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Julie Febvay Dr. Charles S. Demmer Dr. Pascal Retailleau Dr. Jeanne Crassous Dr. Laura Abella Prof. Jochen Autschbach Dr. Arnaud Voituriez Dr. Angela Marinetti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(68):15609-15614
Phosphahelicenes with thiophosphinic acid and ester functions have been obtained by the oxidative photocyclisation of olefins bearing both a benzophenanthrene and a benzophosphole unit. When the method has been extended to olefins bearing a partially saturated benzophospholene unit, a divergent regioselectivity of the photocyclisation step has been observed, leading to new helicenes in which the phosphorus function is located on the external rim of the helical backbone. The observed regioselectivity correlates well with the free-valence numbers of the atoms involved in the photocyclisation reaction (DFT calculations). 相似文献
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Journal of Experimental and Theoretical Physics - In this study, we examine the underlying surface wave dynamics forming an octupole structure of vortices on the air–water interface. The... 相似文献
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Carlos A.M. Abella 《Tetrahedron letters》2008,49(1):145-148
We disclose herein ozonolysis of Morita-Baylis-Hillman adducts originated from aromatic aldehydes. This efficient reaction provides α-ketoesters with different substitution patterns on the aromatic ring. Diastereoselective reduction of the corresponding α-ketoester obtained in the oxidative cleavage step provides α,β-dihydroxy-esters with excellent degree of anti diastereoselection. The method is simple and easy to execute and is therefore a valuable alternative to prepare either α-ketoesters or α,β-dihydroxy-esters. 相似文献
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E. Santoyo R. García R. Abella A. Aparicio S. P. Verma 《Journal of chromatography. A》2001,920(1-2):325-332
A new application of capillary electrophoresis for measuring major and trace anions in thermal water and condensed-steam samples is presented. Ten fluid samples were collected from hydrothermal springs and fumaroles located in a volcanic zone of Deception Island, Antarctica. Anion separation was achieved in less than 6 min using indirect UV detection at 254 nm with a negative power supply (−15 kV). The electrolyte consisted of 4.7 mM sodium chromate, 4.0 mM electroosmotic flow modifier (OFM) hydroxide, 10 mM 2-(N-cyclohexylamino)ethanesulfonic acid and 0.1 mM calcium gluconate (pH 9.1). Major anions (Cl−, SO42, PO4H2−, and CO3H−) were measured using hydrostatic injection (10 cm for 30 s) at 25°C. Trace amounts of anions (F−, Br−, and NO3−) were better determined by electromigration injection (4 kV, 10 s) at 15°C. Good reproducibility of the migration times (<0.72% RSD), a satisfactory linear response and accuracy as well as acceptable detection limits were successfully obtained. 相似文献
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Dr. Lenka Pallova Dr. Etienne S. Gauthier Dr. Laura Abella Marion Jean Dr. Nicolas Vanthuyne Dr. Vincent Dorcet Dr. Laure Vendier Prof. Jochen Autschbach Dr. Jeanne Crassous Dr. Stéphanie Bastin Dr. Vincent César 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(28):7722-7730
The straightforward, multigram-scale synthesis of the partially saturated H6-fluoreno[n]helicenes (n=5 or 7) featuring a central, overcrowded alkene is described. The key cyclization step was based on an intramolecular McMurry reaction from the corresponding 1,5-diketones. Chiral stationary phase HPLC analysis and isomer separation indicate that each helicenic compound is constituted of three diastereoisomers at room temperature, i. e. the configurationally stable (R,R,P)/(S,S,M) pair of enantiomers and an apparently achiral compound resulting from the rapid interconversion between the (R,S,P) and (S,R,M) enantiomers. The partially saturated H6-fluoreno[n]helicenes are oxidatively aromatized to give an efficient access to the corresponding fluoreno[n]helicenes. The chiroptical properties (vibrational and electronic circular dichroism) of the chiral, enantiopure compounds have been measured and analyzed by quantum-chemical calculations, confirming their helicoidal nature. 相似文献
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Patthira Sumsalee Dr. Laura Abella Sitthichok Kasemthaveechok Dr. Nicolas Vanthuyne Marie Cordier Dr. Grégory Pieters Prof. Jochen Autschbach Dr. Jeanne Crassous Dr. Ludovic Favereau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(66):16505-16511
Luminescent exciplexes based on a chiral electron donor and achiral acceptors are reported as a new approach to design circularly polarized (CP) and thermally activated delayed fluorescence (TADF) emitters. This strategy results in rather high CP luminescence (CPL) values with glum up to 7×10−3, one order of magnitude higher in comparison to the CPL signal recorded for the chiral donor alone (glum ∼7×10−4). This increase occurs concomitantly with a CPL sign inversion, as a result of the strong charge-transfer emission character, as experimentally and theoretically rationalized by using a covalent chiral donor-acceptor model. Interestingly, blue, green-yellow and red chiral luminescent exciplexes can be obtained by modifying with the electron accepting character of the achiral unit while keeping the same chiral donor unit. These results bring new (inter)molecular guidelines to obtain simply and efficiently multi-color CP-TADF emitters. 相似文献
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Etienne S. Gauthier Laura Abella Nora Hellou Benoît Darqui Elsa Caytan Thierry Roisnel Nicolas Vanthuyne Ludovic Favereau Monika Srebro‐Hooper J. A. Gareth Williams Jochen Autschbach Jeanne Crassous 《Angewandte Chemie (International ed. in English)》2020,59(22):8394-8400
The first enantiopure chiral‐at‐rhenium complexes of the form fac‐ReX(CO)3(:C^N) have been prepared, where :C^N is a helicene‐N‐heterocyclic carbene (NHC) ligand and X=Cl or I. These have complexes show strong changes in the emission characteristics, notably strongly enhanced phosphorescence lifetimes (reaching 0.7 ms) and increased circularly polarized emission (CPL) activity, as compared to their parent chiral models lacking the helicene unit. The halogen along with its position within the dissymmetric stereochemical environment strongly affect the photophysics of the complexes, particularly the phosphorescence quantum yield and lifetime. These results give fresh insight into fine tuning of photophysical and chiroptical properties of Re‐NHC systems. 相似文献