Dimeric Indenofluorene‐Extended Tetrathiafulvalene Motif for Enhanced Intramolecular Complexation
Line Broløs, Martin Drøhse Kilde, Theis Brock‐Nannestad, Mogens Brøndsted Nielsen
Abstract
Abstract Tetrathiafulvalene (TTF) is a redox‐active compound, which reversibly undergoes two one‐electron oxidations to give stable species. Several features of TTF, such as redox and optical properties as well as geometry and self‐associating nature, can be tuned by extension of the conjugated system with an aromatic linker such as an indenofluorene (IF) moiety. In this work we present the synthesis of a novel dimeric scaffold of IF‐extended TTF (IF‐TTF) in which the units are linked by a rigid 1,4‐bis(2‐ethynylphenyl)buta‐1,3‐diyne moiety. 1 H‐NMR spectroscopic studies reveal that the scaffold is highly prone to form intramolecular IF‐TTF dimer complexes even in the neutral form, and stable radical cation species were formed in solution upon chemical oxidation with tris(4‐bromophenyl)ammoniumyl hexachloroantimonate (‘ magic blue’ ). Electrocrystallization of the rigid scaffold yielded a semi‐conducting material, which proved to be stable at ambient temperature and air.