2 research outputs found
Long Distance Electron Transfer at the Metal/Alkanethiol/Ionic Liquid Interface
The rate constants of simple electron
transfer (ET) reactions in room temperature ionic liquids (ILs) available
now are rather high, typically at the edge of experimental accuracy.
To consider ET phenomena in these media in view of theory developed
earlier for molecular solvents, it is crucial to provide quantitative
comparison of experimental kinetic data for certain reactions. We
report this comparison for ferrocene/ferrocenium reaction. The ET
distance is fixed by Au surface modification by alkanethiol self-assembled
monolayers, which were characterized by in situ scanning tunneling
microscopy. The dependence of ln <i>k</i><sub>app</sub> on
barrier thickness in the range of ca. 6–20 Å is linear,
with a slope typical for the same plots in aqueous media. This result
confirms diabatic mode of Fc oxidation at long distance. The data
for shorter ET distances point to the adiabatic regime of ET at a
bare gold surface, although more detailed computational studies are
required to justify this conclusion
Electrochemical Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy: Correlating Structural Information and Adsorption Processes of Pyridine at the Au(hkl) Single Crystal/Solution Interface
Electrochemical methods are combined
with shell-isolated nanoparticle-enhanced
Raman spectroscopy (EC-SHINERS) for a comprehensive study of pyridine
adsorption on Au(111), Au(100) and Au(110) single crystal electrode
surfaces. The effects of crystallographic orientation, pyridine concentration,
and applied potential are elucidated, and the formation of a second
pyridine adlayer on Au(111) is observed spectroscopically for the
first time. Electrochemical and SHINERS results correlate extremely
well throughout this study, and we demonstrate the potential of EC-SHINERS
for thorough characterization of processes occurring on single crystal
surfaces. Our method is expected to open up many new possibilities
in surface science, electrochemistry and catalysis. Analytical figures
of merit are discussed