ECM - École Centrale de Marseille : UMR7313 (Pôle de l'étoile - Technopole de Château-Gombert - 38 rue Frédéric Joliot-Curie - 13013 Marseille - France)
2MOLTECH-Anjou (MOLTECH-Anjou UMR 6200 CNRS - Université d'Angers, Faculté des Sciences, 2 Boulevard Lavoisier, Bâtiments K et Db - 49045 Angers CEDEX 01 - France)
UA - Université d'Angers : UMR6200 (Université d'Angers - 40 Rue de Rennes, BP 73532 - 49035 Angers CEDEX 01 - France)
Abstract : Introduction of chirality in the field of molecular conductors has received increasing interest in recent years in the frame of modulation of the crystal packing, and hence conducting properties, with the number of stereogenic centers and absolute configuration, e.g., racemic or enantiopure forms. Here, we describe the preparation by electrocrystallization of chiral radical cation salts, based on the donors methyl-ethylenedithio-tetrathiafulvalene (Me-EDT-TTF) 1 and ethyl-ethylenedithio-tetrathiafulvalene (Et-EDT-TTF) 2 containing one stereogenic center, with the perchlorate anion. Donor 1 provided the series of crystalline materials [(rac)-1]ClO4, [(S)-1]2ClO4 and [(R)-1]2ClO4, while for donor 2 only the 1:1 salts [(rac)-2]ClO4 and [(R)-2]ClO4 could be prepared as suitable single crystals for X-ray analysis. The enantiopure salts of 1 show β-type packing and metallic conductivity in the high temperature regime, with room temperature conductivity values of 5–10 S cm−1, whereas compound [(rac)-2]ClO4 is a very poor semiconductor. Tight-binding extended Hückel band structure calculations support the metallic conductivity of the enantiopure salts of 1 and suggest that small structural changes, possibly induced by thermal contraction or pressure, could lead to a pseudo-elliptic closed Fermi surface, typical for a 2D metal
https://hal.univ-angers.fr/hal-03030866 Contributeur : Narcis AvarvariConnectez-vous pour contacter le contributeur Soumis le : lundi 30 novembre 2020 - 11:50:16 Dernière modification le : mardi 4 janvier 2022 - 06:08:23 Archivage à long terme le : : lundi 1 mars 2021 - 18:48:26