title: A (pi-extended tetrathiafulvalene)-fluorene conjugate. Unusual electrochemistry and charge transfer properties: the first observation of a covalent D(2+)-sigma-A(.-) redox state(1).
abstract: The synthesis of novel electrochemically amphoteric TTFAQ-sigma-A compounds (TTFAQ = 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene, sigma = saturated spacer, A = polynitrofluorene acceptor) is reported. Their solution redox behavior is characterized by three single-electron reduction and one two-electron oxidation waves. Electrochemical quasireversibility of the TTFAQ(2+) state and a low E(ox) - E(red) gap ( approximately 0.25 V) for 3-(9-dicyanomethylene-4,5,7-trinitrofluorene-2-sulfonyl)-propionic acid 2-[10-(4,5-dimethyl-[1,3]dithiol-2-ylidene)-9,10-dihydroanthracen-9-ylidene]-5-methyl-[1,3]dithiol-4-ylmethyl ester (10) has enabled the electrochemical generation of the hitherto unknown transient D(2+)-sigma-A(.-) state as observed in cyclic voltammetry and time-resolved spectroelectrochemistry. The ground state of compound 10 was shown to be ionic in the solid but is essentially neutral in solution (according to electron paramagnetic resonance). The X-ray structure of an intermolecular 1:2 complex between 2-[2,7-bis(2-hydroxyethoxy)-9,10-bis(4,5-dimethyl-[1,3]dithiol-2-ylidene)-9,10-dihydroanthracene and 2,5,7-trinitro-4-bromo-9-dicyanomethylenefluorene, 14.(17)(2), reveals, for the first time, full electron transfer in a fluorene charge-transfer complex.
authors.affiliation: Department of Chemistry, University of Durham, Durham DH1 3LE, U.K.
authors.forename: Dmitrii F
authors.initials: DF
authors.lastname: Perepichka
authors.forename: Martin R
authors.initials: MR
authors.lastname: Bryce
authors.forename: Igor F
authors.initials: IF
authors.lastname: Perepichka
authors.forename: Svetlana B
authors.initials: SB
authors.lastname: Lyubchik
authors.forename: Christian A
authors.initials: CA
authors.lastname: Christensen
authors.forename: Nicolas
authors.initials: N
authors.lastname: Godbert
authors.forename: Andrei S
authors.initials: AS
authors.lastname: Batsanov
authors.forename: Eric
authors.initials: E
authors.lastname: Levillain
authors.forename: Eric J L
authors.initials: EJ
authors.lastname: McInnes
authors.forename: Jing P
authors.initials: JP
authors.lastname: Zhao