Rencontres de l'ISM : bannière



Dans le cadre des Rencontres de l'ISM, nous aurons le plaisir d'accueillir pour le séminaire du mois de décembre Dr. Narcis AVARVARI du Laboratoire MOLTECH Anjou  (Université d'Angers).

Narcis Avarvari


"Chirality Related Properties in Helicene and Tetrathiafulvalene based Materials"

Introduction of chirality into molecular precursors is a topic of much current interest as it allows the preparation of multifunctional materials in which the chirality may influence, for example, the conducting properties [1]. One of the strategies we have been developing over the last years consists in using chiral methylated BEDT-TTF and EDT-TTF derivatives in crystalline radical cation salts with diverse anions [2], which allowed us, for example, to observe the electrical magnetochiral anisotropy effect (eMChA) for the first time in a TTF based conductor [3]. Moreover, the relationship between chirality and superconductivity is an intriguing question. The two enantiomeric crystalline radical cation salts κ-[(S,S)-DM-BEDT-TTF]2ClO4 and κ-[(R,R)-DM-BEDT-TTF]2ClO4, showing κ-type arrangement of the organic layers, were investigated in search for superconducting chiral molecular materials [4].
     Another chirality related effect is the chirality induced spin selectivity (CISS) consisting in a preferential spin transmission through a chiral material. In this respect, thiadiazole-helicenes have been used to boost the oxygen evolution reaction (OER) by up to ca. 130 % (at the potential of 1.65 V vs. RHE) of state-of-the-art 2D Ni- and NiFe-based catalysts via the CISS effect [5]. Our results show that the chirality of the helicene molecules is accountable for a great enhancement in the activity of state-of-the-art OER catalysts. The enhancement is related to the electron spin polarization at the catalyst surface. In this contribution we will discuss as well evidences for the occurrence of the CISS effect in chiral tetrathiafulvalenes.

Keywords: CISS effect, eMChA effect, Helicene, Conductivity, TTF

[1] F. Pop, N. Zigon, N. Avarvari, Chem. Rev. 2019, 119, 8435–8478.
[2] N. Mroweh, C. Mézière, M. Allain, P. Auban-Senzier, E. Canadell, N. Avarvari, Chem. Sci. 2020, 11, 10078–10091.
[3] F. Pop, P. Auban-Senzier, E. Canadell, G. L. J. A. Rikken, N. Avarvari, Nat. Commun. 2014, 5, 3757.
[4] N. Mroweh, C. Mézière, F. Pop, P. Auban-Senzier, P. Alemany, E. Canadell, N. Avarvari, Adv. Mater. 2020, 32, 2002811.
[5] Y. Liang, K. Banjac, K. Martin, N. Zigon, S. Lee, N. Vanthuyne, F. A. Garcés-Pineda, J. R. Galán-Mascarós, X. Hu, N. Avarvari, M. Lingenfelder, Nat. Commun. 2022, 13, 3356.


Date : vendredi 22 décembre

Heure : 10h30 - 11h30

Lieu : salle de conférences de l'ISM (3e étage)

Pour plus d'informations:

Contacts : Alexander KUHN & Conférences ISM

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