Chiral Bis(tetrathiafulvalene)-1,2-cyclohexane-diamides

Alexandra Bogdan; Ionuț-Tudor Moraru; Pascale Auban-Senzier; Ion Grosu; Flavia Pop; Narcis Avarvari

doi:10.3390/molecules27206926

Chiral Bis(tetrathiafulvalene)-1,2-cyclohexane-diamides

Molecules. 2022 Oct 15;27(20):6926. doi: 10.3390/molecules27206926.

Authors

Alexandra Bogdan^{1

2}, Ionuț-Tudor Moraru², Pascale Auban-Senzier³, Ion Grosu², Flavia Pop¹, Narcis Avarvari¹

Affiliations

¹ Univ. Angers, CNRS, MOLTECH-Anjou, SFR MATRIX, F-49000 Angers, France.
² Faculty of Chemistry and Chemical Engineering, Department of Chemistry, Babes-Bolyai University, 11 Arany Janos Str., 400028 Cluj-Napoca, Romania.
³ Laboratoire de Physique des Solides, Université Paris-Saclay CNRS UMR 8502, Bât. 510, F-91405 Orsay, France.

Abstract

Chiral bis(TTF) diamides have been obtained in good yields (54-74%) from 1,2-cyclohexane-diamine and the corresponding TTF acyl chlorides. The (R,R)-1 and (S,S)-1 enantiomers have been characterized by circular dichroism and the racemic form by single-crystal X-ray diffraction. The neutral racemic bis(TTF)-diamide shows the formation of a pincer-like framework in the solid state, thanks to the intramolecular S···S interactions. The chemical oxidation in a solution using FeCl₃ provides stable oxidized species, while the electrocrystallization experiments provided radical cation salts. In particular, single-crystal resistivity measurements on the racemic donor with AsF₆^- as a counterion demonstrate semiconductor behavior in this material. The DFT and TD-DFT calculations support the structural and chiroptical features of these new chiral TTF donors.

Keywords: DFT calculations; chirality; chiroptical properties; crystal structure determination; magnetic properties; tetrathiafulvalene.

Grants and funding

Financial support in France from the French Ministry of Foreign Affairs and the University of Angers; Eiffel scholarship for A.B. and the Erasmus international exchange between the University of Angers and Babeş-Bolyai University. Financial support in Romania from the Erasmus+ Program for A.B. and the PN-III-P4-ID-PCCF-2016-0088 grant of the Romanian Ministry of Research, Innovation and Digitalization, CNCS/CCCDI-UEFISCDI.