Diode-like electron transfer across nanostructured films containing a redox ligandBasis of a presentation given at Materials Chemistry Discussion No. 2, 13â 15 September 1999, University of Nottingham, UK.
Gittins, David I.; Bethell, Donald; Nichols, Richard J.; Schiffrin, David J.; Gittins David I.; Department of Chemistry, University of Liverpool; Bethell Donald; Department of Chemistry, University of Liverpool; Nichols Richard J.; Department of Chemistry, University of Liverpool; Schiffrin David J.; Department of Chemistry, University of Liverpool
Журнал:
Journal of Materials Chemistry
Дата:
2000
Аннотация:
Novel redox active dithiols containing the viologen (4,4â ²-bipyridinium group) have been synthesised. Monolayers and multilayers consisting of alternating layers of the dithiol and gold nanoparticles have been self-assembled on a gold substrate and visualised using SPM. Such materials have been investigated for their electroactivity and their ability to mediate electron transfer to an external redox couple, [Ru(NH3)6]<sup>3+/2+</sup>, in aqueous solution. Viologen moieties in these multilayers are addressable electrochemically provided they are within 6â 8 layers of the external surface and it is shown that electron transfer through the deeper layers is very facile as a consequence of the presence of partially filled viologen Ï -orbitals. When the viologen containing dithiol is present in the outer layer, a diode effect is observed; electron transfer from the multilayer to the external couple takes place, but the reverse electron transport is inhibited.
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