title: Highly stable tetrathiafulvalene radical dimers in [3]catenanes.
abstract: Two [3]catenane 'molecular flasks' have been designed to create stabilized, redox-controlled tetrathiafulvalene (TTF) dimers, enabling their spectrophotometric and structural properties to be probed in detail. The mechanically interlocked framework of the [3]catenanes creates the ideal arrangement and ultrahigh local concentration for the encircled TTF units to form stable dimers associated with their discrete oxidation states. These dimerization events represent an affinity umpolung, wherein the inversion in electronic affinity replaces the traditional TTF-bipyridinium interaction, which is over-ridden by stabilizing mixed-valence (TTF)2•+ and radical-cation (TTF•+)2 states inside the 'molecular flasks.' The experimental data, collected in the solid state as well as in solution under ambient conditions, together with supporting quantum mechanical calculations, are consistent with the formation of stabilized paramagnetic mixed-valence dimers, and then diamagnetic radical-cation dimers following subsequent one-electron oxidations of the [3]catenanes.
authors.affiliation: Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Spruell
authors.forename: Ali
authors.initials: A
authors.lastname: Coskun
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Friedman
authors.forename: Ross S
authors.initials: RS
authors.lastname: Forgan
authors.forename: Amy A
authors.initials: AA
authors.lastname: Sarjeant
authors.forename: Ali
authors.initials: A
authors.lastname: Trabolsi
authors.forename: Albert C
authors.initials: AC
authors.lastname: Fahrenbach
authors.forename: Gokhan
authors.initials: G
authors.lastname: Barin
authors.forename: Walter F
authors.initials: WF
authors.lastname: Paxton
authors.forename: Sanjeev K
authors.initials: SK
authors.lastname: Dey
authors.forename: Mark A
authors.initials: MA
authors.lastname: Olson
authors.forename: Diego
authors.initials: D
authors.lastname: Benítez
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Tkatchouk
authors.forename: Michael T
authors.initials: MT
authors.lastname: Colvin
authors.forename: Raanan
authors.initials: R
authors.lastname: Carmielli
authors.forename: Stuart T
authors.initials: ST
authors.lastname: Caldwell
authors.forename: Georgina M
authors.initials: GM
authors.lastname: Rosair
authors.forename: Shanika Gunatilaka
authors.initials: SG
authors.lastname: Hewage
authors.forename: Florence
authors.initials: F
authors.lastname: Duclairoir
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Seymour
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.forename: William A
authors.initials: WA
authors.lastname: Goddard
authors.forename: Michael R
authors.initials: MR
authors.lastname: Wasielewski
authors.forename: Graeme
authors.initials: G
authors.lastname: Cooke
authors.forename: J Fraser
authors.initials: JF
authors.lastname: Stoddart
mesh_terms: D043863:Catenanes / Q000737:chemistry*; D019281:Dimerization
chemical_list: D043863:Catenanes