Activation energies for oxidation of porphyrin monolayers anchored to Au(111).
The activation energy for the oxidation of porphyrin monolayers anchored to gold surfaces is determined via measurement of the temperature dependence of the electron-transfer rates. The activation energy (1) increases with increasing surface concentration of the porphyrin and (2) is significantly lower (8.1-17 versus 37-49 kJ mol(-1)) when smaller, more mobile counterions (Cl(-) versus PF(6)(-)) are used as the supporting electrolyte. Regardless, the lower activation energies do not result in radically different electron-transfer rates for the different types of counterions owing to compensating entropic effects.
Jiao
Jieying
J
Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
Taniguchi
Masahiko
M
Lindsey
Jonathan S
JS
Bocian
David F
DF