Three Redox States of a Diradical Acceptor–Donor–Acceptor Triad: Gating the Magnetic Coupling and the Electron Delocalization

Manuel Souto, Vega Lloveras, Sergi Vela, Maria Fumanal, Imma Ratera*, and Jaume Veciana*, J. Phys. Chem. Lett., 2016, 7 (12), pp 2234–2239. DOI: 10.1021/acs.jpclett.6b00912

The diradical acceptor–donor–acceptor triad 1••, based on two polychlorotriphenylmethyl (PTM) radicals connected through a tetrathiafulvalene(TTF)–vinylene bridge, has been synthesized. The getneration of the mixed-valence radical anion, 1•–, and triradical cation species, 1•••+, obtained upon electrochemical reduction and oxidation, respectively, was monitored by optical and ESR spectroscopy. Interestingly, the modification of electron delocalization and magnetic coupling was observed when the charged species were generated and the changes have been rationalized by theoretical calculations.