silicones. 相似文献
5.
Stefano Barranco Federico Cuccu Dayi Liu Dr. Sylvie Robin Dr. Régis Guillot Prof. Dr. Francesco Secci Dr. Valérie Brenner Dr. Michel Mons Prof. Dr. Pierluigi Caboni Prof. Dr. David J. Aitken Prof. Dr. Angelo Frongia 《European journal of organic chemistry》2023,26(16):e202300183
A stereoselective one-pot double derivatization of cyclobutene-1-carboxylic acid via a mild organic base catalyzed amidation/aza-Michael addition of benzo[d]oxazol-2(3H)-ones has been developed. This unprecedented tandem reaction provides access to novel β-N-heterocyclic cyclobutane carboximide derivatives with a trans geometry. The carboximide moiety reacts smoothly with nucleophiles, allowing access to diverse derivatives of trans-β-N-heterocyclic cyclobutanecarboxylic acid, including peptidomimetic structures. 相似文献
6.
Ion tree‐based structure elucidation of acetophenone dimers (AtA) from Acronychia pedunculata and their identification in extracts by liquid chromatography electrospray ionization LTQ‐Orbitrap mass spectrometry 下载免费PDF全文
Eirini Kouloura Alexios‐Leandros Skaltsounis Sylvie Michel Maria Halabalaki 《Journal of mass spectrometry : JMS》2015,50(3):495-512
Acronychia‐type acetophenones (AtA) is a chemical group of compounds of important structural and biological interest, abundant in Acronychia species. However, there are no data available for their characterization using mass spectrometry. In the current work, AtA have been investigated by multistage high resolution mass spectrometry and both electrospray ionization and atmospheric pressure chemical ionization, in positive and negative mode, were utilized for their structure elucidation and identification. The analysis of AtA using a linear ion trap‐Orbitrap analyzer enabled the structural determination of key fragment ions and cleavages, which can be used for the structural characterization thereof. A systematic nomenclature based on protonated and deprotonated fragment ions under collision‐induced dissociation conditions and decision trees for the structural determination of AtA are proposed. Furthermore, taking advantage of the characteristic fragmentation patterns, a selective Ultra High Performance Liquid Chromatography Electrospray Ionization multistage Mass Spectrometry (UHPLC‐ESI(‐)‐MSn) method was developed and successfully applied for the dereplication of known AtA and the identification of potentially new ones in Acronychia extracts. Despite the structure similarity and the presence of isomers, accurate characterization of known and unknown AtA derivatives was possible. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
Surface and Structural Investigation of a MnOx Birnessite‐Type Water Oxidation Catalyst Formed under Photocatalytic Conditions 下载免费PDF全文
Benjamin J. Deibert Jingming Zhang Paul F. Smith Dr. Karena W. Chapman Dr. Sylvie Rangan Debasis Banerjee Kui Tan Hao Wang Nicholas Pasquale Prof. Feng Chen Prof. Ki‐Bum Lee Prof. G. Charles Dismukes Prof. Yves J. Chabal Prof. Jing Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):14218-14228
Catalytically active MnOx species have been reported to form in situ from various Mn‐complexes during electrocatalytic and solution‐based water oxidation when employing cerium(IV) ammonium ammonium nitrate (CAN) oxidant as a sacrificial reagent. The full structural characterization of these oxides may be complicated by the presence of support material and lack of a pure bulk phase. For the first time, we show that highly active MnOx catalysts form without supports in situ under photocatalytic conditions. Our most active 4MnOx catalyst (~0.84 mmol O2 mol Mn?1 s?1) forms from a Mn4O4 bearing a metal–organic framework. 4MnOx is characterized by pair distribution function analysis (PDF), Raman spectroscopy, and HR‐TEM as a disordered, layered Mn‐oxide with high surface area (216 m2g?1) and small regions of crystallinity and layer flexibility. In contrast, the SMnOx formed from Mn2+ salt gives an amorphous species of lower surface area (80 m2g?1) and lower activity (~0.15 mmol O2 mol Mn?1 s?1). We compare these catalysts to crystalline hexagonal birnessite, which activates under the same conditions. Full deconvolution of the XPS Mn2p3/2 core levels detects enriched Mn3+ and Mn2+ content on the surfaces, which indicates possible disproportionation/comproportionation surface equilibria. 相似文献
8.
Jiri Kudr Sylvie Skalickova Lukas Nejdl Amitava Moulick Branislav Ruttkay–Nedecky Vojtech Adam Rene Kizek 《Electrophoresis》2015,36(19):2367-2379
Nanofluidics is becoming an extensively developing technique in the field of bioanalytical chemistry. Nanoscale hole embed in an insulating membrane is employed in a vast variety of sensing platforms and applications. Although, biological nanopores have several attractive characteristics, in this paper, we focused on the solid‐state nanopores due to their advantages as high stability, possibility of diameter control, and ease of surface functionalizing. A detection method, based on the translocation of analyzed molecules through nanochannels under applied voltage bias and resistive pulse sensing, is well established. Nevertheless, it seems that the new detection methods like measuring of transverse electron tunneling using nanogap electrodes or optical detection can offer significant additional advantages. The aim of this review is not to cite all related articles, but highlight the steps, which in our opinion, meant important progresses in solid‐state nanopore analysis. 相似文献
9.
Amivi Felicite Amoudji Sylvie Arpigny Philippe Moisy Fethi Bedioui 《Electroanalysis》2021,33(8):1871-1876
In this work we report on the electrochemical behavior of Ce(IV)/Ce(III) redox couple in pure N,N-dialkyl amides (N,N-DA), namely N,N-di(2-ethylhexyl)-n-butanamide (DEHBA), N,N-di(2-ethylhexyl)-iso-butanamide (DEHiBA), and N,N-di(2-ethylhexyl)-3,3-dimethyl butanamide (DEHDMBA) equilibrated with nitric aqueous solutions as an entry to the direct electrochemical characterization of plutonium in these extractants. Ce(IV)/Ce(III) redox process was used as a model. Its potential (E1/2≅1.02 V/SCE) is not affected by the temperature and the nature of the N,N-DA and this clearly indicates that the functionalities of these extractants produce the same relative effect on both +IV and +III oxidation states of the cerium cation. Linear variations of the current intensity of the reduction peak of Ce(IV) with the concentration of Ce(IV)/N,N-DAs/HNO3(5 M) solutions were obtained from cyclic voltammograms recorded at 25 °C and 40 °C. Due to the poor definition of the voltammograms in DEHiBA and DEHDMBA, such characterization allows only the evaluation of the performances of the chemical extraction of Ce(IV) from aqueous nitric acid solution by the undiluted DEHBA. To our knowledge, the electrochemical behavior of Ce(IV)/Ce(III) in N,N-DAs was not previously studied and our findings will for sure open the door for further investigations in this field. 相似文献
10.
Nouemsi Soubgui Epiphanie Tene Fongang Rufin Theophile Kamseu Elie Oum Lissouck Rene Andreola Fernanda Boubakar Likiby Rossignol Sylvie Leonelli Cristina 《Journal of Thermal Analysis and Calorimetry》2021,145(6):3003-3018
Journal of Thermal Analysis and Calorimetry - The influence of drying on the microstructure, physical and chemical properties of some tropical wood species has been investigated using... 相似文献