Reversible polycolour change of viologens from violet through transparent to white
The electrochromic properties of 1,1′-dibenzyl-4,4′-bipyridinium and 1,1′-diheptyl-4,4′-bipyridinium were investigated in the presence of MBr (M = Li +, Na +, and K +). The cyclic voltammograms of these viologens showed a white-coloured state in addition to the usual violet one-electron reduction st...
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Published in | Electrochimica acta Vol. 55; no. 1; pp. 165 - 170 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Kidlington
Elsevier Ltd
15.12.2009
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The electrochromic properties of 1,1′-dibenzyl-4,4′-bipyridinium and 1,1′-diheptyl-4,4′-bipyridinium were investigated in the presence of MBr (M
=
Li
+, Na
+, and K
+). The cyclic voltammograms of these viologens showed a white-coloured state in addition to the usual violet one-electron reduction state and the colourless divalent state. Chemical analyses (FT-IR and XPS spectra) of the white film and some control experiments with different supporting electrolytes, MX (X
=
Cl
− and I
−), revealed that the viologens formed water-insoluble ion pairs with tribromide generated by the electrooxidation of monobromide to produce a white film. The film was reversibly decolourized electrochemically to the initial transparent state, providing the polyelectrochromism using the simple viologen/MBr systems. The colouration efficiencies for the violet and the white-coloured states were 170
cm
2/C and 104
cm
2/C, respectively. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0013-4686 1873-3859 |
DOI: | 10.1016/j.electacta.2009.08.029 |