Dr. Xiaozhou Ma received one of two prizes for the best poster presented at the 7th European Conference on Molecular Magnetism which took place in Florence, Italy, the 15th-18th of September 2019.
The title of her poster was “Magnetic Exchange Coupling Promotion in Dinuclear Compounds with Redox-active Ligand”.
Xiaozhou Ma was a PhD student of P. Dechambenoit and R. Clérac who defended on the 11th of September 2019.
This work demonstrates the possibility of modulating the spin state of the FeII sites and subsequently the magnetic properties of a [2×2] FeII grid-like complex by variation of the degree of deprotonation of the hydrazine-based N-H sites of the ligand in the complex. Evidence has been provided, both in the solid state and in solution, towards understanding the strong influence of the spin-crossover process on the pKas of the grid ligands, which exhibit a unique deprotonation pattern. The present study provides a demonstration of the effect of spin state switching of a chemical property, here on ligand pKa in a metallosupramolecular grid.
![modulating the spin state of the FeII sites and subsequently the magnetic properties of a [2x2] FeII grid-like complex](https://sites.google.com/site/m3researchgroup/News/newpublicationinthejournaloftheamericanchemicalsocietyonspinstatechemistry/TOC.fr.jpg?attredirects=0)
Sébastien Dhers, Abhishake Mondal, David Aguilà, Juan Ramírez, Sergi Vela, Pierre Dechambenoit, Mathieu Rouzières, Jonathan R. Nitschke, Rodolphe Clérac & Jean-Marie Lehn. Spin State Chemistry: Modulation of Ligand pKa by Spin State Switching in a [2×2] Iron(II) Grid-Type Complex J. Am. Chem. Soc. 2018, 140 (26), pp 8218–8227 DOI : 10.1021/jacs.8b03735
Incorporating functional molecules into sensor devices is an emerging area in molecular electronics that aims at exploiting the sensitivity of different molecules to their environment and turning it into an electrical signal. Among the emergent and integrated sensors, microelectromechanical systems (MEMS) are promising for their extreme sensitivity to mechanical events. However, to bring new functions to these devices, the functionalization of their surface with molecules is required. Herein, we present original electronic devices made of an organic microelectromechanical resonator functionalized with switchable magnetic molecules. The change of their mechanical properties and geometry induced by the switching of their magnetic state at a molecular level alters the device’s dynamical behavior, resulting in a change of the resonance frequency. We demonstrate that these devices can be operated to sense light or thermal excitation. Moreover, thanks to the collective interaction of the switchable molecules, the device behaves as a non-volatile memory. Our results open up broad prospects of new flexible photo- and thermo-active hybrid devices for molecule-based data storage and sensors.
Matias Urdampilleta, Cedric Ayela,
Pierre-Henri Ducrot, Daniel Rosario-Amorin, Abhishake Mondal, Mathieu
Rouzières, Pierre Dechambenoit, Corine Mathonière, Fabrice Mathieu, Isabelle
Dufour et Rodolphe Clérac
Molecule-based microelectromechanical sensors
Scientific Reports – Mai 2018
DOI: 10.1038/s41598-018-26076-2
A new multi-switchable complex has been rationally assembled using a redox-active and strongly complexing bridging ligand. By simple oxidation/reduction, its magnetic properties can be tuned from a spin-crossover complex, to a single-molecule magnet with an S = 5/2 spin ground state (when once reduced) and to diamagnetic species when twice reduced. This work illustrates experimentally and theoretically how successive redox processes can increase the spin delocalization, and thus promote a dramatic enhancement of the intramolecular magnetic coupling through a bridging ligand, not only in its radical form. This general synthetic approach should help for the intentional design of new high-spin complexes and SMMs, but it could also be extended to systems with higher nuclearities and dimension- alities, for example to obtain high-temperature molecule- based magnets.
Xiaozhou Ma, Elizaveta A. Suturina, Siddhartha De, Philippe Négrier, Mathieu Rouzières, Rodolphe Clérac et Pierre Dechambenoit
Redox-Active Bridging Ligand as a Tool to Promote Spin Delocalization, High Spin Complexes and Magnetic Multi-Switchability
Angewandte Chemie International Edition – Avril 2018
DOI: 10.1002/anie.201803842
Le plus grand hydrocarbure polyaromatique jamais observé par diffraction des rayons X
Des chimistes du Centre de Recherche Paul Pascal (CNRS) ont récemment réussi à analyser par diffraction de rayons X le plus grand hydrocarbure polyaromatique jamais caractérisé par cette technique.
Place and date of Birth:
Mulhouse (Haut Rhin, France)
25 Mars 1982
Institutional address:
Centre de Recherche Paul Pascal
CRPP – CNRS UMR5031
Research team M3
115, avenue du Dr. A. Schweitzer
33600 Pessac, France
Phone: +33 5 56 84 56 71
Fax: +33 5 56 84 56 00
Email: pierre.dechambenoit@crpp.cnrs.fr
Academic degrees
| 2021 | Habilitation à Diriger des Recherches |
| 2008 | Ph. D. at the University Louis Pasteur in Strasbourg, Prof. M. W. Hosseini and Dr. S. Ferlay |
| 2005 | DEA of Transition Metal Chemistry and Molecular Engineering, Mention Bien (Strasbourg) |
| 2003 – 2004 | Licence and Maitrise of Chemistry (Strasbourg) |
| 2001 – 2002 | DEUG in Science of the matter, Mention Très Bien (1st) (Strasbourg) |
Previous positions
| 2009 – 2010 | Post-doctoral Research Associate at the University of California Berkeley, (USA), Prof J. R. Long |
Publications
Author or co-author of 52 research papers published in refereed journals (h factor = 22).
Significant publications
[665]. X. Ma, E. A. Suturina, M. Rouzières, F. Wilhelm, A. Rogalev, R. Clérac and P. Dechambenoit, “A heteroleptic diradical Cr(III) complex with extended spin delocalization and large intramolecular magnetic exchange”, Chem. Commun., 56, 4906-4909, (2020) – 10.1039/d0cc00548g
[647]. X. Ma, E. A. Suturina, M. Rouzières, M. Platunov, F. Wilhelm, A. Rogalev, R. Clérac, P. Dechambenoit, “Using Redox-Active π Bridging Ligand as a Control Switch of Intramolecular Magnetic Interactions”, J. Am. Chem. Soc., 141, 7721-7725 (2019) – 10.1021/jacs.9b03044
[628]. X. Ma, E. A. Suturina, S. De, P. Négrier, M. Rouzières, R. Clérac, P. Dechambenoit, “A Redox-Active Bridging Ligand to Promote Spin Delocalization,
High-Spin Complexes, and Magnetic Multi-Switchability”, Angew. Chem. Int. Ed., 57, 7841-7845 (2018) – 10.1002/anie.201803842
[—]. Dechambenoit, P., Long, J.R., “Microporous magnet”, Chem. Soc. Rev., 40(6), pp. 3249-3265 (2011)