No abstract

Following a renaissance from the 1980s, electrochemistry has developed into sophisticated interdisciplinary science integrating solid-state and surface science and further, biological sciences. Most remarkably, even the single-molecule can now be addressed. Single-molecule electrochemistry covers transition metal complexes, organic redox molecules, fragile biomolecules, and molecular-scale hybrids between metallic nanoparticles and complex molecules, supported by new theoretical frames. We overview here selected areas of molecular scale electrochemistry. After a theoretical minimum, we address complex molecules in electron transfer, enzyme catalysis, and nanoparticle catalysis. Our focus is on issues not so much previously highlighted, such as competition between superexchange and sequential conduction, and resonance features in the transition between the two limits. Another aspect is coherent multi-electron transfer for large bias voltages often needed to drive enough current through solute molecular junctions. We note finally some single-molecule perspectives relating to DNAbased molecules and to spin transitions via chiral molecules.

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 Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

An Fe3+/2+ redox couple in conducting single wall carbon nanotubes filled with water molecules is investigated in the framework of the electron transfer theory and with classical molecular dynamics simulations. The diameter of the nanotubes ranges from 0.8 nm to 3.5 nm. It can be concluded, qualitatively, that the electron transfer rate significantly increases with decreasing nanotube diameter. This effect is explained basically in terms of the solvent reorganization energy. Other factors that can affect the reaction rate are discussed as well.