The 2nd day meeting of kinoa
2023-03-15
The Research Federation "Chirality in Nouvelle Aquitaine" (Ki-NOA) is organizing its 2nd day of scientific meetings and exchanges on the 25th of April at the IECB (2 rue Robert Escarpit, Pessac). This event will take place from 8h50-17h15, and the program is available at https://kinoa.cnrs.fr/2nd-kinoa-meeting/ Registration mandatory before the 7th of April on the framaform sent by email.
Laboratory: all labs
The kinoa tour
2023-02-22
Nous avons eu 10 propositions de visite de labo sur le campus bordelais pour échanger autour de la chiralité. Ces visites se sont tenues entre décembre 2022 et février 2023, avec des échanges scientifiques très constructifs. Merci à tous ceux qui ont donné de leur temps et curiosité 🙂
Laboratory: all labs
2nd Kinoa Meeting-2023
Laboratory:
Félicitation à Alexander et toute l’équipe NSYSA de l’ISM
2023-03-06
Alexander Kuhn, membre très actif de la fédération kinoa, professeur à l’École nationale supérieure de matériaux, d’agroalimentaire et de chimie et chercheur à l’Institut des Sciences Moléculaires a recu l'une des 24 médailles d'argent du CNRS octroyée en 2023. Félicitation de tous à l'équipe NSYSA (NanoSystèmes Analytiques) https://www.cnrs.fr/fr/personne/alexander-kuhn
https://nsysa.ism-bordeaux.cnrs.fr/staff/permanent/22-staff/288-contact-alexander-kuhn-2.html
Laboratory: ISM
Crystal Engineering of Conglomerates: Dilution of Racemate-Forming Fe(II) and Ni(II) Congeners into Conglomerate-Forming [Zn(bpy)3](PF6)2
2023-02-28
Conglomerate formation, where enantiomers within a racemic mixture self-segregate upon crystallization, is an advantageous property for obtaining chirally pure crystals and allows large-scale chiral resolution. However, the prevalence of conglomerates is low and difficult to predict. In this report, we describe our attempts to engineer conglomerates from racemate-forming compounds by integrating them into a conglomerate-forming matrix. In this regard, we found that Ni(II) and Fe(II) form molecular alloys with Zn(II) in [MxZn(1−x)(bpy)3](PF6)2 (where bpy = 2,2′-bipyridyl). Powder X-ray Diffraction (PXRD) and Energy-Dispersive X-ray spectroscopy (EDX) evidenced conglomerate crystallization with Ni(II) concentrations up to about 25%, while it was observed only for much lower concentrations of Fe(II). This can be attributed to the ability of [Ni(bpy)3](PF6)2 to access a metastable conglomerate phase, while no such phase has been detected in [Fe(bpy)3](PF6)2. Furthermore, the chiral phase appears to be favored in fast-growing precipitates, while the racemic phase is favored in slow re-crystallizations for both Ni(II) and Fe(II) molecular alloys. X-ray natural circular dichroism (XNCD) measurements on [Ni0.13Zn0.87(bpy)3](PF6)2 demonstrate the chirality of the nickel molecules within the zinc molecular matrix.
U. Serdan, L. Robin, M. Marchivie, M. Gonidec, P. Rosa, E. Duverger-Nédellec, E. Pouget, P. Sainctavit, M.-A. Arrio, A. Juhin, A. Rogalev, F. Wilhelm and E. A. Hillard Chemistry. 5(1) (2023) 255-268
fig :Molecular alloy of conglomerate [Ni@Zn(bpy)3](PF6)2
Laboratory: ICMCB
Autonomous Chiral Microswimmers with Self‐mixing Capabilities for Highly Efficient Enantioselective Synthesis
2022-12-15
The development of chiral catalysts plays a very important role in various areas of chemical science. Heterogeneous catalysts have the general advantage of allowing a more straightforward separation from the products. One specific case of heterogeneous catalysis is electrocatalysis, being potentially a green chemistry approach. However, a typical drawback is that the redox conversion of molecules occurs only at the electrode/electrolyte interface, and not in the bulk of the electrolyte. The second limitation is that the electrodes have to be physically connected to a power supply to induce the desired reactions. To circumvent these problems, we propose here a complementary approach by replacing macroscopic electrodes with an ensemble of self-propelled redox active microswimmers. They move autonomously in solution while transforming simultaneously a prochiral starting compound into a specific enantiomer with a very high enantiomeric excess, accompanied by a significantly increased production rate of the favorite enantiomer.
S. Arnaboldi, G. Salinas, G. Bonetti, P. Garrigue, R. Cirilli, T. Benincori, A. Kuhn
Angew.Chem.Int.Ed. 61 (2022) e202209098
Laboratory: ISM
Electrochemiluminescent enantioselective detection with chiral-imprinted mesoporous metal surfaces
2022-12-15
Chiral-imprinted mesoporous Pt-Ir alloy surfaces were combined in a synergetic way with electrochemiluminescence (ECL) to detect the two enantiomers of phenylalanine (PA) as a model compound, acting simultaneously as a chiral target and as a co-reactant to generate significant differences in ECL signals. The chiral features of the metal surfaces are converted into an enantioselective electrogeneration of the excited state of the [Ru(bpy)3]2+ dye, which in fine produces the differentiating light emission with up to 20-fold differences in intensity for the two enantiomers. These findings open up the possibility of developing new ECL-based bioassays and microscopy of chiral environments.
S. Butcha, J. Yu, Z. Pasom, B. Goudeau, C. Wattanakit, N. Sojic, A. Kuhn
ChemComm 58 (2022) 10707-10710
Laboratory: ISM
Bipolar electrochemical rotors for the direct transduction of molecular chiral information
2022-12-15
Efficient monitoring of chiral information of bioactive compounds has gained considerable attention, due to their involvement in different biochemical processes. In this work, we propose a novel dynamic system for the easy and straightforward recognition of chiral redox active molecules and its possible use for the efficient measurement of enantiomeric excess in solution. The approach is based on the synergy between the localized enantioselective oxidation of only one of the two antipodes of a chiral molecule and the produced charge-compensating asymmetric proton flux along a bipolar electrode. The resulting clockwise or anticlockwise rotation is triggered only when the probe with the right chirality is present in solution. The angle of rotation shows a linear correlation with the analyte concentration, enabling the quantification of enantiomeric ratios in mixtures where the two antipodes are present in solution. This device was successfully used to simultaneously measure different ratios of the enantiomers of 3,4-dihydroxyphenylalanine and tryptophan. The versatility of the proposed approach opens up the possibility to use such a dynamic system as a straightforward (bio)analytical tool for the qualitative and quantitative discrimination of different redox-active chiral probes.
S. Arnaboldi, G. Salinas, G. Bonetti, R. Cirilli, T. Benincori, A. Kuhn
Biosens. Bioelectron. 218 (2022) 114740
Laboratory: ISM
Wireless electromechanical enantio-responsive valves
2022-12-15
Microfluidic valves based on chemically responsive materials have gained considerable attention in recent years. Herein a wireless enantio-responsive valve triggered by bipolar electrochemistry combined with chiral recognition is reported. A conducting polymer actuator functionalized with the enantiomers of an inherently chiral oligomer was used as bipolar valve to cover a tube loaded with a dye, and immersed in a solution containing chiral analytes. When an electric field is applied, the designed actuator shows a reversible cantilever-type deflection, allowing the release of the dye from the reservoir. The tube can be opened and closed by simply switching the polarity of the system. Qualitative results show the successful release of the colorant, driven by chirality and redox reactions occurring at the bipolar valve. The device works well even in the presence of chemically different chiral analytes in the same solution. These systems open up new possibilities in the field of microfluidics, including also controlled drug delivery applications.
G. Salinas, F. Malacarne, G. Bonetti, R. Cirilli, T. Benincori, S. Arnaboldi, A. Kuhn
Chirality (2022) in press
Laboratory: ISM
Self-assembled monolayer protection of chiral-imprinted mesoporous platinum electrodes for highly enantioselective synthesis
2022-12-15
In modern chemistry, chiral (electro)catalysis is a powerful strategy to produce enantiomerically pure compounds (EPC). However, it still struggles with uncontrollable stereochemistry due to side reactions, eventually producing a racemic mixture. To overcome this important challenge, a well-controlled design of chiral catalyst materials is mandatory to produce enantiomers with acceptable purity. In this context, we propose the synergetic combination of two strategies, namely the elaboration of mesoporous Pt films, imprinted with chiral recognition sites, together with the spatially controlled formation of a self-assembled monolayer. Chiral imprinted metals have been previously suggested as electrode materials for enantioselective recognition, separation and synthesis. However, the outermost surface of such electrodes is lacking chiral information and thus leads to unspecific reactions. Functionalising selectively this part of the electrode with a monolayer of organosulfur ligands allows an almost total suppression of undesired side reactions and thus leads to a boost of enantiomeric excess to values of over 90% when using these surfaces in the frame of enantioselective electrosynthesis. In addition, this strategy also decreases the total reaction time by one order of magnitude. The study therefore opens up promising perspectives for the development of heterogeneous enantioselective electrocatalysis strategies.
S. Butcha, V. Lapeyre, C. Wattanakit, A. Kuhn
  Chem.Sci., 13, 2022, 2339
Laboratory: ISM
Two Prizes during JACC2022 conference
2022-10-06
Two prizes were delivered during JACC2022 :
  • Paola Matozzo (Univ. Rennes-PhD student at ISCR) for the poster  prize for her presentation on ''Exciton coupling chirality in helicene-porphyrin conjugates''
  • Nicolas Bruni (Univ. Bordeaux-PhD student at LOMA) for the young talk prize for his presentation on ''Directed morphogenesis of rewritable chiral liquid crystal supramolecular structures by chiral light''
 
Laboratory: JACC2022
GDR PES “Photo-Electro-Stimulation”
2022-10-20
The ISM will host the next symposium of the GDR PES "Photo-Electro-Stimulation". The goal of this GDR is to put together photochemists, spectroscopists and electrochemists to discuss about the interplay between these fields. The forthcoming symposium will take place from Monday 7th to Wednesday 9th of November at the ENSCBP school in Pessac. Here is the website to register: https://jpes.sciencesconf.org/ You should create an account prior to register in case you do not have already one. Registration is free but compulsory !
Laboratory: ISM
INSCRIPTION TO JACC 2022
2022-06-02
Journées André Collet de la Chiralité
  • October 4-7 (2022) in a wonderfull place in Biarritz
  • deadline for oral abstract submission : June 15th July 15-2022
  • deadline for poster abstract submission : August 31, 2022
  • early bird registration starting : July 1rst July 24, 2022
More information on https://jacc2022.sciencesconf.org
With as Plenary and Keynote speakers :
  • Melanie Schnell
  • Tiziana Benincori
  • Marie-Claire Schanne Klein
  • Hiroshi Yamamoto
  • Eric Meggers
  • Etienne Brasselet
  • Mathieu Raynal
  • Benjamin Abécassis
  • Jess Wade
  • Félix Freire
Laboratory: ICMCB
Kick-off meeting of ANR-CHIMERA
2022-05-10
CHIMERA standing for Chiral Induction from Microns to Electrons for Radiative Anisotropy, also in collaboration with Yann Battie (LCP-A2MP-Université de Lorraine/Metz)
Laboratory: IECB/ISM/CELIA/CBMN
Upcoming virtual event for Chirality.
2022-02-17
the  First Virtual Symposium on Chirality hosted by our very own Associate Editor, Prof. Oliver Trapp. The virtual symposium will take place on Tuesday, 22 February 2022 from 12:00 PM UTC to 2:30 PM UTC Register now to attend for free! We welcome three Chirality authors:
  • Prof. Tamaki Nakano (Institute for Catalysis (ICAT), Hokkaido University, Japan)  Light-induced Conformational Transition of Polymers and Small Molecules
    Based on his work:     Photo racemization of 2,2′-dihydroxy-1,1′-binaphthyl derivatives --- Chirality, 2021. https://doi.org/10.1002/chir.23400
  • Prof. Dr. Alexander Kuhn (Groupe Nanosystèmes Analytiques, Université de Bordeaux, France) Unconventional Electrochemical Approaches for the Direct Readout of Chiral Information
    Based on his work:     Hybrid light-emitting devices for the straightforward readout of chiral information--Chirality, 2021. https://doi.org/10.1002/chir.23370
  • Dr. Peter Wipf (Department of Chemistry, University of Pittsburgh, USA) Enantioselective Imine Additions in the Preparation of Bioactive Lead Compounds Based on his work: Enantioselective synthesis and selective functionalization of 4-aminotetrahydroquinolines as novel glp-1 secretagogues --Chirality, 2021. https://doi.org/10.1002/chir.23403
More information on our speakers and the agenda for the event can be found on our event website.  
Laboratory: Chirality journal
PhotoElectron ELiptical Dichroism : PEELD
2022-02-09
The resonance-enhanced multiphoton ionization of chiral molecules by elliptically polarized laser pulses produces photoelectron angular distributions that are forward/backward asymmetric with respect to the light propagation axis. We investigate this photoelectron elliptical dichroism in the (2 + 1)-photon ionization of fenchone molecules, using wavelength tunable femtosecond UV pulses. We show that the photoelectron elliptical asymmetry is extremely sensitive to the intermediate resonant states involved in the ionization process, and enables electronic couplings to be revealed that do not show up so clearly when using circularly polarized light.
https://hal-cnrs.archives-ouvertes.fr/hal-03547281
Laboratory: CELIA
Revealing the Influence of Molecular Chirality on Tunnel-Ionization Dynamics
2021-12-21
The tunneling of a particle through a barrier is one of the most fascinating quantum phenomena. The motion taking place under the barrier, in a region forbidden by classical mechanics, is the subject of intense debate. Many experiments aim at measuring the time taken by the particle to go through the tunnel. Here, we take a completely different direction, revealing the influence of the dynamics under the barrier on the motion of the outgoing particle. Our approach combines two key elements: the barrier is chiral—its structure cannot be superimposed on its mirror image—and it rotates in time. Specifically, our barrier holds the electrons inside a chiral molecule, set spinning by a photoionizing laser field whose polarization rotates. The electrons must pass through the spinning barrier of the molecule to escape.
Laboratory: CELIA
Optically Active CdSe/CdS Nanoplatelets Exhibiting Both Circular Dichroism and Circularly Polarized Luminescence
2021-11-30
In this paper, chiroptical 2D CdSe/CdS nanoplatelets (NPLs) are prepared by ligand exchange approach, exhibiting both circular dichroism (CD) and circularly polarized luminescence (CPL). Furthermore, the CD and CPL signals are easily tuned via the design of the CdS-island structuration of the shell and its thickness which are controlled with the reaction time.
Laboratory: ICMCB
Ultrafast relaxation investigated by photoelectron circular dichroism: an isomeric comparison of camphor and fenchone
2021-11-26
Circular dichroism in the photoelectron angular distribution decays exponentially in ∼730 fs from a +9% forward amplitude during the first hundreds of femtoseconds to reach an asymptotic −2% backward amplitude after to have photoexcited at ~6 eV. This time-scale is drastically shorter than in fenchone, its isomer. Our analysis allows us to evaluate the impact of the anisotropy of excitation and reveal a breakdown of the Franck-Condon approximation.
Laboratory: CELIA
Interdisciplinarity and Chirality
2021-10-25
Symmetry and Chirality: Where Physics Shakes Hands with Chemistry and Biology by Laurence Barron
Laboratory: a review article
Direct dynamic read-out of molecular chirality with autonomous enzyme-driven swimmers
2021-10-14
This work describes a first example of autonomous miniaturized swimmers which can detect the chirality of molecules present in solution by adapting their trajectories at the air/water interface. In the presence of one enantiomer they will swimm clockwise, in the presence of the other enantiomer the motion will be anti-clockwise. See also press release by CNRS
Laboratory: ISM
Chirality induction to achiral molecules by silica-coated chiral molecular assemblies
2021-07-23
Hybrid silica-organic nanohelices are used to organize a large variety of non-chiral small organic molecules or inorganic anions to nanometer-sized assemblies. Such chiral organization of achiral molecules induces chiroptical properties as detected by vibrational or electronic circular dichroism (CD), as well as from circularly polarized luminescence (CPL). This is a collaborative work with  University of Rome Tor Vergata and University of Kumamoto
Laboratory: CBMN, ISM
Chirality Induction to CdSe Nanocrystals Self-Organized on Silica Nanohelices: Tuning Chiroptical Properties
2021-10-07
An article on CdSe nanocrystals (NCs) grafted on chiral silica nanoribbons, and the resulting induced circular dichroism observed from the NCs.This work is done in the context of LIA-CNPA by a double degree PhD student between Univ. Bordeaux and Kyoto Univ.
Laboratory: CBMN
Bipolar electrochemical measurement of enantiomeric excess with inherently chiral polymer actuators
2021-07-19
An article about the direct visual readout of enantiomeric excess with wireless actuators. The work has been performed together with collegues from Milan and Como.  
Laboratory: ISM
Hybrid light-emitting devices for the straightforward readout of chiral information
2021-10-11
A new article on chiral recognition based on enantioselective oligomers addressed by bipolar electrochemistry. The work has been carried out in collaboration with  collegues from Milan and Como. It has been published in the special issue of Chirality: "Chirality in France".  
Laboratory: ISM
Nanoengineered chiral Pt-Ir alloys for high-performance enantioselective electrosynthesis
2021-02-26
An article about the highly stereoselective electrosynthesis of enantiomers with the help of chiral encoded metal matrices. The work has been performed with collegues from VISTEC in Thailand.
Laboratory: ISM
Nobel prize for Chirality!
2021-10-06
Chirality under the spotlight! "The Nobel Prize in Chemistry 2021 was awarded jointly to Benjamin List and David W.C. MacMillan "for the development of asymmetric organocatalysis."
Laboratory: nobelprize.org
Magneto-chiral anisotropy: From fundamentals to perspectives
2021-10-01
New review article on magneto-chiral anisotropy with colleagues from Grenoble and Angers for the special issue in Chirality: "Chirality in France".   https://www.icmcb-bordeaux.cnrs.fr/
http://lncmi.cnrs.fr/
https://www.univ-angers.fr/fr/recherche/laboratoires/materiaux/moltech-anjou.html
Laboratory: ICMCB
Magnétisme et chiralité
2021-05-18
Chirality is the property of objects, and particularly of molecules, to exist in two different forms that are each other’s mirror image. Chirality plays a vital role in biochemistry, as most molecules of life, ranging from sugars and proteins, via most drugs, right up to DNA, are chiral and this property is essential for their action. Magnetism, despite its millennia-long history, still fascinates. It has found many industrial applications, and new ones are still being developed, spintronics being its most recent offspring. Since Pasteur, scientists have tried to create a link between chirality and magnetism. Although basically very distinct, the two domains share a common and unique phenomenon called magneto-chiral anisotropy (MChA). MChA corresponds to a change in any flux (light, electrical current, heat, sound, etc.) going through a chiral medium, depending on whether it flows parallel or anti-parallel to an external magnetic field. The first predictions of MChA for light appeared in the 1980s. Since then several observations of optical MChA have been reported, but the effects were quite weak and no complete quantitative analysis was presented.  Now a collaboration of researchers from France and the USA have performed detailed measurements and advanced quantum-chemical calculations on well-defined model systems. They find experimentally that for these materials at low temperatures, the difference in light transmission parallel and anti-parallel to a modest magnetic field of 1 Tesla, hardly more than what a refrigerator magnet produces, can be as high as 10 %. Their calculations permit a detailed understanding of these results, and predict even higher anisotropies at higher fields or lower temperatures. The size of the effect and its in-depth understanding now open the road to applications of MChA, which can range from optical diodes to new optical data storage methods. (read also in french, Communication by INP-CNRS)
Laboratory: ICMCB
Bispericyclic Diels–Alder Dimerization of ortho-Quinols in Natural Product (Bio)Synthesis: Bioinspired Chemical 6-Step Synthesis of (+)-Maytenone
2021-04-02
More Information on INC-communication
Laboratory: ISM
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