Chalcogen bonding and variable charge transfer degree in two polymorphs of 1 : 1 conducting salts with segregated stacks

Autor: Maxime Beau, Olivier Jeannin, Marc Fourmigué, Pascale Auban-Senzier, Claude Pasquier, Pere Alemany, Enric Canadell, Ie-Rang Jeon
Přispěvatelé: Agence Nationale de la Recherche (France), Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Ciencia e Innovación (España), Generalitat de Catalunya, Agencia Estatal de Investigación (España), Fourmigué, Marc, Alemany, Pere 0000-0002-3139-6189], Canadell, Enric, Jeon, Ie Rang, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Solides (LPS), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Barcelona, Institut de Ciència de Materials de Barcelona (ICMAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), French National Research Agency Grant ANR [17-ERC3-0003], Generalitat de Catalunya [CEX2019-000917-S, CEX2021-001202-M], Spanish MICIU through the Severo Ochoa FUNFUTURE Excellence Centre distinction [PGC2018-096955-B-C44], Maria de Maeztu Units of Excellence Program [PID2021-128217NB-I00], MICIU, 2021SGR01519, 2021SGR00286, ANR-17-ERC3-0003,MolFerro,Approches moléculaires vers les matériaux ferroélectriques multifonctionnels(2017)
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: CrystEngComm
CrystEngComm, 2023, 25 (21), pp.3189-3197. ⟨10.1039/d3ce00260h⟩
ISSN: 2018-0969
1466-8033
DOI: 10.1039/d3ce00260h⟩
Popis: Harnessing a bis(selenomethyl)tetrathiafulvalene (TTF) derivative as a donor, conducting charge transfer (CT) salts are realized thanks to original packing structures supported by chalcogen bonding (ChB) interactions. Specifically, reaction of EDT-TTF(SeMe)2 (EDT = ethylenedithio) with an acceptor, 2,5-difluoro-7,7,8,8-tetracyanoquinodimethane (F2TCNQ), afforded two polymorphs of 1 : 1 CT salts, α- and β-[EDT-TTF(SeMe)2](F2TCNQ). The donor and the acceptor molecules in both polymorphs organize into segregated and uniform stacks. Based on the structure, the α-salt shows a quasi-complete CT while the β-salt shows a partial CT with ρ ∼±0.8. The oxidation of TTF activates the σ-hole on Se atoms to be engaged in highly linear ChB interactions with the N atoms on F2TCNQ. The formation of directional ChB interactions resulted in original packing structures of the donor and the acceptor stacks that are distinct between α- and β-salts. In particular, the ChB motif observed in the β-salt allows F2TCNQ molecules within the stack to be closer than those in the α-salt. Consequently, the α-salt is a semi-conductor, while the β-salt shows metallic behaviour with a two-step metal-to-insulator (MI) transition. Moreover, the observed MI transition temperature in the β-salt (180 K) is substantially higher than that in other known CT salts, likely owing to the 3D coupling of the modulation in different chains brought about by the -SeMe substituents.
Work in France was supported by the French National Research Agency Grant ANR 17-ERC3-0003 and a PhD grant (to M. Beau) from Région Bretagne. We thank the CDIFX in Rennes for the use of the X-ray diffractometer. Work in Spain was supported by MICIU through Grants PGC2018-096955-B-C44 and PID2021-128217NB-I00, Generalitat de Catalunya (2021SGR01519 and 2021SGR00286). E. C. acknowledges the support of the Spanish MICIU through the Severo Ochoa FUNFUTURE (CEX2019-000917-S) Excellence Centre distinction and P. A. acknowledges the support from the Maria de Maeztu Units of Excellence Program (CEX2021-001202-M).
With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).
Databáze: OpenAIRE
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