Photochromic and Reductive Electrochemical Switching of a Dithiazolylethene with Large Redox Modulation

A new dipyridylthiazolylethene (1 a) and its dicationic analogue (2 a), 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 reducti...

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Bibliographic Details
Published in:	Chemistry : a European journal Vol. 17; no. 7; pp. 2246 - 2255
Main Authors:	Léaustic, Anne, Anxolabéhère-Mallart, Elodie, Maurel, François, Midelton, Stéphanie, Guillot, Régis, Métivier, Rémi, Nakatani, Keitaro, Yu, Pei
Format:	Journal Article
Language:	English
Published:	Weinheim WILEY-VCH Verlag 11-02-2011 WILEY‐VCH Verlag Wiley Subscription Services, Inc
Subjects:	Chemical reactions Chemistry density functional calculations Displays electrochemistry Isomers Joining Mathematical analysis Modulation photochromism redox chemistry reduction Stabilization Switching
Online Access:	Get full text
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Summary:	A new dipyridylthiazolylethene (1 a) and its dicationic analogue (2 a), 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 2 b. Careful electrochemical studies coupled with EPR spectroscopy show that this reductive ring‐closing reaction takes place when 2 a 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 2 b relative to the reduced open‐ring isomer 2 a. In addition, 2 b 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 2 a to 2 b. An open‐and‐shut case: A dithiazolylethene capable of light‐activated and reductive electrochemical switching is designed. The conversion of the open‐ring form (OF2+) of the isomer to the closed‐ring form (CF2+; see picture) results in not only important changes in the electronic absorption and fluorescence properties, but also a redox shift as large as 1 V.
Bibliography:	ark:/67375/WNG-6K9ZF75C-5 istex:90B7194A17579F77F10787F2C1857C0BE256F8AE ArticleID:CHEM201002451 ANR - No. ANR-07-NANO-025-04 CNRS ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0947-6539 1521-3765
DOI:	10.1002/chem.201002451