Tunable Aromaticity and Biradical Character in Tetrathiafulvalene and Tetraselenafulvalene Derivatives

Tetrathiafulvalene
(TTF), tetraselenafulvalene (TSF), and their
derivatives have become well-known for their desirable electronic,
photochemical, and redox properties, with applications in organic
conductors, molecular machines, and charge-transfer materials. Furthermore,
the TTF derivative TTF-2,3,6,7-tetrathiolate has recently been demonstrated
to exhibit tunable biradical character in dimetallic complexes, expanding
its utility to areas including molecular qubits and spintronics. To
complement these recent experimental advances, we elucidate the electronic
structures of a series of TTF and TSF derivatives, investigating the
interplay between biradical character, aromaticity, and redox chemistry
and how they may be modulated.