title: Photochromic and reductive electrochemical switching of a dithiazolylethene with large redox modulation.
abstract: A new dipyridylthiazolylethene (1a) and its dicationic analogue (2a), with two N-methylated pyridyl rings, have been synthesized and structurally characterized. Due to the N-methylation of the pyridyl rings, 2 a displays not only very different photochromic properties, but also undergoes a reductive ring-closing reaction to generate its closed-ring isomer 2b. Careful electrochemical studies coupled with EPR spectroscopy show that this reductive ring-closing reaction takes place when 2a is two-electron reduced. DFT calculations suggest that such a ground-state electrocyclization is driven by a very large stabilization of the reduced closed-ring isomer 2b relative to the reduced open-ring isomer 2a. In addition, 2b exhibits two successive and reversible one-electron reductions at half-wave potentials of 0.04 and -0.14 V versus SCE and a redox modulation as large as 1 V is achieved when passing from 2a to 2b.
authors.affiliation: ICMMO, CNRS UMR 8182, Université Paris Sud 11, Bât 420, 91405 Orsay Cedex, France. anne.leaustic@u-psud.fr
authors.forename: Anne
authors.initials: A
authors.lastname: Léaustic
authors.forename: Elodie
authors.initials: E
authors.lastname: Anxolabéhère-Mallart
authors.forename: François
authors.initials: F
authors.lastname: Maurel
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Midelton
authors.forename: Régis
authors.initials: R
authors.lastname: Guillot
authors.forename: Rémi
authors.initials: R
authors.lastname: Métivier
authors.forename: Keitaro
authors.initials: K
authors.lastname: Nakatani
authors.forename: Pei
authors.initials: P
authors.lastname: Yu